Liver Cancer Institute, Affiliated Zhongshan Hospital，Fudan University, Shanghai 200032, China

Abstract

Objective By analyzing the expression of cluster of differentiation 74(CD74) in hepatocellular carcinoma (HCC) and HCC cell lines, the correlation between the level of CD74 expression and the patients′ prognosis was investigated. Methods The expression of CD74 in high metastatic potential HCC cell lines(MHCC-LM3，MHCC-97H), low metastatic potential HCC cell line(MHCC-97L), and no metastatic potential HCC cell line(Hep-G2) were estimated by Western blot. The paraffin embedded tissues which include intra-tumor and paratumor tissues were collected from 320 patients who had received HCC curative surgical resection and 5 normal liver tissues from the donors of liver tranplantation.The high density tissue micro-array was made of these specimens. Immunol-histochemistry was applied to discover the different levels of CD74 in tumor, paratumor and normal liver tissues. Survival curves were generated by the Kaplan-Meier method and verified by the Logrank test.Cox proportional hazards regression analysis was applied to estimate the prognostic factors in multivariate analysis. Results The expression level of CD74 was significantly higher in low metastatic potential and no metastatic potential HCC cell lines(MHCC-97L 1.224±0.014, Hep-G2 1.374±0.006) than that in high metastatic potential ones(MHCC-LM3 0.622±0.078, MHCC-97H 0.732±0.083).Significant differences can be found between the groups(t=-13.308，-16.849，-10.177，-13.436，-17.057； P 0.05), except gender (χ2=3.954, P<0.05). Kaplan-Meier method showed that patients with positively expression of CD74 had better prognosis than others (χ2=5.620, P<0.05).Cox proportional hazards regression analysis showed that CD74 was a significant and independent prognostic factor of survival ［ hazard ratio (HR)=0.721, 95% confidence interval (CI)=0.522-0.996, P<0.05］. Conclusion The expression of CD74 in hepatocellular carcinoma could be a biomarker of the prognosis and there′s some potential correlation with cancer cell apoptosis.（Chin J Lab Med, 2012,35:47-52） Key words: Carcinoma，hepatocellular; Liver neoplasms; Antigens，differentiation，B-lymphocyte; Histocompatibility antigens class Ⅱ; Prognosis