The Relationship Between The Expression Of WWOX, FHIT Fragile Gene And Clinicopathological Features In Hepatocellular Carcinoma

Objective:To study the relationship between the expression of WWOX,FHIT fragile gene and clinicopathological features in hepatocellular carcinoma (HCC).Methods:The expression of WWOX mRNA was detected by RT-PCR and SYBR Green I Real-time PCR in 44 HCC samples, adjacent liver tissue samples and 5 normal liver tissue samples. The expression of WWOX and FHIT protein were determined by immunohistochemistry (IHC) in 142 HCC samples, adjacent liver tissue samples and 15 normal liver tissue samples. In addition, the expression of WWOX protein was evaluated by Western Blot in 32 HCC samples, adjacent liver tissue samples and 5 normal liver samples. The correlations of WWOX and FHIT to clinicopathologic parameters of HCC were also analyzed.Results:1,The sliced variant4 of WWOX gene was detected in HCC. It contained an in-frame deletion of exon 6-8. Variant4 expression was observed in 70.5% of HCCs,38.6% adjacentliver tissues and 40% normal liver tissue (P<0.01). The occurrence of variant4 had a significant association with cirrhosis (P<0.05).The sliced variant6 of WWOX gene was detected in 72.7%HCC,81.8% adjacentliver tissues and 80% normal liver tissue(P<0.05).It had an amino acid sequence from the first five exons and alternative exon 6. The expression of Variant4 and Variant6 were not associated with sex, AFP lever, tumor size, histological type, grade, vascular invasion, capsuler invasion, satellites formation and recrudesce(P>0.05).2,The expression of the wild-type WWOX gene was significantly lower(P<0.01)than the adjacentliver tissues, which decreased with the tumor differentiation decreased in HCC(P<0.05). The expression of the wild-type WWOX mRNA in HCC with recrudesce was lower than that in those without recrudesce (P<0.05).But it was not associated with sex, age, AFP lever, tumor size, histological type, vascular invasion, capsuler invasion, satellites formation, occurrences of variant4 and variant6(P>0.05).3,The results of IHC showed that absent/redused FHIT and WWOX expression were observed in 68.3% and 77.5% of HCCs, respectively, lower than the adjacent liver tissues and the normal liver tissue. FHIT and WWOX expression were correlated strongly (P<0.01), whereas progressive loss of expression were observed as tumor differentiation decreased and grade increased (P<0.05). Absent/redused FHIT and WWOX expression also demonstrated significant association with the related factors to the tumor invasion and metastasis (P<0.05).The expression of FHIT and WWOX in HCC with recrudesce were lower than that in those without recrudesce (P<0.05). In addition, FHIT and WWOX expression were associated with AFP lever and histological type (P<0.05), not associated with sex, age, HBV infection and cirrhosis. The results of Western Blot also showed that the expression of WWOX in HCC was lower than the adjacent liver tissues.Conclusion:1,FHIT and WWOX expression were correlated positively and strongly in HCC. Absent/redused FHIT and WWOX expression were related to tumor malignant features, which indicated poor outcome.2,The sliced variant4 of WWOX gene might be a molecular target of carcinogens.3,The inactivation of FHIT and WWOX were not caused by the infection of HBV directly.4,FHIT and WWOX might be the tumor suppressors in HCC,contributing to carcinoigenesis and tumor progression.