Methylation and messenger RNA expression of p15INK4b but not p16INK4a are independent risk factors for ovarian cancer.

Published

Journal Article

PURPOSE: The purpose of this research was to compare methylation status and mRNA expression of p15INK4b and p16INK4a in serous epithelial ovarian cancer tissues and normal ovarian tissues. EXPERIMENTAL DESIGN: We analyzed the DNA methylation status and mRNA expression of p15INK4b and p16INK4a in 52 ovarian cancer specimens and 40 normal ovarian specimens by using methylation-specific PCR and real-time reverse transcription-PCR, respectively. RESULTS: Although the p15INK4b and p16INK4a mRNA expression levels were highly correlated with each other (P < 0.001), the methylation status did not seem to be linked with levels of mRNA expression, as no association between the two events was found for either gene. Promoter hypermethylation of p15(INK4b) was more common in ovarian cancer (30.8% for the 52 cases) than in normal ovaries (5% for the 40 controls without ovarian cancer; P = 0.005) but not methylation of p16INK4a (25% for cancer versus 37.5% for normal; P = 0.288). The relative mRNA expression levels of p15INK4b were significantly lower in ovarian cancer (12.9%) than in normal ovaries (41.7%; P = 0.008) but not those of p16INK4a (27% for cases versus 32.8% for controls; P = 0.754). Only high methylation rate and low mRNA expression of p15INK4b were independent risk factors for ovarian cancer (adjusted odds ratio, 5.67; 95% confidence interval, 0.85-37.9 for high methylation rate and odds ratio, 8.98; 95% confidence interval, 1.58-50.9 for low mRNA expression, respectively). CONCLUSIONS: Our results suggest that epigenetic alterations in p15INK4b but not p16INK4a have an important role in ovarian carcinogenesis and that mechanisms other than methylation may exist to reduce gene expression of p15INK4b in ovarian cancer.

Full Text

Duke Authors

Cited Authors

  • Liu, Z; Wang, L-E; Wang, L; Lu, KH; Mills, GB; Bondy, ML; Wei, Q

Published Date

  • July 1, 2005

Published In

Volume / Issue

  • 11 / 13

Start / End Page

  • 4968 - 4976

PubMed ID

  • 16000597

Pubmed Central ID

  • 16000597

International Standard Serial Number (ISSN)

  • 1078-0432

Digital Object Identifier (DOI)

  • 10.1158/1078-0432.CCR-04-2293

Language

  • eng

Conference Location

  • United States