Invasiveness Of Human Osteosarcoma-Associated-Macrophage And Its MCP-1 Expression

The immune system is important in the surveillance of tumorigenesis and progression. But the emphases of research are mainly focused on neoplasms themselves. So it will be meaningful to explore the functional status of immune cells in cancers, also their interactions with tumor cells. Tumor associated macrophages(TAMs) refer to those macrophages infiltrating into the solid tumors. In vitro experiments have established that macrophages can be cytotoxic to tumor cells, but the in vivo conditions are quite different, macrophages under the influences of tumor cells can even promote growth of tumors, perhaps through clearance of necrotic cells and enhancement of angiogenesis. This experiment is designed to explore the possible mutual influences of macrophages and osteosarcoma cells. There are two parts bothof which revealed the significant interactions between the two cells.1. Enhanced Migrating and Invasive ability of Human macrophages inthe Osteosarcoma-Macrophage Coculture Condition Aim: To investigate the motility and invasiveness of monocytes those have been co-cultured with osteosarcoma cells. Methods: An in vitro macrophage-tumor co-culture model was established, and the migrating andinvasive ability of macrophages after co-culture were measured by Transwell test; the MMP-9 expressions of monocytes were detected by gelatin zymography. Results: the migrating and invasive ability of monocytes were increased after co-culture with osteosarcoma cells; gelatin zymography showed that the expression of MMP-9 also increased. Conclusion: osteosarcoma cells may alter the migration and invasiveness of monocytes by degradement of extracellular matrix, thus facilitate their metastases. 2. MCP-1 Expression in the Osteosarcoma-Macrophage CocultureConditionAim: To investigate the regulation of MCP-1 expression in osteosarcoma-macrophage coculture conditions. Methods: The osteosarcoma-macrophage coculture model was established. By using RT-PCR and ELISA methods, MCP-1 expression in both cell lines before and after coculture were measured. Results: The alteration of MCP-1 expression is significant in macrophages, but not in osteosarcoma cells. Conclusion: The macrophages infiltrating tumors may be an important source of MCP-1, It can then be a positive feedback mechanism that accounts for more infiltrating macrophages.