外泌体转运miR-324-5p对胃癌MGC-803细胞增殖及凋亡的影响

Effects of exosome transport miR-324-5p on proliferation and apoptosis of gastric cancer MGC-803 cells

目的探讨外泌体转运微小RNA(miR)-324-5p对胃癌MGC-803细胞增殖及凋亡的影响。方法培养人胃癌细胞系MGC-803并提取外泌体,制备外泌体转运miR-324-5p模拟物(mimic)。细胞分为对照组(细胞不进行处理)、外泌体组(外泌体混悬液)和miR-324-5p mimic组(加入外泌体转运miR-324-5p mimic混悬液),制备移植瘤模型。检测各组摄取外泌体效率。MTT法和流式细胞术检测细胞增殖率和凋亡率,qRT-PCR和Western blotting法检测各组瘤体中miR-324-5p、细胞周期依赖性蛋白激酶抑制因子1A(p21)、细胞周期蛋白D1(CyclinD1)和微管相关蛋白1轻链3(LC3)mRNA及蛋白的表达。结果外泌体组和miR-324-5p mimic组MGC-803细胞摄取外泌体效率分别为60%和57%。与对照组和外泌体组比较,miR-324-5p mimic组MGC-803细胞增殖率降低,凋亡率增加(P<0.05);裸鼠移植瘤质量和CyclinD1 mRNA及蛋白降低,抑瘤率、miR-324-5p、p21、LC3 mRNA及蛋白增加(P<0.05)。结论外泌体转运miR-324-5p能抑制MGC-803细胞增殖和促进MGC-803细胞凋亡,其机制可能是增加移植瘤中p21和LC3水平,降低CyclinD1水平,从而提高抑瘤率,降低移植瘤质量。

Aim To investigate the effects of microRNA(miR-324-5P)on proliferation and apoptosis of gastric cancer MGC-803 cells.Methods Human gastric cancer cell line MGC-803 was cultured and exosomes were extracted to prepare exosome transport miR-324-5p mimic.The cells were divided into control group(cells were not treated),exosome group(exosome suspension)and miR-324-5p mimic group(adding exosome to transport miR-324-5p mimic suspension),and the transplanted tumor model was prepared.The efficiency of exosome uptake in each group was measured.The efficiency of exosome uptake in each group was measured.Cell proliferation rate and apoptosis rate were detected by MTT and flow cytometry.The expression of miR-324-5p,cyclin-dependent protein kinase inhibitor 1A(p21),Cyclin D1(CyclinD1)and microtubule-associated protein 1 light chain 3(LC3)mRNA and protein in each group were detected by qRT-PCR and Western blotting.Results The uptake efficiency of MGC-803 cells in exosome group and miR-324-5p mimic group were 60%and 57%respectively.Compared with control group and exosome group,the proliferation rate of MGC-803 cells decreased and the apoptosis rate increased in miR-324-5p mimic group(P<0.05);the transplanted tumor weight,CyclinD1 mRNA and protein decreased,the tumor inhibition rate,miR-324-5p,p21 and LC3 mRNA and protein increased in miR-324-5p mimic group(P<0.05).Conclusion The exosomal transport miR-324-5p can inhibit the proliferation of MGC-803 cells and promote the apoptosis of MGC-803 cells.The mechanism may be related to increasing the levels of p21 and LC3 in transplanted tumors and reducing the level of CyclinD1,thereby increasing the tumor inhibition rate and reducing transplantation tumor weight.