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- Gasi, Delila, 1982, et al.
(författare)
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Overexpression of full-length ETV1 transcripts in clinical prostate cancer due to gene translocation.
- 2011
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- ETV1 is overexpressed in a subset of clinical prostate cancers as a fusion transcript with many different partners. However, ETV1 can also be overexpressed as a full-length transcript. Full-length ETV1 protein functions differently from truncated ETV1 produced by fusion genes. In this study we describe the genetic background of full-length ETV1 overexpression and the biological properties of different full-length ETV1 isoforms in prostate cancer. Break-apart FISH showed in five out of six patient samples with overexpression of full-length ETV1 a genomic rearrangement of the gene, indicating frequent translocation. We were able to study the rearrangements in more detail in two tumors. In the first tumor 5'-RACE on cDNA showed linkage of the complete ETV1 transcript to the first exon of a prostate-specific two exon ncRNA gene that maps on chromosome 14 (EST14). This resulted in the expression of both full-length ETV1 transcripts and EST14-ETV1 fusion transcripts. In chromosome spreads of a xenograft derived from the second prostate cancer we observed a complex ETV1 translocation involving a chromosome 7 fragment that harbors ETV1 and fragments of chromosomes 4 and 10. Further studies revealed the overexpression of several different full-length transcripts, giving rise to four protein isoforms with different N-terminal regions. Even the shortest isoform synthesized by full-length ETV1 stimulated in vitro anchorage-independent growth of PNT2C2 prostate cells. This contrasts the lack of activity of even shorter N-truncated ETV1 produced by fusion transcripts. Our findings that in clinical prostate cancer overexpression of full-length ETV1 is due to genomic rearrangements involving different chromosomes and the identification of a shortened biologically active ETV1 isoform are highly relevant for understanding the mechanism of ETV1 function in prostate cancer.
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2. |
- Cheng, Wing-Shing, et al.
(författare)
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A novel TARP-promoter-based adenovirus against hormone-dependent and hormone-refractory prostate cancer
- 2004
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Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0016 .- 1525-0024. ; 10:2, s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- TARP (T cell receptor gamma-chain alternate reading frame protein) is a protein that in males is uniquely expressed in prostate epithelial cells and prostate cancer cells. We have previously shown that the transcriptional activity of a chimeric sequence comprising the TARP promoter (TARPp) and the PSA enhancer (PSAe) is strictly controlled by testosterone and highly restricted to cells of prostate origin. Here we report that a chimeric sequence comprising TARPp and the PSMA enhancer (PSMAe) is highly active in testosterone-deprived prostate cancer cells, while a regulatory sequence comprising PSAe, PSMAe, and TARPp (PPT) has high prostate-specific activity both in the presence and in the absence of testosterone. Therefore, the PPT sequence may, in a gene therapy setting, be beneficial to prostate cancer patients that have been treated with androgen withdrawal. A recombinant adenovirus vector with the PPT sequence, shielded from interfering adenoviral sequences by the mouse H19 insulator, yields high and prostate-specific transgene expression both in cell cultures and when prostate cancer, PC-346C, tumors were grown orthotopically in nude mice. Intravenous virus administration reveals both higher activity and higher selectivity for the insulator-shielded PPT sequence than for the immediate-early CMV promoter. Therefore, we believe that an adenovirus with therapeutic gene expression controlled by an insulator-shielded PPT sequence is a promising candidate for gene therapy of prostate cancer.
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