The growth inhibitory effect of mesenchymal stem cells on tumor cells in vitro and in vivo.

Mesenchymal stem cells (MSCs) play an important role in the development and growth of tumor cells. The purpose of this study is to confirm the effect of MSCs on tumor cell growth in vitro and in vivo and to elucidate the mechanism. MSCs were isolated from mouse bone marrow and cocultured with murine hepatoma H22, lymphoma (YAC-1 and EL-4) and rat insulinoma INS-1 cell lines. The growth inhibitory effect of MSCs on tumor cells was tested through MTT and 3H-TdR incorporation assay. The apoptosis induction effect of MSCs on tumor cells was assessed with flow cytometry (FCM) and RT-PCR assay. MSCs were inoculated into BALB/c mice alone or coinoculated with ascitogenous hepatoma cells intraperitonealy, respectively. The tumor growth inhibition of MSCs was investigaed through the incidence and volume of ascites formation, and the immunosuppression effect was studied with splenocyte response to ConA stimulation test and T cell subsets analysis (FCM). The results showed that MSCs exhibited a number-dependent grow...