The profile of miRNAs in extracellular vesicles derived from high-metastatic or low-metastatic gastric cancer cell lines.

Cancer-associated fibroblasts (CAFs) have an important role in the tumor progression. CAFs are heterogeneous, and its subpopulation with distinct functions have been regarded as the major obstacle to CAF targeting therapy. However, it is still unclear how cancer cells mediate CAF subpopulations and create preferable tumor microenvironment for their metastasis. In this study, by using the metastatic cancer cell line models of diffuse-type gastric cancer (DGC), we demonstrate that high-metastatic cancer cell-derived extracellular vesicles (EVs) contribute to the formation of activated fibroblast subpopulations. High-metastatic DGC cells create at least two types of CAF subpopulations: myofibroblastic feature and chemokine producing feature. The CAF subpopulation with chemokine producing feature was selectively induced by high-metastatic DGC cell-derived EVs. We also found that high-metastatic DGC cell-derived EVs contain various miRNAs to induce chemokine expression in the fibroblasts. Our findings suggest that intercellular communications via EVs contribute to establishing the appropriate tumor microenvironment toward cancer metastasis.To ask how high-metastatic DGC cell-derived EVs induced chemokines in the stomach fibroblasts, miRNA microarray analysis of DGC cell-derived EVs was performed. EVs were isolated from the conditioned media of two DGC cell lines: high-metastatic (44As3) and low-metastatic (HSC-44PE). Total RNAs were extracted from these EVs. Microarray analysis was performed using 20ng of EV miRNA.