Gene Summary

Gene:POMC; proopiomelanocortin
Summary:This gene encodes a polypeptide hormone precursor that undergoes extensive, tissue-specific, post-translational processing via cleavage by subtilisin-like enzymes known as prohormone convertases. There are eight potential cleavage sites within the polypeptide precursor and, depending on tissue type and the available convertases, processing may yield as many as ten biologically active peptides involved in diverse cellular functions. The encoded protein is synthesized mainly in corticotroph cells of the anterior pituitary where four cleavage sites are used; adrenocorticotrophin, essential for normal steroidogenesis and the maintenance of normal adrenal weight, and lipotropin beta are the major end products. In other tissues, including the hypothalamus, placenta, and epithelium, all cleavage sites may be used, giving rise to peptides with roles in pain and energy homeostasis, melanocyte stimulation, and immune modulation. These include several distinct melanotropins, lipotropins, and endorphins that are contained within the adrenocorticotrophin and beta-lipotropin peptides. The antimicrobial melanotropin alpha peptide exhibits antibacterial and antifungal activity. Mutations in this gene have been associated with early onset obesity, adrenal insufficiency, and red hair pigmentation. Alternatively spliced transcript variants encoding the same protein have been described. [provided by RefSeq, Nov 2014]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Source:NCBIAccessed: 06 August, 2015


What does this gene/protein do?
Show (24)
Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 06 August 2015 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.

  • Gene Expression
  • Cancer Gene Expression Regulation
  • Lung Cancer
  • Adrenocorticotropic Hormone
  • Skin Cancer
  • Postoperative Care
  • Translocation
  • Tyrosine Transaminase
  • Cancer RNA
  • Hyperplasia
  • Adolescents
  • Zollinger-Ellison Syndrome
  • Oligonucleotide Array Sequence Analysis
  • beta-Endorphin
  • Thymus Neoplasms
  • Chromosome 2
  • Messenger RNA
  • Receptors, Somatostatin
  • Securin
  • Tumor Suppressor Proteins
  • Receptors, Vasopressin
  • Twins, Monozygotic
  • Trans-Activators
  • Steroids
  • Pituitary Gland
  • Proto-Oncogenes
  • X Chromosome
  • Pituitary Tumors
  • alpha-Fetoproteins
  • Somatostatin
  • Cushing Syndrome
  • Stem Cells
  • Peptides
  • Adenoma
  • Ribonucleases
  • X-Ray Computed Tomography
  • Pro-Opiomelanocortin
  • Hereditary Neoplastic Syndromes
  • Immunohistochemistry
  • Promoter Regions
Tag cloud generated 06 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

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

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

Latest Publications: POMC (cancer-related)

Lee AS, Kranzusch PJ, Cate JH
eIF3 targets cell-proliferation messenger RNAs for translational activation or repression.
Nature. 2015; 522(7554):111-4 [PubMed] Related Publications
Regulation of protein synthesis is fundamental for all aspects of eukaryotic biology by controlling development, homeostasis and stress responses. The 13-subunit, 800-kilodalton eukaryotic initiation factor 3 (eIF3) organizes initiation factor and ribosome interactions required for productive translation. However, current understanding of eIF3 function does not explain genetic evidence correlating eIF3 deregulation with tissue-specific cancers and developmental defects. Here we report the genome-wide discovery of human transcripts that interact with eIF3 using photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP). eIF3 binds to a highly specific program of messenger RNAs involved in cell growth control processes, including cell cycling, differentiation and apoptosis, via the mRNA 5' untranslated region. Surprisingly, functional analysis of the interaction between eIF3 and two mRNAs encoding the cell proliferation regulators c-JUN and BTG1 reveals that eIF3 uses different modes of RNA stem-loop binding to exert either translational activation or repression. Our findings illuminate a new role for eIF3 in governing a specialized repertoire of gene expression and suggest that binding of eIF3 to specific mRNAs could be targeted to control carcinogenesis.

Selvanathan SP, Graham GT, Erkizan HV, et al.
Oncogenic fusion protein EWS-FLI1 is a network hub that regulates alternative splicing.
Proc Natl Acad Sci U S A. 2015; 112(11):E1307-16 [PubMed] Article available free on PMC after 17/09/2015 Related Publications
The synthesis and processing of mRNA, from transcription to translation initiation, often requires splicing of intragenic material. The final mRNA composition varies based on proteins that modulate splice site selection. EWS-FLI1 is an Ewing sarcoma (ES) oncoprotein with an interactome that we demonstrate to have multiple partners in spliceosomal complexes. We evaluate the effect of EWS-FLI1 on posttranscriptional gene regulation using both exon array and RNA-seq. Genes that potentially regulate oncogenesis, including CLK1, CASP3, PPFIBP1, and TERT, validate as alternatively spliced by EWS-FLI1. In a CLIP-seq experiment, we find that EWS-FLI1 RNA-binding motifs most frequently occur adjacent to intron-exon boundaries. EWS-FLI1 also alters splicing by directly binding to known splicing factors including DDX5, hnRNP K, and PRPF6. Reduction of EWS-FLI1 produces an isoform of γ-TERT that has increased telomerase activity compared with wild-type (WT) TERT. The small molecule YK-4-279 is an inhibitor of EWS-FLI1 oncogenic function that disrupts specific protein interactions, including helicases DDX5 and RNA helicase A (RHA) that alters RNA-splicing ratios. As such, YK-4-279 validates the splicing mechanism of EWS-FLI1, showing alternatively spliced gene patterns that significantly overlap with EWS-FLI1 reduction and WT human mesenchymal stem cells (hMSC). Exon array analysis of 75 ES patient samples shows similar isoform expression patterns to cell line models expressing EWS-FLI1, supporting the clinical relevance of our findings. These experiments establish systemic alternative splicing as an oncogenic process modulated by EWS-FLI1. EWS-FLI1 modulation of mRNA splicing may provide insight into the contribution of splicing toward oncogenesis, and, reciprocally, EWS-FLI1 interactions with splicing proteins may inform the splicing code.

Riebold M, Kozany C, Freiburger L, et al.
A C-terminal HSP90 inhibitor restores glucocorticoid sensitivity and relieves a mouse allograft model of Cushing disease.
Nat Med. 2015; 21(3):276-80 [PubMed] Related Publications
One function of the glucocorticoid receptor (GR) in corticotroph cells is to suppress the transcription of the gene encoding proopiomelanocortin (POMC), the precursor of the stress hormone adrenocorticotropin (ACTH). Cushing disease is a neuroendocrine condition caused by partially glucocorticoid-resistant corticotroph adenomas that excessively secrete ACTH, which leads to hypercortisolism. Mutations that impair GR function explain glucocorticoid resistance only in sporadic cases. However, the proper folding of GR depends on direct interactions with the chaperone heat shock protein 90 (HSP90, refs. 7,8). We show here that corticotroph adenomas overexpress HSP90 compared to the normal pituitary. N- and C-terminal HSP90 inhibitors act at different steps of the HSP90 catalytic cycle to regulate corticotroph cell proliferation and GR transcriptional activity. C-terminal inhibitors cause the release of mature GR from HSP90, which promotes its exit from the chaperone cycle and potentiates its transcriptional activity in a corticotroph cell line and in primary cultures of human corticotroph adenomas. In an allograft mouse model, the C-terminal HSP90 inhibitor silibinin showed anti-tumorigenic effects, partially reverted hormonal alterations, and alleviated symptoms of Cushing disease. These results suggest that the pathogenesis of Cushing disease caused by overexpression of heat shock proteins and consequently misregulated GR sensitivity may be overcome pharmacologically with an appropriate HSP90 inhibitor.

Lottrup G, Nielsen JE, Skakkebæk NE, et al.
Abundance of DLK1, differential expression of CYP11B1, CYP21A2 and MC2R, and lack of INSL3 distinguish testicular adrenal rest tumours from Leydig cell tumours.
Eur J Endocrinol. 2015; 172(4):491-9 [PubMed] Related Publications
OBJECTIVE: Testicular adrenal rest tumours (TARTs) are a common finding in patients with congenital adrenal hyperplasia (CAH). These tumours constitute a diagnostic and management conundrum and may lead to infertility. TART cells share many functional and morphological similarities with Leydig cells (LCs), and masses consisting of such cells are occasionally misclassified as malignant testicular tumours, which may lead to erroneous orchiectomy in these patients.
DESIGN: In this study, we aimed to investigate the potential of LC developmental markers and adrenal steroidogenic markers in the differential diagnosis of TARTs and malignant LC tumours (LCTs).
METHODS: We investigated mRNA and protein expression of testicular steroidogenic enzymes; CYP11A1 and HSD3B1/2, markers of adrenal steroidogenesis; CYP11B1, CYP21A2 and ACTH receptor/melanocortin 2 receptor (MC2R), and markers of LC maturation; and delta-like 1 homolog (DLK1) and insulin-like 3 (INSL3) in testicular biopsies with TART, orchiectomy specimens with LCTs and samples from human fetal adrenals.
RESULTS: Expression of testicular steroidogenic enzymes was observed in all specimens. All investigated adrenal steroidogenic markers were expressed in TART, and weak reactions for CYP11B1 and MC2R were observed at the protein level in LTCs. TART and fetal adrenals had identical expression profiles. DLK1 was highly expressed and INSL3 not detectable in TART, whereas INSL3 was highly expressed in LCTs.
CONCLUSIONS: The similar expression profiles in TART and fetal adrenals as well as the presence of classical markers of adrenal steroidogenesis lend support to the hypothesis that TART develops from a displaced adrenal cell type. Malignant LCTs seem to have lost DLK1 expression and do not resemble immature LCs. The different expression pattern of DLK1, INSL3 and most adrenocortical markers adds to the elucidation of the histogenesis of testicular interstitial tumours and may facilitate histopathological diagnosis.

Gurzu S, Kadar Z, Sugimura H, et al.
Gastric cancer in young vs old Romanian patients: immunoprofile with emphasis on maspin and mena protein reactivity.
APMIS. 2015; 123(3):223-33 [PubMed] Related Publications
Increasing number of early-onset gastric carcinomas (GCs) and controversial results regarding the differences among young and older patients with this type of cancer are the reasons why correlation of clinicopathological factors with molecular markers is necessary. The aim of our study was to compare the demographic, clinical and immunohistochemical (IHC) aspects in Romanian patients with GC diagnosed below and above 45 years old. In 191 samples provided from patients with GC, the clinicopathological parameters were correlated with a panel of 15 antibodies: E-cadherin, HER-2, VEGF, CD31, CD105, COX-2, maspin, bax, bcl-2, p53, Ki67, MLH-1, MSH-2, mena protein and vimentin. Compared to the conventional cases, GCs diagnosed below 45 years old were more frequently located at the gastroesophageal junction and presented a higher percentage of lymph node metastases. The diffuse type E-cadherin/mena/p53/Ki67/bax-negative cases that displayed nuclear maspin positivity were also more frequently in younger patients. The intestinal type early-onset GCs were the most angiogenic ones, the apoptotic rate being lower than in the intestinal type GCs of the aged. Compared to the conventional cases, in the early-onset GCs the nuclear maspin-mediated antiproliferative activity is more intense in diffuse type while the mena-dependent tumor cell proliferation is more characteristic for intestinal type GCs.

Lee AW, Tyrer JP, Doherty JA, et al.
Evaluating the ovarian cancer gonadotropin hypothesis: a candidate gene study.
Gynecol Oncol. 2015; 136(3):542-8 [PubMed] Related Publications
OBJECTIVE: Ovarian cancer is a hormone-related disease with a strong genetic basis. However, none of its high-penetrance susceptibility genes and GWAS-identified variants to date are known to be involved in hormonal pathways. Given the hypothesized etiologic role of gonadotropins, an assessment of how variability in genes involved in the gonadotropin signaling pathway impacts disease risk is warranted.
METHODS: Genetic data from 41 ovarian cancer study sites were pooled and unconditional logistic regression was used to evaluate whether any of the 2185 SNPs from 11 gonadotropin signaling pathway genes was associated with ovarian cancer risk. A burden test using the admixture likelihood (AML) method was also used to evaluate gene-level associations.
RESULTS: We did not find any genome-wide significant associations between individual SNPs and ovarian cancer risk. However, there was some suggestion of gene-level associations for four gonadotropin signaling pathway genes: INHBB (p=0.045, mucinous), LHCGR (p=0.046, high-grade serous), GNRH (p=0.041, high-grade serous), and FSHB (p=0.036, overall invasive). There was also suggestive evidence for INHA (p=0.060, overall invasive).
CONCLUSIONS: Ovarian cancer studies have limited sample numbers, thus fewer genome-wide susceptibility alleles, with only modest associations, have been identified relative to breast and prostate cancers. We have evaluated the majority of ovarian cancer studies with biological samples, to our knowledge, leaving no opportunity for replication. Using both our understanding of biology and powerful gene-level tests, we have identified four putative ovarian cancer loci near INHBB, LHCGR, GNRH, and FSHB that warrant a second look if larger sample sizes and denser genotype chips become available.

Reincke M, Sbiera S, Hayakawa A, et al.
Mutations in the deubiquitinase gene USP8 cause Cushing's disease.
Nat Genet. 2015; 47(1):31-8 [PubMed] Related Publications
Cushing's disease is caused by corticotroph adenomas of the pituitary. To explore the molecular mechanisms of endocrine autonomy in these tumors, we performed exome sequencing of 10 corticotroph adenomas. We found somatic mutations in the USP8 deubiquitinase gene in 4 of 10 adenomas. The mutations clustered in the 14-3-3 protein binding motif and enhanced the proteolytic cleavage and catalytic activity of USP8. Cleavage of USP8 led to increased deubiqutination of the EGF receptor, impairing its downregulation and sustaining EGF signaling. USP8 mutants enhanced promoter activity of the gene encoding proopiomelanocortin. In summary, our data show that dominant mutations in USP8 cause Cushing's disease via activation of EGF receptor signaling.

Fragoso MC, Alencar GA, Lerario AM, et al.
Genetics of primary macronodular adrenal hyperplasia.
J Endocrinol. 2015; 224(1):R31-43 [PubMed] Related Publications
ACTH-independent macronodular adrenal hyperplasia is a rare cause of Cushing's syndrome (CS), accounting for <2% of all endogenous CS cases; however it is more frequently identified incidentally with sub-clinical cortisol secretion. Recently, cortisol secretion has been shown to be regulated by ectopic corticotropin, which is in turn produced by clusters of steroidogenic cells of the hyperplastic adrenal nodules. Hence, the term 'ACTH-independent' is not entirely appropriate for this disorder. Accordingly, the disease is designated primary macronodular adrenal hyperplasia (PMAH) in this review article. The means by which cortisol production is regulated in PMAH despite the suppressed levels of ACTH of pituitary origin is exceedingly complex. Several molecular events have been proposed to explain the enhanced cortisol secretion, increased cell proliferation, and nodule formation in PMAH. Nonetheless, the precise sequence of events and the molecular mechanisms underlying this condition remain unclear. The purpose of this review is therefore to present new insights on the molecular and genetic profile of PMAH pathophysiology, and to discuss the implications for disease progression.

Duan K, Gomez Hernandez K, Mete O
Clinicopathological correlates of adrenal Cushing's syndrome.
J Clin Pathol. 2015; 68(3):175-86 [PubMed] Related Publications
Endogenous Cushing's syndrome is a rare endocrine disorder that incurs significant cardiovascular morbidity and mortality, due to glucocorticoid excess. It comprises adrenal (20%) and non-adrenal (80%) aetiologies. While the majority of cases are attributed to pituitary or ectopic corticotropin (ACTH) overproduction, primary cortisol-producing adrenal cortical lesions are increasingly recognised in the pathophysiology of Cushing's syndrome. Our understanding of this disease has progressed substantially over the past decade. Recently, important mechanisms underlying the pathogenesis of adrenal hypercortisolism have been elucidated with the discovery of mutations in cyclic AMP signalling (PRKACA, PRKAR1A, GNAS, PDE11A, PDE8B), armadillo repeat containing 5 gene (ARMC5) a putative tumour suppressor gene, aberrant G-protein-coupled receptors, and intra-adrenal secretion of ACTH. Accurate subtyping of Cushing's syndrome is crucial for treatment decision-making and requires a complete integration of clinical, biochemical, imaging and pathology findings. Pathological correlates in the adrenal glands include hyperplasia, adenoma and carcinoma. While the most common presentation is diffuse adrenocortical hyperplasia secondary to excess ACTH production, this entity is usually treated with pituitary or ectopic tumour resection. Therefore, when confronted with adrenalectomy specimens in the setting of Cushing's syndrome, surgical pathologists are most commonly exposed to adrenocortical adenomas, carcinomas and primary macronodular or micronodular hyperplasia. This review provides an update on the rapidly evolving knowledge of adrenal Cushing's syndrome and discusses the clinicopathological correlations of this important disease.

Cheng WC, Chung IF, Tsai CF, et al.
YM500v2: a small RNA sequencing (smRNA-seq) database for human cancer miRNome research.
Nucleic Acids Res. 2015; 43(Database issue):D862-7 [PubMed] Article available free on PMC after 17/09/2015 Related Publications
We previously presented YM500, which is an integrated database for miRNA quantification, isomiR identification, arm switching discovery and novel miRNA prediction from 468 human smRNA-seq datasets. Here in this updated YM500v2 database (http://ngs.ym.edu.tw/ym500/), we focus on the cancer miRNome to make the database more disease-orientated. New miRNA-related algorithms developed after YM500 were included in YM500v2, and, more significantly, more than 8000 cancer-related smRNA-seq datasets (including those of primary tumors, paired normal tissues, PBMC, recurrent tumors, and metastatic tumors) were incorporated into YM500v2. Novel miRNAs (miRNAs not included in the miRBase R21) were not only predicted by three independent algorithms but also cleaned by a new in silico filtration strategy and validated by wetlab data such as Cross-Linked ImmunoPrecipitation sequencing (CLIP-seq) to reduce the false-positive rate. A new function 'Meta-analysis' is additionally provided for allowing users to identify real-time differentially expressed miRNAs and arm-switching events according to customer-defined sample groups and dozens of clinical criteria tidying up by proficient clinicians. Cancer miRNAs identified hold the potential for both basic research and biotech applications.

Köbel M, Madore J, Ramus SJ, et al.
Evidence for a time-dependent association between FOLR1 expression and survival from ovarian carcinoma: implications for clinical testing. An Ovarian Tumour Tissue Analysis consortium study.
Br J Cancer. 2014; 111(12):2297-307 [PubMed] Article available free on PMC after 09/12/2015 Related Publications
BACKGROUND: Folate receptor 1 (FOLR1) is expressed in the majority of ovarian carcinomas (OvCa), making it an attractive target for therapy. However, clinical trials testing anti-FOLR1 therapies in OvCa show mixed results and require better understanding of the prognostic relevance of FOLR1 expression. We conducted a large study evaluating FOLR1 expression with survival in different histological types of OvCa.
METHODS: Tissue microarrays composed of tumour samples from 2801 patients in the Ovarian Tumour Tissue Analysis (OTTA) consortium were assessed for FOLR1 expression by centralised immunohistochemistry. We estimated associations for overall (OS) and progression-free (PFS) survival using adjusted Cox regression models. High-grade serous ovarian carcinomas (HGSC) from The Cancer Genome Atlas (TCGA) were evaluated independently for association between FOLR1 mRNA upregulation and survival.
RESULTS: FOLR1 expression ranged from 76% in HGSC to 11% in mucinous carcinomas in OTTA. For HGSC, the association between FOLR1 expression and OS changed significantly during the years following diagnosis in OTTA (Pinteraction=0.01, N=1422) and TCGA (Pinteraction=0.01, N=485). In OTTA, particularly for FIGO stage I/II tumours, patients with FOLR1-positive HGSC showed increased OS during the first 2 years only (hazard ratio=0.44, 95% confidence interval=0.20-0.96) and patients with FOLR1-positive clear cell carcinomas (CCC) showed decreased PFS independent of follow-up time (HR=1.89, 95% CI=1.10-3.25, N=259). In TCGA, FOLR1 mRNA upregulation in HGSC was also associated with increased OS during the first 2 years following diagnosis irrespective of tumour stage (HR: 0.48, 95% CI: 0.25-0.94).
CONCLUSIONS: FOLR1-positive HGSC tumours were associated with an increased OS in the first 2 years following diagnosis. Patients with FOLR1-negative, poor prognosis HGSC would be unlikely to benefit from anti-FOLR1 therapies. In contrast, a decreased PFS interval was observed for FOLR1-positive CCC. The clinical efficacy of FOLR1-targeted interventions should therefore be evaluated according to histology, stage and time following diagnosis.

Liu DM, Torchen LC, Sung Y, et al.
Evidence for gonadotrophin secretory and steroidogenic abnormalities in brothers of women with polycystic ovary syndrome.
Hum Reprod. 2014; 29(12):2764-72 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
STUDY QUESTION: Are there abnormalities in gonadotrophin secretion, adrenal steroidogenesis and/or testicular steroidogenesis in brothers of women with polycystic ovary syndrome (PCOS)?
SUMMARY ANSWER: Brothers of women with PCOS have increased gonadotrophin responses to gonadotrophin releasing hormone (GnRH) agonist stimulation and alterations in adrenal and gonadal steroidogenesis.
WHAT IS KNOWN ALREADY: PCOS is a complex genetic disease. Male as well as female first-degree relatives have reproductive features of the syndrome. We previously reported that brothers of affected women have elevated circulating dehydroepiandrosterone sulfate levels.
STUDY DESIGN, SIZE, DURATION: This was a case-control study performed in 29 non-Hispanic white brothers of 22 women with PCOS and 18 control men.
PARTICIPANTS/MATERIALS, SETTING, METHODS: PCOS brothers and control men were of comparable age, weight and ethnicity. Adrenocorticotrophic hormone (ACTH) and GnRH agonist stimulation tests were performed. Gonadotrophin responses to GnRH agonist as well as changes in precursor-product steroid pairs (delta, Δ) across steroidogenic pathways in response to ACTH and GnRH agonist were examined.
MAIN RESULTS AND THE ROLE OF CHANCE: Basal total (T) levels did not differ, but dehydroepiandrosterone (DHEA) levels (0.13 ± 0.08 brothers versus 0.22 ± 0.09 controls, nmol/l, P = 0.03) were lower in brothers compared with control men. ACTH-stimulated Δ17-hydroxypregnenolone (17Preg)/Δ17-hydroxyprogesterone (17Prog) (7.8 ± 24.2 brothers versus 18.9 ± 21.3 controls, P = 0.04) and ΔDHEA/Δandrostenedione (AD) (0.10 ± 0.05 brothers versus 0.14 ± 0.08 controls, P = 0.04) were lower in brothers than in the controls. GnRH agonist-stimulated Δ17Prog/ΔAD (0.28 ± 8.47 brothers versus 4.79 ± 10.28 controls, P = 0.003) was decreased and luteinizing hormone (38.6 ± 20.6 brothers versus 26.0 ± 9.8 controls, IU/l, P = 0.02), follicle-stimulating hormone (10.2 ± 7.5 brothers versus 4.8 ± 4.1 controls, IU/l P = 0.002), AD (1.7 ± 1.4 brothers versus 0.9 ± 1.5 controls, nmol/l, P = 0.02) and ΔAD/ΔT (0.16 ± 0.14 brothers versus 0.08 ± 0.12 controls, P = 0.005) responses were increased in brothers compared with controls.
LIMITATIONS, REASONS FOR CAUTION: The modest sample size may have limited our ability to observe other possible differences in steroidogenesis between PCOS brothers and control men.
WIDER IMPLICATIONS OF THE FINDINGS: Decreased ACTH-stimulated Δ17Preg/Δ17Prog and ΔDHEA/ΔAD responses suggested increased adrenal 3β-hydroxysteroid dehydrogenase activity in the brothers. Decreased Δ17Prog/ΔAD and increased ΔAD/ΔT responses to GnRH agonist stimulation suggested increased gonadal 17,20-lyase and decreased gonadal 17β-hydroxysteroid dehydrogenase activity in the brothers. Increased LH and FSH responses to GnRH agonist stimulation suggested neuroendocrine alterations in the regulation of gonadotrophin secretion similar to those in their proband sisters. These changes in PCOS brothers may reflect the impact of PCOS susceptibility genes and/or programming effects of the intrauterine environment.
STUDY FUNDING/COMPETING INTERESTS: This research was supported by P50 HD044405 (A.D.), K12 HD055884 (L.C.T.), U54 HD034449 (A.D., R.S.L.) from the National Institute of Child Health and Development. Some hormone assays were performed at the University of Virginia Center for Research in Reproduction Ligand Assay and Analysis Core that is supported by U54 HD28934 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Partial support for some of the clinical studies was provided by UL1 RR025741 and UL1 TR000150 (Northwestern University Clinical and Translational Sciences Institute) from the National Center for Research Resources, National Institutes of Health, which is now the National Center for Advancing Translational Sciences. The authors have no conflict of interest to declare.

Conway K, Edmiston SN, May R, et al.
DNA methylation profiling in the Carolina Breast Cancer Study defines cancer subclasses differing in clinicopathologic characteristics and survival.
Breast Cancer Res. 2014; 16(5):450 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
INTRODUCTION: Breast cancer is a heterogeneous disease, with several intrinsic subtypes differing by hormone receptor (HR) status, molecular profiles, and prognosis. However, the role of DNA methylation in breast cancer development and progression and its relationship with the intrinsic tumor subtypes are not fully understood.
METHODS: A microarray targeting promoters of cancer-related genes was used to evaluate DNA methylation at 935 CpG sites in 517 breast tumors from the Carolina Breast Cancer Study, a population-based study of invasive breast cancer.
RESULTS: Consensus clustering using methylation (β) values for the 167 most variant CpG loci defined four clusters differing most distinctly in HR status, intrinsic subtype (luminal versus basal-like), and p53 mutation status. Supervised analyses for HR status, subtype, and p53 status identified 266 differentially methylated CpG loci with considerable overlap. Genes relatively hypermethylated in HR+, luminal A, or p53 wild-type breast cancers included FABP3, FGF2, FZD9, GAS7, HDAC9, HOXA11, MME, PAX6, POMC, PTGS2, RASSF1, RBP1, and SCGB3A1, whereas those more highly methylated in HR-, basal-like, or p53 mutant tumors included BCR, C4B, DAB2IP, MEST, RARA, SEPT5, TFF1, THY1, and SERPINA5. Clustering also defined a hypermethylated luminal-enriched tumor cluster 3 that gene ontology analysis revealed to be enriched for homeobox and other developmental genes (ASCL2, DLK1, EYA4, GAS7, HOXA5, HOXA9, HOXB13, IHH, IPF1, ISL1, PAX6, TBX1, SOX1, and SOX17). Although basal-enriched cluster 2 showed worse short-term survival, the luminal-enriched cluster 3 showed worse long-term survival but was not independently prognostic in multivariate Cox proportional hazard analysis, likely due to the mostly early stage cases in this dataset.
CONCLUSIONS: This study demonstrates that epigenetic patterns are strongly associated with HR status, subtype, and p53 mutation status and may show heterogeneity within tumor subclass. Among HR+ breast tumors, a subset exhibiting a gene signature characterized by hypermethylation of developmental genes and poorer clinicopathologic features may have prognostic value and requires further study. Genes differentially methylated between clinically important tumor subsets have roles in differentiation, development, and tumor growth and may be critical to establishing and maintaining tumor phenotypes and clinical outcomes.

Loher P, Londin ER, Rigoutsos I
IsomiR expression profiles in human lymphoblastoid cell lines exhibit population and gender dependencies.
Oncotarget. 2014; 5(18):8790-802 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
For many years it was believed that each mature microRNA (miRNA) existed as a single entity with fixed endpoints and a 'static' and unchangeable primary sequence. However, recent evidence suggests that mature miRNAs are more 'dynamic' and that each miRNA precursor arm gives rise to multiple isoforms, the isomiRs. Here we report on our identification of numerous and abundant isomiRs in the lymphoblastoid cell lines (LCLs) of 452 men and women from five different population groups. Unexpectedly, we find that these isomiRs exhibit an expression profile that is population-dependent and gender-dependent. This is important as it indicates that the LCLs of each gender/population combination have their own unique collection of mature miRNA transcripts. Moreover, each identified isomiR has its own characteristic abundance that remains consistent across biological replicates indicating that these are not degradation products. The primary sequences of identified isomiRs differ from the known miRBase miRNA either at their 5´-endpoint (leads to a different 'seed' sequence and suggests a different targetome), their 3´-endpoint, or both simultaneously. Our analysis of Argonaute PAR-CLIP data from LCLs supports the association of many of these newly identified isomiRs with the Argonaute silencing complex and thus their functional roles through participation in the RNA interference pathway.

Xie H, Lee L, Scicluna P, et al.
Novel functions and targets of miR-944 in human cervical cancer cells.
Int J Cancer. 2015; 136(5):E230-41 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
Altered expression of specific microRNAs (miRNAs) has been observed in human cervical cancer. However, the biological functions of many of these miRNAs are yet to be discovered. We previously showed that miR-944 is significantly more abundant in cervical cancer tissues than their normal counterparts. In this study, we investigated the functions and targets of miR-944 in human cervical cancer cells. MiR-944 is located in the intron of the tumor protein p63 (TP63) gene, which is frequently overexpressed in cervical carcinomas. Using gain- and loss-of-function experiments in vitro, we demonstrate that miR-944 promotes cell proliferation, migration and invasion, but has no effect on apoptosis, in human cervical cancer cells. To identify the targets of miR-944, we performed photoactivatable-ribonucleoside-enhanced crosslinking and immunoprecipitation followed by deep sequencing. Among the candidate targets, we validated HECW2 (HECT domain ligase W2) and S100PBP (S100P binding protein) as direct targets of miR-944 using luciferase reporter assays and western blot analysis. Our findings reveal novel functions and targets of miR-944 in human cervical cancer cells, which may provide new insights of its role in cervical carcinogenesis.

Espiard S, Ragazzon B, Bertherat J
Protein kinase A alterations in adrenocortical tumors.
Horm Metab Res. 2014; 46(12):869-75 [PubMed] Related Publications
Stimulation of the cAMP pathway by adrenocorticotropin (ACTH) is essential for adrenal cortex maintenance, glucocorticoid and adrenal androgens synthesis, and secretion. Various molecular and cellular alterations of the cAMP pathway have been observed in endocrine tumors. Protein kinase A (PKA) is a central key component of the cAMP pathway. Molecular alterations of PKA subunits have been observed in adrenocortical tumors. PKA molecular defects can be germline in hereditary disorders or somatic in sporadic tumors. Heterozygous germline inactivating mutations of the PKA regulatory subunit RIα gene (PRKAR1A) can be observed in patients with ACTH-independent Cushing's syndrome (CS) due to primary pigmented nodular adrenocortical disease (PPNAD). PRKAR1A is considered as a tumor suppressor gene. Interestingly, these mutations can also be observed as somatic alterations in sporadic cortisol-secreting adrenocortical adenomas. Germline gene duplication of the catalytic subunits Cα (PRKACA) has been observed in patients with PPNAD. Furthermore, exome sequencing revealed recently activating somatic mutations of PRKACA in about 40% of cortisol-secreting adrenocortical adenomas. In vitro and in vivo functional studies help in the progress to understand the mechanisms of adrenocortical tumors development due to PKA regulatory subunits alterations. All these alterations are observed in benign oversecreting tumors and are mimicking in some way cAMP pathway constitutive activation. On the long term, unraveling these alterations will open new strategies of pharmacological treatment targeting the cAMP pathway in adrenal tumors and cortisol-secretion disorders.

Ye S, Yang L, Zhao X, et al.
Bioinformatics method to predict two regulation mechanism: TF-miRNA-mRNA and lncRNA-miRNA-mRNA in pancreatic cancer.
Cell Biochem Biophys. 2014; 70(3):1849-58 [PubMed] Related Publications
Altered expressions of microRNAs (miRNAs) are reported in pancreatic cancer and associate with cancer pathogenesis, apoptosis, and cell growth, thereby functioning as either tumor suppressors or oncogenes. However, the majority of studies focus on defining the regulatory functions of miRNAs, whereas few investigations are directed toward assessing how the miRNA themselves are transcriptionally regulated. In this study, integration of published multi-level expression data and bioinformatics computational approach was used to predict two regulation mechanisms: transcription factors (TF)-miRNA-mRNA regulation and long non-coding RNA(lncRNA)-miRNA-mRNA regulation. To identify differentially expressed mRNAs, miRNAs, and lncRNAs, we integrated microarray expression data in pancreatic cancer tissues and normal tissues. Combination of differentially expressed mRNAs and miRNAs with miRNA-mRNA interactions based on crosslinking and immunoprecipitation followed by high-throughput sequencing (CLIP-Seq) data from StarBas, we constructed miRNA-mRNA regulatory network. Then we constructed two regulatory networks including TF-miRNA-mRNA and lncRNA-miRNA-mRNA based on chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) data from ChIPBase and CLIP-Seq data. A total of 4385 mRNAs, 500 miRNAs, and 21 lncRNAs were differentially expressed, of which, 18 mRNAs and 54 miRNAs are with high confidence. In miRNA-mRNA regulatory network, interrelated miRNAs target 1701 differentially regulated mRNAs. By constructing regulatory network, 19miRNAs including hsa-miR-137, hsa-miR-206, hsa-miR-429, hsa-miR-320d, and hsa-miR-320c are predicted to participate in lncRNA-miRNA-mRNA regulation. Furthermore, 8 miRNAs including hsa-mir-137, hsa-mir-206, hsa-mir-429, hsa-mir-375, hsa-mir-326, hsa-mir-217, hsa-mir-301b, and hsa-mir-184 are predicted to participate in TF-miRNA-mRNA regulation. In an integrated data analysis, we reveal large-scale effects of interrelated miRNAs and provide a model for predicting the mechanism of miRNAs disorder. Our study provides a new insight into understanding the transcriptional regulation of pancreatic cancer.

Kelemen LE, Terry KL, Goodman MT, et al.
Consortium analysis of gene and gene-folate interactions in purine and pyrimidine metabolism pathways with ovarian carcinoma risk.
Mol Nutr Food Res. 2014; 58(10):2023-35 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
SCOPE: We reevaluated previously reported associations between variants in pathways of one-carbon (1-C) (folate) transfer genes and ovarian carcinoma (OC) risk, and in related pathways of purine and pyrimidine metabolism, and assessed interactions with folate intake.
METHODS AND RESULTS: Odds ratios (OR) for 446 genetic variants were estimated among 13,410 OC cases and 22,635 controls, and among 2281 cases and 3444 controls with folate information. Following multiple testing correction, the most significant main effect associations were for dihydropyrimidine dehydrogenase (DPYD) variants rs11587873 (OR = 0.92; p = 6 × 10⁻⁵) and rs828054 (OR = 1.06; p = 1 × 10⁻⁴). Thirteen variants in the pyrimidine metabolism genes, DPYD, DPYS, PPAT, and TYMS, also interacted significantly with folate in a multivariant analysis (corrected p = 9.9 × 10⁻⁶) but collectively explained only 0.2% of OC risk. Although no other associations were significant after multiple testing correction, variants in SHMT1 in 1-C transfer, previously reported with OC, suggested lower risk at higher folate (p(interaction) = 0.03-0.006).
CONCLUSION: Variation in pyrimidine metabolism genes, particularly DPYD, which was previously reported to be associated with OC, may influence risk; however, stratification by folate intake is unlikely to modify disease risk appreciably in these women. SHMT1 SNP-by-folate interactions are plausible but require further validation. Polymorphisms in selected genes in purine metabolism were not associated with OC.

Abdel-Malek ZA, Swope VB, Starner RJ, et al.
Melanocortins and the melanocortin 1 receptor, moving translationally towards melanoma prevention.
Arch Biochem Biophys. 2014; 563:4-12 [PubMed] Related Publications
Beginning in the last decade of the twentieth century, the fields of pigment cell research and melanoma have witnessed major breakthroughs in the understanding of the role of melanocortins in human pigmentation and the DNA damage response of human melanocytes to solar ultraviolet radiation (UV). This began with the cloning of the melanocortin 1 receptor (MC1R) gene from human melanocytes and the demonstration that the encoded receptor is functional. Subsequently, population studies found that the MC1R gene is highly polymorphic, and that some of its variants are associated with red hair phenotype, fair skin and poor tanning ability. Using human melanocytes cultured from donors with different MC1R genotypes revealed that the alleles associated with red hair color encode for a non-functional receptor. Epidemiological studies linked the MC1R red hair color variants to increased melanoma risk. Investigating the impact of different MC1R variants on the response of human melanocytes to UV led to the important discovery that the MC1R signaling activates antioxidant, DNA repair and survival pathways, in addition to stimulation of eumelanin synthesis. These effects of MC1R were absent in melanocytes expressing 2 MC1R red hair color variants that result in loss of function of the receptor. The importance of the MC1R in reducing UV-induced genotoxicity in melanocytes led us to design small peptide analogs of the physiological MC1R agonist α-melanocortin (α-melanocyte stimulating hormone; α-MSH) for the goal of utilizing them for melanoma chemoprevention.

Murasawa S, Kageyama K, Sugiyama A, et al.
Inhibitory effects of SOM230 on adrenocorticotropic hormone production and corticotroph tumor cell proliferation in vitro and in vivo.
Mol Cell Endocrinol. 2014; 394(1-2):37-46 [PubMed] Related Publications
Adrenocorticotropic hormone (ACTH) production by pituitary corticotroph adenomas is the main cause of Cushing's disease. A drug that targets pituitary ACTH-secreting adenomas would aid treatment of Cushing's disease. Octreotide, a somatostatin receptor type 2 (SSTR2)-preferring somatostatin analogue, has no effect on ACTH secretion in patients with Cushing's disease. The multiligand SOM230 (pasireotide) displays a much higher affinity for SSTR1 and SSTR5 than octreotide and suppresses ACTH secretion in cultures of human corticotroph tumors to a greater extent than octreotide. In the present in vitro and in vivo study, we determined the effect of SOM230 on ACTH production and cell proliferation of AtT-20 corticotroph tumor cells. SOM230 decreased proopiomelanocortin (POMC) mRNA levels in AtT-20 cells and ACTH levels in the culture medium of these cells, suggesting that SOM230 suppresses ACTH synthesis and secretion in corticotroph tumor cells. SOM230 also decreased cell proliferation and both cyclic adenosine monophosphate response element-binding protein and Akt phosphorylation in AtT-20 cells. SSTR5 knockdown inhibited the SOM230-induced decreases in cell proliferation. Fluorescence-activated cell sorting analyses revealed that SOM230 did not attenuate cell cycle progression. Tumor weight in mice xenografted with AtT-20 cells and treated with SOM230 was significantly lower than in AtT-20-xenografted control mice. SOM230 also significantly decreased plasma ACTH levels, and POMC and pituitary tumor transforming gene mRNA levels in the tumor cells. Thus, SOM230 inhibits ACTH production and corticotroph tumor cell proliferation in vitro and in vivo.

Fuentes-Mattei E, Velazquez-Torres G, Phan L, et al.
Effects of obesity on transcriptomic changes and cancer hallmarks in estrogen receptor-positive breast cancer.
J Natl Cancer Inst. 2014; 106(7) [PubMed] Article available free on PMC after 01/10/2015 Related Publications
BACKGROUND: Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon.
METHODS: We analyzed transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ breast cancer patients. We generated transgenic (MMTV-TGFα;A (y) /a) and orthotopic/syngeneic (A (y) /a) obese mouse models to investigate the effect of obesity on tumorigenesis and tumor progression and to determine biological mechanisms using whole-genome transcriptome microarrays and protein analyses. We used a coculture system to examine the impact of adipocytes/adipokines on breast cancer cell proliferation. All statistical tests were two-sided.
RESULTS: Functional transcriptomic analysis of patients revealed the association of obesity with 59 biological functional changes (P < .05) linked to cancer hallmarks. Gene enrichment analysis revealed enrichment of AKT-target genes (P = .04) and epithelial-mesenchymal transition genes (P = .03) in patients. Our obese mouse models demonstrated activation of the AKT/mTOR pathway in obesity-accelerated mammary tumor growth (3.7- to 7.0-fold; P < .001; n = 6-7 mice per group). Metformin or everolimus can suppress obesity-induced secretion of adipokines and breast tumor formation and growth (0.5-fold, P = .04; 0.3-fold, P < .001, respectively; n = 6-8 mice per group). The coculture model revealed that adipocyte-secreted adipokines (eg, TIMP-1) regulate adipocyte-induced breast cancer cell proliferation and invasion. Metformin suppress adipocyte-induced cell proliferation and adipocyte-secreted adipokines in vitro.
CONCLUSIONS: Adipokine secretion and AKT/mTOR activation play important roles in obesity-accelerated breast cancer aggressiveness in addition to hyperinsulinemia, estrogen signaling, and inflammation. Metformin and everolimus have potential for therapeutic interventions of ER+ breast cancer patients with obesity.

Haecker I, Renne R
HITS-CLIP and PAR-CLIP advance viral miRNA targetome analysis.
Crit Rev Eukaryot Gene Expr. 2014; 24(2):101-16 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
MiRNAs regulate gene expression by binding predominantly to the 3' untranslated region (UTR) of target transcripts to prevent their translation and/or induce target degradation. In addition to the more than 1200 human miRNAs, human DNA tumor viruses such as Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) encode miRNAs. Target predictions indicate that each miRNA targets hundreds of transcripts, many of which are regulated by multiple miRNAs. Thus, target identification is a big challenge for the field. Most methods used currently investigate single miRNA-target interactions and are not able to analyze complex miRNA-target networks. To overcome these challenges, cross-linking and immunoprecipitation (CLIP), a recently developed method to study direct RNA-protein interactions in living cells, has been successfully applied to miRNA target analysis. It utilizes Argonaute (Ago)-immunoprecipitation to isolate native Ago-miRNA-mRNA complexes. In four recent publications, two variants of the CLIP method (HITS-CLIP and PAR-CLIP) were utilized to determine the targetomes of human and viral miRNAs in cells infected with the gamma-herpesviruses KSHV and EBV, which are associated with a number of human cancers. Here, we briefly introduce herpesvirus-encoded miRNAs and then focus on how CLIP technology has largely impacted our understanding of viral miRNAs in viral biology and pathogenesis.

Vanharanta S, Marney CB, Shu W, et al.
Loss of the multifunctional RNA-binding protein RBM47 as a source of selectable metastatic traits in breast cancer.
Elife. 2014; 3 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
The mechanisms through which cancer cells lock in altered transcriptional programs in support of metastasis remain largely unknown. Through integrative analysis of clinical breast cancer gene expression datasets, cell line models of breast cancer progression, and mutation data from cancer genome resequencing studies, we identified RNA binding motif protein 47 (RBM47) as a suppressor of breast cancer progression and metastasis. RBM47 inhibited breast cancer re-initiation and growth in experimental models. Transcriptome-wide HITS-CLIP analysis revealed widespread RBM47 binding to mRNAs, most prominently in introns and 3'UTRs. RBM47 altered splicing and abundance of a subset of its target mRNAs. Some of the mRNAs stabilized by RBM47, as exemplified by dickkopf WNT signaling pathway inhibitor 1, inhibit tumor progression downstream of RBM47. Our work identifies RBM47 as an RNA-binding protein that can suppress breast cancer progression and demonstrates how the inactivation of a broadly targeted RNA chaperone enables selection of a pro-metastatic state.

Almeida MQ, Kaupert LC, Brito LP, et al.
Increased expression of ACTH (MC2R) and androgen (AR) receptors in giant bilateral myelolipomas from patients with congenital adrenal hyperplasia.
BMC Endocr Disord. 2014; 14:42 [PubMed] Article available free on PMC after 01/10/2015 Related Publications
BACKGROUND: Although chronic adrenocorticotropic hormone (ACTH) and androgen hyperstimulation are assumed to be involved in the pathogenesis of adrenal myelolipomas associated with poor-compliance patients with congenital adrenal hyperplasia (CAH), the expression of their receptors has not yet been demonstrated in these tumors so far.
METHODS: We analyzed Melanocortin 2 receptor (MC2R), Androgen Receptor (AR), Leptin (LEP), and Steroidogenic factor 1 (SF1) expression using real-time qRT-PCR in two giant bilateral adrenal myelolipomas from two untreated simple virilizing CAH cases and in two sporadic adrenal myelolipomas. In addition, the X-chromosome inactivation pattern and CAG repeat numbers in AR exon 1 gene were evaluated in the 4 cases.
RESULTS: The MC2R gene was overexpressed in myelolipomas from 3 out of 4 patients. AR overexpression was detected in 2 tumors: a giant bilateral myelolipoma in a CAH patient and a sporadic case. Simultaneous overexpression of AR and MC2R genes was found in two of the cases. Interestingly, the bilateral giant myelolipoma associated with CAH that had high androgen and ACTH levels but lacked MC2R and AR overexpression presented a significantly shorter AR allele compared with other tumors. In addition, X-chromosome inactivation pattern analysis showed a polyclonal origin in all tumors, suggesting a stimulatory effect as the trigger for tumor development.
CONCLUSION: These findings are the first evidence for MC2R or AR overexpression in giant bilateral myelolipomas from poor-compliance CAH patients.

Suwannalert P, Kariya R, Suzu I, Okada S
The effects of Salacia reticulata on anti-cellular oxidants and melanogenesis inhibition in alpha-MSH-stimulated and UV irradiated B16 melanoma cells.
Nat Prod Commun. 2014; 9(4):551-4 [PubMed] Related Publications
The purposes of this study were to investigate the inhibitory effects of Salacia reticulata Tul. root extract on cellular oxidants and melanogenesis in B16 melanoma cells. Cells treated with non-toxic doses of S. reticulata root extract were investigated for their effects on melanogenesis, cellular tyrosinase activity and cellular oxidant scavenging activity. The results indicated that S. reticulata extract inhibited melanin synthesis and tyrosinase activity in alpha-MSH-induced or UV-irradiated B16 melanoma cells in a dose dependent manner. Additionally, the extract also exhibited anti-cellular oxidants in UV-induced radical melanoma cells. Altogether, these results suggested that S. reticulata root extract has roles in suppression of melanogenesis and oxidant inhibition. S. reticulata root extract may be a potential source for the development of pharmaceutical products for treatment of skin hyperpigmentation disorders.

Hoang B, Ernsting MJ, Murakami M, et al.
Docetaxel-carboxymethylcellulose nanoparticles display enhanced anti-tumor activity in murine models of castration-resistant prostate cancer.
Int J Pharm. 2014; 471(1-2):224-33 [PubMed] Article available free on PMC after 25/08/2015 Related Publications
Docetaxel (DTX) remains the only effective drug for prolonging survival and improving quality of life of metastatic castration resistant prostate cancer (mCRPC) patients. Despite some clinical successes with DTX-based therapies, advent of cumulative toxicity and development of drug resistance limit its long-term clinical application. The integration of nanotechnology for drug delivery can be exploited to overcome the major intrinsic limitations of DTX therapy for mCRPC. We evaluated whether reformulation of DTX by facile conjugation to carboxymethylcellulose nanoparticles (Cellax) can improve the efficacy and safety of the drug in s.c. and bone metastatic models of CRPC. A single dose of the nanoparticles completely regressed s.c. PC3 tumor xenografts in mice. In addition, Cellax elicited fewer side effects compared to native DTX. Importantly, Cellax did not increase the expression of drug resistance molecules in androgen-independent PC3 prostate cancer cells in comparison with DTX. Lastly, in a bone metastatic model of CRPC, Cellax treatment afforded a 2- to 3-fold improvement in survival and enhancements in quality-of-life of the animals over DTX and saline controls. These results demonstrate the potential of Cellax in improving the treatment of mCRPC.

Sahakitrungruang T, Srichomthong C, Pornkunwilai S, et al.
Germline and somatic DICER1 mutations in a pituitary blastoma causing infantile-onset Cushing's disease.
J Clin Endocrinol Metab. 2014; 99(8):E1487-92 [PubMed] Related Publications
CONTEXT: Pituitary blastoma causing Cushing's syndrome in infancy is very rare, and its molecular pathomechanism is not well understood.
OBJECTIVE: Our objective was to identify genetic changes of a pituitary blastoma causing infantile-onset Cushing's syndrome in a Thai girl without a family history of cancers.
METHODS: Genomic DNA from both leukocytes and tumor tissues was used for whole-exome sequencing (WES) and Sanger sequencing of DICER1. The cDNA reverse-transcribed from RNA extracted from both leukocytes and tumor tissues was used for Sanger sequencing, quantitative real-time PCR (qRT-PCR), and pyrosequencing of DICER1.
RESULTS: WES of leukocytes identified a novel heterozygous c.3046delA (p.S1016VfsX1065) mutation in the DICER1 gene. WES of the tumor tissues detected the same frameshift germline mutation and another novel somatic missense c.5438A→T (p.E1813V) mutation. Both mutations were validated by Sanger sequencing. Quantitative real-time PCR revealed that the DICER1 mRNA levels of the tumor tissues were 54% compared with those of her leukocytes. Pyrosequencing showed that the deletion allele constituted 12% and 0% of the DICER1 cDNA of the proband's leukocytes and tumor tissues, respectively.
CONCLUSION: Our study extends the phenotypic and mutational spectrum of DICER1 mutations to include infantile-onset Cushing's disease and 2 novel mutations. Loss of function of both DICER1 alleles appears to be crucial to initiate tumor development.

Ruiz I, Martín-Arruti M, Lopez-Lopez E, Garcia-Orad A
Lack of association between deficient mismatch repair expression and outcome in endometrial carcinomas of the endometrioid type.
Gynecol Oncol. 2014; 134(1):20-3 [PubMed] Related Publications
OBJECTIVE: Endometrial carcinomas of the endometrioid type (EEC) are associated with a good prognosis. However, about 20% of them recur and new prognostic markers are needed. Microsatellite instability (MSI), associated with mismatch repair (MMR) deficiency, is a frequent alteration in EECs that has been associated with prognosis. However, its prognostic impact on EECs remains unclear. The aim of the present study was to clarify the relationship between MMR deficiency and outcome in a large cohort of well classified EECs.
METHODS: A total of 212 EEC samples were analyzed by immunohistochemistry for the MMR genes MLH-1, MSH-2, MSH-6 and PMS-2. Kaplan-Meier survival analysis and log-rank tests were performed to study the prognostic significance of dMMR taking into account clinical and pathological parameters.
RESULTS: We observed no association between MMR deficiency and OS or PFS in our 212 EEC patients (p-value=0.6565 and 0.4380, respectively). When we performed the analysis in different FIGO-stage groups, we did not find association between MMR and OS or PFS in stages I, I/II or III/IV. When we analyzed the specific group of patients with lymphatic invasion separately, MMR expression was not associated with OS or PFS either.
CONCLUSIONS: MMR deficiency does not seem to be a good prognostic marker in endometrioid type endometrial carcinomas.

Paronetto MP, Bernardis I, Volpe E, et al.
Regulation of FAS exon definition and apoptosis by the Ewing sarcoma protein.
Cell Rep. 2014; 7(4):1211-26 [PubMed] Related Publications
The Ewing sarcoma protein EWS is an RNA and DNA binding protein implicated in transcription, pre-mRNA splicing, and DNA damage response. Using CLIP-seq, we identified EWS RNA binding sites in exonic regions near 5' splice sites. A prominent target was exon 6 of the FAS/CD95 receptor, which is alternatively spliced to generate isoforms with opposing activities in programmed cell death. Depletion and overexpression experiments showed that EWS promotes exon 6 inclusion and consequently the synthesis of the proapoptotic FAS/CD95 isoform, whereas an EWS-FLI1 fusion protein characteristic of Ewing sarcomas shows decreased activity. Biochemical analyses revealed that EWS binding promotes the recruitment of U1snRNP and U2AF65 to the splice sites flanking exon 6 and therefore exon definition. Consistent with a role for EWS in the regulation of programmed cell death, cells depleted of EWS show decreased sensitivity to FAS-induced apoptosis, and elevated EWS expression enhances apoptosis in EWS-haploinsufficient Ewing sarcoma cells.

Zuccotti P, Colombrita C, Moncini S, et al.
hnRNPA2/B1 and nELAV proteins bind to a specific U-rich element in CDK5R1 3'-UTR and oppositely regulate its expression.
Biochim Biophys Acta. 2014; 1839(6):506-16 [PubMed] Related Publications
Cyclin-dependent kinase 5 regulatory subunit 1 (CDK5R1) encodes p35, a specific activator of cyclin-dependent kinase 5 (CDK5). CDK5 and p35 have a fundamental role in neuronal migration and differentiation during CNS development. Both the CDK5R1 3'-UTR's remarkable size and its conservation during evolution strongly indicate an important role in post-transcriptional regulation. We previously validated different regulatory elements in the 3'-UTR of CDK5R1, which affect transcript stability, p35 levels and cellular migration through the binding with nELAV proteins and miR-103/7 miRNAs. Interestingly, a 138 bp-long region, named C2.1, was identified as the most mRNA destabilizing portion within CDK5R1 3'-UTR. This feature was maintained by a shorter region of 73 bp, characterized by two poly-U stretches. UV-CL experiments showed that this region interacts with protein factors. UV-CLIP assays and pull-down experiments followed by mass spectrometry analysis demonstrated that nELAV and hnRNPA2/B1 proteins bind to the same U-rich element. These RNA-binding proteins (RBPs) were shown to oppositely control CDK5R1 mRNA stability and p35 protein content at post-trascriptional level. While nELAV proteins have a positive regulatory effect, hnRNPA2/B1 has a negative action that is responsible for the mRNA destabilizing activity both of the C2.1 region and of the full-length 3'-UTR. In co-expression experiments of hnRNPA2/B1 and nELAV RBPs we observed an overall decrease of p35 content. We also demonstrated that hnRNPA2/B1 can downregulate nELAV protein content but not vice versa. This study, by providing new insights on the combined action of different regulatory factors, contributes to clarify the complex post-transcriptional control of CDK5R1 gene expression.

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