目的：考察miR-200c对三阴性乳腺癌（triple negative breast cancer，TNBC）细胞MDA-MB-231的增殖、凋亡和迁移的影响及其代谢相关的分子机制。方法：以过表达miR-200c的MDA-MB-231（miR-200c-231）细胞、无过表达miR-200c的阴性对照细胞miR-NC-231及其移植瘤裸鼠模型为研究对象，qPCR检测细胞和移植瘤组织中miR-200c及其他相关基因的表达水平，免疫组化技术分析瘤组织中Ki67阳性细胞数量，Transwell小室法检测细胞的迁移能力，流式细胞术检测细胞的凋亡率，Western blotting检测细胞及组织中增殖、迁移和代谢相关信号通路多种蛋白的表达，Seahorse能量代谢检测仪检测细胞的基础耗氧率（oxygen comsumpition rate，OCR）、细胞外酸度（extracellular acidification rate，ECAR）和代谢表型变化，液相质谱联用技术检测细胞中代谢产物的变化。结果：miR-200c-231细胞及其移植瘤组织中 miR-200c 表达较 miR-NC-231细胞显著增加（P<0.05或P<0.01），miR-200c-231移植瘤质量和体积均显著下降、瘤组织中Ki67阳性细胞数明显减少（P<0.01），miR-200c-231细胞的迁移能力下降、细胞凋亡率提高（均P<0.01）。同时伴随着ZEB1/2、Vimentin、cyclinD1的表达下调及cleaved PARP表达的提高（P<0.05或P<0.01），STAT1/3和NF-κB的磷酸化水平降低（均P<0.05）而cAMP通路蛋白的磷酸化水平提高（P<0.05）。miR-200c-231细胞的OCR提高和ECAR降低、色氨酸2，3-加二氧酶（tryptophan-2,3-dioxygenase 2，TDO2）表达下降（P<0.05或P<0.01），细胞内10种抗肿瘤代谢物质含量提高（P<0.05或P<0.01）。结论：miR-200c靶向TDO2调控TNBC细胞MDA-MB-231胞内抗肿瘤代谢产物水平、促使细胞代谢类型由依赖糖酵解为主向有氧呼吸类型转化，并失活STAT3和NF-κB通路而激活cAMP通路，从而影响MDA-MB-231细胞的恶性生物学行为。

Objective:To investigate the effects of miR-200c on the proliferation, apoptosis and migration of triple negative breast cancer cell (TNBC) MDA-MB-231 and its metabolism-related molecular mechanism. Methods: miR-200c-231 (MDA-MB-231 over‐expressing miR-200c) cells, miR-NC-231 (MDA-MB-231 transfected with miRNA-negative control) and the corresponding transplant‐ed tumor models in nude mice were used as the study subjects. qPCR was used to detect the content of miR-200c and other related genes in cells and transplanted tumor tissues. The number of Ki67 positive cells in tumor tissue was analyzed by immunohistochemistry.The migration and apoptosis of cells were examined by Transwell chamber method and Flow cytometry, respectively. The expressions of proteins associated with proliferation, migration, and metabolism related signaling pathways in cells and tissues were confirmed by Western blotting. The changes of oxygen consumption rate (OCR), extracellular acidification rate (ECAR) and metabolic phenotype were detected by Seahorse energy metabolism detector. UPLC/LTQ-Orbitrap-MS technique was used to profile the difference of metabo‐lites in cells. Results: The content of miR-200c in miR-200c-231 cells was significantly higher than that in miR-NC-231 cells. The mass of miR-200c-231 transplanted tumor notably decreased, and the number of Ki67 positive cells in tumor tissues also decreased significantly.The migration ability of miR-200c-231 cells decreased and the apoptosis rate increased (all P<0.01), accompanied with declined expres‐sions of ZEB1/2, Vimentin, cyclin D1 and increased expression of cleaved PARP (P<0.05 or P<0.01), as well as decreased phosphorylation lever of STAT1/3 and NF-κB but incresed phosphorylation lever of CAMP(all P<0.05). Overexpression of miR-200c in MDA-MB-231 cells increased OCR and the content of 10 antitumor metabolites, but decreased ECAR and tryptophan 2,3-plus dioxidase (TDO2) expression (P<0.05 or P<0.01). Conclusion: miR-200c targeting TDO2 elevates the level of intracellular anticancer metabolites in TNBC MDAMB-231 cells, promotes the transformation from glycolysis to aerobic respiration phenotype, and inactivates STAT3 and NF-κB pathy‐way but activates cAMP pathway TNBC MDA-MB-231 cells, thus affects the malignant biological behaviors of MDA-MB-231 cells.

国家自然科学基金资助项目（No. 81773946, No. 81573673, No. 81001666）