中文摘要：

该研究探讨了人脐带间充质干细胞（human umbilical cord-derived mesenchymal stem cells,h UC-MSCs）提取物对人肺腺癌细胞A549增殖和迁移能力的影响及其作用机制。利用超声破碎法制备h UC-MSCs提取物,并处理经链球菌溶血素O（streptolysin O,SLO）通透的A549细胞。采用MTT法、平板克隆形成实验检测h UC-MSCs提取物对A549细胞增殖的影响,Transwell实验检测细胞迁移能力,实时荧光定量PCR检测促凋亡基因胱冬肽酶-3（caspase-3）、胱冬肽酶-9（caspase-9）、抑癌基因RUNX3（runt-related transcription factor 3）和存活蛋白基因（survivin）的m RNA水平,亚硫酸氢盐测序检测RUNX3启动子区Cp G岛甲基化水平。结果发现,经h UC-MSCs提取物处理后,A549细胞的增殖、迁移能力均显著降低,caspase-3、caspase-9和RUNX3 m RNA水平显著升高,survivin m RNA的表达量显著降低,RUNX3启动子区Cp G岛显著去甲基化。该研究结果表明,h UC-MSCs提取物可能通过逆转RUNX3启动子区甲基化状态恢复其表达,并通过提高caspase-3、caspase-9表达及降低survivin的表达来抑制A549的增殖及迁移能力。

英文摘要：

In this study, the effects of cell extracts from human umbilical cord-derived mesenchymal stem cells（h UC-MSCs） on the proliferation and migration of human lung cancer A549 cells were studied. After permeated by streptolysin O（SLO）, A549 cells were cultured in medium containing h UC-MSCs extracts. Then, the proliferation of A549 cells were assessed by the MTT and colony formation assay. The invasion of A549 cells were examined by the transwell chambers assay. Meanwhile, the m RNA expression of pro-apoptotic gene caspase-3 and caspase-9, tumor suppressor gene RUNX3（runt-related transcription factor 3） and anti-apoptotic gene survivin were detected by real-time quantitative PCR. The DNA methylation status in the promoter region of RUNX3 gene were detected by bisulfite sequencing. The results showed that the proliferation and migration of A549 cells were significantly decreased after h UC-MSCs extracts treatment and the m RNA levels of caspase-3, caspase-9 and RUNX3 were significantly increased, while the m RNA level of survivin was significantly decreased and the Cp G islands on the promoter of RUNX3 was significantly demethylated. These results demonstrated that h UC-MSCs extracts inhibited the proliferation and migration of A549 cells probably through reversing RUNX3 expression by demethylated its promoter region, activating the expression of caspase-3, caspase-9 and inhibiting the expression of survivin.