DECREASED EXPRESSION AND RARE SOMATIC MUTATION OF THE CIP1 WAF1 GENE IN HUMAN HEPATOCELLULAR-CARCINOMA/

CIP1/WAF1, a critical downstream effector of tumor suppressor p53, enc odes a cyclin-dependent kinase inhibitor. By Northern blot analysis, t he CIP1/WAF1 mRNA level in the tumor was significantly lower than that in the corresponding normal liver from 19 Japanese patients with hepa tocellular carcinoma P <0.05). In the tumor from only one; out of 19 p atients (5%), somatic mutations of the CIP1/WAF1 as well as that of p5 3 gene were identified by RT-PCR/SSCP analysis. These results suggest that the decreased CIP1/WAF1 expression is involved in the carcinogene sis or the progression of hepatocellular carcinoma. (C) 1997 Elsevier Science Ireland Ltd.