Abstract 3640: Overexpression of five novel biomarkers in human prostate tissues and cell lines

Introduction and Objective: Our laboratory has identified several expressed sequence tags (ESTs) from primary prostate cancer (PCa) Stage T2b tissue and five were identified as Prostate and breast cancer overexpressed 1 (PBOV1), Calcium channel, voltage-dependent, l type, alpha 1d subunit (CACNA1D), Tomoregulin-1 (TMEFF1), and Copine-1 & 4 (CPNE1 & CPNE 4). PBOV1 gene is overexpressed in prostate, breast and bladder cancers and CACNA1D exists in several isoforms but little is known about their role in cancer biology. TMEFF1 is predominantly expressed in the brain and is also a cancer testes antigen. The Copines are a novel family of ubiquitous Ca2+-dependent, phospholipid-binding proteins and there is very little known about their role in cancer etiopathogenesis. We have studied their expression in cancerous and benign cancer adjacent areas of radical prostatectomy specimens as well as their protein levels in PCa, BPH and normal prostate cell lines. Methods: Nineteen sets of RNA samples, extracted from PCa tissues and respective benign adjacent areas were received from Dr. DeMarzo. From 50ng of RNA, cDNA was generated and the real-time PCR for expression was done using SsoFast EvaGreen supermix kit in an iCycler instrument (BioRad Laboratories) utilizing the gene specific primers. For calculating relative expression, a portion of β-actin was also amplified using a validated primer set (OriGene). Alongside cell lines of PCa (PC3, DU145 & LNCaP); of Benign prostatic hyperplasia (BPH) and of normal prostate (PrEC) were grown in cultures and total protein was extracted from each. Using specific antibodies, the presence of these proteins were identified by Western blotting. Results: When compared to the corresponding benign adjacent areas, the expression increased significantly in cancer tissues of: 12 samples for PBOV1, 14 samples for CACNA1D, 7 samples for TMEFF1, 9 samples for CPNE1 and 13 samples for CPNE4. Also, preliminary proteomic data by Western blotting in cell line extracts also demonstrates differential expression in PCa and control cell lines: PBOV1 was expressed in PC3, DU145 & BPH; TMEFF1 in PC3 & DU145 (not tested in BPH & PrEC); CACNA1D in PC3, DU145 & LNCaP; CPNE1 in BPH & PrEC and CPNE4 in none of the cell lines. Conclusions: The increased expression of these novel biomarkers in cancer areas vs. the benign cancer-adjacent may be very useful in establishing significant ratios and cut-off values to determine their potential clinical applications. Currently we continue correlating these altered expressions with Gleason grades, stages and other outcomes using a larger sample size. We also continue to study the role of these biomarkers in the pathogenesis of more aggressive prostate cancer phenotypes. Source of Funding: NIH U54CA143803 grant, Prostate Cancer Foundation and the Patana Fund Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3640. doi:1538-7445.AM2012-3640