In ovarian epithelial carcinogenesis, p16 and p53 show higher immunohistochemical staining frequencies in malignant tumors and are associated with poor prognoses. p14 was only analyzed in carcinomas, with conflicting results.
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.
The present findings of the frequent and variable p14 gene abnormalities, including rare-type ones with or without sufficient mutational effect in glioma cell lines, might be of value for better understanding of the p14 gene and its related pathways in glioma carcinogenesis.
Our observation of frequent p14 gene abnormalities (90%) and inactivation (40-60%) was in striking contrast to the same pathological subtype of systemic lymphoma in which p14 gene abnormalities and inactivation were infrequent, suggesting a difference in carcinogenesis between PCNSL and systemic lymphoma.
Of 91 fully characterized cases, 41 (45%) had p53 mutations alone, 17 (19%) had p14 methylation alone, 30 (33%) had neither, but only 3 (3%) had both p53 mutations and p14 methylation. p14 methylation is an early event in colorectal carcinogenesis, being detectable in normal aging epithelium by using sensitive assays.
Although the number of cases we analyzed was not large, alterations identified in the Rb, p53, p16, p15 and p14 genes are of significance and might be associated with tumorigenesis in NK cell neoplasms.