Objective: To analyse the relationship between methylation status of the 5' CpG island and mRNA expression of the p16 gene in endometrial carcinoma.
Methods: Methylation status of p16 gene was determined by methylation-sensitive restriction enzymes, PCR and p16 mRNA expression was evaluated by RT-PCR in a series of 8 specimens with normal endometrium(NE), 6 with simple and complex hyperplasia(SCH), 6 with atypical hyperplasia (AH) and 38 with endometrial carcinoma(EC).
Results: Eight specimens of NE displayed no methylation and showed normal expression of the p16 mRNA. In 1 of the 6 AH and 13 of the 38(34.21%) EC, there was methylation of p16 exon 1; 5 of the 6 SCH showed overexpression of p16 mRNA, 4 of the 6 AH and 27 of the 38 (71.05%) EC exhibited decrease or loss of p16 mRNA expression.
Conclusion: Hypermethylation of p16 gene is an early event of endometrial carcinogenesis and is associated with the progression of endometrial carcinoma. Hypermethylation is highly correlated with inhibition of p16 gene transcription.