H3K9me3 enrichment on the p16 promoter was measured by immunoprecipitation-PCR (ChIP-PCR) analyses, and 39 cases of hepatitis B virus (HBV) associated-hepatocellular carcinoma (HCC) and corresponding noncancerous liver tissues were also examined.
KLRG1 impairs CD4+ T cell responses via p16ink4a and p27kip1 pathways: role in hepatitis B vaccine failure in individuals with hepatitis C virus infection.
HBV infection could affect methylation on p16(INK4A), GSTP1, CDH1(E-cadherin), RASSF1A, p21(WAF1/CIP1) genes, which may play important roles in the development of HCC.
HBV infection is associated with p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and RB gene methylation (P = 0.048, 0.035, 0.02); HBV-DNA replication is associated with p14 (ARF) , p15 (INK4B) , p16 (INK4A) , and RB gene methylation (P = 0.048, 0.035, 0.02); high rate of p14 (ARF) , p15 (INK4B) , and p16 (INK4A) in HCC with HBV infection suggests that HBV-induced hypermethylation may be one of the mechanisms of HBV involved in hepatocellular carcinogenesis.
To quantitatively assess the gradual changes of the promoter methylation of p14ARF, p15INK4b, p16INK4a and CCND2 genes in hepatitis B virus (HBV) infection-related HCC.
Hepatitis B virus X protein induces hypermethylation of p16(INK4A) promoter via DNA methyltransferases in the early stage of HBV-associated hepatocarcinogenesis.
In addition, the potentials of HBx to inactivate Rb and subsequently inhibit cellular senescence almost completely disappeared when levels of p16(INK4a) were recovered either by exogenous complementation or inhibition of the promoter hypermethylation.
The hypermethylation frequency of GSTP1 and RASSF1A showed significant difference between HCCs and liver cirrhosis with or without HBV infection (P<0.05), but differences of the hypermethylation status of APC, E-cadherin, and P16 were not statistically significant.
Other HBV factors including hepatitis B surface antigen and hepatitis B core antigen, tissue HBV-DNA levels and HBV x gene mutations had no relation to the methylation status of p16(INK4A) promoter.
This study provides the first evidence that this protein generated in vivo from an alternative reading frame of the hepatitis B virus genome activates T-cell responses in hepatitis B virus-infected patients.
Other HBV factors including hepatitis B surface antigen and hepatitis B core antigen, tissue HBV-DNA levels and HBV x gene mutations had no relation to the methylation status of p16(INK4A) promoter.
Generally, these results indicate that persistent HBV infection may be associated with high rate of p16 methylation, and involved in development of HCC through this way.
Generally, these results indicate that persistent HBV infection may be associated with high rate of p16 methylation, and involved in development of HCC through this way.
The frequency of p16INK4A hypermethylation tended to be higher in hepatitis C virus-related tumors (23 of 32, 72%) than in hepatitis B virus-related tumors (6 of 13, 46%; P=0.1).
In addition, p16 methylation status of five cell lines with or without HBV infection was examined to test whether the high frequency of hypermethylation is related to HBV infection.
In our study, we screened HCCs resulting from HCV infection (51 cases), HBV infection (26 cases) or excess alcohol intake (23 cases) for alterations in genes involved in the RB1 pathway (p16(INK4a), p15(INK4b), RB1, CDK4 and cyclin D1), the p53 pathway (p53, p14(ARF) and MDM2) and the Wnt pathway (beta-catenin, APC).
In addition, p16 methylation status of five cell lines with or without HBV infection was examined to test whether the high frequency of hypermethylation is related to HBV infection.
Our results suggest that methylation of the p16 promoter and the resulting loss of p16 protein expression are early events in a subset of hepatocarcinogenesis and that their detection is useful in the follow up of patients with a high risk of developing HCC, such as those with hepatitis B or C viral infections.