Study On Correlation Of Bcl-2 And Fas/FasL In Biliary Duct Neoplasm

Objective: To study the expression of Bcl-2 protein and Fas/FasL protein in gallbladder carcinoma, and their biological behaviors and correlation. And to assess its ability to induce apoptosis and immune escape. Methods: Avidin-biotin-peroxidase complex method was used to study the expression of Bcl-2 and Fas/FasL in 33 cases of gallbladder carcinoma, 19 cases of gallbladder adenoma, 3 cases of gallbladder epithelial dysplasia and 20 cases of chronic cholecystis. The expression of FasL in 48 specimens of human hilar cholangiocacinoma resected in operation and cultured QBC939 cholangiocarcinoma cell line was detected by immunohistochemistry. TUNEL was used to detect apoptotic cells. Results: The positive rates of Bcl-2 in carcinoma, adenoma and dysplasia were 78.8%(26/33), 73.7%(14/19) and 100%(3/3) respectively, there were not significant difference among them. The positive rates of Bcl-2 in cholecystis was 40%(8/20). The positive rates of Bcl-2 in carcinoma and adenoma were significantly higher than in cholecystis (p<0.05): The positive rates of FasL in carcinoma, adenoma and dysplasia were 81.8%(27/33), 84.2%(16/19) and 100%(3/3) respectively, there were not significant difference among them. The positive rates of FasL in cholecystis were 55%(11/20). The positive rates of FasL in carcinoma and adenoma were significantly higher than in cholecystis (p<0.05). The expression of Bcl-2 and FasL were not correlated with metastasis and differentiation. The positive rates of Fas in cholecystis, adenoma and dysplasia were 80%(16/20), 73.7%(14/19) and 100%(3/3) respectively, there were not significant difference among them. The positive rates of Fas in carcinoma were 39.4%(13/33), which was significant lower than in cholecytis and adenoma (p<0.05). And the positive rates of Fas in poorly-differentiated carcinoma were significantly lower than in well-moderated-differentiated carcinoma (p<0.05), but it was not correlated with metastasis. The expression of FasL and Bcl-2 in gallbladder carcinoma took on some extent positive correlation(r_s=0.478, P<0.005), the expression of Fas and Bcl-2 in gallbladder carcinoma took on some extent negative correlation(r_s=-0.316, P<0.05), the expression of Fas and FasL in gallbladder carcinoma were not significant correlation. Prevalent expression of FasL was detected in 48 resected hilarcholangiocarcinomas examined. TUNEL staining disclosed a high level of cell death among lymphocytes infiltrating FasL positive areas of tumor. FasL protein was expressed in cholangiocarcinoma cells. Conclusions: The expression of Bcl-2 and Fas/FasL might be correlated with the biological behaviors of gallbladder carcinoma. And there might be some extent coordinated regulation among them. The hilar cholangiocarcinoma eludes immunological surveillance by inducing, via the Fas/ FasL system , the apoptosis of activated lymphocytes.