7.7: Presentation session: Poster session and reception: “Modeling the effect of melanoma tumor cell growth in the presence of natural killer cells”

Cancer is the 2^nd leading cause of death in the United States. Many people develop cancer, but the immune system kills these cells without the need for outside treatments. In cancer progression, however, tumor cells may evade the immune system. How this happens is not fully understood. Natural killer cells (NK) are one of many immune cells to show tumor cell lysis. Specifically, the natural cytotoxicity receptors NKp46, NKp44 and NKp30, and the c-type lectin receptor NKG2D on NK cells, are crucial in killing the tumor cells. MICA, one of several possible activating ligands for NKG2D, is broadly expressed on human tumor cells of epithelial origin. MICA, in combination with various matrix metalloproteinases (MMPs), appears to be involved in both tumor elimination and tumor growth. Tumor growth tends to increase in the presence of soluble MICA but decreases when high levels of MICA bind to the tumor cell. MMPs have been implicated in the shedding of MICA from the tumor surface. A mathematical model was developed to simulate the interactions between NK cells and tumor cells in the presence of MMPs. Using MATLAB®, continuous partial differential equations were created based on data from published literature. Within these equations are twelve state variables and various parameters, the values of which will be determined through experimentation. Results of model simulations with 3 different initial concentration values of MMPs show how this biochemical affects the ability of NK cells to attack tumor cells.