目的 研究尼美舒利联合吉西他滨对人非小细胞肺癌NCI-H1975细胞增殖和凋亡的影响。方法 采用MTT法测定尼美舒利联合吉西他滨对NCI-H1975细胞生长的抑制作用。流式细胞仪检测尼美舒利（100 μmol/L）组、吉西他滨（20 nmol/L）组和联合用药（尼美舒利100 μmol/L+吉西他滨20 nmol/L）组对NCI-H1975细胞周期和凋亡的影响。Western blotting检测各组对Bcl-2、Bax、Cleaved caspase-3蛋白表达的影响。结果 尼美舒利对NCI-H1975细胞的生长具有抑制作用，且呈剂量相关性，IC₅₀为（298.76±2.79）μmol/L；吉西他滨的IC₅₀为（78.64±3.14）nmol/L，尼美舒利与吉西他滨联合作用后，能明显增加后者对NCI-H1975细胞增殖的抑制作用，二者有明显的协同作用。尼美舒利联合吉西他滨将细胞阻滞在G₀/G₁期，而S和G₂/M期均有所减少。与单药组相比，联合用药组能显著升高细胞的凋亡率（P<0.05）。与单药组相比，联合用药组明显下调Bcl-2蛋白的表达（P<0.05），上调Bax和Cleaved caspase-3蛋白的表达（P<0.05）。结论 尼美舒利联合吉西他滨能明显抑制肿瘤细胞的增殖，诱导细胞凋亡，其效果优于单用吉西他滨组，其机制与影响细胞周期调控，下调Bcl-2蛋白表达、上调Bax和Cleaved caspase-3蛋白表达水平有关。

Objective To study the effects of nimesulide combined with gemcitabine on proliferation and apoptosis of human non-small cell lung cancer NCI-H1975 cells. Methods MTT assay was used to determine the inhibitory effect of nimesulide combined with gemcitabine on the growth of NCI-H1975 cells. Flow cytometry was used to detect the cell cycle and apoptosis of NCI-H1975 in the nimesulide (100 μmol/L) group, the gemcitabine (20 nmol/L) group, and the combination (nimesulide 100 μmol/L + gemcitabine 20 nmol/L) group. The expression of Bcl-2, Bax, and Cleaved caspase-3 protein was detected by Western blotting. Results Nimesulide inhibited the growth of NCI-H1975 cells in a dose-dependent manner with an IC₅₀ of (298.76 ±2.79) μmol/L. The IC₅₀ of gemcitabine was (78.64 ±3.14) nmol/L. The combination of nimesulide and gemcitabine significantly increased the inhibitory effect of the latter on the proliferation of NCI-H1975 cells. The ratio of nimesulide plus gemcitabine to cells in the gemcitabine group was significantly increased in the G₀/G₁ phase, while the S and G₂/M phases were reduced. Compared with the single-agent group, the apoptosis rate in the combined group was significantly increased (P < 0.05). Compared with the single-agent group, the combination group could significantly down-regulate Bcl-2 protein expression (P < 0.05), but up-regulate Bax and Cleaved caspase-3 protein expression (P < 0.05). Conclusion Nimesulide combined with gemcitabine can significantly inhibit the proliferation of tumor cells and induce apoptosis. The effect is better than that of gemcitabine alone. The mechanism and effect of cell cycle regulation, down-regulation of Bcl-2 protein expression, up-regulation of Bax and Caspase-3 protein expression levels are related.

R966

国家自然科学基金资助项目（81472474）；天津市卫生局科技基金资助项目（201242034）