CD97 promotes gastric cancer cell proliferation and invasion through exosome-mediated MAPK signaling pathway  

作　　者：Chao Li Da-Ren Liu Guo-Gang Li Hou-Hong Wang Xiao-Wen Li Wei Zhang Yu-Lian Wu Li Chen 

机构地区：[1]Department of Surgery,Second Affiliated Hospital,College of Medicine,Zhejiang University [2]Department of Orthopedics,Second Affiliated Hospital,College of Medicine,Zhejiang University

出　　处：《World Journal of Gastroenterology》2015年第20期6215-6228,共14页世界胃肠病学杂志（英文版）

基　　金：Supported by National Natural Science Foundation of China,No.81101837;Research Fund for the Doctoral Program of Higher Education of China,No.20110101120129;Zhejiang Medical Health Science and Technology Plan,No.2013KYB124

摘　　要：AIM: To investigate the mechanism underlying the promoting role of CD97 in gastric cancer cell proliferation and invasion. METHODS: Two types of exosomes released by gastric cancer cells with high(SGC/wt) or low(SGC/kd) CD97 expression were isolated by ultracentrifugation and identified by electron microscopy and western blot analysis. The influences of the two exosomes on gastric cancer cell proliferation and invasion were investigated by proliferation and Matrigel invasion assays. Exosomal mi RNAs were subsequently isolated from the two samples and their mi RNA profiles were compared via microarray assay analysis. Reverse transcriptionquantitative real-time polymerase chain reaction was used to validate the microarray assay. Target genes of the differently expressed micro RNAs were predicted based on five independent algorithms and were then subjected to gene oncology enrichment and Kyoto encyclopedia of genes and genomes(KEGG) pathway analysis. After identifying the pathway that was the most likely altered, tumor cells were treated with the two exosomes at different concentrations, and the pathway activation was identified through western blot analysis.RESULTS: Exosomes isolated from SGC/wt cells significantly promoted tumor cell proliferation in a dose-dependent manner in vitro. SGC/wt exosomesalso significantly elevated the invasiveness of both SGC/wt(129.67 ± 8.327 vs 76.00 ± 5.292, P < 0.001) and SGC/kd(114.52 ± 9.814 vs 45.73 ± 4.835, P < 0.001) cells as compared to the exosomes released by SGC/kd cells. Microarray assay of the two exosomes revealed that 62 mi RNAs were differently regulated with a signal intensity of > 500 and a false discovery rate < 0.05. The following KEGG analysis defined the MAPK signaling pathway as the most likely candidate pathway that regulated tumor cell proliferation and invasion. Through western blot analysis, significant up-regulations of phosphorylated MAPKs, including extracellular signal-regulated kinase, Jun NH2-terminal kinase, and p38 mitogen-activated protein kinaAIM: To investigate the mechanism underlying the promoting role of CD97 in gastric cancer cell proliferation and invasion. METHODS: Two types of exosomes released by gastric cancer cells with high(SGC/wt) or low(SGC/kd) CD97 expression were isolated by ultracentrifugation and identified by electron microscopy and western blot analysis. The influences of the two exosomes on gastric cancer cell proliferation and invasion were investigated by proliferation and Matrigel invasion assays. Exosomal mi RNAs were subsequently isolated from the two samples and their mi RNA profiles were compared via microarray assay analysis. Reverse transcriptionquantitative real-time polymerase chain reaction was used to validate the microarray assay. Target genes of the differently expressed micro RNAs were predicted based on five independent algorithms and were then subjected to gene oncology enrichment and Kyoto encyclopedia of genes and genomes(KEGG) pathway analysis. After identifying the pathway that was the most likely altered, tumor cells were treated with the two exosomes at different concentrations, and the pathway activation was identified through western blot analysis.RESULTS: Exosomes isolated from SGC/wt cells significantly promoted tumor cell proliferation in a dose-dependent manner in vitro. SGC/wt exosomesalso significantly elevated the invasiveness of both SGC/wt(129.67 ± 8.327 vs 76.00 ± 5.292, P < 0.001) and SGC/kd(114.52 ± 9.814 vs 45.73 ± 4.835, P < 0.001) cells as compared to the exosomes released by SGC/kd cells. Microarray assay of the two exosomes revealed that 62 mi RNAs were differently regulated with a signal intensity of > 500 and a false discovery rate < 0.05. The following KEGG analysis defined the MAPK signaling pathway as the most likely candidate pathway that regulated tumor cell proliferation and invasion. Through western blot analysis, significant up-regulations of phosphorylated MAPKs, including extracellular signal-regulated kinase, Jun NH2-terminal kinase, and p38 mitogen-activated protein kina

关 键 词：CD97 EXOSOME Proliferation INVASION miRNA GASTRIC cancer 

分 类 号：R735.2[医药卫生—肿瘤]