Tumor Cells Can Regulate The Function Of Macrophage To Promote The Tumor Proliferation

Objective: Study the interaction between tumor cells and immune cells (macrophages) in the tumor micro-environment and their functional changes. After macrophages were cultured with tumor cells, their function of anti-tumor effect change to the promotion of tumor cell proliferation. And further study focused on how do such changes happen and what are the effective stimulations are, as well as related molecular mechanism..Methods: 1. The tumor cells and macrophages co-culture for 72 hours, this is the initial interaction between macrophages and tumor cells, and these macrophages were co-cultured with tumor cells once again, the control group is tumor cells cultured alone group, as well as freshly isolated macrophages and tumor cells co-culture group, using the cell counting methods and flow cytometry to detect the macrophages' function on tumor cell proliferation.(which were co-cultured with tumor cells hereinafter referred to as "and After the tumor cells co-cultured macrophages ") 2. Macrophages and tumor cells co-cultured in two wells. To observe whether the macrophages have the ability to promote tumor proliferation after they co-cultured with tumor cells without direct interaction. 3. Establishing tumor bearing mice by inoculating tumor cells and these after the tumor cells co-cultured macrophages into the thigh muscles of the mice. The control group is inoculating with tumor cells to the thigh muscles of mice alone as well as the mixture of freshly isolated macrophages and tumor cells. Observe the difference between the experimental group and control group in tumor formation. 4. Use these after the tumor cells co-cultured macrophages to immunize the tumor body in mice by inoculating such cells into tumor body. Control group is inoculating freshly isolated macrophages into tumor body. Observe these after the tumor cells co-cultured macrophages' effect on the growth of tumor. 5. Stimulate macrophages at different stages of growth by adding the supernatant of tumor cells by freeze-thaw processing, which is imitating tumor micro-environment, then use flow cytometry to detect the changes in surface markers of macrophages after they were stimulated. 6. Stimulate macrophages at different stages of growth by adding the supernatant of tumor cells by freeze-thaw processing, use RT-PCR to detect changes in gene expression.of macrophages after they were stimulated.Results: 1. The results of experiment in vitro showed that after co-cultured with tumor cells macrophages could significantly promote the growth of H22 tumor cells compared with the control group. And the situation is also the same when macrophages and tumor cells cultured in two cells without direct interaction. 2. In vivo experiments macrophages after co-cultured with tumor cells could promote the tumor formation in speed when the mice were injected with the mixture of tumor cells and treated macrophages compared with two couredntrol group of freshly isolated macrophages and tumor cells and only tumor cells. 3. The macrophages after co-cultured with tumor cells can promote tumor development when injected these treated macrophages to the tumor body. 4. The result of flow cytometry showed that the supernatant of tumor cells by freeze-thaw processing have the ability to enhance macrophages' ability to promoting tumor cell proliferation. 5. Macrophages isolated and cultured in vitro, their surface markers Gr1, CD11b, F4/80 expression changed. 6. VEGF and PDGF expression in macrophage enhanced after stimulating with the supernatant of tumor cells by freeze-thaw processing.Conclusion: Immune cells such as macrophages in tumor micro-environment interacted with the tumor cells, their function changed into a tumor growth-promoting factor, to help tumor cells in the escaping from the immune system. And such change is a result of tumor cells releasing something during the process of interaction between tumor cells and macrophages, they give singals to induce macrophages and change the macrophage phenotype of macrophages through the release of VEGF and PDGF and other factors to promote tumor cell proliferation.