ABSTRACT
AIM: To observe the effects of aspirin and prostaglandin E_2 (PGE_2) on the cell viability and cell cycle in SW1990 human pancreatic carcinoma cell lines, and to investigate the mechanisms of aspirin-induced growth inhibition and cell cycle arrest. METHODS: After incubated with aspirin or PGE_2 and their combination, the viability of SW1990 cells was measured by MTT assay. The levels of intracellular PGE_2 were determined by ELISA. The effects of aspirin or PGE_2 on cell cycle were investigated by flow cytometry (FCM). The expression of p21~ Wafl/cipl and p27~ Kipl/pic2 (the cyclin-dependent kinase inhibitors) were analyzed by Western blotting. RESULTS: Aspirin could inhibit the growth of cells and level of intracellular PGE_2 in a dose-dependent manner. Aspirin enhanced the expression of p21~ Wafl/cipl and p27~ Kipl/pic2 and induced cell cycle arrest at G_0/G_1 phase. PGE_2 increased the cell viability of SW1990 cells. However, it couldn't antagonize the changes of cell viability and cell cycle that induced by aspirin. CONCLUSIONS: The inhibitory effects of aspirin on growth and cell cycle of pancreatic carcinoma cells might not be mediated by a COX-dependent pathway completely. Cell cycle arrest induced by aspirin might be associated with up-regulation of p21~ Wafl/cipl and p27~ Kipl/pic2 .