肿瘤相关巨噬细胞(Tumor Associated Macrophage,TAM)是在肿瘤中浸润的巨噬细胞.体外大量实验证实巨噬细胞对肿瘤具有杀伤作用,然而从肿瘤的整个发展历程来看,巨噬细胞的杀伤作用并不明显,因为巨噬细胞是个多效应的细胞,在肿瘤微环境影响下,巨噬细胞很可能为肿瘤细胞建立一种稳定生存环境,包括清理坏死肿瘤细胞并建立新的血运、抑制其他免疫细胞功能、分泌促肿瘤生长因子、溶解基质等.为明确肿瘤相关巨噬细胞在骨肉瘤侵袭过程中所起的作用及两种细胞的相互作用对单核细胞趋化蛋白-1表达的影响.
    本实验进行了以下两个方面的研究并获得相应的实验结果：
    一、骨肉瘤细胞增强单核细胞的迁移及侵袭能力 巨噬细胞在炎症、类风湿等病理状态下能够分泌蛋白酶等物质,降解基质,从而消灭病原体或造成组织损伤.本部分实验观察骨肉瘤细胞对巨噬细胞前体-单核细胞侵袭能力的影响,探讨肿瘤浸润单核巨噬细胞协助肿瘤侵袭的作用.利用Transwell体外模型检测骨肉瘤对单核细胞迁移及侵袭能力的改变；明胶酶谱方法检测骨肉瘤作用后单核细胞表达MMP-9的改变.骨肉瘤细胞明显增强了单核细胞迁移及侵袭能力,明胶酶谱结果提示骨肉瘤作用后单核细胞表达MMP-9增强.肿瘤细胞能够增强单核细胞的迁移及侵袭能力,并可能是通过增强单核细胞MMP-9的表达而实现 第四军医大学硕士学位论文的.
    二、骨肉瘤细胞与巨噬细胞共培养中MCP一1表达的调节 目前认为,单核细胞趋化蛋白一1(MCP一l)在单核细胞向肿瘤细胞趋化过程中起主要作用,但其来源及表达调节机制尚不明确.以往研究多认为肿瘤细胞是MCP一1的主要来源,Heimdal等研究则发现,体外与低表达MCP一1的头颈部鳞癌组织共培养的巨噬细胞是MCP一1的重要来源.这说明肿瘤组织中MCP一1的来源尚需进一步研究.本研究利用体外的共培养模型,研究在共培养条件下,骨肉瘤细胞及巨噬细胞MCP一1的表达.建立骨肉瘤细胞与巨噬细胞体外共培养模型,利用RT-PCR及EUSA的方法检测共培养对两种细胞MCP一1表达的影响.共培养前后骨肉瘤细胞表达MCP一1变化不明显,而巨噬细胞则显著增强.在肿瘤组织中浸润的巨噬细胞可能是MCP一1的重要来源之一,可通过正反馈的机制使更多单核细胞向肿瘤局部浸润.肿瘤相关巨噬细胞(TAM)在肿瘤中浸润的数量与组织所表达MCP一1的水平具有相关性.因此,调控肿瘤组织中MCP一1及其受体活性,特别是肿瘤相关巨噬细胞的数量和活性,避免其促肿瘤的特性,有望成为肿瘤辅助治疗的手段之一.
    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.

相关阅读：
肝细胞生长因子修饰兔骨髓间充质干细胞的实验研究
美用强力生长因子催生新血管
具有抗菌活性的巨噬细胞
德发现巨噬细胞可作大脑“清洁工”