[Expression of CAS in hepatocellular carcinoma tissues and its relationship with HBV infection]

To explore whether the cellular apoptosis susceptibility (CAS) protein could serve as a pathologic marker for HCC diagnosis and the roles of CAS expression in HBV infection associated HCC.

The expression of CAS protein in HCC and its paracarcinoma tissues, non-tumor liver cirrhosis and hepatitis tissues were detected by immunohistochemistry. Meanwhile, HBsAg, HBcAg and HBV DNA in HCC tissues with HBV infection were examined by immunohistochemistry and in situ hybridization respectively.

The expression of CAS protein was significantly higher in HCC than in its paracarcinomas tissues (P < 0.01), and higher in paracarcinomas tissues than in non-tumor liver cirrhosis and hepatitis tissues (P < 0.01). Poorly differentiated tumors immunochemically stained stronger than moderately or well differentiated (P < 0.01). CAS protein expression was significantly higher in HBV-infected HCC tissues than that of in non-HBV infection (P < 0.01). Meanwhile, in HBV-infected HCC tissues, the staining intensity score of CAS protein in HBV DNA positive HCC tissues was significantly higher than HBV DNA negative tissues (P < 0.05).

Higher expression of CAS protein is found in HCC tissues,and the intensity of CAS protein expression is related closely to tumor differentiation. We suggested that CAS protein might serve as a marker for HCC diagnosis and differentiation estimation, and deduced that CAS might play an important role in the initiation of HBV infection associated HCC through upregulating expression of CAS.