Frequency and transcript variant analysis of gene fusions between TMPRSS2 and ETS transcription factor genes in prostate cancer

Abstract

To investigate the frequencies and types of fusions between the transmembrane protease serine 2 (TMPRSS2), ETS-related gene (ERG), ETS variant-1 (ETV1), and ETS variant-4 (ETV4) genes in prostate cancer (PCa) and significance thereof. Biopsy samples of prostate were obtained under transrectal ultrasound (TRUS) from 32 PCa patients, aged (74 +/- 8) and 34 patients with benign prostate hyperplasia (BPH). Nested RT-PCR and direct DNA sequencing were used to detect the fusion genes of TMPRSS2/ERG, TMPRSS2/ETV1, and TMPRSS2/ETV4. The association between the fusion-positive tumor rate and Gleason grading was analyzed. Of the 32 PCa patients, TMPRSS2/ERG fusion was detected in 17 cases (53.1%), including 5 variant fusion transcripts one of which was newly discovered with the GenBank accession number of EU090248. TMPRSS2/ETV1 fusion was detected in only 2 cases (6.3%), including one newly discovered variant fusion transcripts with the GenBank accession number of EU090249. TMPRSS2/ETV4 fusion was not detected. The positive rates of TMPRSS2/ERG and TMPRSS2/ETV1 fusions showed no statistical association with the Gleason grade (P = 0.169). No fusion between the TMPRSS2 and ETS transcription factor genes was detected in the 34 BPH samples. TMPRSS2/ERG and TMPRS22/ETV1 fusion genes with different subtypes exist in the tissues of PCa. TMPRSS2/ERG and TMPRSS2/ETV1 fusion genes may be used as diagnostic tools for PCa.