ABSTRACT
Objective To investigate the effects of nimesulide, a selective cyclooxygenase-2 (COX-2) inhibitor, on human cholangiocarcinoma QBC939 cell line in vitro. Methods The effects of nimesulide on QBC939 cells were observed with the following techniques: the influence of nimesulide on the proliferation of QBC939 cells was determined by MTT assay; the apoptosis of QBC939 cells was viewed and measured by transmission electron microscopy and flow cytometry, respectively; the expressions of proliferation cell nuclear antigen (PCNA) and COX-2 of cholangiocarcinoma cells were detected by immunocytochemistry. Results Nimesulide inhibited the expressions of PCNA and COX-2 and the proliferation of cholangiocarcinoma QBC939 cells, whose effects intensified as the dose increased and time elongated. Flow cytometry showed that the apoptotic rates of QBC939 cells increased significantly as the dose of nimesulide increased. The typical morphologic features of apoptosis were also observed by transmission electron microscopy. Conclusion Nimesulide significantly inhibits the proliferation of QBC939 cells in vitro by inducting cell apoptosis, which may be associated with the downregulation of COX-2 expression, and it also presents the features of dose and time dependents.