Abstract: Objective To study and analyze the expression of the cluster of differentiation 74,CD74 in tissues of gallbladder cancer and its correlation of the expression of EGFR.Methods We used the immunohistochemistry to analyze the expressions of CD74 and EGFR in tissues of gallbladder cancer from 54 patients.The clinicopathological characters of gallbladder cancer patients and the expression of CD74 was also studied.We used the western blot to analyze the expression of CD74 in the fresh gallbladder cancer tissues.The Spearman rank correlation was used to analyze the association between CD74 and EGFR.
Results The expression of CD74 had no difference between men and women,and the expression of CD74 had no correlation with the age of patients(P>0.05).The expression of CD74 in poorly differentiated gallbladder cancer tissues was significantly higher than that in moderately and well differentiated gallbladder cancer(P<0.05).The expression of CD74 with highly invasion depth was significantly higher than that in low invasion depth(P<0.05),but there was no significant difference with the N stage of tumor tissue(P>0.05).There was significant difference in the expression of CD74 between gallbladder carcinoma with early TNM stage and gallbladder carcinoma with poor TNM stage(P<0.05).Spearman rank correlation analysis showed that the IOD value of IHC of CD74 was positively correlated with the IOD value of EGFR.
Conclusion CD74 is highly expressed in poorly differentiated gallbladder cancer,and it is positively correlated with EGFR.It is a potential target for the treatment of gallbladder cancer.

Key words: gallbladder cancer, cluster of differentiation 74, epidermal growth factor receptor；correlation analysis