|Alternative Title||Effect of oxygen-laden mesenchymal stem cell on gastric cancer chemotherapy and its mechanism
|Place of Conferral||兰州
|Abstract||目的:胃癌是严重危害人类健康的恶性肿瘤，作为胃癌主要治疗手段的化疗其耐药问题日益严重，缺氧是造成胃癌化疗耐药的重要原因。本课题利用间充质干细胞对胃癌的靶向趋化性，构建表达血红蛋白的间充质干细胞，使其充分携氧后作用于缺氧的胃癌细胞，给予临床比较常用的胃癌化疗药物，观察携氧后的间充质干细胞对胃癌化疗效果的影响，并从分子水平探讨其影响胃癌化疗效果可能的机制，以确定这种靶向治疗方法的可行性。结果：培养的间充质干细胞及胃癌细胞均符合其标准生物学特点。测序结果显示表达于间充质干细胞中的血红蛋白基因序列符合Gene bank中HBA2及HBB基因序列。病毒转染率达到80%，感染复数（MOI）为10。经IPTG及血红素诱导后，Western blotting 能够检测到血红蛋白的表达。Transwell 结果显示与普通的间充质干细胞一样，表达血红蛋白的间充质干细胞也具备向胃癌细胞迁移的能力。MTT实验及统计分析结果显示与单纯的化疗相比，携氧间充质干细胞联合化疗组对各株胃癌细胞的抑制率更高，凋亡检测结果也显示携氧间充质干细胞干预组具有更高的凋亡率。对各组HIF-1α、MDR1及VEGF基因表达的定量PCR检测结果表明：不论是对于MKN-45细胞株还是SGC-7901细胞组，与未加任何干预的细胞相比，携氧间充质干细胞干预组细胞中HIF-1α、MDR1及VEGF均表现出明显的下降趋势。
|Other Abstract||Objective: Gastric cancer seriously threatens the human health. As a main therapeutic method, chemotherapy of gastric cancer is faced with great challenge, especially the multidrug resistance. Hypoxia is an important factor which results in failure of chemotherapy for gastric cancer. Taking the utility of the tropism of mesenchymal stem cells (MSCs) to gastric cancer, we make MSCs as a vehicle to expression hemoglobin gene, and place them in a circumstance full of oxygen to carry enough oxygen. As a first approach to investigate the possibility of MSCs as vehicle to supply oxygen for cancers, this study was carried out to determine the effect of oxygen-laden mesenchymal stem cells function on the gastric cancer chemotherapy. Further, we investigate the molecular mechanism of the results to confirm the feasibility of this targeted gene therapy method.
Results: The cultured MSCs and gastric cancer cells conformed to their typical characteristics. HBA2 and HBB gene sequence expressed in MSC-hemo-GFP was consistent with NM_000517(HBA2) and NM_000518(HBB) in Genebank and the marker protein GFP could be observed by fluorescence microscopy in the MSC-hemo-GFP group and MSC-GFP group.After induced by IPTG and hemin, hemoglobin protein could be detected by western blotting.These MSC-hemo cells were verified having the capability to migrate to cancer cells as MSCs as reported.The results of MTT assay and statistical analysis showed that the killing effect of oxygen-laden MSC-hemo and chemotheraputics groups were stronger both in MKN-45 and SGC-7901 cell lines than the other two groups(p<0.05). The apoptosis detection also showed that the oxygen-laden MSC-hemo groups had higher apoptosis rate. The results of quantitive PCR showed that no matter for MKN-45 or for SGC-7901, comparing with no intervention groups, the expression of HIF-1α, MDR1 and VEGF all decreased in the oxygen-laden MSCs-hemo intervention groups.
Conclusion: Our results suggest that Oxygen-laden MSC-hemo significantly enhanced the effect of chemotheraputics treatment on gastric cancer cells.Taking MSCs as a vehicle to supple oxygen for solid tumor maybe a novel way to improve the hypoxia condition of tumor tissues and improve the effect of chemotherapy of gastric cancer. The target of oxygen-laden MSC-hemo functioned on gastric cancer chemotherapy was HIF-1α. The companied decrease of MDR1 and VEGF reduced the MDR for chemotherapy of gastric cancer.|
周雅丽. 携氧间充质干细胞对胃癌化疗效果的影响及其机制研究[D]. 兰州. 兰州大学,2015.
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