Loss of fragile histidine triad protein in human hepatocellular carcinoma

AIM: To investigate the expression of fragile histidine triad (FHIT) gene protein, Fhit, which is recently thought to be a candidate tumor suppressor. Abnormal expression of fragile histidine triad has been found in a variety of human cancers,but little is known about its expression in human hepatocellular carcinogenesis and evolution.METHODS: Sections of 83 primary human hepatocellular carcionoma with corresponding para-neoplastic liver tissue and 10 normal liver tissue were evaluated immunohistochemically for Fhit protein expression.RESULTS: All normal liver tissue and para-neoplastic liver tissue showed a strong expression of Fhit, whereas 50 of 83(65.0 %) carcinomas showed a marked loss or absence of Fhit expression. The differences of Fhit expression between carcinoma and normal or para-neoplastic liver tissue werehighly significant (P=0.000). The proportion of carcinomas with reduced Fhit expression showed an increasing trend (a) with decreasing differentiation or higher histological grade (P=0.219); (b) in tumors with higher clinical stage Ⅲ and ⅣV (91.3 %, P=0.000), compared with tumors with lower stage Ⅰ and Ⅱ (27.6 %); and (c) in cancers with bigger tumor size (＞50 mm) (75.0 %, P=0.017), compared withsmaller tumor size (≤ 50 mm). CONCLUSION: FHIT inactivation seems to be both an earlyand a later event, associated with carcinogenesis andprogression to more aggressive hepatocellular carcinomas.Thus, evaluation of Fhit expression by immunohistochemistryin hepatocellular carcinoma may provide important diagnosticand prognostic information in clinical application.