The frequencies of LOH in two microsatellite sites, D9s171 and D9s1604, in p16 genome were associated with development of gastric cancer and no significant correlation was demonstrated between the LOH frequency and the cell differentiated types of tumor cells or clinical stages.
To investigate the expression of human telomerase reverse transcriptase gene (hTRT) in gastric cancer (GC) and its relevance with cell cycle regulators including P16INK4, cyclin and P53.
p16(INK4a) and p14(ARF) genes are frequently inactivated by homozygous deletion and methylation of the 5'CpG islands in gastric cancer, which may play an important role in the carcinogenesis of gastric cancer.
The overexpression of p16 seems to be a common event in the development of both intestinal and diffuse type of gastric cancer and it is likely that it may be driven by features of the neoplastic state.
These results suggest that p16(INK4a) promoter hypermethylation is an early and frequent event in gastric carcinogenesis and may serve as a new prognostic biomarker for the risk of gastric cancers.
In an effort to explore the underlying mechanism for the p16(INK4)-negative cases, a prospective study was also performed on 20 cases of gastric cancer to compare the level of the p16(INK4) protein with the methylation status of the p16(INK4) promoter.
In the present study, we investigated the 5' CpG island hypermethylation of hMLH1, E-cadherin and p16 in 61 primary gastric cancers (GCs) by using combined bisulfite restriction analysis (COBRA) and methylation-specific PCR (MSP), and their MSI status.