Introduction and Objectives
Recent studies have reported that a high proportion of prostate cancers express fusion genes. These fusion genes occur when the 5′ region of an androgen regulated gene (mainly TMPRSS2) merges with one gene of the ETS family transcription factors. TMPRSS2-ERG is the most frequently detected fusion gene (50–70% in PCa). This fusion gene was also detected in 20% of HGPIN and 7% of BPH samples. The aim of this study was to investigate further the presence of this fusion gene in prostatic benign hyperplasia samples.
Material and Methods
FISH analysis was applied in a number of BPH samples, derived from TURPS. Two BAC clones (RP11–137J13 and RP11–24A11), were directly labeled by nick translation with Spectrum Green and Spectrum Texas Red respectively (Vysis). Probe labeling and FISH were performed using Vysis reagents according to manufacturers’ protocols. Visualization and analysis of the hybridization results was obtained with an Axioplan Imaging fluorescence microscope (Zeiss, Germany) with appropriate filters and MetaSystems ISIS FISH imaging software (MetaSystems).
Results
Herein, 24 BPH have been analyzed so far. Four of the 24 BPH samples were tested positive – by FISH – for TMPRSS/ERG fusion.
Conclusions
TMPRSS2: ETS fusion genes can be detected by FISH analysis in a proportion of benign prostatic hyperplasias. The detection of this fusion gene in BPH supports the hypothesis that this fusion may arose early in the prostate cancer development. The detection of fusion genes in BPH addresses the need of further studies to support the clinical use of these genes as diagnostic and prognostic marker in prostate cancer.
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Copyright
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.