Gene Summary

Gene:STAR; steroidogenic acute regulatory protein
Aliases: STARD1
Summary:The protein encoded by this gene plays a key role in the acute regulation of steroid hormone synthesis by enhancing the conversion of cholesterol into pregnenolone. This protein permits the cleavage of cholesterol into pregnenolone by mediating the transport of cholesterol from the outer mitochondrial membrane to the inner mitochondrial membrane. Mutations in this gene are a cause of congenital lipoid adrenal hyperplasia (CLAH), also called lipoid CAH. A pseudogene of this gene is located on chromosome 13. [provided by RefSeq, Jul 2008]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:steroidogenic acute regulatory protein, mitochondrial
Source:NCBIAccessed: 15 March, 2017


What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 15 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.

Tag cloud generated 15 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

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: STAR (cancer-related)

Nitta T, Koike H, Miyao T, et al.
YM155 Reverses Statin Resistance in Renal Cancer by Reducing Expression of Survivin.
Anticancer Res. 2017; 37(1):75-80 [PubMed] Related Publications
AIM: The purpose of the present study was to clarify whether treatment with YM155, a novel small-molecule inhibitor of survivin, reverses statin resistance in statin-resistant renal cell cancer (RCC).
MATERIALS AND METHODS: We induced simvastatin resistance in a renal clear cell carcinoma cell line (Caki-1-staR). In vitro and in vivo models were used to test the efficacy of YM155 and simvastatin.
RESULTS: Survivin gene expression was significantly stronger in Caki-1-staR cells than in its parent cells (Caki-1). In Caki-1-staR cells, YM155 significantly reduced expression of survivin gene and cell proliferation in a dose-dependent manner. Treatment with YM155 significantly reversed simvastatin resistance in Caki-1-staR cells. YM155 significantly inhibited the growth of Caki-1-staR tumors in a nude mouse tumor xenograft model. Furthermore, YM155 significantly enhanced the antitumor effects of simvastatin on Caki-1-staR tumors.
CONCLUSION: Our results indicate that inhibition of survivin by YM155 overcomes statin resistance in RCC cells.

Yeong J, Thike AA, Tan PH, Iqbal J
Identifying progression predictors of breast ductal carcinoma in situ.
J Clin Pathol. 2017; 70(2):102-108 [PubMed] Related Publications
Ductal carcinoma in situ (DCIS) refers to neoplastic epithelial cells proliferating within the mammary ducts of the breast, which have not breached the basement membrane nor invaded surrounding tissues. Traditional thinking holds that DCIS represents an early step in a linear progression towards invasive ductal carcinoma (IDC). However, as only approximately half of DCIS cases progress to IDC, important questions around the key determinants of malignant progression need to be answered. Recent studies have revealed that molecular differences between DCIS and IDC cells are not found at the genomic level; instead, altered patterns of gene expression and post-translational regulation lead to distinct transcriptomic and proteomic profiles. Therefore, understanding malignant progression will require a different approach that takes into account the diverse tumour cell extrinsic factors driving changes in tumour cell gene expression necessary for the invasive phenotype. Here, we review the roles of the tumour stroma (including mesenchymal cells, immune cells and the extracellular matrix) and myoepithelial cells in malignant progression and make a case for a more integrated approach to the study and assessment of DCIS and its progression, or lack thereof, to invasive disease.

Bell D, Raza SM, Bell AH, et al.
Whole-transcriptome analysis of chordoma of the skull base.
Virchows Arch. 2016; 469(4):439-49 [PubMed] Related Publications
Fourteen skull base chordoma specimens and three normal specimens were microdissected from paraffin-embedded tissue. Pools of RNA from highly enriched preparations of these cell types were subjected to expression profiling using whole-transcriptome shotgun sequencing. Using strict criteria, 294 differentially expressed transcripts were found, with 28 % upregulated and 72 % downregulated. The transcripts were annotated using NCBI Entrez Gene and computationally analyzed with the Ingenuity Pathway Analysis program. From these significantly changed expressions, the analysis identified 222 cancer-related transcripts. These 294 differentially expressed genes and non-coding RNA transcripts provide here a set to specifically define skull base chordomas and to identify novel and potentially important targets for diagnosis, prognosis, and therapy of this cancer. Significance Genomic profiling to subtype skull base chordoma reveals potential candidates for specific biomarkers, with validation by IHC for selected candidates. The highly expressed developmental genes T, LMX1A, ZIC4, LHX4, and HOXA1 may be potential drivers of this disease.

Lane D
p53: out of Africa.
Genes Dev. 2016; 30(8):876-7 [PubMed] Free Access to Full Article Related Publications
Somatic mutations in the tumor suppressor gene p53 occur in more than half of all human cancers. Rare germline mutations result in the Li-Fraumeni cancer family syndrome. In this issue ofGenes&Development, Jennis and colleagues (pp. 918-930) use an elegant mouse model to examine the affect of a polymorphism, P47S (rs1800371), in the N terminus of p53 that is found in Africans as well as more than a million African Americans. Remarkably, the single nucleotide change causes the mice to be substantially tumor-prone compared with littermates, suggesting that this allele causes an increased risk of developing cancer. The defect in p53 function is traced to a restriction in downstream gene regulation that reduces cell death in response to stress.

Tan WJ, Cima I, Choudhury Y, et al.
A five-gene reverse transcription-PCR assay for pre-operative classification of breast fibroepithelial lesions.
Breast Cancer Res. 2016; 18(1):31 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Breast fibroepithelial lesions are biphasic tumors and include fibroadenomas and phyllodes tumors. Preoperative distinction between fibroadenomas and phyllodes tumors is pivotal to clinical management. Fibroadenomas are clinically benign while phyllodes tumors are more unpredictable in biological behavior, with potential for recurrence. Differentiating the tumors may be challenging when they have overlapping clinical and histological features especially on core biopsies. Current molecular and immunohistochemical techniques have a limited role in the diagnosis of breast fibroepithelial lesions. We aimed to develop a practical molecular test to aid in distinguishing fibroadenomas from phyllodes tumors in the pre-operative setting.
METHODS: We profiled the transcriptome of a training set of 48 formalin-fixed, paraffin-embedded fibroadenomas and phyllodes tumors and further designed 43 quantitative polymerase chain reaction (qPCR) assays to verify differentially expressed genes. Using machine learning to build predictive regression models, we selected a five-gene transcript set (ABCA8, APOD, CCL19, FN1, and PRAME) to discriminate between fibroadenomas and phyllodes tumors. We validated our assay in an independent cohort of 230 core biopsies obtained pre-operatively.
RESULTS: Overall, the assay accurately classified 92.6 % of the samples (AUC = 0.948, 95 % CI 0.913-0.983, p = 2.51E-19), with a sensitivity of 82.9 % and specificity of 94.7 %.
CONCLUSIONS: We provide a robust assay for classifying breast fibroepithelial lesions into fibroadenomas and phyllodes tumors, which could be a valuable tool in assisting pathologists in differential diagnosis of breast fibroepithelial lesions.

Bell D, Bell AH, Bondaruk J, et al.
In-depth characterization of the salivary adenoid cystic carcinoma transcriptome with emphasis on dominant cell type.
Cancer. 2016; 122(10):1513-22 [PubMed] Related Publications
BACKGROUND: Adenoid cystic carcinoma (ACC), 1 of the most common salivary gland malignancies, arises from the intercalated ducts, which are composed of inner ductal epithelial cells and outer myoepithelial cells. The objective of this study was to determine the genomic subtypes of ACC with emphasis on dominant cell type to identify potential specific biomarkers for each subtype and to improve the understanding of this disease.
METHODS: A whole-genome expression study was performed based on 42 primary salivary ACCs and 5 normal salivary glands. RNA from these specimens was subjected to expression profiling with RNA sequencing, and results were analyzed to identify transcripts in epithelial-dominant ACC (E-ACC), myoepithelial-dominant ACC (M-ACC), and all ACC that were expressed differentially compared with the transcripts in normal salivary tissue.
RESULTS: In total, the authors identified 430 differentially expressed transcripts that were unique to E-ACC, 392 that were unique to M-ACC, and 424 that were common to both M-ACC and E-ACC. The sets of E-ACC-specific and M-ACC-specific transcripts were sufficiently large to define and differentiate E-ACC from M-ACC. Ingenuity pathway analysis identified known cancer-related genes for 60% of the E-ACC transcripts, 69% of the M-ACC transcripts, and 68% of the transcripts that were common in both E-ACC and M-ACC. Three sets of highly expressed candidate genes-distal-less homeobox 6 (DLX6) for E-ACC; protein keratin 16 (KRT16), SRY box 11 (SOX11), and v-myb avian myeloblastosis viral oncogene homolog (MYB) for M-ACC; and engrailed 1 (EN1) and statherin (STATH), which are common to both E-ACC and M-ACC)-were further validated at the protein level.
CONCLUSIONS: The current results enabled the authors to identify novel potential therapeutic targets and biomarkers in E-ACC and M-ACC individually, with the implication that EN1, DLX6, and OTX1 (orthodenticle homeobox 1) are potential drivers of these cancers. Cancer 2016;122:1513-22. © 2016 American Cancer Society.

Fang Y, Fullwood MJ
Roles, Functions, and Mechanisms of Long Non-coding RNAs in Cancer.
Genomics Proteomics Bioinformatics. 2016; 14(1):42-54 [PubMed] Free Access to Full Article Related Publications
Long non-coding RNAs (lncRNAs) play important roles in cancer. They are involved in chromatin remodeling, as well as transcriptional and post-transcriptional regulation, through a variety of chromatin-based mechanisms and via cross-talk with other RNA species. lncRNAs can function as decoys, scaffolds, and enhancer RNAs. This review summarizes the characteristics of lncRNAs, including their roles, functions, and working mechanisms, describes methods for identifying and annotating lncRNAs, and discusses future opportunities for lncRNA-based therapies using antisense oligonucleotides.

Winther M, Alsner J, Sørensen BS, et al.
Hypoxia-regulated MicroRNAs in Gastroesophageal Cancer.
Anticancer Res. 2016; 36(2):721-30 [PubMed] Related Publications
BACKGROUND/AIM: The present study aimed to identify hypoxia-regulated microRNAs (HRMs) in vitro and investigate the clinical role of candidate HRMs in patients with gastroesophageal cancer (GEC).
MATERIALS AND METHODS: microRNA expression changes induced by hypoxia in human GEC cell lines were measured with microarrays and validated by quantitative real-time polymerase chain reaction. Candidate HRMs were measured in pre-therapeutic tumor samples from 195 patients with GEC.
RESULTS: Expression of miR-210 was shown to be significantly induced in esophageal squamous cell carcinoma (9.26-fold, p<0.001) and adenocarcinoma cell lines (4.95-fold, p<0.001) and miR-27a-star was significantly up-regulated in adenocarcinoma cell lines (4.79-fold, p=0.04). A weak but significant correlation between miR-210 expression and a 15-gene hypoxia signature was observed (Pearson r correlation: r=0.38, p<0.001). No significant associations of HRMs and clinical outcome in patients with GEC were identified.
CONCLUSION: This study supports the involvement of hypoxia on miRNAs in vitro and confirms the role of miR-210 as being a universal HRM.

Akincilar SC, Unal B, Tergaonkar V
Reactivation of telomerase in cancer.
Cell Mol Life Sci. 2016; 73(8):1659-70 [PubMed] Free Access to Full Article Related Publications
Activation of telomerase is a critical step in the development of about 85 % of human cancers. Levels of Tert, which encodes the reverse transcriptase subunit of telomerase, are limiting in normal somatic cells. Tert is subjected to transcriptional, post-transcriptional and epigenetic regulation, but the precise mechanism of how telomerase is re-activated in cancer cells is poorly understood. Reactivation of the Tert promoter involves multiple changes which evolve during cancer progression including mutations and chromosomal re-arrangements. Newly described non-coding mutations in the Tert promoter region of many cancer cells (19 %) in two key positions, C250T and C228T, have added another layer of complexity to telomerase reactivation. These mutations create novel consensus sequences for transcription factors which can enhance Tert expression. In this review, we will discuss gene structure and function of Tert and provide insights into the mechanisms of Tert reactivation in cancers, highlighting the contribution of recently identified Tert promoter mutations.

Zhang B, Wang Y, Zhai G
Biomedical applications of the graphene-based materials.
Mater Sci Eng C Mater Biol Appl. 2016; 61:953-64 [PubMed] Related Publications
Graphene, a rapidly rising star, has gained extensive research interests lately due to its excellent properties--such as the exceptional optical, electrical, thermal and mechanical features--which are superior to other materials, so it is called "two-dimensional magical materials". This article presents diverse types and various properties of graphene-based materials, and the current methods for the surface modifications of the graphene-based materials are briefly described. In addition, the in vivo and in vitro cytotoxicity of graphene-based materials are comprehensively discussed. What's more, a summary of its biomedical applications such as drug/gene delivery, photothermal therapy, photodynamic therapy and multimodality therapy is also offered. Finally, an outlook of the graphene-based materials and the challenges in this field are briefly discussed.

Jun-Hao ET, Gupta RR, Shyh-Chang N
Lin28 and let-7 in the Metabolic Physiology of Aging.
Trends Endocrinol Metab. 2016; 27(3):132-41 [PubMed] Related Publications
The Lin28/let-7 molecular switch has emerged as a central regulator of growth signaling pathways and metabolic enzymes. Initially discovered to regulate developmental timing in the nematode, the Lin28/let-7 pathway of RNA regulation has gained prominence for its role in mammalian stem cells, cancer cells, tissue development, and aging. By regulating RNAs, the pathway coordinates cellular growth and cellular metabolism to influence metabolic physiology. Here, we review this regulatory mechanism and its impact on cancers, which reactivate Lin28, cardiovascular diseases, which implicate let-7, human genome-wide association studies (GWAS) of growth, and metabolic diseases, which implicate the Lin28/let-7 pathway. We also highlight questions relating to Barker's Hypothesis and the potential actions of the Lin28/let-7 pathway on programming long-lasting epigenetic effects.

Koh CM, Sabò A, Guccione E
Targeting MYC in cancer therapy: RNA processing offers new opportunities.
Bioessays. 2016; 38(3):266-75 [PubMed] Free Access to Full Article Related Publications
MYC is a transcription factor, which not only directly modulates multiple aspects of transcription and co-transcriptional processing (e.g. RNA-Polymerase II initiation, elongation, and mRNA capping), but also indirectly influences several steps of RNA metabolism, including both constitutive and alternative splicing, mRNA stability, and translation efficiency. As MYC is an oncoprotein whose expression is deregulated in multiple human cancers, identifying its critical downstream activities in tumors is of key importance for designing effective therapeutic strategies. With this knowledge and recent technological advances, we now have multiple angles to reach the goal of targeting MYC in tumors, ranging from the direct reduction of MYC levels, to the dampening of selected house-keeping functions in MYC-overexpressing cells, to more targeted approaches based on MYC-induced secondary effects.

Liu FL, Mo EP, Yang L, et al.
Autophagy is involved in TGF-β1-induced protective mechanisms and formation of cancer-associated fibroblasts phenotype in tumor microenvironment.
Oncotarget. 2016; 7(4):4122-41 [PubMed] Free Access to Full Article Related Publications
Transforming growth factor-β1 (TGF-β1) present in tumor microenvironment acts in a coordinated fashion to either suppress or promote tumor development. However, the molecular mechanisms underlying the effects of TGF-β1 on tumor microenvironment are not well understood. Our clinical data showed a positive association between TGF-β1 expression and cancer-associated fibroblasts (CAFs) in tumor microenvironment of breast cancer patients. Thus we employed starved NIH3T3 fibroblasts in vitro and 4T1 cells mixed with NIH3T3 fibroblasts xenograft model in vivo to simulate nutritional deprivation of tumor microenvironment to explore the effects of TGF-β1. We demonstrated that TGF-β1 protected NIH3T3 fibroblasts from Star-induced growth inhibition, mitochondrial damage and cell apoptosis. Interestingly, TGF-β1 induced the formation of CAFs phenotype in starvation (Star)-treated NIH3T3 fibroblasts and xenografted Balb/c mice, which promoted breast cancer tumor growth. In both models, autophagy agonist rapamycin increased TGF-β1-induced protective effects and formation of CAFs phenotypes, while autophagy inhibitor 3-methyladenine, Atg5 knockdown or TGF-β type I receptor kinase inhibitor LY-2157299 blocked TGF-β1 induced these effects. Taken together, our results indicated that TGF-β/Smad autophagy was involved in TGF-β1-induced protective effects and formation of CAFs phenotype in tumor microenvironment, which may be used as therapy targets in breast cancer.

Ma NK, Lim JK, Leong MF, et al.
Collaboration of 3D context and extracellular matrix in the development of glioma stemness in a 3D model.
Biomaterials. 2016; 78:62-73 [PubMed] Related Publications
A hierarchy of cellular stemness exists in certain cancers, and any successful strategy to treat such cancers would have to eliminate the self-renewing tumor-initiating cells at the apex of the hierarchy. The cellular microenvironment, in particular the extracellular matrix (ECM), is believed to have a role in regulating stemness. In this work, U251 glioblastoma cells are cultured on electrospun polystyrene (ESPS) scaffolds coated with an array of 7 laminin isoforms to provide a 3D model for stem cell-related genes and proteins expression studies. We observed collaboration between 3D context and laminins in promoting glioma stemness. Depending on the laminin isoform presented, U251 cells cultured on ESPS scaffolds (3D) exhibited increased expression of stemness markers compared to those cultured on tissue culture polystyrene (2D). Our results indicate the influence of 3D (versus 2D) context on integrin expression, specifically, the upregulation of the laminin-binding integrins alpha 6 and beta 4. By a colony forming assay, we showed enhanced clonogenicity of cells grown on ESPS scaffolds in collaboration with laminins 411, 421, 511 and 521. Evaluation of patient glioma databases demonstrated significant enrichment of integrin and ECM pathway networks in tumors of worse prognosis, consistent with our observations. The present results demonstrate how 3D versus 2D context profoundly affects ECM signaling, leading to stemness.

Seibold P, Schmezer P, Behrens S, et al.
A polymorphism in the base excision repair gene PARP2 is associated with differential prognosis by chemotherapy among postmenopausal breast cancer patients.
BMC Cancer. 2015; 15:978 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Personalized therapy considering clinical and genetic patient characteristics will further improve breast cancer survival. Two widely used treatments, chemotherapy and radiotherapy, can induce oxidative DNA damage and, if not repaired, cell death. Since base excision repair (BER) activity is specific for oxidative DNA damage, we hypothesized that germline genetic variation in this pathway will affect breast cancer-specific survival depending on treatment.
METHODS: We assessed in 1,408 postmenopausal breast cancer patients from the German MARIE study whether cancer specific survival after adjuvant chemotherapy, anthracycline chemotherapy, and radiotherapy is modulated by 127 Single Nucleotide Polymorphisms (SNPs) in 21 BER genes. For SNPs with interaction terms showing p<0.1 (likelihood ratio test) using multivariable Cox proportional hazard analyses, replication in 6,392 patients from nine studies of the Breast Cancer Association Consortium (BCAC) was performed.
RESULTS: rs878156 in PARP2 showed a differential effect by chemotherapy (p=0.093) and was replicated in BCAC studies (p=0.009; combined analysis p=0.002). Compared to non-carriers, carriers of the variant G allele (minor allele frequency=0.07) showed better survival after chemotherapy (combined allelic hazard ratio (HR)=0.75, 95% 0.53-1.07) and poorer survival when not treated with chemotherapy (HR=1.42, 95% 1.08-1.85). A similar effect modification by rs878156 was observed for anthracycline-based chemotherapy in both MARIE and BCAC, with improved survival in carriers (combined allelic HR=0.73, 95% CI 0.40-1.32). None of the SNPs showed significant differential effects by radiotherapy.
CONCLUSIONS: Our data suggest for the first time that a SNP in PARP2, rs878156, may together with other genetic variants modulate cancer specific survival in breast cancer patients depending on chemotherapy. These germline SNPs could contribute towards the design of predictive tests for breast cancer patients.

Shen M, Linn YC, Ren EC
KIR-HLA profiling shows presence of higher frequencies of strong inhibitory KIR-ligands among prognostically poor risk AML patients.
Immunogenetics. 2016; 68(2):133-44 [PubMed] Related Publications
The expression and interaction between killer cell immunoglobulin-like receptors (KIRs) and HLA are known to be associated with pathogenesis of diseases, including hematological malignancies. Presence of B haplotype KIR in donors is associated with a lower relapse risk for acute myeloid leukemia (AML) after hematopoietic stem cell transplants (HSCT). However, the association of KIR and HLA repertoire with disease development and other clinical features is not well studied for AML. In this study, 206 Chinese patients with AML were analyzed for their FAB subtypes, risk groups, and chemo-responsiveness to assess possible association with their KIR and HLA profile. The results revealed that a B-content score of 2 was significantly more prevalent in AML patients when compared to normal controls. Notably, there is also a differential frequency in the distribution of B haplotype KIR across distinct FAB subtypes, where the M3 subtype had significantly lower frequencies of B haplotype KIR compared to the M5 subtype (p < 0.05). In addition, the stronger inhibitory KIR ligands HLA-C2 and HLA-Bw4-80I were present in significantly higher frequencies in the prognostically "poor" risk group compared to those with "favourable" risk (p < 0.01). Taken together, these associations with clinical features of AML suggest a role of the KIR-HLA repertoire in the development and biological behavior of AML.

Carmona FJ, Montemurro F, Kannan S, et al.
AKT signaling in ERBB2-amplified breast cancer.
Pharmacol Ther. 2016; 158:63-70 [PubMed] Free Access to Full Article Related Publications
The PI3K/AKT pathway is the focus of several targeted therapeutic agents for a variety of malignancies. In ERBB2-amplified breast cancer, the hyperactivation of this signaling cascade is associated with resistance to ERBB2-targeted therapy. This can occur through gain-of-function alterations or compensatory mechanisms that enter into play upon pharmacological pressure. The strong rationale in combining anti-ERBB2 agents with PI3K/AKT inhibitors, together with the identification of genomic alterations conferring sensitivity to targeted inhibition, are guiding the design of clinical studies aimed at preventing the emergence of drug resistance and achieving more durable response. In the present review, we describe the involvement of this pathway in breast cancer pathogenesis, with an emphasis on AKT kinases, and provide insight into currently available targeted agents for the treatment of ERBB2-amplified breast cancer. Finally, we provide preliminary data on a novel AKT3 mutation detected in the context of resistance to anti-ERBB2 therapy as an example of genomics-based approaches towards uncovering novel actionable targets in this setting.

Monaco G, van Dam S, Casal Novo Ribeiro JL, et al.
A comparison of human and mouse gene co-expression networks reveals conservation and divergence at the tissue, pathway and disease levels.
BMC Evol Biol. 2015; 15:259 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: A deeper understanding of differences and similarities in transcriptional regulation between species can uncover important information about gene functions and the role of genes in disease. Deciphering such patterns between mice and humans is especially important since mice play an essential role in biomedical research.
RESULTS: Here, in order to characterize evolutionary changes between humans and mice, we compared gene co-expression maps to evaluate the conservation of co-expression. We show that the conservation of co-expression connectivity of homologous genes is negatively correlated with molecular evolution rates, as expected. Then we investigated evolutionary aspects of gene sets related to functions, tissues, pathways and diseases. Genes expressed in the testis, eye and skin, and those associated with regulation of transcription, olfaction, PI3K signalling, response to virus and bacteria were more divergent between mice and humans in terms of co-expression connectivity. Surprisingly, a deeper investigation of the PI3K signalling cascade revealed that its divergence is caused by the most crucial genes of this pathway, such as mTOR and AKT2. On the other hand, our analysis revealed that genes expressed in the brain and in the bone, and those associated with cell adhesion, cell cycle, DNA replication and DNA repair are most strongly conserved in terms of co-expression network connectivity as well as having a lower rate of duplication events. Genes involved in lipid metabolism and genes specific to blood showed a signature of increased co-expression connectivity in the mouse. In terms of diseases, co-expression connectivity of genes related to metabolic disorders is the most strongly conserved between mice and humans and tumor-related genes the most divergent.
CONCLUSIONS: This work contributes to discerning evolutionary patterns between mice and humans in terms of gene interactions. Conservation of co-expression is a powerful approach to identify gene targets and processes with potential similarity and divergence between mice and humans, which has implications for drug testing and other studies employing the mouse as a model organism.

Babu D, Fullwood MJ
3D genome organization in health and disease: emerging opportunities in cancer translational medicine.
Nucleus. 2015; 6(5):382-93 [PubMed] Free Access to Full Article Related Publications
Organizing the DNA to fit inside a spatially constrained nucleus is a challenging problem that has attracted the attention of scientists across all disciplines of science. Increasing evidence has demonstrated the importance of genome geometry in several cellular contexts that affect human health. Among several approaches, the application of sequencing technologies has substantially increased our understanding of this intricate organization, also known as chromatin interactions. These structures are involved in transcriptional control of gene expression by connecting distal regulatory elements with their target genes and regulating co-transcriptional splicing. In addition, chromatin interactions play pivotal roles in the organization of the genome, the formation of structural variants, recombination, DNA replication and cell division. Mutations in factors that regulate chromatin interactions lead to the development of pathological conditions, for example, cancer. In this review, we discuss key findings that have shed light on the importance of these structures in the context of cancers, and highlight the applicability of chromatin interactions as potential biomarkers in molecular medicine as well as therapeutic implications of chromatin interactions.

Chong YK, Sandanaraj E, Koh LW, et al.
ST3GAL1-Associated Transcriptomic Program in Glioblastoma Tumor Growth, Invasion, and Prognosis.
J Natl Cancer Inst. 2016; 108(2) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Cell surface sialylation is associated with tumor cell invasiveness in many cancers. Glioblastoma is the most malignant primary brain tumor and is highly infiltrative. ST3GAL1 sialyltransferase gene is amplified in a subclass of glioblastomas, and its role in tumor cell self-renewal remains unexplored.
METHODS: Self-renewal of patient glioma cells was evaluated using clonogenic, viability, and invasiveness assays. ST3GAL1 was identified from differentially expressed genes in Peanut Agglutinin-stained cells and validated in REMBRANDT (n = 390) and Gravendeel (n = 276) clinical databases. Gene set enrichment analysis revealed upstream processes. TGFβ signaling on ST3GAL1 transcription was assessed using chromatin immunoprecipitation. Transcriptome analysis of ST3GAL1 knockdown cells was done to identify downstream pathways. A constitutively active FoxM1 mutant lacking critical anaphase-promoting complex/cyclosome ([APC/C]-Cdh1) binding sites was used to evaluate ST3Gal1-mediated regulation of FoxM1 protein. Finally, the prognostic role of ST3Gal1 was determined using an orthotopic xenograft model (3 mice groups comprising nontargeting and 2 clones of ST3GAL1 knockdown in NNI-11 [8 per group] and NNI-21 [6 per group]), and the correlation with patient clinical information. All statistical tests on patients' data were two-sided; other P values below are one-sided.
RESULTS: High ST3GAL1 expression defines an invasive subfraction with self-renewal capacity; its loss of function prolongs survival in a mouse model established from mesenchymal NNI-11 (P < .001; groups of 8 in 3 arms: nontargeting, C1, and C2 clones of ST3GAL1 knockdown). ST3GAL1 transcriptomic program stratifies patient survival (hazard ratio [HR] = 2.47, 95% confidence interval [CI] = 1.72 to 3.55, REMBRANDT P = 1.92 x 10⁻⁸; HR = 2.89, 95% CI = 1.94 to 4.30, Gravendeel P = 1.05 x 10⁻¹¹), independent of age and histology, and associates with higher tumor grade and T2 volume (P = 1.46 x 10⁻⁴). TGFβ signaling, elevated in mesenchymal patients, correlates with high ST3GAL1 (REMBRANDT gliomacor = 0.31, P = 2.29 x 10⁻¹⁰; Gravendeel gliomacor = 0.50, P = 3.63 x 10⁻²⁰). The transcriptomic program upon ST3GAL1 knockdown enriches for mitotic cell cycle processes. FoxM1 was identified as a statistically significantly modulated gene (P = 2.25 x 10⁻⁵) and mediates ST3Gal1 signaling via the (APC/C)-Cdh1 complex.
CONCLUSIONS: The ST3GAL1-associated transcriptomic program portends poor prognosis in glioma patients and enriches for higher tumor grades of the mesenchymal molecular classification. We show that ST3Gal1-regulated self-renewal traits are crucial to the sustenance of glioblastoma multiforme growth.

Bei JX, Su WH, Ng CC, et al.
A GWAS Meta-analysis and Replication Study Identifies a Novel Locus within CLPTM1L/TERT Associated with Nasopharyngeal Carcinoma in Individuals of Chinese Ancestry.
Cancer Epidemiol Biomarkers Prev. 2016; 25(1):188-92 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Genetic loci within the major histocompatibility complex (MHC) have been associated with nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV)-associated cancer, in several GWAS. Results outside this region have varied.
METHODS: We conducted a meta-analysis of four NPC GWAS among Chinese individuals (2,152 cases; 3,740 controls). Forty-three noteworthy findings outside the MHC region were identified and targeted for replication in a pooled analysis of four independent case-control studies across three regions in Asia (4,716 cases; 5,379 controls). A meta-analysis that combined results from the initial GWA and replication studies was performed.
RESULTS: In the combined meta-analysis, rs31489, located within the CLPTM1L/TERT region on chromosome 5p15.33, was strongly associated with NPC (OR = 0.81; P value 6.3 × 10(-13)). Our results also provide support for associations reported from published NPC GWAS-rs6774494 (P = 1.5 × 10(-12); located in the MECOM gene region), rs9510787 (P = 5.0 × 10(-10); located in the TNFRSF19 gene region), and rs1412829/rs4977756/rs1063192 (P = 2.8 × 10(-8), P = 7.0 × 10(-7), and P = 8.4 × 10(-7), respectively; located in the CDKN2A/B gene region).
CONCLUSIONS: We have identified a novel association between genetic variation in the CLPTM1L/TERT region and NPC. Supporting our finding, rs31489 and other SNPs in this region have been reported to be associated with multiple cancer sites, candidate-based studies have reported associations between polymorphisms in this region and NPC, the TERT gene has been shown to be important for telomere maintenance and has been reported to be overexpressed in NPC, and an EBV protein expressed in NPC (LMP1) has been reported to modulate TERT expression/telomerase activity.
IMPACT: Our finding suggests that factors involved in telomere length maintenance are involved in NPC pathogenesis.

Teo PY, Cheng W, Hedrick JL, Yang YY
Co-delivery of drugs and plasmid DNA for cancer therapy.
Adv Drug Deliv Rev. 2016; 98:41-63 [PubMed] Related Publications
Cancer is an extremely complex disease involving multiple signaling pathways that enable tumor cells to evade programmed cell death, thus making cancer treatment extremely challenging. The use of combination therapy involving both gene therapy and chemotherapy has resulted in enhanced anti-cancer effects and has become an increasingly important strategy in medicine. This review will cover important design parameters that are incorporated into delivery systems for the co-administration of drug and plasmid-based nucleic acids (pDNA and shRNA), with particular emphasis on polymers as delivery materials. The unique challenges faced by co-delivery systems and the strategies to overcome such barriers will be discussed. In addition, the advantages and disadvantages of combination therapy using separate carrier systems versus the use of a single carrier will be evaluated. Finally, future perspectives in the design of novel platforms for the combined delivery of drugs and genes will be presented.

Grinchuk OV, Motakis E, Yenamandra SP, et al.
Sense-antisense gene-pairs in breast cancer and associated pathological pathways.
Oncotarget. 2015; 6(39):42197-221 [PubMed] Free Access to Full Article Related Publications
More than 30% of human protein-coding genes form hereditary complex genome architectures composed of sense-antisense (SA) gene pairs (SAGPs) transcribing their RNAs from both strands of a given locus. Such architectures represent important novel components of genome complexity contributing to gene expression deregulation in cancer cells. Therefore, the architectures might be involved in cancer pathways and, in turn, be used for novel drug targets discovery. However, the global roles of SAGPs in cancer pathways has not been studied. Here we investigated SAGPs associated with breast cancer (BC)-related pathways using systems biology, prognostic survival and experimental methods. Gene expression analysis identified 73 BC-relevant SAGPs that are highly correlated in BC. Survival modelling and metadata analysis of the 1161 BC patients allowed us to develop a novel patient prognostic grouping method selecting the 12 survival-significant SAGPs. The qRT-PCR-validated 12-SAGP prognostic signature reproducibly stratified BC patients into low- and high-risk prognostic subgroups. The 1381 SAGP-defined differentially expressed genes common across three studied cohorts were identified. The functional enrichment analysis of these genes revealed the GABPA gene network, including BC-relevant SAGPs, specific gene sets involved in cell cycle, spliceosomal and proteasomal pathways. The co-regulatory function of GABPA in BC cells was supported using siRNA knockdown studies. Thus, we demonstrated SAGPs as the synergistically functional genome architectures interconnected with cancer-related pathways and associated with BC patient clinical outcomes. Taken together, SAGPs represent an important component of genome complexity which can be used to identify novel aspects of coordinated pathological gene networks in cancers.

Leal LF, Bueno AC, Gomes DC, et al.
Inhibition of the Tcf/beta-catenin complex increases apoptosis and impairs adrenocortical tumor cell proliferation and adrenal steroidogenesis.
Oncotarget. 2015; 6(40):43016-32 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: To date, there is no effective therapy for patients with advanced/metastatic adrenocortical cancer (ACC). The activation of the Wnt/beta-catenin signaling is frequent in ACC and this pathway is a promising therapeutic target.
AIM: To investigate the effects of the inhibition of the Wnt/beta-catenin in ACC cells.
METHODS: Adrenal (NCI-H295 and Y1) and non-adrenal (HeLa) cell lines were treated with PNU-74654 (5-200 μM) for 24-96 h to assess cell viability (MTS-based assay), apoptosis (Annexin V), expression/localization of beta-catenin (qPCR, immunofluorescence, immunocytochemistry and western blot), expression of beta-catenin target genes (qPCR and western blot), and adrenal steroidogenesis (radioimmunoassay, qPCR and western blot).
RESULTS: In NCI-H295 cells, PNU-74654 significantly decreased cell proliferation 96 h after treatment, increased early and late apoptosis, decreased nuclear beta-catenin accumulation, impaired CTNNB1/beta-catenin expression and increased beta-catenin target genes 48 h after treatment. No effects were observed on HeLa cells. In NCI-H295 cells, PNU-74654 decreased cortisol, testosterone and androstenedione secretion 24 and 48 h after treatment. Additionally, in NCI-H295 cells, PNU-74654 decreased SF1 and CYP21A2 mRNA expression as well as the protein levels of STAR and aldosterone synthase 48 h after treatment. In Y1 cells, PNU-74654 impaired corticosterone secretion 24 h after treatment but did not decrease cell viability.
CONCLUSIONS: Blocking the Tcf/beta-catenin complex inhibits the Wnt/beta-catenin signaling in adrenocortical tumor cells triggering increased apoptosis, decreased cell viability and impairment of adrenal steroidogenesis. These promising findings pave the way for further experiments inhibiting the Wnt/beta-catenin pathway in pre-clinical models of ACC. The inhibition of this pathway may become a promising adjuvant therapy for patients with ACC.

An S, Yang Y, Ward R, et al.
A-Raf: A new star of the family of raf kinases.
Crit Rev Biochem Mol Biol. 2015; 50(6):520-31 [PubMed] Related Publications
The Ras-Raf-MEK-MAPK (mitogen-activated protein kinase)-signaling pathway plays a key role in the regulation of many cellular functions, including cell proliferation, differentiation and transformation, by transmitting signals from membrane receptors to various cytoplasmic and nuclear targets. One of the key components of this pathway is the serine/threonine protein kinase, Raf. The Raf family kinases (A-Raf, B-Raf and C-Raf) have been intensively studied since being identified in the early 1980s as retroviral oncogenes, especially with respect to the discovery of activating mutations of B-Raf in a large number of tumors which led to intensified efforts to develop drugs targeting Raf kinases. This also resulted in a rapid increase in our knowledge of the biological functions of the B-Raf and C-Raf isoforms, which may in turn be contrasted with the little that is known about A-Raf. The biological functions of A-Raf remain mysterious, although it appears to share some of the basic properties of the other two isoforms. Recently, emerging evidence has begun to reveal the functions of A-Raf, of which some are kinase-independent. These include the inhibition of apoptosis by binding to MST2, acting as safeguard against oncogenic transformation by suppressing extracellular signal-regulated kinases (ERK) activation and playing a role in resistance to Raf inhibitors. In this review, we discuss the regulation of A-Raf protein expression, and the roles of A-Raf in apoptosis and cancer, with a special focus on its role in resistance to Raf inhibitors. We also describe the scaffold functions of A-Raf and summarize the unexpected complexity of Raf signaling.

Li B, Xu WW, Guan XY, et al.
Competitive Binding Between Id1 and E2F1 to Cdc20 Regulates E2F1 Degradation and Thymidylate Synthase Expression to Promote Esophageal Cancer Chemoresistance.
Clin Cancer Res. 2016; 22(5):1243-55 [PubMed] Related Publications
PURPOSE: Chemoresistance is a major obstacle in cancer therapy. We found that fluorouracil (5-FU)-resistant esophageal squamous cell carcinoma cell lines, established through exposure to increasing concentrations of 5-FU, showed upregulation of Id1, IGF2, and E2F1. We hypothesized that these genes may play an important role in cancer chemoresistance.
EXPERIMENTAL DESIGN: In vitro and in vivo functional assays were performed to study the effects of Id1-E2F1-IGF2 signaling in chemoresistance. Quantitative real-time PCR, Western blotting, immunoprecipitation, chromatin immunoprecipitation, and dual-luciferase reporter assays were used to investigate the molecular mechanisms by which Id1 regulates E2F1 and by which E2F1 regulates IGF2. Clinical specimens, tumor tissue microarray, and Gene Expression Omnibus datasets were used to analyze the correlations between gene expressions and the relationships between expression profiles and patient survival outcomes.
RESULTS: Id1 conferred 5-FU chemoresistance through E2F1-dependent induction of thymidylate synthase expression in esophageal cancer cells and tumor xenografts. Mechanistically, Id1 protects E2F1 protein from degradation and increases its expression by binding competitively to Cdc20, whereas E2F1 mediates Id1-induced upregulation of IGF2 by binding directly to the IGF2 promoter and activating its transcription. The expression level of E2F1 was positively correlated with that of Id1 and IGF2 in human cancers. More importantly, concurrent high expression of Id1 and IGF2 was associated with unfavorable patient survival in multiple cancer types.
CONCLUSIONS: Our findings define an intricate E2F1-dependent mechanism by which Id1 increases thymidylate synthase and IGF2 expressions to promote cancer chemoresistance. The Id1-E2F1-IGF2 regulatory axis has important implications for cancer prognosis and treatment.

Aswad L, Yenamandra SP, Ow GS, et al.
Genome and transcriptome delineation of two major oncogenic pathways governing invasive ductal breast cancer development.
Oncotarget. 2015; 6(34):36652-74 [PubMed] Free Access to Full Article Related Publications
Invasive ductal carcinoma (IDC) is a major histo-morphologic type of breast cancer. Histological grading (HG) of IDC is widely adopted by oncologists as a prognostic factor. However, HG evaluation is highly subjective with only 50%-85% inter-observer agreements. Specifically, the subjectivity in the assignment of the intermediate grade (histologic grade 2, HG2) breast cancers (comprising ~50% of IDC cases) results in uncertain disease outcome prediction and sub-optimal systemic therapy. Despite several attempts to identify the mechanisms underlying the HG classification, their molecular bases are poorly understood.We performed integrative bioinformatics analysis of TCGA and several other cohorts (total 1246 patients). We identified a 22-gene tumor aggressiveness grading classifier (22g-TAG) that reflects global bifurcation in the IDC transcriptomes and reclassified patients with HG2 tumors into two genetically and clinically distinct subclasses: histological grade 1-like (HG1-like) and histological grade 3-like (HG3-like). The expression profiles and clinical outcomes of these subclasses were similar to the HG1 and HG3 tumors, respectively. We further reclassified IDC into low genetic grade (LGG = HG1+HG1-like) and high genetic grade (HGG = HG3-like+HG3) subclasses. For the HG1-like and HG3-like IDCs we found subclass-specific DNA alterations, somatic mutations, oncogenic pathways, cell cycle/mitosis and stem cell-like expression signatures that discriminate between these tumors. We found similar molecular patterns in the LGG and HGG tumor classes respectively.Our results suggest the existence of two genetically-predefined IDC classes, LGG and HGG, driven by distinct oncogenic pathways. They provide novel prognostic and therapeutic biomarkers and could open unique opportunities for personalized systemic therapies of IDC patients.

Kim ES, Samanta A, Cheng HS, et al.
Effect of oncogene activating mutations and kinase inhibitors on amino acid metabolism of human isogenic breast cancer cells.
Mol Biosyst. 2015; 11(12):3378-86 [PubMed] Related Publications
We investigated the changes in amino acid (AA) metabolism induced in MCF10A, a human mammary epithelial cell line, by the sequential knock-in of K-Ras and PI3K mutant oncogenes. Differentially regulated genes associated to AA pathways were identified on comparing gene expression patterns in the isogenic cell lines. Additionally, we monitored the changes in the levels of AAs and transcripts in the cell lines treated with kinase inhibitors (REGO: a multi-kinase inhibitor, PI3K-i: a PI3K inhibitor, and MEK-i: a MEK inhibitor). In total, 19 AAs and 58 AA-associated transcripts were found to be differentially regulated by oncogene knock-in and by drug treatment. In particular, the multi-kinase and MEK inhibitor affected pathways in K-Ras mutant cells, whereas the PI3K inhibitor showed a major impact in the K-Ras/PI3K double mutant cells. These findings may indicate the dependency of AA metabolism on the oncogene mutation pattern in human cancer. Thus, future therapy might include combinations of kinase inhibitors and drug targeting enzymes of AA pathways.

Munkley J, Oltean S, Vodák D, et al.
The androgen receptor controls expression of the cancer-associated sTn antigen and cell adhesion through induction of ST6GalNAc1 in prostate cancer.
Oncotarget. 2015; 6(33):34358-74 [PubMed] Free Access to Full Article Related Publications
Patterns of glycosylation are important in cancer, but the molecular mechanisms that drive changes are often poorly understood. The androgen receptor drives prostate cancer (PCa) development and progression to lethal metastatic castration-resistant disease. Here we used RNA-Seq coupled with bioinformatic analyses of androgen-receptor (AR) binding sites and clinical PCa expression array data to identify ST6GalNAc1 as a direct and rapidly activated target gene of the AR in PCa cells. ST6GalNAc1 encodes a sialytransferase that catalyses formation of the cancer-associated sialyl-Tn antigen (sTn), which we find is also induced by androgen exposure. Androgens induce expression of a novel splice variant of the ST6GalNAc1 protein in PCa cells. This splice variant encodes a shorter protein isoform that is still fully functional as a sialyltransferase and able to induce expression of the sTn-antigen. Surprisingly, given its high expression in tumours, stable expression of ST6GalNAc1 in PCa cells reduced formation of stable tumours in mice, reduced cell adhesion and induced a switch towards a more mesenchymal-like cell phenotype in vitro. ST6GalNAc1 has a dynamic expression pattern in clinical datasets, beingsignificantly up-regulated in primary prostate carcinoma but relatively down-regulated in established metastatic tissue. ST6GalNAc1 is frequently upregulated concurrently with another important glycosylation enzyme GCNT1 previously associated with prostate cancer progression and implicated in Sialyl Lewis X antigen synthesis. Together our data establishes an androgen-dependent mechanism for sTn antigen expression in PCa, and are consistent with a general role for the androgen receptor in driving important coordinate changes to the glycoproteome during PCa progression.

Karapetsas A, Giannakakis A, Dangaj D, et al.
Overexpression of GPC6 and TMEM132D in Early Stage Ovarian Cancer Correlates with CD8+ T-Lymphocyte Infiltration and Increased Patient Survival.
Biomed Res Int. 2015; 2015:712438 [PubMed] Free Access to Full Article Related Publications
Infiltration of cytotoxic T-lymphocytes in ovarian cancer is a favorable prognostic factor. Employing a differential expression approach, we have recently identified a number of genes associated with CD8+ T-cell infiltration in early stage ovarian tumors. In the present study, we validated by qPCR the expression of two genes encoding the transmembrane proteins GPC6 and TMEM132D in a cohort of early stage ovarian cancer patients. The expression of both genes correlated positively with the mRNA levels of CD8A, a marker of T-lymphocyte infiltration [Pearson coefficient: 0.427 (p = 0.0067) and 0.861 (p < 0.0001), resp.]. GPC6 and TMEM132D expression was also documented in a variety of ovarian cancer cell lines. Importantly, Kaplan-Meier survival analysis revealed that high mRNA levels of GPC6 and/or TMEM132D correlated significantly with increased overall survival of early stage ovarian cancer patients (p = 0.032). Thus, GPC6 and TMEM132D may serve as predictors of CD8+ T-lymphocyte infiltration and as favorable prognostic markers in early stage ovarian cancer with important consequences for diagnosis, prognosis, and tumor immunobattling.

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