Guangyao Dai1, Xiaoguang Yao2, Yubin Zhang1, Jianbin Gu1, Yunfeng Geng1, Fei Xue1, Jingcheng Zhang3. 1. First Hospital of Shijiazhuang City, Department of General Surgery, Shijiazhuang, China. 2. Hebei University of Chinese Medicine, Hebei Key Laboratory of Integrative Medicine on Liver-kidney Patterns, Shijiazhuang, China; Hebei University of Chinese Medicine, College of Integrative Medicine, Shijiazhuang, China. 3. First Hospital of Shijiazhuang City, Department of General Surgery, Shijiazhuang, China. Electronic address: jingcheng.zhang@outlook.com.
Abstract
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. Co-culturing 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-β and SM α-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.
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. Co-culturing 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-β and SM α-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.
Authors: Maya Malaab; Ludivine Renaud; Naoko Takamura; Kip D Zimmerman; Willian A da Silveira; Paula S Ramos; Sandra Haddad; Marc Peters-Golden; Loka R Penke; Bethany Wolf; Gary Hardiman; Carl D Langefeld; Thomas A Medsger; Carol A Feghali-Bostwick Journal: Ann Rheum Dis Date: 2021-11-08 Impact factor: 19.103