The effects of cyclooxygenase-2 gene silencing by siRNA on cell proliferation, cell apoptosis, cell cycle and tumorigenicity of Capan-2 human pancreatic cancer cells

The prognosis of pancreatic cancer is still very poor. No specific effective gene therapy for pancreatic cancer has been found. As a key enzyme of the metabolic process of arachidonic acid, cyclooxygenase-2 (COX-2) has been found to be closely related to the tumorigenesis of epithelial cancers. However, the antitumor effect of small interfering RNA (siRNA) targeting COX-2 in pancreatic cancer has not yet been verified. Therefore, the aim of this study was to investigate the effects of COX-2 gene silencing by siRNA on cell proliferation, cell apoptosis, cell cycle and tumorigenicity of pancreatic cancer cells. COX-2 mRNA was detected by RT-PCR and real-time PCR. COX-2 protein was detected by Western blotting. The cell proliferation was measured by cell counting using microscopy. The cell apoptosis and cell cycle were measured by flow cytometry. The tumorigenicity of Capan-2 pancreatic cancer cells transfected with COX-2 siRNA was evaluated using a nude mouse xenograft model. The expression of COX-2 mRNA as well as COX-2 protein were downregulated after COX-2 siRNA transfection. COX-2 siRNA could inhibit the growth of Capan-2 cells significantly by decreasing the cell proliferation, increasing cell apoptosis and regulating cell cycle as well. In vivo experiments demonstrated that the mean volume and weight of subcutaneous xenografts in nude mice derived from Capan-2 cells transfected with COX-2 siRNA were significantly decreased. COX-2 siRNA could inhibit the growth of Capan-2 pancreatic cancer cells and also decrease the tumorigenicity of Capan-2 cells, implicating a new potential therapeutic target in pancreatic cancer.