肿瘤源性外泌体miR-21对胃癌细胞增殖和凋亡的影响

Effect of tumor-derived exosome miR-21 on proliferation and apoptosis of gastric cancer cells

目的初步探究肿瘤外泌体miR-21对胃癌细胞增殖和凋亡的影响。方法通过ExoQuick提取并分离得到胃癌细胞SGC-7091外泌体,采用电子显微镜观察外泌体直径大小,Western blot法检测外泌体标志性白细胞分化抗原群63(cluster of differentiation 63,CD63)和肿瘤易感基因101蛋白(tumor susceptibility gene 101 protein,TSG101)。外泌体与胃癌SGC-7091细胞共培养24 h后实时荧光定量PCR检测miR-21表达,TUNEL染色检测细胞凋亡情况,Western blot法检测增殖蛋白细胞周期蛋白D1(cyclin D1)以及凋亡相关蛋白B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)和caspase-3蛋白表达。结果成功提取分离40~100 nm SGC-7091细胞源性外泌体颗粒,其表达TSG101和CD63蛋白。外泌体与SGC-7091细胞共培养促进miR-21表达(P<0.01),降低TUNEL染色阳性细胞数目(P<0.01),促进细胞增殖(P<0.01),下调caspase-3表达(P<0.01),上调Bcl-2和cyclin D1表达(均P<0.01)。结论肿瘤细胞来源外泌体可以通过递送miR-21促进胃癌细胞增殖,抑制细胞凋亡进而加快胃癌转移。

Objective To preliminarily explore the effect of tumor-derived exosome miR-21 on the proliferation and apoptosis of gastric cancer cells.Methods ExoQuick was used to extract and isolate the exosomes from gastric cancer SGC-7091 cells.The diameters of exo-somes were observed by electron microscope.Western blot was used to detect the cluster of differentiation 63(CD63)and tumor susceptibility gene 101(TSG101)protein.Exosomes were co-cultured with gastric cancer SGC-7091 cells for 24 h.Then miR-21 expression was detected by real-time fluorescent quantitative PCR,cell apoptosis was detected by TUNEL staining,and Western blot was used to detect the expression of proliferation protein cyclin D1 and apoptosis-related protein B lymphoma-2 gene(Bcl-2)and caspase-3.Results The 40-100 nm SGC-7091 cell-derived exosomal particles were successfully extracted and separated,which expressed TSG101 and CD63 proteins.Co-culture of exosomes and SGC-7091 cells promoted the miR-21 expression(P<0.01),decreased the number of TUNEL staining positive cells(P<0.01),promoted cell proliferation(P<0.01),down-regulated the caspase-3 expression(P<0.01),and up-regulated the expression of Bcl-2 and cyclin D1(both P<0.01).Conclusion Tumor cell-derived exosomes can promote gastric cancer cell proliferation and inhibit cell apoptosis by delivering miR-21 to accelerate gastric cancer metastasis.