Amplification of PVT1 contributes to the pathophysiology of ovarian and breast cancer.

TitleAmplification of PVT1 contributes to the pathophysiology of ovarian and breast cancer.
Publication TypeJournal Article
Year of Publication2007
AuthorsGuan Y, Kuo W-L, Stilwell JL, Takano H, Lapuk AV, Fridlyand J, Mao J-H, Yu M, Miller MA, Santos JL, Kalloger SE, Carlson JW, Ginzinger DG, Celniker SE, Mills GB, Huntsman DG, Gray JW
JournalClin Cancer Res
Volume13
Issue19
Pagination5745-55
Date Published2007 Oct 1
ISSN1078-0432
KeywordsApoptosis, Breast Neoplasms, Chromosome Aberrations, Chromosomes, Human, Pair 8, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Genome, Humans, In Situ Hybridization, Fluorescence, Ovarian Neoplasms, Proteins, Proto-Oncogene Proteins c-myc, RNA, Long Noncoding, Transcription, Genetic, Treatment Outcome
Abstract

PURPOSE: This study was designed to elucidate the role of amplification at 8q24 in the pathophysiology of ovarian and breast cancer because increased copy number at this locus is one of the most frequent genomic abnormalities in these cancers.EXPERIMENTAL DESIGN: To accomplish this, we assessed the association of amplification at 8q24 with outcome in ovarian cancers using fluorescence in situ hybridization to tissue microarrays and measured responses of ovarian and breast cancer cell lines to specific small interfering RNAs against the oncogene MYC and a putative noncoding RNA, PVT1, both of which map to 8q24.RESULTS: Amplification of 8q24 was associated with significantly reduced survival duration. In addition, small interfering RNA-mediated reduction in either PVT1 or MYC expression inhibited proliferation in breast and ovarian cancer cell lines in which they were both amplified and overexpressed but not in lines in which they were not amplified/overexpressed. Inhibition of PVT1 expression also induced a strong apoptotic response in cell lines in which it was overexpressed but not in lines in which it was not amplified/overexpressed. Inhibition of MYC, on the other hand, did not induce an apoptotic response in cell lines in which MYC was amplified and overexpressed.CONCLUSIONS: These results suggest that MYC and PVT1 contribute independently to ovarian and breast pathogenesis when overexpressed because of genomic abnormalities. They also suggest that PVT1-mediated inhibition of apoptosis may explain why amplification of 8q24 is associated with reduced survival duration in patients treated with agents that act through apoptotic mechanisms.

DOI10.1158/1078-0432.CCR-06-2882
Alternate JournalClin. Cancer Res.
PubMed ID17908964
Grant ListCA58207 / CA / NCI NIH HHS / United States
CA64602 / CA / NCI NIH HHS / United States
CA83639 / CA / NCI NIH HHS / United States