Influences of umbilical cord mesenchymal stem cells and their exosomes on tumor cell phenotypes

Mesenchymal stem cells (MSCs), extensively utilized in contemporary stem cell research, hold significant potential in the treatment of neoplastic diseases. This study aims to investigate the influences of umbilical cord mesenchymal stem cells (UMSCs) and their exosomes (UMSCs-exos) on tumor cell phenotypes. UMSCs and UMSCs-exos, isolated from human umbilical cord tissue, were validated for isolation efficiency and differentiation capacity using flow cytometry, electron microscopy, and cell staining. MDA-MB-231, BGC-823, A549, and LN-229, which are human breast (BC), gastric (GC), lung carcinoma (LC) cells and glioma cells, respectively, were treated with UMSCs and UMSCs-exos. Cell counting kit-8 (CCK-8), cell scratch-wound, and Transwell assays were performed on treated cultures to observe the phenotypic changes induced by UMSCs- and UMSCs-exos-treated cancer cells. The results demonstrated that UMSCs highly express PE-labeled positive surface antigens and exhibit low expression of FITC-labeled negative surface antigens, alongside possessing osteogenic and adipogenic differentiation potentials. Electron microscopy revealed UMSCs-exos to be approximately 30-150 nm in diameter, averaging 126.62±1.64 nm, and displaying increased Tsg101, CD9, and CD63 protein expression. Moreover, MDA-MB-231 and BGC-823 cells exhibited enhanced proliferation, invasion, and migration upon UMSCs and UMSCs-exos treatment. In contrast, A549 cells showed minimal alteration to invasiveness but a marked increase in proliferation and migration capabilities, while LN-229 cells displayed a phenotype indicative of suppressed activity. In conclusion, UMSCs and UMSCs-exos effectively promote the growth of BC and LC cells and inhibit the activity of GC and glioma cells, presenting promising avenues for future neoplastic disease treatments.