BACKGROUNDTo study the effect and possible mechanism of cyclooxygenase-2 selective inhibitor, nimesulide (NIM), combined with cisplatin (DDP) on human lung cancer.

METHODSThe proliferation and apoptosis of human lung cancer cell line A549 were evaluated by MTT reduction assay and flow cytometry respectively. The inhibitory effects of NIM and DDP to neoplasia were verified on subcutaneous implanted tumor of nude mice.

RESULTSBoth NIM and DDP could inhibit A549 cell proliferation in a concentration dependent pattern. When NIM (25 μmol/L) and DDP (≥1 mg/L) were combined, the inhibitory effect was enhanced in a synergistic or additive pattern. Both NIM (25 μmol/L) and DDP (3 mg/L) could significantly increase the apoptosis of A549 cells ( P < 0.05, P < 0.01), and this action was remarkably increased when DDP was combined with NIM ( P < 0.01, P < 0.01). NIM and DDP could inhibit the growth of subcutaneous implanted tumor on nude mice and the inhibitory rate of NIM combined with DDP was significantly higher than that of NIM or DDP alone ( P < 0.01, P < 0.01).

CONCLUSIONSNIM combined with DDP shows significantly synergistic anti-tumor effects on lung cancer cell line A549 and subcutaneous implanted tumor on nude mice, which may be achieved by enhancement of growth inhibition and apoptosis induction to tumor cells.