Significance of MRP1/CD9 protein expression in human hepatocellular carcinoma

Objective To investigate the expression of MRP1/CD9 protein in human hepatocellular carcinoma (HCC),and its relationship to carcinoma invasion and metastasis. Methods The specimens of tissue microarray from 152 primary hepatocellular carcinomas with paracancerous liver tissue, 22 tumor emboli , 4 intrahepatic satellite metastases, 17 extrahepatic metastases ,and 5 normal livers, respectively, were constructed and used for detection of MRP1/CD9 expression by immunohistochemistry. Results Immunohistochemical analysis of tissue microarrays demonstrated MRP1/CD9 protein expression in 27.0%(41/152)of the primary HCCs. The expression of MRP1/CD9 protein was higher in HCCs without cancer thrombi than in those with cancer thrombi (40.48%vs21.82%,P0.05). MRP1/CD9 protein expression was also inversely correlated with the tumor size (≤10cm vs 10cm, P0.01), pathological grade (P=0.043), and the serum level of AFP (≤20μg/L vs 20μg/L, P=0.029). Conclusions Loss of MRP1/CD9 protein expression may be associated with invasion and metastases of hepatocellular carcinoma.