巨噬细胞通过激活肿瘤细胞STAT3调节糖代谢促进乳腺癌复发转移的作用和机制研究

Current studies have found that stromal cells promote tumor progression and metastasis, through not only the paracrine secretion of cytokines or chemokines, but also intermediate metabolites. We have found that macrophages co-cultured with apoptotic MCF-7 had increased tumor growth and metastatic ability in vitro and in vivo. Simultaneously, medium from coculture could increase glucose uptake and lactate production. Furthermore, IL-6 and IL-10 expression in macrophage was increased as well as STAT3 phosphorylation in MCF-7, which is an important switch activator of aerobic glycolysis. We assumed that TAMs may promote breast cancer metastasis via regulating aerobic glycolysis by secreting cytokines activating STAT3 pathway. This study aims to explore the effect of tumor associated macrophages to tumor cell aerobic glycolysis and its possible mechanism through Protein Chips analysis and antibody blocking experiment based on a coculture model of macrophages and tumor cells after chemotherapy which would improve the theory of tumor associated macrophages orchestration effect in tumor occurrence and development and would provide the theoretical basis for seeking therapeutic targets of clinical treatment towards breast cancer recurrence and metastasis.

最近研究发现肿瘤微环境中成纤维细胞不仅通过分泌细胞因子促进肿瘤进展转移，也通过调节肿瘤代谢参与该过程。目前未见关于巨噬细胞调控肿瘤细胞糖代谢的报道。我们前期研究发现，巨噬细胞与凋亡乳腺癌细胞共培养的上清促进MCF-7细胞葡萄糖消耗和乳酸产生，增加乳腺癌干细胞比例，促进乳腺癌细胞增殖、成瘤和转移。进一步分析发现，共培养的巨噬细胞中IL-6、IL-10等细胞因子表达上调，乳腺癌细胞中有氧糖酵解开关分子STAT3磷酸化水平升高。据此我们提出巨噬细胞可能通过分泌细胞因子激活肿瘤细胞STAT3通路来调节有氧糖酵解并促进乳腺癌增殖转移的假说。本研究拟构建巨噬细胞与凋亡乳腺癌细胞共培养的模型模拟化疗后肿瘤微环境，观察巨噬细胞对乳腺癌细胞有氧糖酵解的影响，并通过共培养上清蛋白芯片分析和抗体阻断及抑制剂干扰实验探讨巨噬细胞中关键细胞因子及其调控糖酵解的分子机制，为寻找乳腺癌复发转移治疗新靶点提供理论依据。

研究背景.肿瘤微环境中成纤维细胞不仅通过分泌细胞因子促进肿瘤进展转移，也通过调节肿瘤代谢参与该过程。目前未见关于巨噬细胞调控肿瘤细胞糖代谢的报道。我们前期研究发现，巨噬细胞与凋亡乳腺癌细胞共培养的上清促进MCF-7细胞葡萄糖消耗和乳酸产生，增加乳腺癌干细胞比例，促进乳腺癌细胞增殖、成瘤和转移。进一步分析发现，共培养的巨噬细胞中IL-6、IL-10等细胞因子表达上调，乳腺癌细胞中有氧糖酵解开关分子STAT3磷酸化水平升高。据此我们提出巨噬细胞可能通过分泌细胞因子激活肿瘤细胞STAT3通路来调节有氧糖酵解并促进乳腺癌增殖转移的假说。.研究内容.采用巨噬细胞与凋亡乳腺癌细胞系共培养模型模拟化疗后乳腺癌生长的微环境，探讨共培养后乳腺癌细胞在增殖转移、有氧糖酵解、细胞线粒体功能和差异基因表达等方面的改变。同时延伸探讨和鉴定天然化合物槲皮素在抑制乳腺癌干细胞活性方面的作用和机制。.研究结果.化疗诱导凋亡的肿瘤微环境中巨噬细胞可以促进乳腺癌细胞增殖转移。肿瘤微环境中巨噬细胞可以通过上调IL-6增加葡萄糖消耗、乳酸生产和ROS生成，促进糖酵解过程。高比例巨噬细胞浸润以及乳酸脱氢酶表达同乳腺癌患者预后相关。槲皮素可以诱导乳腺癌细胞凋亡并抑制乳腺癌细胞增殖转移。通过激活PI3K/Akt/mTOR信号通路抑制乳腺癌干细胞（CD44+/CD24-）亚群的活性、生长和转移。.科学意义.本研究丰富和完善了肿瘤相关巨噬细胞促进肿瘤发生发展机制的理论。为肿瘤微环境对乳腺癌代谢的影响和机制的阐明以及乳腺癌转移预防和治疗提供新的靶点和依据。