Mesenchymal Stem Cells Target Gastric Cancer and Deliver Epirubicin via Tunneling Nanotubes for Enhanced Chemotherapy

Background: A reduced effective local concentration significantly contributes to the unsatisfactory therapeutic results of epirubicin in gastric cancer. Mesenchymal stem cells exhibit targeted chemotaxis towards solid tumors and form tunneling nanotubes with tumor cells, facilitating the delivery of various substances. This study demonstrates the novelty of mesenchymal stem cells in releasing epirubicin into gastric cancer cells through tunneling nanotubes. Objective: Epirubicin delivery to gastric cancer cells using mesenchymal stem cells. Methods: In vitro transwell migration assays, live cell tracking, and in vivo targeting assays were used to demonstrate the chemotaxis of mesenchymal stem cells towards gastric cancer. We verified the targeted chemotaxis of mesenchymal stem cells towards gastric cancer cells and the epirubicin loading ability using a high-content imaging system (Equipment type:Operetta CLS). Additionally, tunneling nanotube formation and the targeted release of epirubicin-loaded mesenchymal stem cells co-cultured with gastric cancer cells through mesenchymal stem cell-tunneling nanotubes into gastric cancer cells was observed using Operetta CLS. Results: Mesenchymal stem cells demonstrated targeted chemotaxis towards gastric cancer, with effective epirubicin loading and tolerance. Co-culturing induced tunneling nanotube formation between these cells. Epirubicin-loaded mesenchymal stem cells were released into gastric cancer cells through tunneling nanotubes, significantly increasing their non-viability compared to the negative control group (p < 0.05). Conclusions: We identified a novel approach for precisely targeting epirubicin release in gastric cancer cells. Therefore, mesenchymal stem cell-tunneling nanotubes could serve as a potential tool for targeted delivery of drugs, enhancing their chemotherapeutic effects in cancer cells.