Inhibition of COX-2 and activation of peroxisome proliferator-activated receptor γ synergistically inhibits proliferation and induces apoptosis of human pancreatic carcinoma cells

Although inhibition of cyclooxygenase-2 (COX-2) or activation of peroxisome proliferators-activated receptor γ (PPAR-γ) leads to growth inhibition in malignancies, the synergistic anti-tumor effects of combination of COX-2 inhibitor (NS-398) and PPAR-γ agonist (rosiglitazone) on the human pancreatic cancer cells remains unknown. Here, we evaluated the effects of NS-398 and/or rosiglitazone on the cell proliferation and apoptosis in a pancreatic cancer cell line, SW1990. NS-398 and rosiglitazone decreased cell proliferation in a dose- and time-dependent manner. Proliferating cell nuclear antigen (PCNA) labeling index significantly decreased in the cells treated with either NS-398 or rosiglitazone. Both NS-398 and rosiglitazone alone induced apoptotic cell death of SW1990. The combination of NS-398 and rosiglitazone exerted synergistic effects on proliferation inhibition, and apoptosis induction in SW1990 cells, with down-regulation of Bcl-2 and up-regulation of Bax expression. Our results indicate that simultaneous targeting of COX-2 and PPAR-γ inhibits pancreatic cancer development more effectively than targeting each molecule alone.