Toll-like receptor 3-mediated modulation of umbilical cord mesenchymal stem cell phenotype and pancreatic cancer cell responses during coculture

Mesenchymal stem cells (MSCs) are progenitor cells isolated from various tissues and are crucial for tissue repair, immune support, and anticancer therapies. MSC functions such as migration, immunomodulation, and regeneration are regulated through Toll-like receptors (TLRs). In particular, TLR3 activation enhances the immunosuppressive and therapeutic capabilities of MSCs. This research employed human umbilical cord-derived MSCs (UCMSCs) and investigated the effects of TLR3 stimulation on their viability, phenotype-associated gene expression, and during co-culture with Panc-1 pancreatic cancer cells. UCMSCs were cultured and characterized for mesenchymal markers by flow cytometry. TLR3-based signaling was modulated using Poly(A:U) (an agonist) and CU-CPT4a (an antagonist). Cell viability was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay, and relative gene expression was measured employing quantitative reverse transcription polymerase chain reaction. Panc-1 cells were co-cultured with UCMSCs to evaluate TLR3-mediated effects. Data are presented as the means +/- standard error of the mean, with statistical significance determined by analysis of variance (p <= 0.05). The TLR3 agonist improved cell viability, whereas the antagonist reduced it. Additionally, both regulated the expression of CD44, CDH1, and VIMs. When UCMSCs and Panc-1 cells were cocultured at 10:1, TLR3 affected the expression of MSC-related genes, including CD44, CDH1, CLDN1, VIM, ZEB1, MMP9, MMP2, TIMP1, VEGFR2, and PLAU. Thus, TLR3-based signaling influenced the viability, maintenance of the mesenchymal phenotype, and Panc-1 cocultureassociated phenotype in UCMSCs. These results underscore the crucial role of TLR3-based signaling in modulating UCMSC function and suggest its potential utility in enhancing MSC-based therapeutic strategies. We believe that these results can help elucidate the role of TLR3-based signaling on UCMSC functions and provide a basis for future research.