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

Abstract

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: 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.