Colorectal cancer cell-derived exosomes containing miR-10b regulate fibroblast cells via the PI3K/Akt pathway
Colorectal cancer cell-derived exosomes containing miR-10b regulate fibroblast cells via the PI3K/Akt pathway
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DOI：
10.1016/j.bulcan.2017.12.009
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发表时间：
2018-04-01
影响因子：
1.2
通讯作者：
Zhang, Jingcheng
中科院分区：
文献类型：
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作者：
Dai, Guangyao;Yao, Xiaoguang;Zhang, Jingcheng
癌症相关成纤维细胞（CAFs）促进结直肠癌（CRC）细胞的增殖。然而，CAFs在肿瘤微环境中形成的机制尚不清楚。外泌体可能参与激活caf。方法利用miRNA表达谱阵列测定CRC细胞分泌外泌体的miRNA表达谱，并通过富集分析鉴定出与正常细胞相比表达有显著差异的潜在miRNA。然后通过生物信息学分析评估候选mirna的预测靶标。采用实时qPCR、western blot和细胞周期分析来评估候选外泌体mirna的作用。应用荧光素酶报告基因检测来确认候选外泌体mirna是否控制目标通路的表达。建立CRC异种移植小鼠模型，评价肿瘤在体内的生长情况。结果CRC细胞的>外泌体中miR-10b的水平明显高于正常结肠上皮细胞的外泌体。此外，将含有miR-10b的外泌体转移到成纤维细胞。生物信息学分析发现PIK3CA是miR-10b的潜在靶点。荧光素酶报告基因检测证实miR-10b直接抑制PIK3CA的表达。与含有miR-10b的外泌体共培养成纤维细胞可显著抑制PIK3CA表达，降低PI3K/Akt/mTOR通路活性。最后，含有miR-10b的外泌体减少了成纤维细胞的增殖，但促进了tgf - β和SM α -肌动蛋白的表达，这表明外泌体miR-10b可能激活成纤维细胞成为表达肌成纤维细胞标记物的CAFs。这些活化的成纤维细胞能够在体外和体内促进结直肠癌的生长。结论> crc来源的外泌体通过调节周围基质细胞积极促进疾病进展，基质细胞随后获得CAFs的特征。
Background > Cancer-associated fibroblasts (CAFs) contribute to the proliferation of colorectal cancer(CRC) cells. However, the mechanism by which CAFs develop in the tumor microenvironment remains unknown. Exosomes may be involved in activating CAFs.Methods > Using a miRNA expression profiling array, we determined the miRNA expression profile of secretory exosomes in CRC cells and then identified potential miRNAs with significant differential expression compared to normal cells via enrichment analysis. Predicted targets of candidate miRNAs were then assessed via bioinformatics analysis. Realtime qPCR, western blot, and cell cycle analyses were performed to evaluate the role of candidate exosomal miRNAs. Luciferase reporter assays were applied to confirm whether candidate exosomal miRNAs control target pathway expression. A CRC xenograft mouse model was constructed to evaluate tumor growth in vivo.Results > Exosomes from CRC cells contained significantly higher levels of miR-10b than did exosomes from normal colorectal epithelial cells. Moreover, exosomes containing miR-10b were transferred to fibroblasts. Bioinformatics analysis identified PIK3CA, as a potential target of miR-10b. Luciferase reporter assays confirmed that miR-10b directly inhibited PIK3CA expression. Coculturing fibroblasts with exosomes containing miR-10b significantly suppressed PIK3CA expression and decreased PI3K/Akt/mTOR pathway activity. Finally, exosomes containing miR-10b reduced fibroblast proliferation but promoted expression of TGF-beta and SM alpha-actin, suggesting that exosomal miR-10b may activate fibroblasts to become CAFs that express myofibroblast markers. These activated fibroblasts were able to promote CRC growth in vitro and in vivo.Conclusion > CRC-derived exosomes actively promote disease progression by modulating surrounding stromal cells, which subsequently acquire features of CAFs.