The Effects of Granulocyte Macrophage Stimulating Factor on Cancer Cell Viability in vitro and in vivo 2307997

Abstract Introduction Previous research has shown that mast cells (MC) can induce cancer cell apoptosis through the release of mediators they produce following FcεRI and non-FcεRI mechanisms. However, it is not clear which mediators induce this response. Mast cells produce copious amounts of Granulocyte Macrophage Stimulating Factor (GMCSF) which is primarily known for stimulating the immune system by activating and recruiting white blood cells. The purpose of this study was to determine what direct effect GMCSF has on cancer cells in vitro and in vivo. Methods Several human cancer cell lines including: AU565, BT474, and MDA-MB-231 were incubated with varying concentrations of human GMCSF and the morphological changes and viability were assessed in vitro. For in vivo studies, tumors were established in Nu/Nu immunocompromised mice after injection with the same cancer cells. Mouse tumors were injected with or without varying concentrations of GMCSF and tumor size and lifespan measured. Results Statistically significant cancer apoptosis was determined using flow cytometry of the in vitro study. In Vivo studies are underway. Conclusion GMCSF may have a direct killing effect on cancer cells in addition to the well-established immune stimulation actions described previously. These results also suggest this mechanism contributes to anti-tumor effects of MC and provide guidance in rationally designing MC for cancer immunotherapy strategies. Funding Source National Institutes of Health, 1R15CA46430-01A1 Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)