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Detection of novel variant TMPRSS2 /ERG fusion transcripts suggests independent genomic alterations may underlie origin of multi-centric prostate cancer. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.10029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10029 Background: Most of the early successes in identifying chromosomal translocations in neoplasias came from the study of hematological malignancies and sarcomas, with limited evidence that consistent genomic rearrangements were present in epithelial malignancies. Recently it was reported that ∼75% of prostate cancers carry a genomic rearrangement leading to fusion of the TMPRSS2 locus to either the ERG or ETV1 genes (both ETS transcription factors). In the fusion gene, the androgen-sensitive promoter elements of TMPRSS2 are thought to mediate over-expression of these ETS transcription factors. Over-activity of the ETS family of transcription factors has been suggested to be involved in the transition from pre-neoplasia to carcinoma as they regulate genes involved in processes such as adhesion, motility, invasion and angiogenesis. Methods: Using both RT-PCR and FISH with published primers and BACs respectively we analyzed 15 samples of prostatic carcinoma from radical prostatectomies and sequenced a subset of the TMPRSS2/ERG fusions. Results: We have found ERG-TMPRSS2 fusion transcripts in 6 samples and no ETV1-TMPRSS2 fusions. Of the 6 fusion tumours, 5 were Gleason 7 and 1 was Gleason 9. Tumour stages ranged from T2a-T3b. One sample with multi-centric carcinoma exhibited 2 distinct in-frame rearrangements generating novel TMPRSS2 /ERG fusion transcripts. Variant I TMPRSS2/ERG transcript was 430 bp and it led to fusion of exons 1 and 2 of the TMPRSS2 gene with exons 5 and 6 of the ERG gene. Variant II TMPRSS2/ERG fusion transcript was slightly smaller at 350 bp and it led to fusion of exon 1 of the TMPRSS2 gene to exons 5 and 6 of the ERG gene. These novel transcripts appear to be smaller than the published fusion proteins but preliminary analysis suggests that all known regulatory and functional protein domains are maintained. Conclusions: The demonstration of two new TMPRSS2/ERG variant fusion transcripts in prostate cancer deserves further study to evaluate their functional impact and prognostic and pathological importance. Moreover the presence of two distinct transcripts within a single multi-centric tumor provides genomic evidence that independent clonal neoplasms can arise synchronously in prostate cancer. No significant financial relationships to disclose.
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Clinical and molecular characteristics of pediatric gastrointestinal stromal tumors (GISTs). J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.8537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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