// Wusheng Yan 1 , 2 , * , Muhammad Jamal 1 , 2 , * , Shyh-Han Tan 1 , 2 , * , Yingjie Song 1 , 2 , Denise Young 1 , 2 , Yongmei Chen 1 , 2 , Shilpa Katta 1 , 2 , Kai Ying 1 , 2 , Lakshmi Ravindranath 1 , 2 , Tarah Woodle 2 , Indu Kohaar 1 , 2 , Jennifer Cullen 1 , 2 , 3 , Jacob Kagan 4 , Sudhir Srivastava 4 , Albert Dobi 1 , 2 , 3 , David G. McLeod 1 , 2 , 3 , Inger L. Rosner 1 , 2 , 3 , Isabell A. Sesterhenn 5 , Alagarsamy Srinivasan 1 , 2 , Shiv Srivastava 1 , 2 , 3 and Gyorgy Petrovics 1 , 2 , 3 1 Henry Jackson Foundation for the Advancement of Military Medicine (HJF), Bethesda, MD, USA 2 Center for Prostate Disease Research, Department of Surgery, Uniformed Services University of the Health Sciences and the Walter Reed National Military Medical Center, Bethesda, MD, USA 3 John P. Murtha Cancer Center, Walter Reed National Military Medical Center, Bethesda, MD, USA 4 Division of Cancer Prevention, National Cancer Institute, NIH, Bethesda, MD, USA 5 Joint Pathology Center, Silver Spring, MD, USA * These authors contributed equally to this work Correspondence to: Gyorgy Petrovics, email: gpetrovics@cpdr.org Shiv Srivastava, email: shsr629@gmail.com Keywords: prostate cancer; NanoString; prognostic biomarker; biochemical recurrence; ERG Received: July 04, 2019 Accepted: October 19, 2019 Published: November 05, 2019 ABSTRACT Background: As a major cause of morbidity and mortality among men, prostate cancer is a heterogenous disease, with a vast heterogeneity in the biology of the disease and in clinical outcome. While it often runs an indolent course, local progression or metastasis may eventually develop, even among patients considered "low risk" at diagnosis. Therefore, biomarkers that can discriminate aggressive from indolent disease at an early stage would greatly benefit patients. We hypothesized that tissue specimens from early stage prostate cancers may harbor predictive signatures for disease progression. Methods: We used a cohort of radical prostatectomy patients with longitudinal follow-up, who had tumors with low grade and stage that revealed no signs of future disease progression at surgery. During the follow-up period, some patients either remained indolent (non-BCR) or progressed to biochemical recurrence (BCR). Total RNA was extracted from tumor, and adjacent normal epithelium of formalin-fixed-paraffin-embedded (FFPE) specimens. Differential gene expression in tumors, and in tumor versus normal tissues between BCR and non-BCR patients were analyzed by NanoString using a customized CodeSet of 151 probes. Results: After controlling for false discovery rates, we identified a panel of eight genes ( ERG, GGT1, HDAC1, KLK2, MYO6, PLA2G7, BICD1 and CACNAID ) that distinguished BCR from non-BCR patients. We found a clear association of ERG expression with non-BCR, which was further corroborated by quantitative RT-PCR and immunohistochemistry assays. Conclusions: Our results identified ERG as the strongest predictor for BCR and showed that potential prognostic prostate cancer biomarkers can be identified from FFPE tumor specimens.
The prostate transmembrane protein androgen induced 1 (PMEPA1) gene is highly expressed in prostate epithelial cells and is a direct transcriptional target for the androgen receptor (AR). AR protein levels are controlled by the AR-PMEPA1 negative feedback loop through NEDD4-E3 ligase. Reduced expression of PMEPA1 observed in prostate tumors, suggests that loss of PMEPA1 may play critical roles in prostate tumorigenesis. This study focuses on epigenetic mechanisms of reduced PMEPA1 expression in the cancer of the prostate (CaP). Benign (n = 77) and matched malignant (n = 77) prostate epithelial cells were laser capture micro-dissected from optimum cutting temperature embedded frozen prostate sections from 42 Caucasian American (CA) and 35 African American (AA) cases. Purified DNA specimens were analyzed for CpG methylation of the PMEPA1 gene. PMEPA1 mRNA expression levels were evaluated by qRT-PCR. Analysis of PMEPA1 methylation and mRNA expression in the same tumor cell populations indicated a significant inverse correlation between mRNA expression and methylation in CaP (P = 0.0115). We noted higher frequency of CpG methylation within the evaluated first intronic region of the PMEPA1 gene in prostate tumors of CA men as compared with AA. In CaP cell lines, PMEPA1 expression was induced and AR protein levels were diminished in response to treatment with the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (decitabine). Cell culture-based studies demonstrated that decitabine restores PMEPA1 expression in AR-positive CaP cell lines. This report reveals the potential role of PMEPA1 gene methylation in the regulation of AR stability. Thus, downregulation of PMEPA1 may result in increased AR protein levels and function in CaP cells, contributing to prostate tumorigenesis.
<div>Abstract<p><i>FGFR3</i> and <i>PIK3CA</i> are among the most frequently mutated genes in bladder tumors. We hypothesized that recurrent mutations in these genes might be caused by common carcinogenic exposures such as smoking and other factors. We analyzed 2,816 bladder tumors with available data on <i>FGFR3</i> and/or <i>PIK3CA</i> mutations, focusing on the most recurrent mutations detected in ≥10% of tumors. Compared to tumors with other <i>FGFR3</i>/<i>PIK3CA</i> mutations, <i>FGFR3</i>-Y375C was more common in tumors from smokers than never-smokers (<i>P</i> = 0.009), while several APOBEC-type driver mutations were enriched in never-smokers: <i>FGFR3</i>-S249C (<i>P</i> = 0.013) and <i>PIK3CA</i>-E542K/<i>PIK3CA</i>-E545K (<i>P</i> = 0.009). To explore possible causes of these APOBEC-type mutations, we analyzed RNA sequencing (RNA-seq) data from 798 bladder tumors and detected several viruses, with BK polyomavirus (BKPyV) being the most common. We then performed IHC staining for polyomavirus (PyV) Large T-antigen (LTAg) in an independent set of 211 bladder tumors. Overall, by RNA-seq or IHC-LTAg, we detected PyV in 26 out of 1,010 bladder tumors with significantly higher detection (<i>P</i> = 4.4 × 10<sup>−5</sup>), 25 of 554 (4.5%) in non–muscle-invasive bladder cancers (NMIBC) versus 1 of 456 (0.2%) of muscle-invasive bladder cancers (MIBC). In the NMIBC subset, the <i>FGFR3</i>/<i>PIK3CA</i> APOBEC-type driver mutations were detected in 94.7% (18/19) of PyV-positive versus 68.3% (259/379) of PyV-negative tumors (<i>P</i> = 0.011). BKPyV tumor positivity in the NMIBC subset with <i>FGFR3</i>- or <i>PIK3CA</i>-mutated tumors was also associated with a higher risk of progression to MIBC (<i>P</i> = 0.019). In conclusion, our results support smoking and BKPyV infection as risk factors contributing to bladder tumorigenesis in the general patient population through distinct molecular mechanisms.</p>Prevention Relevance:<p>Tobacco smoking likely causes one of the most common mutations in bladder tumors (<i>FGFR3</i>-Y375C), while viral infections might contribute to three others (<i>FGFR3</i>-S249C, <i>PIK3CA</i>-E542K, and <i>PIK3CA</i>-E545K). Understanding the causes of these mutations may lead to new prevention and treatment strategies, such as viral screening and vaccination.</p></div>
'%3e%3ccircle r='20' fill='%23008'/%3e%3ccircle r='17.5' fill='%23fff'/%3e%3ccircle r='3.5' fill='%23008'/%3e%3cg id='d'%3e%3cg id='c'%3e%3cg id='b'%3e%3cg id='a' fill='%23008'%3e%3ccircle r='.875' transform='rotate(7.5 -8.75 133.5)'/%3e%3cpath d='M0 17.5.6 7 0 2l-.6 5L0 17.5z'/%3e%3c/g%3e%3cuse xlink:href='%23a' transform='rotate(15)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(30)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(60)'/%3e%3c/g%3e%3cuse xlink:href='%23d' transform='rotate(120)'/%3e%3cuse xlink:href='%23d' transform='rotate(-120)'/%3e%3c/g%3e%3c/svg%3e)