目的：探讨慢病毒介导的生长分化因子15（growth differentiation factor 15， GDF15）基因低表达对胶质瘤U373细胞对化疗药物替尼泊苷（teniposide，VM-26）和顺铂（cisplatin，DDP）耐药性的影响及其可能的机制。方法： 将靶向GDF15的 GDF15-RNAi克隆入慢病毒载体GV248，构建shRNA慢病毒LV-GDF15-RNAi，用无关序列构建阴性对照慢病毒LV-RNAi，分别稳定转染U373细胞，Western blotting检测转染对细胞内GDF15表达的影响。用梯度质量浓度的VM-26（0.1、0.5、2.5和12.5 μg/ml）和DDP（0.08、0.4、2和10 μg/ml）处理LV-GDF15-RNAi组和LV-RNAi组细胞48 h，MTT法、Hoechst/PI双染检测LV-GDF15-RNAi转染对U373细胞VM-26、DDP耐药性的影响，Western blotting检测LV-GDF15-RNAi转染对U373细胞凋亡相关蛋白Bcl-2、Bcl-xL、P53和 Caspase-3表达的影响。结果：成功构建稳定低表达GDF15的U373细胞系，LV-GDF15-RNAi组细胞内GDF15表达较LV-RNAi组和野生型U373细胞显著降低（0.013±0.001 vs 0.622±0.068、 0.601±0.004，均P<001）。VM-26和DDP在最低浓度时，LV-GDF15-RNAi组细胞存活率即显著高于LV-RNAi组\[VM-26 0.1 μg/ml：(91.84±264)% vs (80.71±2.66)%，P<0.01；DDP 0.08 μg/ml：(102.35±6.79)% vs (85.10±3.69)%，P<0.01\]，随药物浓度升高差异更加显著。相同浓度的VM-26或DDP处理下，LV-GDF15-RNAi组细胞凋亡数均少于LV-RNAi组；同时，LV-GDF15-RNAi组的Bcl-2和Bcl-xL的表达量比LV-RNAi组显著增多（P<0.05或P<0.01），Caspase-3和P53的表达量显著下降（P<0.05或P<001）。结论：下调胶质瘤U373细胞中GDF15水平能够增强细胞对VM-26和DDP的耐药性，其机制可能与GDF15调控Bcl-2、Bcl-xL、P53和Caspase-3的表达有关。

Objective: To determine the effect of the growth differentiation factor 15 (GDF15) gene in resistance of glioma cells to chemotherapeutic agents cisplatin (DDP) and teniposide (Vumon, VM-26) in vitro. Methods: Glioma U373 cells were infected with a lentiviral vector expressing a small hairpin RNA targeting the GDF15 gene (LV-GDF15-RNAi) and a control lentiviral vector (LV-RNAi), respectively. Stably infected cells were then treated with VM-26 (01, 0.5, 2.5 and 12.5 μg/ml) and DDP (0.08, 0.4, 2 and 10 μg/ml). After treatment for 48 h, cell viability was assessed by MTT assay and Hoechst/PI staining to evaluate differences in resistance to VM-26 and DDP, and changes in Bcl-2, Bcl-xL, P53 and caspase-3 proteins were analyzed by Western blotting. Results: GDF15 protein content was significantly lower in LV-GDF15-RNAi-infected U373 cells (0.013±0.001) than in LV-RNAi-infected (0.622±0.068) and wild-type U373 cells (0.601±0.004) (P<0.01); survival rate was significantly different between LV-GDF15-RNAi-infected (91.84±2.64)% and LV-RNAi-infected (80.71±2.66)% in the presence of VM-26 and DDP at the lowest concentrations used (P<0.01) and the difference became more significant as the concentrations were increasing. Under the treatment with VM-26 or DDP at the same concentration, the number of apoptotic cells was significantly lower in LV-GDF15-RNAi-infected cells than that in LV-RNAi-infected cells (P<0.05). In association with changes in apoptosis, protein levels of Bcl-2 and Bcl-xL were significantly higher (P<0.05) but protein levels of P53 and caspase-3 were significantly lower (P<0.01) in LV-GFD 15-RNAi-infected cells than in LV-RNAi-infected cells. Conclusion: Down-regulation of the GDF15 gene may increase the resistance of glioma cells to VM-26 and DDP, possibly through regulating the expression of Bcl-2, Bcl-xL, P53and caspase-3.

国家自然科学基金青年科学基金资助项目（No. 30701030），天津市应用基础及前沿技术研究计划资助（No. 11JCYBJC14900），国家高技术研究发展（863计划）计划资助项目（No. 2012AA021003）。