Branched DNA probes were designed to detect TMPRSS2-ERG gene fusion in prostate cancer cell lines. Nonquantitative nested reverse transcription (RT)-PCR and fluorescence in situ hybridization (FISH) were used to ascertain TMPRSS2-ERG gene fusion status in prostate tissues.
The branched DNA assay detected TMPRSS2-ERG gene fusion from less than 200 pg of prostate cancer RNA, whereas more than 600 pg of RNA was required for fusion gene detection by one step real-time RT-PCR. In evaluation of clinical prostatectomy specimens, the branched DNA assay showed a concordant detectable fusion signal in all 9 clinical samples that had fusion detected by nested RT-PCR or FISH. Moreover, branched DNA detected gene fusion in 2 of 16 prostate cancer tissue specimens that was not detected by FISH or nested RT-PCR.
Our findings demonstrate a branched DNA assay that is effective for detection of TMPRSS2-ERG gene fusion in prostate cancer clinical specimens, thus providing an alternative method to ascertain TMPRSS2-ERG gene fusion in human prostate cancer tissue.