| [ Summary ] |
The mammalian cell cycle is controlled by regulators of the G1 to S transition such as tumor suppresser proteins, p53 and retinoblastoma (RB) ; cyclin Dl and cyclin dependent kinase 4; and inhibitors of cyclin dependent kinese, pl6INK4A. Recently, aberrations of these cell cycle-related genes and methylation of promoters of pl61NK4A have been reported to contribute to the formation and development of cancer. In human hepatocellular carcinoma (HCC), high rates of aberration have been detected in the p53 and RB genes. Loss of heterozygosity (LOH) of chromosome 13q and 17p was detected frequently in HCC cases. The aberration of these genes was observed more frequently when there was poor differentiation and in advanced HCCs. On the other hand, genetic alteration of the cyclin D1 and pl6INK4A genes was not so frequent, which suggests that disruption of the cell cycle-related genes results in the progression of HCC. |