CD147介导耐药胰腺癌干细胞的化疗抵抗性及其线粒体机制

Our previous studies indicated that there existed the heterogeneity of drug sensitivity in pancreatic cancer stem cells. The real culprit leading to therapeutic resistance could be resistant pancreatic cancer stem cells. Therefore, to reverse the therapeutic resistance of pancreatic cancer cells, it is crucial to explore the survival mechanisms of resistant pancreatic cancer stem cells. Recent literature showed that resistant pancreatic cancer stem cells depended on mitochondrial oxidative phosphorylation for survival, but the activating mechanism for mitochondrial oxidative phosphorylation has not been elucidated. Our previous study proved that the expression level of CD147 affected the ratio of resistant pancreatic cancer stem cells. And, the upregulation of CD147 expression was consistent with the enhancement of mitochondrial contents and reactive oxygen species levels in drug resistant pancreatic cancer cells. In CD147 over-expressed tumor spheres, the important molecule of oxidative phosphorylation electron transport chain complex I, NDUFS1 or STAT3, were both changed accordingly, suggesting that CD147 may promote the chemo-resistance of resistant pancreatic cancer stem cells by affecting the mitochondrial oxidative phosphorylation. In this project, we would take advantage of the patient-derived xenograft (PDX) and 3D cell culture model, with the view of metabolic epigenetics to explore the role of CD147 in affecting mitochondrial oxidative phosphorylation by regulating NDUFS1 or pser727STAT3 mediated activation of complex I, and then promoting chemo-resistance of resistant pancreatic cancer stem cell. The completion of this project would benefit to the development of a novel therapeutic target and strategy for successful treatment of patients with pancreatic cancer.

申请者前期研究表明，胰腺癌干细胞具有药物治疗敏感性的异质性，仅其中耐药性胰腺癌干细胞是治疗抵抗的真正根源。探讨耐药性胰腺癌干细胞抵抗治疗的生存机制，对于逆转胰腺癌细胞的耐药性至关重要。新近文献证明，耐药性胰腺癌干细胞的存活依赖于线粒体氧化磷酸化，但其氧化磷酸化激活的机制尚不清楚。我们近期预实验发现，CD147表达水平影响耐药性胰腺癌干细胞比例，其水平上调与耐药性胰腺癌干细胞线粒体含量增加及呼吸功能增强一致；CD147过表达肿瘤微球体细胞中，影响氧化磷酸化电子传递链复合物I的重要分子NDUFS1或STAT3表达发生改变，提示CD147可能调控了线粒体呼吸机制。本项目拟利用PDX和细胞3D培养模型，以代谢表观遗传学视角，研究CD147通过调控NDUFS1或pser727STAT3介导的复合物I活性，调节氧化磷酸化，进而促进耐药性胰腺癌干细胞化疗抵抗的新机制，为胰腺癌耐药防治提供新策略和新靶点。

探讨耐药性胰腺癌干细胞抵抗治疗的生存机制，对于逆转胰腺癌细胞的耐药性至关重要。耐药性胰腺癌干细胞的存活依赖于线粒体氧化磷酸化，但其氧化磷酸化激活机制尚不清楚。本项目围绕研究目标，利用人源肿瘤组织移植（PDX）和肿瘤微球体3D培养等体内、外模型，通过耐药细胞肿瘤微球体富集-流式分选的序贯模式分离鉴定了耐药胰腺癌干细胞；通过Seahorse细胞能量代谢分析系统进行了线粒体氧化磷酸化代谢特征的分析，发现线粒体电子传递链复合物I的活性显著增强，并调控了胰腺癌干细胞的潜能；采用基因编辑与慢病毒载体技术构建CD147表达下降/缺失或过表达/回复胰腺癌细胞，发现CD147对耐药胰腺癌干细胞、线粒体氧化磷酸化代谢及电子传递链复合物I的活性具有显著的影响；通过转录组测序、人干细胞转录因子芯片检测、组织芯片多重免疫荧光染色以及质谱技术，深入阐明了CD147通过上调线粒体内膜电子传递链复合物I活性的关键亚单位NDUFS1或线粒体pser727STAT3表达、增加复合物I活性、促进氧化磷酸化代谢、进而增强耐药胰腺癌干细胞潜能及化疗抵抗的新机制；回答了耐药性胰腺癌干细胞如何能抵抗化疗杀伤并生存的关键科学问题；研究成果为开发更有效的胰腺癌耐药防治新策略提供新靶点，也为拓展CD147抗体药物的治疗应用提供新线索。课题执行过程中，发表SCI论文3篇，培养博、硕士研究生4人，其中毕业博士研究生1名、硕士研究生1名，目前在读硕士研究生2名。课题负责人李玲作为团队带头人获得空军军医大学创新团队奖（2019），陕西省中青年科技创新领军人才（2017）和首届中国药学会-以岭生物医药青年奖（2016），并获得陕西省科学技术一等奖（2016）。