Detection of prostate specific ETS fusion transcripts in cancer samples

Aim. To detect ETS fusion transcripts in Ukrainian population and to analyze a possible relationship between the ETS fusion transcripts and clinical characteristics of prostate cancer. Methods. Quantitative PCR (q-PCR) was used to analyze the expression of six fusion transcripts at the mRNA level. The amplified products were analyzed by gel electrophoresis and direct sequencing. We analyzed 37 fresh frozen samples of prostate cancer tissues, 37 paired conventionally normal prostate tissue samples and 20 samples of adenomas. Results. Six ETS fusion transcripts of TMPRSS2 with ERG, ETV1, ETV4, ETV5 were analyzed. Only one out of six fusion ETS transcripts was detected in a cohort of 37 Ukrainian patients with prostate adenocarcinoma. The frequency of detection of the TMPRSS2-ERG fusion transcript in prostate cancer tissues was 56.8 %. The TMPRSS2-ERG expression was also detected in 16 normal prostate tissue samples (43.2 %) and in 4 prostate adenoma samples (20 %). No correlation was found between the frequency of the TMPRSS2-ERG in carcinoma samples and clinical characteristics of the samples. However, an analysis of relative gene expression in all the investigated groups has shown the altered TMPRSS2-ERG expression in some groups with different Gleason scores of prostate adenocarcinoma compared to adenomas and normal tissue samples. The most elevatedTMPRSS2-ERG expression was found in the prostate adenocarcinoma group with the Gleason score > 7. Conclusions. We detected the TMPRSS2-ERG fusion transcript (EF194202.1) in prostate tumor samples as adenocarcinoma (the frequency was 56.8 %) with different Gleason score and some paired normal prostate tissues as adenoma samples in our group of Ukrainian population. The obtained results show that the TMPRSS2-ERG fusion transcript is present at early stages of cancer development. In the further studies we plan to test whether the TMPRSS2-ERG fusion transcript can be used as a diagnostic marker of prostate cancer development.