Murine bone marrow stromal cells pulsed with homologous tumor-derived exosomes inhibit proliferation of liver cancer cells

Increasing evidence shows that bone marrow stromal cells (BMSCs) have antitumor activities both in vitro and in animal models. Further studies fleshed out the supportive data that the antitumor activity of BMSCs could be markedly enhanced by cytokines such as IL-2 and IFN-beta (interferon). However, powerful strategies to activate BMSCs other than by genetically engineering interventions are still required. In this study, new methods of generating antitumor activities of murine marrow-originated MSCs pulsed with homologous tumor-derived exosomes (TEX) were explored to yield potent immune effectors against hepatocellular carcinoma cells in vitro. The results showed that BMSCs pulsed with exosomes and IFN-gamma exhibited increased migration ability with a result of 163.22 +/- A 26.90 versus 129.89 +/- A 29.28 cells/HP by transwell determination (p < 0.05). The inhibition of homologous hepatocellular carcinoma cells line H-22 cells by exosomes pulsed BMSCs was significantly increased by 41.9 % compared with control (p < 0.05), and flow cytometry analysis showed that the cell cycle of H-22 cells was arrested in G(0)/G(1) phase. Meanwhile, western blot analysis showed that PCNA protein expression in the supernatant of H-22 cells was significantly decreased. This study demonstrated that BMSCs pulsed with TEX could enhance its antitumor activities, which might be regarded as a novel promising antitumor treatment.