TMPRSS2

Gene Summary

Gene:TMPRSS2; transmembrane protease, serine 2
Aliases: PP9284, PRSS10
Location:21q22.3
Summary:This gene encodes a protein that belongs to the serine protease family. The encoded protein contains a type II transmembrane domain, a receptor class A domain, a scavenger receptor cysteine-rich domain and a protease domain. Serine proteases are known to be involved in many physiological and pathological processes. This gene was demonstrated to be up-regulated by androgenic hormones in prostate cancer cells and down-regulated in androgen-independent prostate cancer tissue. The protease domain of this protein is thought to be cleaved and secreted into cell media after autocleavage. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2008]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:transmembrane protease serine 2
Source:NCBIAccessed: 13 March, 2017

Ontology:

What does this gene/protein do?
Show (9)

Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 13 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Proteomics
  • Transcriptome
  • Zinc Finger E-box-Binding Homeobox 1
  • FISH
  • Estrogen Receptors
  • Cell Proliferation
  • Prostate
  • Trans-Activators
  • Androgens
  • RTPCR
  • Gene Expression Profiling
  • Tumor Antigens
  • Neoplasm Recurrence, Local
  • Staging
  • Adenocarcinoma
  • PTEN
  • Prostate Cancer
  • Sensitivity and Specificity
  • Tosyl Compounds
  • Oncogene Fusion Proteins
  • Prostatectomy
  • Oligonucleotide Array Sequence Analysis
  • Chromosome 21
  • Synaptophysin
  • Ultraviolet Rays
  • Immunohistochemistry
  • Cancer Gene Expression Regulation
  • Prostatic Neoplasms, Castration-Resistant
  • Prostate-Specific Antigen
  • Disease Progression
  • Protein Array Analysis
  • ETV1
  • TMPRSS2
  • Radiotherapy, Image-Guided
  • Gene Fusion
  • Messenger RNA
  • Neoplasm Grading
  • ERG
  • Suppression, Genetic
  • RB1
  • Recurrence
  • Gene Rearrangement
  • Biomarkers, Tumor
  • ROC Curve
Tag cloud generated 13 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Entity Topic PubMed Papers
Prostate CancerTMPRSS2 and Prostate Cancer View Publications430
Prostate CancerETV1 translocations in Prostate Cancer
Gene fusions involving the erythroblast transformation-specific (ETS) transcription factors ERG, ETV1, ETV4, ETV5, and FLI1 are a common feature of prostate carcinomas. Most frequently, the androgen-activated gene TMPRSS2 is fused to the ERG gene, but less frequently involving ETV1, ETV4 ,ETV5 and over 12 fusion partners identified so far.
View Publications87
Prostate CancerERG-TMPRSS2 Fusion in Prostate Cancer
The fusion of ERG and TMPRSS2 (21q22.3) is common in prostate cancer. It may be caused by intronic deletion or translocation.
See: More details below...

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

ERG-TMPRSS2 Fusion in Prostate Cancer

The fusion of ERG and TMPRSS2 (21q22.3) is common in prostate cancer. It may be caused by intronic deletion or translocation.

See also: Prostate Cancer - Clinical and Research information
See also: TMPRSS2.htm gene

Latest Publications

Berg KD
The prognostic and predictive value of TMPRSS2-ERG gene fusion and ERG protein expression in prostate cancer biopsies.
Dan Med J. 2016; 63(12) [PubMed] Related Publications
BACKGROUND: The clinical course of prostate carcinoma (PCa) is very heterogeneous. Consequently, a personalised approach for risk stratification and treatment planning is important. Recently, it has become evident that PCa, also at the genomic level, is heterogeneous. An early and common alteration is the gene fusion between the transmembrane protease serine 2 (TMPRSS2) gene and the v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) gene resulting in expression of the oncoprotein ERG. The gene fusion is present in approximately half of PCa patients and the resultant two subgroups demonstrate marked differences in their genomic signatures. It has been hypothesised that genomic alterations can explain some of the observed heterogeneity in the clinical course of PCa. In order to conduct an analysis of the prognostic and predictive value of ERG protein expression in PCa biopsies, the thesis sought to evaluate: 1) the concordance in ERG expression between biopsies and radical prostatectomies: 2) the association between expression of ERG protein and the risk of PCa progression during active surveillance (AS), and 3) the association between ERG protein expression and response to primary castration-based treatment for advanced PCa.
MATERIAL AND METHODS: The included patients derived from the institutional AS cohort and an institutional cohort of advanced PCa patients undergoing first line castration-based androgen deprivation therapy (ADT). The 265 patients in the AS cohort were enrolled prospectively between October 2002 and October 2012 and were followed with regular digital rectal examinations, PSA measurements, and repeated biopsies. The advanced PCa cohort comprised of 194 patients diagnosed between January 2000 and December 2011 and was established retrospectively by a standardised extraction of patient data. Immunohistochemical (IHC) assessment for ERG protein expression was performed in all tumours containing diagnostic specimens (AS cohort: n = 459; advanced PCa cohort: n = 968), re-biopsies during AS (n = 402), and deferred radical prostatectomy specimens following AS (n = 86). An anti-ERG rabbit monoclonal primary antibody (clone: EPR3864, dilution 23 μg/ml) was used. Fluorescence in situ hybridisation (FISH) for the TMPRSS2-ERG gene fusion was performed in 76 selected biopsies from the AS cohort using the ZytoLight TriCheck Probe, SPEC ERG/TMPRSS2.
RESULTS: Based on the AS cohort, Study 1 found a 97.3% concordance between the FISH assay and the IHC assay. The IHC assessments of ERG expression in diagnostic biopsies, re-biopsies, and radical prostatectomy specimens demonstrated a low proportion of temporal ERG reclassification. During four rounds of re-biopsies, 6.6% of the patients experienced ERG reclassification, and depending on the number biopsy specimens included 5.8-10.5% of the patients were ERG reclassified after radical prostatectomy. In Study 2, 46.4% of the AS patients were categorised as ERG-positive, whereas 53.6% were categorised as ERG-negative. After median 4.1 years follow-up, a significantly higher risk of disease progression was observed in men with ERG-positive tumours corresponding to a two-year cumulative incidence of 58.6% (95% CI: 48.7-68.5) and 21.7% (95% CI: 14.3-29.1) in the ERG-positive and the ERG-negative group, respectively. In the multiple causespecific Cox analyses, ERG expression was a strong and independent predictor of overall disease progression (HR: 2.45, 95% CI: 1.62-3.72) and histopathological progression in repeated biopsies (HR: 3.06, 95% CI: 1.78-5.26), and ERG status increased the discriminative ability for predicting disease progression significantly. Study 3 included 194 patients with advanced PCa treated with firstline ADT. In total, 54.1% had ERG-positive tumours and 45.9% had ERG-negative tumours. With a median of 6.8 years of follow-up, the risk of developing castration-resistant PCa (CRPC) did not differ between the ERG subgroups (p = 0.51). Finally, inclusion of ERG status in a multiple cause-specific Cox model did not increase the discriminative ability for predicting CRPC development during the first 8 years of ADT.
CONCLUSION: The thesis has demonstrated that assessment of ERG protein expression is feasible in biopsy specimens, and a high concordance was found between the IHC assay and FISH assessment of ERG rearrangement. The low proportion of ERG reclassification between biopsies and prostatectomies supports the use of ERG assessment in biopsies to characterise the individual patient's ERG status. ERG status harbours important prognostic value in terms of tumour progression for patients managed on AS, whereas ERG expression has no predictive value for ADT response in men with advanced PCa undergoing first-line castration-based ADT. The overall conclusion of the thesis is that ERG protein expression provides valuable prognostic information in low-risk PCa managed observationally, and ERG expression might be used to personalise follow-up regimens in future AS programmes.

Koo KM, Wee EJ, Trau M
High-speed biosensing strategy for non-invasive profiling of multiple cancer fusion genes in urine.
Biosens Bioelectron. 2017; 89(Pt 2):715-720 [PubMed] Related Publications
Aberrant chromosal rearrangements, such as the multiple variants of TMPRSS2:ERG fusion gene mutations in prostate cancer (PCa), are promising diagnostic and prognostic biomarkers due to their specific expression in cancerous tissue only. Additionally, TMPRSS2:ERG variants are detectable in urine to provide non-invasive PCa diagnostic sampling as an attractive surrogate for needle biopsies. Therefore, rapid and simplistic assays for identifying multiple urinary TMPRSS2:ERG variants are potentially useful to aid in early cancer detection, immediate patient risk stratification, and prompt personalized treatment. However, current strategies for simultaneous detection of multiple gene fusions are limited by tedious and prolonged experimental protocols, thus limiting their use as rapid clinical screening tools. Herein, we report a simple and rapid gene fusion strategy which expliots the specificity of DNA ligase and the speed of isothermal amplification to simultaneously detect multiple fusion gene RNAs within a short sample-to-answer timeframe of 60min. The method has a low detection limit of 2 amol (1000 copies), and was successfully applied for non-invasive fusion gene profiling in patient urine samples with subsequent validation by a PCR-based gold standard approach.

Jiang H, Mao X, Huang X, et al.
TMPRSS2:ERG fusion gene occurs less frequently in Chinese patients with prostate cancer.
Tumour Biol. 2016; 37(9):12397-12402 [PubMed] Related Publications
Prostate cancer is the commonest male malignancy in the Western world, but its morbidity is much lower in China. The principal aim of this study was to evaluate the frequency of TMPRSS2:ERG fusion in Chinese prostate cancer patients using immunohistochemistry and reverse transcription polymerase chain (RT-PCR). In addition, we compared the ERG protein expression with TMPRSS2:ERG fusion gene. The relationship between ERG expression and clinicopathologic features was also examined. Samples from patients who underwent radical prostatectomies in Changhai Hospital (Shanghai, China) were collected and stored in ethically approved tissue banks. One hundred seventy-four prostate cancer tissue samples and 10 normal tissues were marked on standard hematoxylin-eosin (HE) sections, punched out of the paraffin blocks and inserted into a recipient block using tissue arrayer instruments. Immunohistochemistry and RT-PCR were employed to detect TMPRSS2:ERG fusion gene. ERG was highly expressed in the nuclei of endothelial cells of vessels and weak cytoplasmic staining was occasionally observed. ERG positive staining was present in 14.9 % (26/174) of the tumor samples in microarray. All benign prostate samples were found to be negative. RT-PCR results revealed that 11.1 % (15/135) were TMPRSS2:ERG fusion positive. Altogether, there was a good agreement of ERG immunostaining with the presence of TMPRSS2:ERG. However, no correlation was observed between ERG expression and age, Gleason score, stage, surgical margin, and seminal vesicle involvement in Chinese patients. In the present study, we identified a high correlation between ERG expression and ERG TMPRSS2:ERG, with 100 % sensitivity and 88.9 % specificity. The expression level of ERG was unrelated to the age, Gleason score, stage, surgical margin, and seminal vesicle involvement. Therefore, the association between ERG expression and prostate cancer based on Chinese population should be further investigated in the future.

Kim H, Skowronski J, Den RB
Prognostic outlier genes for enhanced prostate cancer treatment.
Future Oncol. 2017; 13(3):249-261 [PubMed] Related Publications
AIM: To review the current landscape of outlier genes in the field of prostate cancer.
METHODS: A comprehensive review was performed.
RESULTS: Prostate cancer continues to be a significant worldwide health issue. In the era of personalized medicine, more emphasis is being placed on the ability to determine the timing, intensity and type of treatment, according to each patient's unique disease. Several commercial tests are available to determine the risk of aggressive prostate cancer based on genomic biomarkers and gene expression. Outlier genes represent a form of cancer classification that focuses on bimodal expression of a gene in a specific subset of patients. Outlier genes identified in prostate cancer include TMPRSS2-ERG, SPINK1, ScHLAP1, NVL, SMC4 and SQLE.
CONCLUSION: Classifying patient prostate cancers by outlier genes may allow for individualized cancer therapies and improved cancer therapy outcomes.

Kulda V, Topolcan O, Kucera R, et al.
Prognostic Significance of TMPRSS2-ERG Fusion Gene in Prostate Cancer.
Anticancer Res. 2016; 36(9):4787-93 [PubMed] Related Publications
BACKGROUND/AIM: Current research of prostate cancer (PCa) offers a promising way of identifying patients with adverse prognosis who do benefit from radical treatment that can affect quality of life as resections are associated with numerous side-effects. The aim of our study was to evaluate the relationship of TMPRSS2-ERG fusion gene status, tumor tissue prostate-specific antigen (PSA), prostate cancer antigen 3 (PCA3), miR-23b, miR-26a and miR-221 expression levels in combination with preoperative serum PSA level to the risk of PCa recurrence after radical prostatectomy.
PATIENTS AND METHODS: The study group consisted of 108 patients who underwent radical prostatectomy. PSA was measured in peripheral blood collected preoperativelly. The expression of TMPRSS2-ERG transcript and the expression of miR-23b, miR-26a and miR-221 in formalin-fixed, paraffin-embedded (FFPE) tumor tissues was analyzed by reverse transcription (RT) real-time polymerase chain reaction (PCR).
RESULTS: Significantly shorter time to recurrence was observed in patients with high expression of TMPRSS2-ERG (p=0.0020). High levels of preoperative PSA (>10.0 ng/ml) proved to be marker of shorter time to recurrence (p=0.0153). The most promising marker of the risk of recurrence after radical prostatectomy was a combination of high level of preoperative serum PSA and high expression of TMPRSS2-ERG fusion transcript in tumor tissue (p=0.0001).
CONCLUSION: A combination of high preoperative serum PSA and high expression of TMPRSS2-ERG could be promising in distinguishing those tumors that are aggressive and life-threatening.

Krstanoski Z, Vokac NK, Zagorac A, et al.
TMPRSS2:ERG gene aberrations may provide insight into pT stage in prostate cancer.
BMC Urol. 2016; 16(1):35 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: TMPRSS2:ERG gene aberration may be a novel marker that improves risk stratification of prostate cancer before definitive cancer therapy, but studies have been inconclusive.
METHODS: The study cohort consisted of 202 operable prostate cancer Slovenian patients who underwent laparoscopic radical prostatectomy. We retrospectively constructed tissue microarrays of their prostatic specimens for fluorescence in situ hybridization, with appropriate signals obtained in 148 patients for subsequent statistical analyses.
RESULTS: The following genetic aberrations were found: TMPRSS2:ERG fusion, TMPRSS2 split (a non-ERG translocation) and ERG split (an ERG translocation without involvement of TMPRSS2). TMPRSS2:ERG gene fusion happened in 63 patients (42 %), TMPRSS2 split in 12 patients and ERG split in 8 patients. Association was tested between TMPRSS2:ERG gene fusion and several clinicopathological variables, i.e., pT stage, extended lymph node dissection status, and Gleason score, correcting for multiple comparisons. Only the association with pT stage was significant at p = 0.05: Of 62 patients with pT3 stage, 34 (55 %) had TMPRSS2:ERG gene fusion. In pT3 stage patients, stronger (but not significant) association between eLND status and TMPRSS2:ERG gene fusion was detected. We detected TMPRSS2:ERG gene fusion in 64 % of the pT3 stage patients where we did not perform an extended lymph node dissection.
CONCLUSIONS: Our results indicate that it is possible to predict pT3 stage at final histology from TMPRSS2:ERG gene fusion at initial core needle biopsy. FISH determination of TMPRSS2:ERG gene fusion may be particularly useful for patients scheduled to undergo a radical prostatectomy in order to improve oncological and functional results.

Kaffenberger SD, Barbieri CE
Molecular subtyping of prostate cancer.
Curr Opin Urol. 2016; 26(3):213-8 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
PURPOSE OF REVIEW: The recent publication of The Cancer Genome Atlas molecular taxonomy of primary prostate cancer highlights the increased understanding of the genomic basis of human prostate cancer, but also emphasizes the complexity and heterogeneity of prostate cancer.
RECENT FINDINGS: Seven molecular subclasses have been defined on the basis of early genomic alterations, which are largely mutually exclusive.
SUMMARY: We review the recent advances in the genomic understanding of human prostate cancer, with focus on molecular subclassification. Broadly, prostate cancer can be classified based upon whether specific genomic rearrangements, such as the Transmembrane Protease, Serine 2-ETS-related gene fusion occur or whether specific alterations such as Speckle-type POZ protein and forkhead box A1 mutations occur. The molecular drivers remain to be identified in a further quarter of human prostate cancers. Depending upon the molecular subclassification and the coincident genomic alterations, specific clinical insights can be gained from this information, including associations with pathologic factors, race, and prognosis, as well as the possibility for future precision therapies.

Liu W
DNA alterations in the tumor genome and their associations with clinical outcome in prostate cancer.
Asian J Androl. 2016 Jul-Aug; 18(4):533-42 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
Although most prostate cancer (PCa) cases are not life-threatening, approximately 293 000 men worldwide die annually due to PCa. These lethal cases are thought to be caused by coordinated genomic alterations that accumulate over time. Recent genome-wide analyses of DNA from subjects with PCa have revealed most, if not all, genetic changes in both germline and PCa tumor genomes. In this article, I first review the major, somatically acquired genomic characteristics of various subtypes of PCa. I then recap key findings on the relationships between genomic alterations and clinical parameters, such as biochemical recurrence or clinical relapse, metastasis and cancer-specific mortality. Finally, I outline the need for, and challenges with, validation of recent findings in prospective studies for clinical utility. It is clearer now than ever before that the landscape of somatically acquired aberrations in PCa is highlighted by DNA copy number alterations (CNAs) and TMPRSS2-ERG fusion derived from complex rearrangements, numerous single nucleotide variations or mutations, tremendous heterogeneity, and continuously punctuated evolution. Genome-wide CNAs, PTEN loss, MYC gain in primary tumors, and TP53 loss/mutation and AR amplification/mutation in advanced metastatic PCa have consistently been associated with worse cancer prognosis. With this recently gained knowledge, it is now an opportune time to develop DNA-based tests that provide more accurate patient stratification for prediction of clinical outcome, which will ultimately lead to more personalized cancer care than is possible at present.

Boutros PC, Fraser M, van der Kwast T, Bristow RG
Clonality of localized and metastatic prostate cancer.
Curr Opin Urol. 2016; 26(3):219-24 [PubMed] Related Publications
PURPOSE OF REVIEW: The influence of the long life-history of prostate cancer on the temporal and spatial variability of the tumour genome is now being elucidated. Multiregion sequencing to identify spatio-genomic differences in prostate tumour mutation profiles combined with computational approaches can map the evolution and transit of tumour cells throughout an individual patient.
RECENT FINDINGS: A series of recent studies have demonstrated that a prostate tumour is often composed of different subclones, with varying genetic similarity. As such, a single biopsy specimen may be insufficient to make accurate clinical predictions from molecular biomarkers, greatly complicating the application of biopsy-based tools for precision medicine. In addition, subclones that arise outside of the primary tumour can seed new metastases and circulate between sites within a patient.
SUMMARY: The mutational complexity of multiple tumour clones within the same individual, which respond differently to specific treatments, suggests the need for multimodal interventions.

Petrovics G, Li H, Stümpel T, et al.
A novel genomic alteration of LSAMP associates with aggressive prostate cancer in African American men.
EBioMedicine. 2015; 2(12):1957-64 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
Evaluation of cancer genomes in global context is of great interest in light of changing ethnic distribution of the world population. We focused our study on men of African ancestry because of their disproportionately higher rate of prostate cancer (CaP) incidence and mortality. We present a systematic whole genome analyses, revealing alterations that differentiate African American (AA) and Caucasian American (CA) CaP genomes. We discovered a recurrent deletion on chromosome 3q13.31 centering on the LSAMP locus that was prevalent in tumors from AA men (cumulative analyses of 435 patients: whole genome sequence, 14; FISH evaluations, 101; and SNP array, 320 patients). Notably, carriers of this deletion experienced more rapid disease progression. In contrast, PTEN and ERG common driver alterations in CaP were significantly lower in AA prostate tumors compared to prostate tumors from CA. Moreover, the frequency of inter-chromosomal rearrangements was significantly higher in AA than CA tumors. These findings reveal differentially distributed somatic mutations in CaP across ancestral groups, which have implications for precision medicine strategies.

Qu X, Jeldres C, Glaskova L, et al.
Identification of Combinatorial Genomic Abnormalities Associated with Prostate Cancer Early Recurrence.
J Mol Diagn. 2016; 18(2):215-24 [PubMed] Free Access to Full Article Related Publications
Multiple biomarkers are needed to distinguish aggressive from indolent prostate cancer. We tested the prognostic utility of a three-marker fluorescent in situ hybridization (FISH) panel (TMPRSS2/ERG rearrangements, AR gain, and PTEN deletion) in a retrospective cohort (n = 210; median follow-up, 5.7 years). PTEN deletion was associated with an increased risk of biochemical recurrence (BcR; hazard ratio, 3.58; 95% CI, 1.39-9.22; P < 0.01) by multivariable Cox regression analyses and earlier BcR (P < 0.02) by Kaplan-Meier analysis. AR gain coexisted with X-chromosome gain and was associated with advanced tumor stage. When this panel was applied, two categories of combinatorial abnormalities proved clinically important. First, PTEN deletion without TMPRSS2/ERG rearrangement was enriched in pT3/4 tumors (70% versus 48%) and tumors with Gleason grades of 8 to 9 (60% versus 17%) compared with the entire cohort. These patients had earlier BcR than patients with normal FISH panel results (P < 0.01). In contrast, patients with PTEN deletion and ERG rearrangement had a BcR rate similar to patients who tested normal for all three markers (P > 0.1). Second, AR gain and concurrent trisomy 10 without TMPRSS2/ERG rearrangement were enriched in pT3/4 tumors and tumors with Gleason grades of 8 to 9. The three-marker FISH panel demonstrated prognostic utility and identified genomic aberrations associated with advanced disease state and early BcR in prostate cancer.

Metzger E, Willmann D, McMillan J, et al.
Assembly of methylated KDM1A and CHD1 drives androgen receptor-dependent transcription and translocation.
Nat Struct Mol Biol. 2016; 23(2):132-9 [PubMed] Related Publications
Prostate cancer evolution is driven by a combination of epigenetic and genetic alterations such as coordinated chromosomal rearrangements, termed chromoplexy. TMPRSS2-ERG gene fusions found in human prostate tumors are a hallmark of chromoplexy. TMPRSS2-ERG fusions have been linked to androgen signaling and depend on androgen receptor (AR)-coupled gene transcription. Here, we show that dimethylation of KDM1A at K114 (to form K114me2) by the histone methyltransferase EHMT2 is a key event controlling androgen-dependent gene transcription and TMPRSS2-ERG fusion. We identified CHD1 as a KDM1A K114me2 reader and characterized the KDM1A K114me2-CHD1 recognition mode by solving the cocrystal structure. Genome-wide analyses revealed chromatin colocalization of KDM1A K114me2, CHD1 and AR in prostate tumor cells. Together, our data link the assembly of methylated KDM1A and CHD1 with AR-dependent transcription and genomic translocations, thereby providing mechanistic insight into the formation of TMPRSS2-ERG gene fusions during prostate-tumor evolution.

Kluth M, Meyer D, Krohn A, et al.
Heterogeneity and chronology of 6q15 deletion and ERG-fusion in prostate cancer.
Oncotarget. 2016; 7(4):3897-904 [PubMed] Free Access to Full Article Related Publications
Prostate cancer is notorious for its heterogeneity, which poses a problem for the applicability of diagnostic molecular markers. However, heterogeneity analysis can provide valuable information on the chronology in which molecular alterations arise. Here, we constructed a heterogeneity tissue microarray (TMA) comprising samples from 10 different tumor areas of 189 prostate cancers each in order to study the sequence of two frequent molecular alterations, i.e. 6q15 deletion and TMPRSS2:ERG fusion. Previous work shows a marked inverse relationship between these alterations, suggesting that presence of one of these alterations might impact development of the other. 6q15 deletion was analyzed by fluorescence in situ hybridization and ERG-expression by immunohistochemistry. Only 6.6% of 334 ERG-positive but 28.4% of 440 ERG-negative TMA spots showed 6q15 deletions (p < 0.0001). A breakdown of these data to the level of tumor foci revealed 6q deletions in 138 tumor foci that were large enough to have at least 3 analyzable TMA spots. These included 42 tumor foci with homogeneous ERG positivity and 16 with homogeneous 6q15 deletions. Remarkably, six of the 42 homogeneously ERG-positive tumor foci (14.3%) harbored small 6q15-deleted areas, but none of the 34 6q15-deleted foci showed areas of ERG positivity (p = 0.022). In conclusion, our data suggest that ERG-fusion can precede 6q15 deletion, but not vice versa. The complete absence of ERG-positive tumor areas in 6q15-deleted tumor foci further suggest that the functional consequences of 6q15 deletions may prevent the development of TMPRSS2:ERG fusions.

Meller S, Meyer HA, Bethan B, et al.
Integration of tissue metabolomics, transcriptomics and immunohistochemistry reveals ERG- and gleason score-specific metabolomic alterations in prostate cancer.
Oncotarget. 2016; 7(2):1421-38 [PubMed] Free Access to Full Article Related Publications
Integrated analysis of metabolomics, transcriptomics and immunohistochemistry can contribute to a deeper understanding of biological processes altered in cancer and possibly enable improved diagnostic or prognostic tests. In this study, a set of 254 metabolites was determined by gas-chromatography/liquid chromatography-mass spectrometry in matched malignant and non-malignant prostatectomy samples of 106 prostate cancer (PCa) patients. Transcription analysis of matched samples was performed on a set of 15 PCa patients using Affymetrix U133 Plus 2.0 arrays. Expression of several proteins was immunohistochemically determined in 41 matched patient samples and the association with clinico-pathological parameters was analyzed by an integrated data analysis. These results further outline the highly deregulated metabolism of fatty acids, sphingolipids and polyamines in PCa. For the first time, the impact of the ERG translocation on the metabolome was demonstrated, highlighting an altered fatty acid oxidation in TMPRSS2-ERG translocation positive PCa specimens. Furthermore, alterations in cholesterol metabolism were found preferentially in high grade tumors, enabling the cells to create energy storage. With this integrated analysis we could not only confirm several findings from previous metabolomic studies, but also contradict others and finally expand our concepts of deregulated biological pathways in PCa.

Murphy SJ, Karnes RJ, Kosari F, et al.
Integrated analysis of the genomic instability of PTEN in clinically insignificant and significant prostate cancer.
Mod Pathol. 2016; 29(2):143-56 [PubMed] Related Publications
Patients with clinically insignificant prostate cancer remain a major over-treated population. PTEN loss is one of the most recurrent alterations in prostate cancer associated with an aggressive phenotype, however, the occurrence of PTEN loss in insignificant prostate cancer has not been reported and its role in the separation of insignificant from significant prostate cancer is unclear. An integrated analysis of PTEN loss was, therefore, performed for structural variations, point mutations and protein expression in clinically insignificant (48 cases) and significant (76 cases) prostate cancers treated by radical prostatectomy. Whole-genome mate pair sequencing was performed on tumor cells isolated by laser capture microdissection to characterize PTEN structural alterations. Fluorescence in situ hybridization probes were constructed from the sequencing data to detect the spectrum of these PTEN alterations. PTEN loss by mate pair sequencing and fluorescence in situ hybridization occurred in 2% of insignificant, 13% of large volume Gleason score 6, and 46% of Gleason score 7 and higher cancers. In Gleason score 7 cancers with PTEN loss, PTEN alterations were detected in both Gleason pattern 3 and 4 in 57% of cases by mate pair sequencing, 75% by in situ hybridization and 86% by immunohistochemistry. PTEN loss by sequencing was strongly associated with TMPRSS2-ERG fusion, biochemical recurrence, PTEN loss by in situ hybridization and protein loss by immunohistochemistry. The complex nature of PTEN rearrangements was unveiled by sequencing, detailing the heterogeneous events leading to homozygous loss of PTEN. PTEN point mutation was present in 5% of clinically significant tumors and not in insignificant cancer or high-grade prostatic intraepithelial neoplasia. PTEN loss is infrequent in clinically insignificant prostate cancer, and is associated with higher grade tumors. Detection of PTEN loss in Gleason score 6 cancer in a needle biopsy specimen indicates a higher likelihood of clinically significant prostate cancer.

Demidenko R, Razanauskas D, Daniunaite K, et al.
Frequent down-regulation of ABC transporter genes in prostate cancer.
BMC Cancer. 2015; 15:683 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: ATP-binding cassette (ABC) transporters are transmembrane proteins responsible for the efflux of a wide variety of substrates, including steroid metabolites, through the cellular membranes. For better characterization of the role of ABC transporters in prostate cancer (PCa) development, the profile of ABC transporter gene expression was analyzed in PCa and noncancerous prostate tissues (NPT).
METHODS: TaqMan Low Density Array (TLDA) human ABC transporter plates were used for the gene expression profiling in 10 PCa and 6 NPT specimens. ABCB1 transcript level was evaluated in a larger set of PCa cases (N = 78) and NPT (N = 15) by real-time PCR, the same PCa cases were assessed for the gene promoter hypermethylation by methylation-specific PCR.
RESULTS: Expression of eight ABC transporter genes (ABCA8, ABCB1, ABCC6, ABCC9, ABCC10, ABCD2, ABCG2, and ABCG4) was significantly down-regulated in PCa as compared to NPT, and only two genes (ABCC4 and ABCG1) were up-regulated. Down-regulation of ABC transporter genes was prevalent in the TMPRSS2-ERG-negative cases. A detailed analysis of ABCB1 expression confirmed TLDA results: a reduced level of the transcript was identified in PCa in comparison to NPT (p = 0.048). Moreover, the TMPRSS2-ERG-negative PCa cases showed significantly lower expression of ABCB1 in comparison to NPT (p = 0.003) or the fusion-positive tumors (p = 0.002). Promoter methylation of ABCB1 predominantly occurred in PCa and was rarely detected in NPT (p < 0.001).
CONCLUSIONS: The study suggests frequent down-regulation of the ABC transporter genes in PCa, especially in the TMPRSS2-ERG-negative tumors.

Fallahabadi ZR, Noori Daloii MR, Mahdian R, et al.
Frequency of PTEN alterations, TMPRSS2-ERG fusion and their association in prostate cancer.
Gene. 2016; 575(2 Pt 3):755-60 [PubMed] Related Publications
BACKGROUND: Phosphatase and tensin homolog (PTEN) gene aberration and trans membrane protease, serine 2 (TMPRSS2)-v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) fusion are the most prevalent genomic events in prostate cancer. In this study we aimed to evaluate the frequency of PTEN alteration and TMPRSS2-ERG fusion and possible link between these two biomarkers in Iranian men.
METHODS: We assessed 42 fresh frozen tissue samples of prostate cancer (PCA) obtained by radical prostatectomy, interrogating the TMPRSS2-ERG fusion gene along with PTEN gene status using Real Time PCR and FISH methods.
RESULTS: Using Real Time PCR we identified the TMPRSS2-ERG fusion in 64% (27/42) of tumor samples, which was confirmed by FISH technique, giving 21 positive samples with deletion, suggesting the presence of TMPRSS2-ERG fusion gene. By contrast, PTEN deletion was detected in 52% (11/21) of PCA samples, which all showed low expression in Real Time. Concomitance of PTEN deletion or low expression and TMPRSS2-ERG fusion was present in PCA samples (P=0.005). All of the PTEN deletion samples showed TMPRSS2-ERG fusion, (11/11, 100%) while not all of the TMPRSS2-ERG fusion positive samples showed PTEN deletion. None of 29 cases of BPH and 8 cases of normal zone of tumor tissue showed TMPRSS2-ERG fusion.
CONCLUSIONS: These results indicate that PTEN loss occurs in cooperation with TMPRSS2-ERG fusion in PCA. While the majority of PCA samples harbor TMPRSS2-ERG fusion as well as PTEN gene deletion, normal tissues do not show these molecular aberrations.

Bu H, Narisu N, Schlick B, et al.
Putative Prostate Cancer Risk SNP in an Androgen Receptor-Binding Site of the Melanophilin Gene Illustrates Enrichment of Risk SNPs in Androgen Receptor Target Sites.
Hum Mutat. 2016; 37(1):52-64 [PubMed] Free Access to Full Article Related Publications
Genome-wide association studies have identified genomic loci, whose single-nucleotide polymorphisms (SNPs) predispose to prostate cancer (PCa). However, the mechanisms of most of these variants are largely unknown. We integrated chromatin-immunoprecipitation-coupled sequencing and microarray expression profiling in TMPRSS2-ERG gene rearrangement positive DUCaP cells with the GWAS PCa risk SNPs catalog to identify disease susceptibility SNPs localized within functional androgen receptor-binding sites (ARBSs). Among the 48 GWAS index risk SNPs and 3,917 linked SNPs, 80 were found located in ARBSs. Of these, rs11891426:T>G in an intron of the melanophilin gene (MLPH) was within a novel putative auxiliary AR-binding motif, which is enriched in the neighborhood of canonical androgen-responsive elements. T→G exchange attenuated the transcriptional activity of the ARBS in an AR reporter gene assay. The expression of MLPH in primary prostate tumors was significantly lower in those with the G compared with the T allele and correlated significantly with AR protein. Higher melanophilin level in prostate tissue of patients with a favorable PCa risk profile points out a tumor-suppressive effect. These results unravel a hidden link between AR and a functional putative PCa risk SNP, whose allele alteration affects androgen regulation of its host gene MLPH.

Kim JH, Hong SK
Potential Utility of Novel Biomarkers in Active Surveillance of Low-Risk Prostate Cancer.
Biomed Res Int. 2015; 2015:475920 [PubMed] Free Access to Full Article Related Publications
Active surveillance (AS) is now an accepted management strategy for men with low-risk localized prostate cancer (PCa). However, detecting disease progression in a patient selected for AS remains a challenge. It is crucial to know what will serve as the best parameter to correctly identify tumors that progress to a more aggressive phenotype so as not to miss the window of curability. Several biomarkers are now being actively investigated as novel tools to improve PCa risk assessments. To date, several serum, urinary, and tissue biomarkers have shown promising prognostic value. %[-2]proPSA and PHI showed improved predictive value for an unfavorable biopsy conversion at annual surveillance biopsy in the AS program. PCA3 and TMPRSS2:ERG had additional independent predictive value for the prediction of PCa detection and progression, although PCA3 was limited in predicting aggressive cancer. Other tissue biomarkers also showed promising ability to predict disease progression. Although several of these novel biomarkers have an improved predictive accuracy that is better than classical parameters, there is still a need for further well-designed, large, multicenter, prospective trials to avoid common bias and clinical validation.

Kissick HT, On ST, Dunn LK, et al.
The transcription factor ERG increases expression of neurotransmitter receptors on prostate cancer cells.
BMC Cancer. 2015; 15:604 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The TMPRSS2-ERG gene fusion occurs in about half of prostate cancer (PCa) cases and results in overexpression of the transcription factor ERG. Overexpression of ERG has many effects on cellular function. However, how these changes enhance cell growth and promote tumor development is unclear.
METHODS: To investigate the role of ERG, LNCaP and PC3 cells were transfected with ERG and gene expression and metabolic profile were analyzed.
RESULTS: Our data show that expression of ERG induces overexpression of many nicotinicacetylcholine receptors (nAChRs). In addition, metabolic profiling by LC-MS/MS revealed elevated production of several neurotransmitters in cells expressing ERG. Consistently, treatment of ERG-expressing cells with nicotine induced elevated calcium influx, GSK3β (Ser9) phosphorylation and cell proliferation. Finally, we show that PCa patientswho are smokers have larger tumors if their tumors are TMPRSS2-ERG gene fusion positive.
CONCLUSION: Collectively, our data suggest that ERG sensitizes prostate tumor cells to neurotransmitter receptor agonists like nicotine.

Latest Publications: TMPRSS2 (cancer-related)

Dondoo TO, Fukumori T, Daizumoto K, et al.
Galectin-3 Is Implicated in Tumor Progression and Resistance to Anti-androgen Drug Through Regulation of Androgen Receptor Signaling in Prostate Cancer.
Anticancer Res. 2017; 37(1):125-134 [PubMed] Related Publications
BACKGROUND: Castration-resistant prostate cancer (CRPC)-related deaths are increasing worldwide. Therefore, clarification of the mechanisms of hormone-related tumor progression and resistance to anti-androgen drugs is useful in order to develop strategies for appropriate treatment of CRPC. Galectin-3 has been shown to be correlated with tumor progression in a variety of cancer types through the regulation of tumor proliferation, angiogenesis, and apoptosis.
MATERIALS AND METHODS: We examined tumor cell invasion and migration using the xCELLigence system. Control LNCaP and galectin-3-expressing LNCaP (LNCaP-Gal-3) cells were cultured with androgen-depleted medium with 5% charcoal-stripped serum. Cells were treated for 24 h with or without dihydrotestosterone alone or combined with MDV3100 and bicalutamide; gene profile was then analyzed by microarray analysis and mRNA expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). We evaluated tumor growth using spheroids and xenograft tumor growth in a mouse model.
RESULTS: In vitro, LNCaP-Gal-3 cells promoted both cell migration and invasion in an androgen-independent manner compared to control LNCaP cells. Galectin-3 also enhanced anchorage-independent growth and xenograft tumor growth even after castration. Importantly, galectin-3 greatly enhanced transcriptional activity of the androgen receptor (AR), especially on treatment with dihydrotestosterone. In microarray and qRT-PCR analyses, galectin-3 increased the expression of several AR-target genes, such as kallikrein-related peptidase 3 (KLK3), and transmembrane protease, serine 2 (TMPRSS2). These AR-target genes were not fully suppressed by anti-androgen drugs such as bicalutamide or MDV3100. Galectin-3 significantly inhibited the effect induced by anti-androgen drugs MDV3100 and bicalutamide, suggesting that galectin-3 may be involved in resistance to anti-androgen drug through enhancement of transcriptional activity of AR and expression of AR-related genes.
CONCLUSION: These results suggest that galectin-3 is a potential target molecule for future treatment of anti-androgen drug-resistant prostate cancer.

Berg KD
The prognostic and predictive value of TMPRSS2-ERG gene fusion and ERG protein expression in prostate cancer biopsies.
Dan Med J. 2016; 63(12) [PubMed] Related Publications
BACKGROUND: The clinical course of prostate carcinoma (PCa) is very heterogeneous. Consequently, a personalised approach for risk stratification and treatment planning is important. Recently, it has become evident that PCa, also at the genomic level, is heterogeneous. An early and common alteration is the gene fusion between the transmembrane protease serine 2 (TMPRSS2) gene and the v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) gene resulting in expression of the oncoprotein ERG. The gene fusion is present in approximately half of PCa patients and the resultant two subgroups demonstrate marked differences in their genomic signatures. It has been hypothesised that genomic alterations can explain some of the observed heterogeneity in the clinical course of PCa. In order to conduct an analysis of the prognostic and predictive value of ERG protein expression in PCa biopsies, the thesis sought to evaluate: 1) the concordance in ERG expression between biopsies and radical prostatectomies: 2) the association between expression of ERG protein and the risk of PCa progression during active surveillance (AS), and 3) the association between ERG protein expression and response to primary castration-based treatment for advanced PCa.
MATERIAL AND METHODS: The included patients derived from the institutional AS cohort and an institutional cohort of advanced PCa patients undergoing first line castration-based androgen deprivation therapy (ADT). The 265 patients in the AS cohort were enrolled prospectively between October 2002 and October 2012 and were followed with regular digital rectal examinations, PSA measurements, and repeated biopsies. The advanced PCa cohort comprised of 194 patients diagnosed between January 2000 and December 2011 and was established retrospectively by a standardised extraction of patient data. Immunohistochemical (IHC) assessment for ERG protein expression was performed in all tumours containing diagnostic specimens (AS cohort: n = 459; advanced PCa cohort: n = 968), re-biopsies during AS (n = 402), and deferred radical prostatectomy specimens following AS (n = 86). An anti-ERG rabbit monoclonal primary antibody (clone: EPR3864, dilution 23 μg/ml) was used. Fluorescence in situ hybridisation (FISH) for the TMPRSS2-ERG gene fusion was performed in 76 selected biopsies from the AS cohort using the ZytoLight TriCheck Probe, SPEC ERG/TMPRSS2.
RESULTS: Based on the AS cohort, Study 1 found a 97.3% concordance between the FISH assay and the IHC assay. The IHC assessments of ERG expression in diagnostic biopsies, re-biopsies, and radical prostatectomy specimens demonstrated a low proportion of temporal ERG reclassification. During four rounds of re-biopsies, 6.6% of the patients experienced ERG reclassification, and depending on the number biopsy specimens included 5.8-10.5% of the patients were ERG reclassified after radical prostatectomy. In Study 2, 46.4% of the AS patients were categorised as ERG-positive, whereas 53.6% were categorised as ERG-negative. After median 4.1 years follow-up, a significantly higher risk of disease progression was observed in men with ERG-positive tumours corresponding to a two-year cumulative incidence of 58.6% (95% CI: 48.7-68.5) and 21.7% (95% CI: 14.3-29.1) in the ERG-positive and the ERG-negative group, respectively. In the multiple causespecific Cox analyses, ERG expression was a strong and independent predictor of overall disease progression (HR: 2.45, 95% CI: 1.62-3.72) and histopathological progression in repeated biopsies (HR: 3.06, 95% CI: 1.78-5.26), and ERG status increased the discriminative ability for predicting disease progression significantly. Study 3 included 194 patients with advanced PCa treated with firstline ADT. In total, 54.1% had ERG-positive tumours and 45.9% had ERG-negative tumours. With a median of 6.8 years of follow-up, the risk of developing castration-resistant PCa (CRPC) did not differ between the ERG subgroups (p = 0.51). Finally, inclusion of ERG status in a multiple cause-specific Cox model did not increase the discriminative ability for predicting CRPC development during the first 8 years of ADT.
CONCLUSION: The thesis has demonstrated that assessment of ERG protein expression is feasible in biopsy specimens, and a high concordance was found between the IHC assay and FISH assessment of ERG rearrangement. The low proportion of ERG reclassification between biopsies and prostatectomies supports the use of ERG assessment in biopsies to characterise the individual patient's ERG status. ERG status harbours important prognostic value in terms of tumour progression for patients managed on AS, whereas ERG expression has no predictive value for ADT response in men with advanced PCa undergoing first-line castration-based ADT. The overall conclusion of the thesis is that ERG protein expression provides valuable prognostic information in low-risk PCa managed observationally, and ERG expression might be used to personalise follow-up regimens in future AS programmes.

Koo KM, Wee EJ, Trau M
High-speed biosensing strategy for non-invasive profiling of multiple cancer fusion genes in urine.
Biosens Bioelectron. 2017; 89(Pt 2):715-720 [PubMed] Related Publications
Aberrant chromosal rearrangements, such as the multiple variants of TMPRSS2:ERG fusion gene mutations in prostate cancer (PCa), are promising diagnostic and prognostic biomarkers due to their specific expression in cancerous tissue only. Additionally, TMPRSS2:ERG variants are detectable in urine to provide non-invasive PCa diagnostic sampling as an attractive surrogate for needle biopsies. Therefore, rapid and simplistic assays for identifying multiple urinary TMPRSS2:ERG variants are potentially useful to aid in early cancer detection, immediate patient risk stratification, and prompt personalized treatment. However, current strategies for simultaneous detection of multiple gene fusions are limited by tedious and prolonged experimental protocols, thus limiting their use as rapid clinical screening tools. Herein, we report a simple and rapid gene fusion strategy which expliots the specificity of DNA ligase and the speed of isothermal amplification to simultaneously detect multiple fusion gene RNAs within a short sample-to-answer timeframe of 60min. The method has a low detection limit of 2 amol (1000 copies), and was successfully applied for non-invasive fusion gene profiling in patient urine samples with subsequent validation by a PCR-based gold standard approach.

Jiang H, Mao X, Huang X, et al.
TMPRSS2:ERG fusion gene occurs less frequently in Chinese patients with prostate cancer.
Tumour Biol. 2016; 37(9):12397-12402 [PubMed] Related Publications
Prostate cancer is the commonest male malignancy in the Western world, but its morbidity is much lower in China. The principal aim of this study was to evaluate the frequency of TMPRSS2:ERG fusion in Chinese prostate cancer patients using immunohistochemistry and reverse transcription polymerase chain (RT-PCR). In addition, we compared the ERG protein expression with TMPRSS2:ERG fusion gene. The relationship between ERG expression and clinicopathologic features was also examined. Samples from patients who underwent radical prostatectomies in Changhai Hospital (Shanghai, China) were collected and stored in ethically approved tissue banks. One hundred seventy-four prostate cancer tissue samples and 10 normal tissues were marked on standard hematoxylin-eosin (HE) sections, punched out of the paraffin blocks and inserted into a recipient block using tissue arrayer instruments. Immunohistochemistry and RT-PCR were employed to detect TMPRSS2:ERG fusion gene. ERG was highly expressed in the nuclei of endothelial cells of vessels and weak cytoplasmic staining was occasionally observed. ERG positive staining was present in 14.9 % (26/174) of the tumor samples in microarray. All benign prostate samples were found to be negative. RT-PCR results revealed that 11.1 % (15/135) were TMPRSS2:ERG fusion positive. Altogether, there was a good agreement of ERG immunostaining with the presence of TMPRSS2:ERG. However, no correlation was observed between ERG expression and age, Gleason score, stage, surgical margin, and seminal vesicle involvement in Chinese patients. In the present study, we identified a high correlation between ERG expression and ERG TMPRSS2:ERG, with 100 % sensitivity and 88.9 % specificity. The expression level of ERG was unrelated to the age, Gleason score, stage, surgical margin, and seminal vesicle involvement. Therefore, the association between ERG expression and prostate cancer based on Chinese population should be further investigated in the future.

Box A, Alshalalfa M, Hegazy SA, et al.
High alpha-methylacyl-CoA racemase (AMACR) is associated with ERG expression and with adverse clinical outcome in patients with localized prostate cancer.
Tumour Biol. 2016; 37(9):12287-12299 [PubMed] Related Publications
Alpha-methylacyl-CoA racemase (AMACR) is a well-characterized marker extensively utilized in prostate cancer (PCA) diagnosis. However, the prognostic value of AMACR expression and its relation to TMPRSS2-ERG gene rearrangement as one of the most common molecular alterations in PCA is not fully explored. AMACR expression was investigated in a cohort of 218 men with localized PCA treated by radical prostatectomy and correlated with ERG and various clinical and pathological parameters. In vitro studies assessed AMACR changes to ERG knockdown and other related genes. In addition, bioinformatics validated the significance of AMACR/ERG expression and assessed relevant genetic signatures in relation to AMACR/ERG expression. AMACR expression was significantly associated with disease progression and with ERG (p ∼0). Seventeen percent of cancer foci showed negative/weak AMACR expression while being ERG positive. High AMACR expression was significantly associated with positive surgical margins (p = 0.01), specifically in tumors with lower Gleason score <7, with ∼95 % exhibiting positive surgical margin (p = 0.008). High AMACR showed marginal association with PSA biochemical recurrence (BCR) (p = 0.06) which was slightly more pronounced in ERG-positive tumors (p = 0.04). This was validated in other public cohorts. However, in this cohort, the association with BCR was not statistically significant in multivariate analysis (p = 0.09). Using in vitro cellular models, AMACR messenger RNA (mRNA) expression, but not protein levels, showed an association with ERG expression. We report for the first time a significant association between AMACR and ERG with prognostic implication. Patients with high AMACR/ERG-positive PCA may be at higher risk for disease progression, and additional studies in larger cohorts are needed to confirm the above findings. Functional studies investigating the molecular pathways connecting AMACR and ERG may provide an additional insight into PCA progression pathways.

Kim H, Skowronski J, Den RB
Prognostic outlier genes for enhanced prostate cancer treatment.
Future Oncol. 2017; 13(3):249-261 [PubMed] Related Publications
AIM: To review the current landscape of outlier genes in the field of prostate cancer.
METHODS: A comprehensive review was performed.
RESULTS: Prostate cancer continues to be a significant worldwide health issue. In the era of personalized medicine, more emphasis is being placed on the ability to determine the timing, intensity and type of treatment, according to each patient's unique disease. Several commercial tests are available to determine the risk of aggressive prostate cancer based on genomic biomarkers and gene expression. Outlier genes represent a form of cancer classification that focuses on bimodal expression of a gene in a specific subset of patients. Outlier genes identified in prostate cancer include TMPRSS2-ERG, SPINK1, ScHLAP1, NVL, SMC4 and SQLE.
CONCLUSION: Classifying patient prostate cancers by outlier genes may allow for individualized cancer therapies and improved cancer therapy outcomes.

Kulda V, Topolcan O, Kucera R, et al.
Prognostic Significance of TMPRSS2-ERG Fusion Gene in Prostate Cancer.
Anticancer Res. 2016; 36(9):4787-93 [PubMed] Related Publications
BACKGROUND/AIM: Current research of prostate cancer (PCa) offers a promising way of identifying patients with adverse prognosis who do benefit from radical treatment that can affect quality of life as resections are associated with numerous side-effects. The aim of our study was to evaluate the relationship of TMPRSS2-ERG fusion gene status, tumor tissue prostate-specific antigen (PSA), prostate cancer antigen 3 (PCA3), miR-23b, miR-26a and miR-221 expression levels in combination with preoperative serum PSA level to the risk of PCa recurrence after radical prostatectomy.
PATIENTS AND METHODS: The study group consisted of 108 patients who underwent radical prostatectomy. PSA was measured in peripheral blood collected preoperativelly. The expression of TMPRSS2-ERG transcript and the expression of miR-23b, miR-26a and miR-221 in formalin-fixed, paraffin-embedded (FFPE) tumor tissues was analyzed by reverse transcription (RT) real-time polymerase chain reaction (PCR).
RESULTS: Significantly shorter time to recurrence was observed in patients with high expression of TMPRSS2-ERG (p=0.0020). High levels of preoperative PSA (>10.0 ng/ml) proved to be marker of shorter time to recurrence (p=0.0153). The most promising marker of the risk of recurrence after radical prostatectomy was a combination of high level of preoperative serum PSA and high expression of TMPRSS2-ERG fusion transcript in tumor tissue (p=0.0001).
CONCLUSION: A combination of high preoperative serum PSA and high expression of TMPRSS2-ERG could be promising in distinguishing those tumors that are aggressive and life-threatening.

Krstanoski Z, Vokac NK, Zagorac A, et al.
TMPRSS2:ERG gene aberrations may provide insight into pT stage in prostate cancer.
BMC Urol. 2016; 16(1):35 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: TMPRSS2:ERG gene aberration may be a novel marker that improves risk stratification of prostate cancer before definitive cancer therapy, but studies have been inconclusive.
METHODS: The study cohort consisted of 202 operable prostate cancer Slovenian patients who underwent laparoscopic radical prostatectomy. We retrospectively constructed tissue microarrays of their prostatic specimens for fluorescence in situ hybridization, with appropriate signals obtained in 148 patients for subsequent statistical analyses.
RESULTS: The following genetic aberrations were found: TMPRSS2:ERG fusion, TMPRSS2 split (a non-ERG translocation) and ERG split (an ERG translocation without involvement of TMPRSS2). TMPRSS2:ERG gene fusion happened in 63 patients (42 %), TMPRSS2 split in 12 patients and ERG split in 8 patients. Association was tested between TMPRSS2:ERG gene fusion and several clinicopathological variables, i.e., pT stage, extended lymph node dissection status, and Gleason score, correcting for multiple comparisons. Only the association with pT stage was significant at p = 0.05: Of 62 patients with pT3 stage, 34 (55 %) had TMPRSS2:ERG gene fusion. In pT3 stage patients, stronger (but not significant) association between eLND status and TMPRSS2:ERG gene fusion was detected. We detected TMPRSS2:ERG gene fusion in 64 % of the pT3 stage patients where we did not perform an extended lymph node dissection.
CONCLUSIONS: Our results indicate that it is possible to predict pT3 stage at final histology from TMPRSS2:ERG gene fusion at initial core needle biopsy. FISH determination of TMPRSS2:ERG gene fusion may be particularly useful for patients scheduled to undergo a radical prostatectomy in order to improve oncological and functional results.

Kirby R
The role of PSA in detection and management of prostate cancer.
Practitioner. 2016; 260(1792):17-21, 3 [PubMed] Related Publications
The prostate specific antigen (PSA) test clearly provides the opportunity for clinically relevant prostate cancer to be detected at a stage when treatment options are greater and outcomes may be improved. However, in some patients the PSA test may lead to investigations which can identify clinically insignificant cancers which would not have become evident in a man's lifetime. In addition, a raised PSA may often indicate benign prostatic enlargement, and this may provide an opportunity for treatment of this condition before complications develop. The lack of sensitivity and specificity that characterises PSA testing in the initial diagnosis of prostate cancer largely disappears after treatment of localised prostate cancer, especially after surgery. Three monthly PSA measurement is usually recommended for the first year after primary treatment. Subsequently less frequent testing is required. A PSA rise after primary treatment usually indicates biochemical recurrence and often the need for further therapy. There are two promising urinary RNA biomarkers, prostate cancer antigen 3 (PCA3) and fusion gene TMPRSS2:ERG, both of which aim to distinguish between men with low-risk (indolent) and those with aggressive (clinically significant) cancers.

Merz C, von Mässenhausen A, Queisser A, et al.
IL-6 Overexpression in ERG-Positive Prostate Cancer Is Mediated by Prostaglandin Receptor EP2.
Am J Pathol. 2016; 186(4):974-84 [PubMed] Related Publications
Prostate cancer is the most diagnosed cancer in men and multiple risk factors and genetic alterations have been described. The TMPRSS2-ERG fusion event and the overexpression of the transcription factor ERG are present in approximately 50% of all prostate cancer patients, however, the clinical outcome is still controversial. Prostate tumors produce various soluble factors, including the pleiotropic cytokine IL-6, regulating cellular processes such as proliferation and metastatic segregation. Here, we used prostatectomy samples in a tissue microarray format and analyzed the co-expression and the clinicopathologic data of ERG and IL-6 using immunohistochemical double staining and correlated the read-out with clinicopathologic data. Expression of ERG and IL-6 correlated strongly in prostate tissue samples. Forced expression of ERG in prostate tumor cell lines resulted in significantly increased secretion of IL-6, whereas the down-regulation of ERG decreased IL-6 secretion. By dissecting the underlying mechanism in prostate tumor cell lines we show the ERG-mediated up-regulation of the prostanoid receptors EP2 and EP3. The prostanoid receptor EP2 was overexpressed in human prostate cancer tissue. Furthermore, the proliferation rate and IL-6 secretion in DU145 cells was reduced after treatment with EP2-receptor antagonist. Collectively, our study shows that the expression of ERG in prostate cancer is linked to the expression of IL-6 mediated by the prostanoid receptor EP2.

Kaffenberger SD, Barbieri CE
Molecular subtyping of prostate cancer.
Curr Opin Urol. 2016; 26(3):213-8 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
PURPOSE OF REVIEW: The recent publication of The Cancer Genome Atlas molecular taxonomy of primary prostate cancer highlights the increased understanding of the genomic basis of human prostate cancer, but also emphasizes the complexity and heterogeneity of prostate cancer.
RECENT FINDINGS: Seven molecular subclasses have been defined on the basis of early genomic alterations, which are largely mutually exclusive.
SUMMARY: We review the recent advances in the genomic understanding of human prostate cancer, with focus on molecular subclassification. Broadly, prostate cancer can be classified based upon whether specific genomic rearrangements, such as the Transmembrane Protease, Serine 2-ETS-related gene fusion occur or whether specific alterations such as Speckle-type POZ protein and forkhead box A1 mutations occur. The molecular drivers remain to be identified in a further quarter of human prostate cancers. Depending upon the molecular subclassification and the coincident genomic alterations, specific clinical insights can be gained from this information, including associations with pathologic factors, race, and prognosis, as well as the possibility for future precision therapies.

Graff RE, Meisner A, Ahearn TU, et al.
Pre-diagnostic circulating sex hormone levels and risk of prostate cancer by ERG tumour protein expression.
Br J Cancer. 2016; 114(8):939-44 [PubMed] Article available free on PMC after 12/04/2017 Related Publications
BACKGROUND: Experimental studies have shown androgen receptor stimulation to facilitate formation of the TMPRSS2:ERG gene fusion in prostate cell lines. No study has tested whether higher pre-diagnostic circulating sex hormone levels in men increase risk of developing TMPRSS2:ERG-positive prostate cancer specifically.
METHODS: We conducted a nested case-control study of 200 prostate cancer cases and 1057 controls from the Physicians' Health Study and Health Professionals Follow-up Study. We examined associations between pre-diagnostic circulating levels of total testosterone, free testosterone, DHT, androstanediol glucuronide, estradiol, and SHBG and risk of prostate cancer by TMPRSS2:ERG status. TMPRSS2:ERG was estimated by ERG immunohistochemistry. We used multivariable unconditional polytomous logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for risk of ERG-positive (n=94) and, separately, ERG-negative (n=106) disease.
RESULTS: Free testosterone was significantly associated with the risk of ERG-positive prostate cancer (OR: 1.37, 95% CI: 1.05-1.77), but not ERG-negative prostate cancer (OR: 1.09, 95% CI: 0.86-1.38) (Pdiff=0.17). None of the remaining hormones evaluated showed clear differential associations with ERG-positive vs ERG-negative disease.
CONCLUSIONS: These findings provide some suggestive evidence that higher pre-diagnostic free testosterone levels are associated with an increased risk of developing TMPRSS2:ERG-positive prostate cancer.

Liu W
DNA alterations in the tumor genome and their associations with clinical outcome in prostate cancer.
Asian J Androl. 2016 Jul-Aug; 18(4):533-42 [PubMed] Article available free on PMC after 12/04/2017 Related Publications
Although most prostate cancer (PCa) cases are not life-threatening, approximately 293 000 men worldwide die annually due to PCa. These lethal cases are thought to be caused by coordinated genomic alterations that accumulate over time. Recent genome-wide analyses of DNA from subjects with PCa have revealed most, if not all, genetic changes in both germline and PCa tumor genomes. In this article, I first review the major, somatically acquired genomic characteristics of various subtypes of PCa. I then recap key findings on the relationships between genomic alterations and clinical parameters, such as biochemical recurrence or clinical relapse, metastasis and cancer-specific mortality. Finally, I outline the need for, and challenges with, validation of recent findings in prospective studies for clinical utility. It is clearer now than ever before that the landscape of somatically acquired aberrations in PCa is highlighted by DNA copy number alterations (CNAs) and TMPRSS2-ERG fusion derived from complex rearrangements, numerous single nucleotide variations or mutations, tremendous heterogeneity, and continuously punctuated evolution. Genome-wide CNAs, PTEN loss, MYC gain in primary tumors, and TP53 loss/mutation and AR amplification/mutation in advanced metastatic PCa have consistently been associated with worse cancer prognosis. With this recently gained knowledge, it is now an opportune time to develop DNA-based tests that provide more accurate patient stratification for prediction of clinical outcome, which will ultimately lead to more personalized cancer care than is possible at present.

Penney KL, Pettersson A, Shui IM, et al.
Association of Prostate Cancer Risk Variants with TMPRSS2:ERG Status: Evidence for Distinct Molecular Subtypes.
Cancer Epidemiol Biomarkers Prev. 2016; 25(5):745-9 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
BACKGROUND: Numerous genetic variants have been confirmed as prostate cancer risk factors. These variants may confer susceptibility to the development of specific molecular alterations during tumor initiation and progression. The TMPRSS2:ERG gene fusion occurs in roughly 50% of prostate cancers. Genetic risk variants may influence the development of this fusion. We sought to determine whether prostate cancer risk variants are differentially associated with TMPRSS2:ERG fusion-positive and negative cancer.
METHODS: In the Health Professionals Follow-up Study and Physicians' Health Study Tumor Cohort, we evaluated the associations of 39 prostate cancer risk SNPs with TMPRSS2:ERG fusion status, measured by ERG protein expression. Logistic regression was performed to generate OR and 95% confidence intervals. The primary outcome was ERG(+) (n = 227) versus ERG(-) (n = 260) prostate cancer. A secondary outcome was ERG(+) or ERG(-) cancer versus controls without cancer.
RESULTS: Six of 39 SNPs were significantly associated (P < 0.05) with ERG(+) versus ERG(-) disease. Three SNPs were exclusively associated with the risk of ERG(+), one with risk of ERG(-), and two with associations trending in opposite directions for ERG(+) and ERG(-) Only two significant SNPs would be expected by chance.
CONCLUSIONS: Prostate cancer genetic risk variants are differentially associated with the development of ERG(+) and ERG(-) prostate cancer.
IMPACT: Our findings suggest the molecular process of prostate carcinogenesis may be distinct for men with different underlying genetic predisposition. When examining risk factors for prostate cancer, the integration of molecular subtypes may enhance understanding of the etiology of this disease. Cancer Epidemiol Biomarkers Prev; 25(5); 745-9. ©2016 AACR.

Wu J, Chi L, Chen Z, et al.
Functional analysis of the TMPRSS2:ERG fusion gene in cisplatin‑induced cell death.
Mol Med Rep. 2016; 13(4):3173-80 [PubMed] Related Publications
The TMPRSS2:E‑twenty‑six (ETS) gene fusion occurs frequently in a high proportion of patients with prostate cancer (PCa) in Western countries, and the aberrant expression of TMPRSS2: v‑ETS avian erythroblastosis virus E26 oncogene homolog (ERG), the most common form of the corresponding protein, can regulate cell migration and contribute to tumor invasion and metastasis. However, its association with other cellular events, and in particular, cell death, remain unknown. To examine the function of such fusion genes, an expression plasmid containing the TMPRSS2:ERG (T1/E5) sequence (ΔERG) from a patient sample was constructed and transiently transfected into DU145 cells, which do not express the fusion gene. It was found that the overexpression of ΔERG significantly inhibited the ability of cisplatin to induce apoptosis in DU145 cells. By contrast, VCaP cells, which do contain TMPRSS2:ERG, were sensitized to cisplatin‑induced apoptosis through siRNA inhibition of the fusion gene. To elucidate the underlying mechanism, a stable cell line expressing the ΔERG gene was constructed. Expression of ΔERG did not affect cell migration, but did protect cells from DNA damage and apoptosis induced by cisplatin. Furthermore, knockdown of ΔERG by short interfering RNA resulted in cells regaining their sensitivity to cisplatin. Finally, the gene coding for activating transcription factor 5, which is important for cell survival, may be upregulated by ΔERG. Taken together, these data point to a new function of the TMPRSS2:ERG fusion gene in regulating the apoptotic pathway.

Petrovics G, Li H, Stümpel T, et al.
A novel genomic alteration of LSAMP associates with aggressive prostate cancer in African American men.
EBioMedicine. 2015; 2(12):1957-64 [PubMed] Article available free on PMC after 01/05/2017 Related Publications
Evaluation of cancer genomes in global context is of great interest in light of changing ethnic distribution of the world population. We focused our study on men of African ancestry because of their disproportionately higher rate of prostate cancer (CaP) incidence and mortality. We present a systematic whole genome analyses, revealing alterations that differentiate African American (AA) and Caucasian American (CA) CaP genomes. We discovered a recurrent deletion on chromosome 3q13.31 centering on the LSAMP locus that was prevalent in tumors from AA men (cumulative analyses of 435 patients: whole genome sequence, 14; FISH evaluations, 101; and SNP array, 320 patients). Notably, carriers of this deletion experienced more rapid disease progression. In contrast, PTEN and ERG common driver alterations in CaP were significantly lower in AA prostate tumors compared to prostate tumors from CA. Moreover, the frequency of inter-chromosomal rearrangements was significantly higher in AA than CA tumors. These findings reveal differentially distributed somatic mutations in CaP across ancestral groups, which have implications for precision medicine strategies.

Graff RE, Pettersson A, Lis RT, et al.
Dietary lycopene intake and risk of prostate cancer defined by ERG protein expression.
Am J Clin Nutr. 2016; 103(3):851-60 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: There is limited evidence that supports etiologically distinct molecular subtypes of prostate cancer, the identification of which may improve prevention. Given their antioxidant properties, we hypothesized that lycopene and tomato sauce may be especially protective against diseases harboring the common gene fusion transmembrane protease, serine 2 (TMPRSS2):v-ets avian erythroblastosis virus E26 oncogene homolog (ERG).
OBJECTIVE: We aimed to examine associations between estimated lycopene and tomato sauce intake and the risk of prostate cancer defined by ERG protein expression subtype.
DESIGN: Our study population consisted of a prospective cohort of 46,719 men from the Health Professionals Follow-Up Study. TMPRSS2:ERG was assessed by ERG immunohistochemistry on tumor tissue microarrays constructed from radical prostatectomy specimens. We used multivariable competing risk models to calculate HRs and 95% CIs for the risk of ERG-positive and, separately, ERG-negative disease. We implemented inverse probability weighting to account for evaluating ERG status only in surgically treated cases.
RESULTS: During 23 y of follow-up, 5543 men were diagnosed with prostate cancer, among whom 884 were assayed for ERG (426 ERG-positive). With inclusion of only the latter cases, increasing cumulative average tomato sauce intake was associated with a decreased risk of prostate cancer overall (≥2 servings/wk compared with <1 serving/mo; multivariable HR: 0.70; 95% CI: 0.52, 0.95; P-trend = 0.002). With respect to molecular subtypes, cumulative average tomato sauce intake was associated with a decreased risk of ERG-positive disease (HR: 0.54; 95% CI: 0.37, 0.81; P-trend = 0.004) but not with ERG-negative disease (HR: 0.96; 95% CI: 0.62, 1.50; P-trend = 0.10) (P-heterogeneity = 0.04). Increasing quintiles of lycopene intake were associated with a decreased risk of both subtypes (P-heterogeneity = 0.79). Inverse probability weighting did not materially change the results.
CONCLUSIONS: Our results lend some support to the hypothesis that prostate cancers that harbor TMPRSS2:ERG may be etiologically distinct from fusion-negative cancers. In particular, tomato sauce consumption may play a role in reducing TMPRSS2:ERG-positive disease.

Sanguedolce F, Cormio A, Brunelli M, et al.
Urine TMPRSS2: ERG Fusion Transcript as a Biomarker for Prostate Cancer: Literature Review.
Clin Genitourin Cancer. 2016; 14(2):117-21 [PubMed] Related Publications
Prostate cancer (PCa) is one of the most common male malignancies. Serum prostate-specific antigen (PSA) is one of the most valuable biomarkers in tumor biology and remains the standard marker in detecting and monitoring PCa. However, the high number of serum PSA false positive and false negative results make the identification of novel biomarkers extremely welcome to improve our diagnostic accuracy in detecting PCa and distinguishing the aggressive from the indolent ones. In this study, we analyzed the current role of urinary gene fusion transcripts involving v-ets erythroblastosis virus E26 oncogene homolog, commonly known as ERG, and the androgen-regulated gene transmembrane protease, serine 2 (TMPRSS2), as a biomarker for PCa. Used as a single marker, urinary TMPRSS2:ERG has low sensitivity but high specificity. However, its combination with the other urinary marker PCa antigen 3 (PCA3) has been reported to provide high specificity and sensitivity. Finally, a commercially available assay combining serum PSA with urinary PCA3 and TMPRSS2:ERG provides a 90% specificity and 80% sensitivity in diagnosing PCa. Urinary TMPRSS2:ERG also seems to be indicative of PCa aggressiveness upon biopsy. Should these findings be confirmed in larger studies, urinary TMPRSS2:ERG might become a valuable test not only for diagnosing PCa but also for distinguishing the aggressive tumors from the indolent ones.

Metzger E, Willmann D, McMillan J, et al.
Assembly of methylated KDM1A and CHD1 drives androgen receptor-dependent transcription and translocation.
Nat Struct Mol Biol. 2016; 23(2):132-9 [PubMed] Related Publications
Prostate cancer evolution is driven by a combination of epigenetic and genetic alterations such as coordinated chromosomal rearrangements, termed chromoplexy. TMPRSS2-ERG gene fusions found in human prostate tumors are a hallmark of chromoplexy. TMPRSS2-ERG fusions have been linked to androgen signaling and depend on androgen receptor (AR)-coupled gene transcription. Here, we show that dimethylation of KDM1A at K114 (to form K114me2) by the histone methyltransferase EHMT2 is a key event controlling androgen-dependent gene transcription and TMPRSS2-ERG fusion. We identified CHD1 as a KDM1A K114me2 reader and characterized the KDM1A K114me2-CHD1 recognition mode by solving the cocrystal structure. Genome-wide analyses revealed chromatin colocalization of KDM1A K114me2, CHD1 and AR in prostate tumor cells. Together, our data link the assembly of methylated KDM1A and CHD1 with AR-dependent transcription and genomic translocations, thereby providing mechanistic insight into the formation of TMPRSS2-ERG gene fusions during prostate-tumor evolution.

Kluth M, Meyer D, Krohn A, et al.
Heterogeneity and chronology of 6q15 deletion and ERG-fusion in prostate cancer.
Oncotarget. 2016; 7(4):3897-904 [PubMed] Free Access to Full Article Related Publications
Prostate cancer is notorious for its heterogeneity, which poses a problem for the applicability of diagnostic molecular markers. However, heterogeneity analysis can provide valuable information on the chronology in which molecular alterations arise. Here, we constructed a heterogeneity tissue microarray (TMA) comprising samples from 10 different tumor areas of 189 prostate cancers each in order to study the sequence of two frequent molecular alterations, i.e. 6q15 deletion and TMPRSS2:ERG fusion. Previous work shows a marked inverse relationship between these alterations, suggesting that presence of one of these alterations might impact development of the other. 6q15 deletion was analyzed by fluorescence in situ hybridization and ERG-expression by immunohistochemistry. Only 6.6% of 334 ERG-positive but 28.4% of 440 ERG-negative TMA spots showed 6q15 deletions (p < 0.0001). A breakdown of these data to the level of tumor foci revealed 6q deletions in 138 tumor foci that were large enough to have at least 3 analyzable TMA spots. These included 42 tumor foci with homogeneous ERG positivity and 16 with homogeneous 6q15 deletions. Remarkably, six of the 42 homogeneously ERG-positive tumor foci (14.3%) harbored small 6q15-deleted areas, but none of the 34 6q15-deleted foci showed areas of ERG positivity (p = 0.022). In conclusion, our data suggest that ERG-fusion can precede 6q15 deletion, but not vice versa. The complete absence of ERG-positive tumor areas in 6q15-deleted tumor foci further suggest that the functional consequences of 6q15 deletions may prevent the development of TMPRSS2:ERG fusions.

Sung JY, Jeon HG, Jeong BC, et al.
Correlation of ERG immunohistochemistry with molecular detection of TMPRSS2-ERG gene fusion.
J Clin Pathol. 2016; 69(7):586-92 [PubMed] Related Publications
AIMS: TMPRSS2/E26 transformation-specific (ETS) family gene fusion in prostate carcinoma (PCa) can be detected by several methods including immunohistochemistry (IHC) for ETS-related gene (ERG), the diagnostic utility of which has not been clearly defined.
METHODS: We explored TMPRSS2-ERG gene rearrangement status in 132 patients with PCa with four detection methods including fluorescence in situ hybridisation for TMPRSS2-ERG fusion, real-time reverse transcription PCR (RT-qPCR) for ERG and TMPRSS-ERG fusion transcript mRNA and IHC for ERG.
RESULTS: Concordant results were found in 126 cases for the four detection methods and the remaining six cases showed discrepancy in one method: two cases in IHC, three cases in RT-qPCR for ERG and one case in RT-qPCR for fusion transcript. In discordant cases, the majority results were determined as final fusion status. Analysis of discrepancy cases for ERG IHC showed that weak immunoreactivity for ERG should be regarded as equivocal and that even strong immunoreactivity can be false positive. The overall incidence of TMPRSS-ERG gene fusion was 24%.
CONCLUSIONS: ERG IHC is a useful surrogate test for the detection of TMPRSS2-ERG gene fusion, but it needs to be interpreted with caution and definite judgement should not be based on IHC alone. A relatively low incidence of TMPRSS2-ERG gene fusion was demonstrated in this Korean cohort.

Gavrilov K, Seo YE, Tietjen GT, et al.
Enhancing potency of siRNA targeting fusion genes by optimization outside of target sequence.
Proc Natl Acad Sci U S A. 2015; 112(48):E6597-605 [PubMed] Free Access to Full Article Related Publications
Canonical siRNA design algorithms have become remarkably effective at predicting favorable binding regions within a target mRNA, but in some cases (e.g., a fusion junction site) region choice is restricted. In these instances, alternative approaches are necessary to obtain a highly potent silencing molecule. Here we focus on strategies for rational optimization of two siRNAs that target the junction sites of fusion oncogenes BCR-ABL and TMPRSS2-ERG. We demonstrate that modifying the termini of these siRNAs with a terminal G-U wobble pair or a carefully selected pair of terminal asymmetry-enhancing mismatches can result in an increase in potency at low doses. Importantly, we observed that improvements in silencing at the mRNA level do not necessarily translate to reductions in protein level and/or cell death. Decline in protein level is also heavily influenced by targeted protein half-life, and delivery vehicle toxicity can confound measures of cell death due to silencing. Therefore, for BCR-ABL, which has a long protein half-life that is difficult to overcome using siRNA, we also developed a nontoxic transfection vector: poly(lactic-coglycolic acid) nanoparticles that release siRNA over many days. We show that this system can achieve effective killing of leukemic cells. These findings provide insights into the implications of siRNA sequence for potency and suggest strategies for the design of more effective therapeutic siRNA molecules. Furthermore, this work points to the importance of integrating studies of siRNA design and delivery, while heeding and addressing potential limitations such as restricted targetable mRNA regions, long protein half-lives, and nonspecific toxicities.

Meller S, Meyer HA, Bethan B, et al.
Integration of tissue metabolomics, transcriptomics and immunohistochemistry reveals ERG- and gleason score-specific metabolomic alterations in prostate cancer.
Oncotarget. 2016; 7(2):1421-38 [PubMed] Free Access to Full Article Related Publications
Integrated analysis of metabolomics, transcriptomics and immunohistochemistry can contribute to a deeper understanding of biological processes altered in cancer and possibly enable improved diagnostic or prognostic tests. In this study, a set of 254 metabolites was determined by gas-chromatography/liquid chromatography-mass spectrometry in matched malignant and non-malignant prostatectomy samples of 106 prostate cancer (PCa) patients. Transcription analysis of matched samples was performed on a set of 15 PCa patients using Affymetrix U133 Plus 2.0 arrays. Expression of several proteins was immunohistochemically determined in 41 matched patient samples and the association with clinico-pathological parameters was analyzed by an integrated data analysis. These results further outline the highly deregulated metabolism of fatty acids, sphingolipids and polyamines in PCa. For the first time, the impact of the ERG translocation on the metabolome was demonstrated, highlighting an altered fatty acid oxidation in TMPRSS2-ERG translocation positive PCa specimens. Furthermore, alterations in cholesterol metabolism were found preferentially in high grade tumors, enabling the cells to create energy storage. With this integrated analysis we could not only confirm several findings from previous metabolomic studies, but also contradict others and finally expand our concepts of deregulated biological pathways in PCa.

Ahearn TU, Pettersson A, Ebot EM, et al.
A Prospective Investigation of PTEN Loss and ERG Expression in Lethal Prostate Cancer.
J Natl Cancer Inst. 2016; 108(2) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: PTEN is a tumor suppressor frequently deleted in prostate cancer that may be a useful prognostic biomarker. However, the association of PTEN loss with lethal disease has not been tested in a large, predominantly surgically treated cohort.
METHODS: In the Health Professionals Follow-up Study and Physicians' Health Study, we followed 1044 incident prostate cancer cases diagnosed between 1986 and 2009 for cancer-specific and all-cause mortality. A genetically validated PTEN immunohistochemistry (IHC) assay was performed on tissue microarrays (TMAs). TMPRSS2:ERG status was previously assessed in a subset of cases by a genetically validated IHC assay for ERG. Cox proportional hazards models adjusting for age and body mass index at diagnosis, Gleason grade, and clinical or pathologic TNM stage were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association with lethal disease. All statistical tests were two-sided.
RESULTS: On average, men were followed 11.7 years, during which there were 81 lethal events. Sixteen percent of cases had complete PTEN loss in all TMA cores and 9% had heterogeneous PTEN loss across cores. After adjustment for clinical-pathologic variables, complete PTEN loss was associated with lethal progression (HR = 1.8, 95% CI = 1.2 to 2.9). The association of PTEN loss (complete or heterogeneous) with lethal progression was only among men with ERG-negative (HR = 3.1, 95% CI = 1.7 to 5.7) but not ERG-positive (HR = 1.2, 95% CI = 0.7 to 2.2) tumors.
CONCLUSIONS: PTEN loss is independently associated with increased risk of lethal progression, particularly in the ERG fusion-negative subgroup. These validated and inexpensive IHC assays may be useful for risk stratification in prostate cancer.

Murphy SJ, Karnes RJ, Kosari F, et al.
Integrated analysis of the genomic instability of PTEN in clinically insignificant and significant prostate cancer.
Mod Pathol. 2016; 29(2):143-56 [PubMed] Related Publications
Patients with clinically insignificant prostate cancer remain a major over-treated population. PTEN loss is one of the most recurrent alterations in prostate cancer associated with an aggressive phenotype, however, the occurrence of PTEN loss in insignificant prostate cancer has not been reported and its role in the separation of insignificant from significant prostate cancer is unclear. An integrated analysis of PTEN loss was, therefore, performed for structural variations, point mutations and protein expression in clinically insignificant (48 cases) and significant (76 cases) prostate cancers treated by radical prostatectomy. Whole-genome mate pair sequencing was performed on tumor cells isolated by laser capture microdissection to characterize PTEN structural alterations. Fluorescence in situ hybridization probes were constructed from the sequencing data to detect the spectrum of these PTEN alterations. PTEN loss by mate pair sequencing and fluorescence in situ hybridization occurred in 2% of insignificant, 13% of large volume Gleason score 6, and 46% of Gleason score 7 and higher cancers. In Gleason score 7 cancers with PTEN loss, PTEN alterations were detected in both Gleason pattern 3 and 4 in 57% of cases by mate pair sequencing, 75% by in situ hybridization and 86% by immunohistochemistry. PTEN loss by sequencing was strongly associated with TMPRSS2-ERG fusion, biochemical recurrence, PTEN loss by in situ hybridization and protein loss by immunohistochemistry. The complex nature of PTEN rearrangements was unveiled by sequencing, detailing the heterogeneous events leading to homozygous loss of PTEN. PTEN point mutation was present in 5% of clinically significant tumors and not in insignificant cancer or high-grade prostatic intraepithelial neoplasia. PTEN loss is infrequent in clinically insignificant prostate cancer, and is associated with higher grade tumors. Detection of PTEN loss in Gleason score 6 cancer in a needle biopsy specimen indicates a higher likelihood of clinically significant prostate cancer.

Böttcher R, Henderson DJ, Dulla K, et al.
Human phosphodiesterase 4D7 (PDE4D7) expression is increased in TMPRSS2-ERG-positive primary prostate cancer and independently adds to a reduced risk of post-surgical disease progression.
Br J Cancer. 2015; 113(10):1502-11 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: There is an acute need to uncover biomarkers that reflect the molecular pathologies, underpinning prostate cancer progression and poor patient outcome. We have previously demonstrated that in prostate cancer cell lines PDE4D7 is downregulated in advanced cases of the disease. To investigate further the prognostic power of PDE4D7 expression during prostate cancer progression and assess how downregulation of this PDE isoform may affect disease outcome, we have examined PDE4D7 expression in physiologically relevant primary human samples.
METHODS: About 1405 patient samples across 8 publically available qPCR, Affymetrix Exon 1.0 ST arrays and RNA sequencing data sets were screened for PDE4D7 expression. The TMPRSS2-ERG gene rearrangement status of patient samples was determined by transformation of the exon array and RNA seq expression data to robust z-scores followed by the application of a threshold>3 to define a positive TMPRSS2-ERG gene fusion event in a tumour sample.
RESULTS: We demonstrate that PDE4D7 expression positively correlates with primary tumour development. We also show a positive association with the highly prostate cancer-specific gene rearrangement between TMPRSS2 and the ETS transcription factor family member ERG. In addition, we find that in primary TMPRSS2-ERG-positive tumours PDE4D7 expression is significantly positively correlated with low-grade disease and a reduced likelihood of progression after primary treatment. Conversely, PDE4D7 transcript levels become significantly decreased in castration resistant prostate cancer (CRPC).
CONCLUSIONS: We further characterise and add physiological relevance to PDE4D7 as a novel marker that is associated with the development and progression of prostate tumours. We propose that the assessment of PDE4D7 levels may provide a novel, independent predictor of post-surgical disease progression.

Hargrove AE, Martinez TF, Hare AA, et al.
Tumor Repression of VCaP Xenografts by a Pyrrole-Imidazole Polyamide.
PLoS One. 2015; 10(11):e0143161 [PubMed] Free Access to Full Article Related Publications
Pyrrole-imidazole (Py-Im) polyamides are high affinity DNA-binding small molecules that can inhibit protein-DNA interactions. In VCaP cells, a human prostate cancer cell line overexpressing both AR and the TMPRSS2-ERG gene fusion, an androgen response element (ARE)-targeted Py-Im polyamide significantly downregulates AR driven gene expression. Polyamide exposure to VCaP cells reduced proliferation without causing DNA damage. Py-Im polyamide treatment also reduced tumor growth in a VCaP mouse xenograft model. In addition to the effects on AR regulated transcription, RNA-seq analysis revealed inhibition of topoisomerase-DNA binding as a potential mechanism that contributes to the antitumor effects of polyamides in cell culture and in xenografts. These studies support the therapeutic potential of Py-Im polyamides to target multiple aspects of transcriptional regulation in prostate cancers without genotoxic stress.

Salman JW, Schoots IG, Carlsson SV, et al.
Prostate Specific Antigen as a Tumor Marker in Prostate Cancer: Biochemical and Clinical Aspects.
Adv Exp Med Biol. 2015; 867:93-114 [PubMed] Related Publications
In this chapter the use of prostate specific antigen (PSA) as a tumor marker for prostate cancer is discussed. The chapter provides an overview of biological and clinical aspects of PSA. The main drawback of total PSA (tPSA) is its lack of specificity for prostate cancer which leads to unnecessary biopsies. Moreover, PSA-testing poses a risk of overdiagnosis and subsequent overtreatment. Many PSA-based markers have been developed to improve the performance characteristics of tPSA. As well as different molecular subforms of tPSA, such as proPSA (pPSA) and free PSA (fPSA), and PSA derived kinetics as PSA-velocity (PSAV) and PSA-doubling time (PSADT). The prostate health index (phi), PSA-density (PSAD) and the contribution of non PSA-based markers such as the urinary transcripts of PCA3 and TMPRSS-ERG fusion are also discussed. To enable further risk stratification tumor markers are often combined with clinical data (e.g. outcome of DRE) in so-called nomograms. Currently the role of magnetic resonance imaging (MRI) in the detection and staging of prostate cancer is being explored.

Wright JL, Chéry L, Holt S, et al.
Aspirin and NSAID use in association with molecular subtypes of prostate cancer defined by TMPRSS2:ERG fusion status.
Prostate Cancer Prostatic Dis. 2016; 19(1):53-6 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The TMPRSS2:ERG (T2E) gene fusion is the most common rearrangement in prostate cancer (PCa). It is unknown if these molecular subtypes have a different etiology. We evaluated aspirin and non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) in association with T2E fusion status.
METHODS: Subjects were from a population-based case-control study of PCa. T2E fusion status for prostatectomy cases (n=346) was determined by fluorescence in situ hybridization. Medication use was determined from questionnaires. Logistic regression, controlling for age, race, PCa family history and PSA screening, was used to evaluate the association of T2E fusion status according to medication use.
RESULTS: T2E fusion was present in 171 (49%) cases, with younger cases more likely to be fusion positive (P<0.01). Current aspirin use was associated with a 37% risk reduction of T2E-positive tumors (adjusted odds ratio (OR) 0.63, 95% confidence interval 0.43-0.93). Aspirin use was not associated with T2E negative PCa (adjusted OR 0.99, 0.69-1.42). There were no associations between PCa fusion status and use of nonaspirin NSAIDs or acetaminophen.
CONCLUSIONS: Aspirin was associated with a significant reduction in the relative risk of T2E fusion positive, but not T2E negative, PCa. As inflammation and androgen pathways are implicated in prostate carcinogenesis, additional studies of anti-inflammatory medications in relation to these PCa subtypes are warranted.

Pal RP, Kockelbergh RC, Pringle JH, et al.
Immunocytochemical detection of ERG expression in exfoliated urinary cells identifies with high specificity patients with prostate cancer.
BJU Int. 2016; 117(4):686-96 [PubMed] Related Publications
OBJECTIVES: To evaluate the immunocytochemical detection of ERG protein in exfoliated cells as a means of identifying patients with prostate cancer (PCa) before prostate biopsy.
MATERIALS AND METHODS: Urine samples (30 mL) were collected after digital rectal examination (DRE) from 159 patients with an elevated age-specific prostate-specific antigen (PSA) and/or an abnormal DRE who underwent prostate biopsy. In all cases, exfoliated urinary cells from half of the urine sample underwent immunocytochemical assessment for ERG protein expression. Exfoliated cells in the remaining half underwent assessment of TMPRSS2:ERG status using either nested reverse-transcriptase (RT)-PCR (151 cases) or fluorescence in situ hybridization (FISH; eight cases). Corresponding tissue samples were evaluated using FISH to determine chromosomal gene fusion tissue status and immunohistochemistry (IHC) to determine ERG protein expression. Results were correlated with clinicopathological variables.
RESULTS: The sensitivity and specificity of urinary ERG immunocytochemistry (ICC) for PCa were 22.7 and 100%, respectively. ERG ICC results correlated with advanced tumour grade, stage and higher serum PSA. In comparison, urine TMPRSS2:ERG transcript analysis had 27% sensitivity and 98% specificity for PCa detection. On tissue IHC, ERG staining was highly specific for PCa. In all, 52% of cancers harboured foci of ERG staining; however, only 46% of cancers that were found to have ERG overexpression were positive on urine ICC. The ERG ICC results showed strong concordance with urinary RT-PCR and FISH, and tissue IHC and FISH.
CONCLUSION: This is the first study to show that cytological gene fusion detection using ICC is feasible and identifies patients with adverse disease markers. ERG ICC was highly specific, but this technique was less sensitive than RT-PCR.

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