Expression of autophagy-related proteins Beclin-1 and LC3A and proliferation marker Ki-67 in calculous and acalculous human gallbladder epithelium.

Background: Autophagy is an inducible intracellular process that has been studied mostly in cancer and less in inflammatory diseases. To establish the relation between cholecystitis (calculous and acalculous) and autophagy, we studied the expressions of immunohistochemical markers Beclin-1, LC3A, and Ki-67 in gallbladder epithelium and their significance in the induction of autophagy. Methods: Adult human gallbladder tissues were obtained from 100 patients (45 male, 55 female) who underwent cholecystectomy. According to the findings, the patients were divided into two groups: group A (calculous gallbladder: 24 male, 46 female; mean age 52.6 +/- 16.0 years) and group B (acalculous gallbladder: 21 male, nine female; mean age 65.3 +/- 12.4 years). The expressions of immunohistochemical markers Beclin-1, LC3A, and Ki-67 in gallbladder epithelium were studied using immunohistochemistry techniques. Results: Beclin-1 expression was correlated with LC3A expression in group A with increased Beclin-1 expression promoting LC3A expression (p =0.0001). In group B, the LC3A expression did not follow Beclin-1 expression (p=0.09). The mean percentage of Beclin-1 expression in group A patients was 23.8 % compared to group B patients, where the corresponding percentage was only 17.3 %. Corresponding mean percent expressions of LC3A in groups A and B were 38.9 % and 50.7 %, respectively. The expression of Ki-67 was higher in group A patients compared to group B patients. The mean percentage of Ki-67 expression in group A patients was 3.75 %, whereas, in group B patients, it was only 0.5 % (statistically significantly different; p=0.0003). Conclusion: In the epithelium of calculous cholecystitis, overexpression of LC3A is related to Beclin-1 overexpression, which reinforces the view that Beclin-1 promotes autophagy in stone cholecystitis.