LncRNA-MEG3 对胃癌生物学特性 及铂类化疗敏感性的研究

目的 探讨LncRNA-MEG3 对胃癌增殖、凋亡及顺铂化疗敏感性的影响。方法 以人正 常胃黏膜上皮细胞GES1 作为对照细胞，实时荧光定量聚合酶链反应（qRT-PCR）检测胃癌MKN28、 SGC7901、AGS 及BGC823 细胞中LncRNA-MEG3 的表达；将过表达MEG3 的质粒转染BGC823 细胞作为 pcDNA3.1-MEG3 组，转染空白质粒的阴性对照作为pcDNA3.1 组，同时设置Control 组；将BGC823 细胞 分为pcDNA3.1 组、pcDNA3.1-MEG3 组、顺铂组及pcDNA3.1-MEG3+ 顺铂组。qRT-PCR 检测转染48 h 后细胞中LncRNA-MEG3 的表达；pcDNA3.1-MEG3、顺铂单独或共同处理BGC823 细胞，细胞计数试剂 盒法及流式细胞仪分别检测细胞活力及凋亡率；Western blotting 检测STAT3、磷酸化的信号转导与转录因 子3（p-STAT3）、Cyclin D1 和Bcl-2 的表达。结果 胃癌细胞中LncRNA-MEG3 的表达均低于GES1 细胞 （P <0.05）；4 组LncRNA-MEG3 相对表达量比较，差异有统计学意义（P <0.05）；pcDNA3.1-MEG3 组和顺 铂组Cyclin D1、Bcl-2 及p-STAT3 的蛋白表达低于pcDNA3.1 组（P <0.05），细胞凋亡率高于pcDNA3.1 组 （P <0.05）。结论 胃癌细胞中LncRNA-MEG3 表达降低，过表达LncRNA-MEG3 可降低胃癌细胞活力并诱 导细胞凋亡，增加顺铂的化疗敏感性，其机制与下调STAT3 信号通路有关。

Effect of LncRNA-MEG3 on proliferation and apoptosis of gastric cancer and chemosensitivity of cisplatin

Objective To investigate the effect of LncRNA-MEG3 on the proliferation and apoptosis of gastric cancer and the chemosensitivity of cisplatin. Methods Using human normal gastric epithelial cell GES1 as control cells, the expressions of LncRNA-MEG3 in MKN28, SGC7901, AGS and BGC823 gastric cancer cells were detected by qRT-PCR; the plasmid that overexpressed MEG3 was transfected into BGC823 cells (pcDNA3.1- MEG3 group), and blank plasmid was added as negative control (pcDNA3.1 group), and blank control group was set up, and the expression of LncRNA-MEG3 was detected by qRT-PCR cells transfected with 48h; BGC823 cells were treated by pcDNA3.1-MEG3 and cisplatin alone or together, and CCK8 assay and flow cytometry were used to detect cell viability and apoptosis rate; the expression of STAT3, p-STAT3Cyclin D1 and Bcl-2 protein were detected by western blotting. Results The expression of LncRNA-MEG3 in gastric cancer cells was lower than that in GES1 cells (P < 0.05); the relative expression of LncRNA-MEG3 in four groups was significantly different (P < 0.05); the expressions of Cyclin D1, Bcl-2 and p-STAT3 protein were significantly lower in pcDNA3.1-MEG3 group and cisplatin group than those in pcDNA3.1 group, but apoptosis rate was significantly higher (P < 0.05). Conclusions The expression of LncRNA-MEG3 decreases in gastric cancer cells. Overexpression of LncRNA-MEG3 can reduce gastric cancer cell viability and induce cell apoptosis, and increase the chemosensitivity of cisplatin, which is related to downregulation of STAT3 signaling pathway.