Expression Of Rb And P57～(kip2) In Human Hepatocarcinogenesis

Objective: To study the expression and correlation of Rb p57kip2 related to cell cycle regulation in hepatocellular carcinogenesis and to identify the molecular mechanism of hepatocarcinogenesis in views of cell cycle alterationMethods: The expression of Rb p57kip2 protein and p57kip2 mRNA in total 88 samples of normal liver tissues, chronic hepatitis, liver cirrhosis, paratumor cirrhosis, hepatocellular carcinoma were detected by the methods of immunohistochemistry and in situ hybridization(ISH)Results: No expression of Rb p57kip2 in normal liver tissues; the expressions of Rb protein in chronic hepatitis were noted to be higher, whereas they were significantly reduced in liver cirrhosis; and they were continuously higher from paratumor cirrhosis to hepatocellular carcinoma The expressions of Rb protein in paratumor cirrhosis were higher than that in liver cirrhosis ,whereas there were no significant differences between the expressions of Rb protein in paratumor cirrhosis and that in HCCo p57kip2 protein level was increasingly higher from normal liver tissues to chronic hepatitis, but the expressions of p57kip2 protein in liver cirrhosis were significantly decreased; and they were increasingly higher in paratumorcirrhosis and hepatocellular carcinoma There were no significant differences between the expressions of p57kip2 protein in paratumor cirrhosis and that in HCC The poorer differention of HCC was, the lower expressions of p57kip2 were In addition, there were nuclear staining patterns of Rb p57kip2 positive cell in chronic hepatitis and liver cirrhosis, while cytoplasmic staining patterns were found in paratumor cirrhosis of Rb p57kip2 positive cellsThere were no significant differences between both patterns in HCC of Rb, p57kip2 positive cellsConclusion: The results indicated that alterations of Rb and p57kip2 should be involved in the occurrence.development and differentiation of HCCo The paratumor cirrhosis may be a sequential lesion of precancerous cirrhosis around HCCo Reduce or loss of Rb protein may be caused by the unbalanced regulation of pl6-CyclinD1-CDK4/CDK6-Rb-E2F positive feedback system. The decrease of p57kip2 mRNA indicated that p57kip2 may be involved in hepatocarcinoma genesis and prognosis...