目的： 研究含笑内酯（micheliolide，MCL）对结直肠癌细胞奥沙利铂（oxaliplatin，OxP）敏感性的影响及其可能的作用机制。方法： 采用2 μmol/L MCL、100 μmol/L OxP 单独或联合处理结直肠癌HCT116、Lovo细胞，CCK-8法、平板克隆实验分别检测对细胞活力和体外克隆形成能力的影响；HCT116细胞转染GFP-LC3慢病毒后采用2、5 μmol/L MCL分别处理24 h，荧光显微镜下直接观察MCL诱导HCT116细胞中自噬小体聚集情况，WB检测MCL对LC3B-Ⅰ、LC3B-Ⅱ、p62和STAT3表达的影响；Autodock Version构建MCL和STAT3的分子对接模型。结果： 2 μmol/L MCL联合100 μmol/L OxP后，可以导致结直肠癌HCT116和LoVo细胞活力显著降低（均P<0.01），使HCT116细胞的克隆形成率显著降低（P<0.01）；2、5 μmol/L MCL处理组HCT116细胞自噬率均显著高于对照组（均P<0.01），LC3B Ⅱ/Ⅰ比例为对照组的3.25和5.78倍，p62表达水平为对照组的25.5%和9.8%，STAT3的磷酸化水平为对照组的2.18和3.87倍；分子对接结果显示MCL可能和STAT3蛋白在体内直接结合。结论： MCL可能通过STAT3通路促进结直肠癌细胞自噬，从而增强其对OxP的敏感性。

Objective: To study the effect of micheliolide (MCL) on the sensitivity of colorectal cancer cells to oxaliplatin (OxP) and its possible mechanism.Methods: HCT116 and LoVo cells were treated with 2 μmol/L MCL and 100 μmol/L OxP alone or in combination. The cell viability and colony forming ability in vitro were detected by CCK-8 and plate cloning formation assay, respectively. After being transfected with GFP-LC3 lentivirus, HCT116 cells were respectively treated with 2 μmol/L and 5 μmol/L MCL for 24 h. The aggregation of autophagy bodies in HCT116 cells induced by MCL was observed under fluorescence microscope. The effects of MCL on the expressions of LC3B-Ⅰ, LC3B-Ⅱ, p62 and STAT3 were detected by WB assay; the molecular docking model of MCL and STAT3 was constructed by Autodock version.Results: After the treatment of 2 μmol/L MCL combined with 100 μmol/L OxP, the activity of HCT116 and LoVo cells as well as the colony forming ability of HCT116 cells significantly decreased (all P < 0.01). After HCT116 cells were treated with 2 and 5 μmol/L MCL, the autophagy rate of cells in the treatment groups was significantly higher than that of the control group (all P < 0.01), the LC3B Ⅱ/Ⅰ ratio was 3.25 and 5.78 times that of the control group, the expression level of p62 was 25.5% and 9.8% of the control group, and the phosphorylation level of STAT3 was 2.18 and 3.87 times that of the control group. Molecular docking results showed that MCL might directly bind to STAT3 protein in vivo.Conclusion: MCL may enhance the sensitivity of colorectal cancer cells to OxP by promoting autophagy through STAT3 pathway.

R735.3；R730.54；R730.53

天津市科技支撑重点研发计划资助项目（No. 19YFZCSY00420）；天津市重大疾病防治科技重大专项资助项目（No. 18ZXDBSY00040）；天津市卫生健康委员会项目资助（No. 2017057，No. 2014kZ053，No. 16KG154）；南开大学国家重点实验室开放课题资助项目（No. 2018094）