Nallasivam Palanisamy
Henry Ford Health System, USA
Title: Unraveling tumor heterogeneity in prostate cancer by combined immunohistochemistry and RNA in situ hybridization |
Biography
Biography: Nallasivam Palanisamy
Abstract
Prostate cancer (PCa) remains the most commonly diagnosed cancer in American men with an estimated incidence of 220,800 new cases and accounting for 27,540 cancer related deaths in 2015. The genetic basis of 50-60% of PCa is attributable to rearrangements in ETS genes (ERG, ETV1, ETV4, ETV5), BRAF, RAF1 and overexpression of SPINK1. The discovery and validation of reliable diagnostic methods are warranted to detect these molecular rearrangements. ETS gene rearrangements are typically detected by FISH and PCR methods. Recently, monoclonal antibodies against ERG have been developed which detect the truncated ERG protein and are strongly correlated with ERG rearrangement as detected by FISH. However, due to the lack of specific antibodies for ETV1, ETV4 and ETV5 genes, in situ detection of these markers is not feasible. We developed a novel RNA in situ hybridization (RNA-ISH) based assay for in situ detection of ETV1, ETV4, and ETV5 in formalin fixed paraffin embedded (FFPE) tissues from prostate needle biopsies, prostatectomy, and metastatic PCa specimens using RNA probes developed by advanced cell diagnostics. Further, with combined RNA-ISH and IHC we identified rare subset of prostate cancer with dual ETS gene rearrangements in independent tumor foci. The high specificity and sensitivity of RNA-ISH provides an alternate method for the in situ detection of ETS gene aberrations in prostate cancer.