UDP/P2Y6对巨噬细胞的免疫调控在肺癌发生、发展中的功能和机制研究

The purinergic receptor P2Y6 plays very important roles in bone, cardiovascular, endocrine and immune system, but the role and mechanism of P2Y6 in regulation of tumor microenvironment still needs to be further investigated. Our previous study showed that P2Y6 is involved in development, differentiation and polarization of macrophages as well as facilitates the expression of CCL-2 in tumor associate macrophages (TAM). Furthermore, P2Y6 is highly expressed in lung cancer and most other cancer tissues which is correlated with poor prognosis of lung cancer patients. In addition, the formation and progression of Lewis lung cancer and infiltration of TAM were both restricted obviously in P2Y6 knockout mice, suggested that P2Y6 may promote lung cancer formation through regulation the function of TAM. Thus, we propose to systematically investigate relationship between P2Y6 and TAM polarization which facilitate the progression of lung caner. Meanwhile, we will explore the mechanisms and key regulators in regulation of TAM function through P2Y6. Besides, we will also investigate the dominant role of P2Y6 regulated TAM in lung cancer formation and progression in animal, cellular and molecular level. Our study will reveal the potential relations between nucleotide as “danger signals” in regulation of tumor microenvironment and lay a foundation for discovering novel anti-tumor drugs based on purinergic receptors.

嘌呤类受体P2Y6在骨骼、心血管、内分泌、免疫等系统中发挥重要作用，但在肿瘤免疫调控方面的功能及机制尚待阐明。我们发现：P2Y6能够调控巨噬细胞的发育、分化及极化等过程，能明显提高肿瘤相关巨噬细胞（TAM）关键趋化因子CCL2的表达；同时P2Y6在肺癌等肿瘤中表达显著升高，且与肿瘤的不良预后成正相关；在P2Y6敲除小鼠体内肿瘤生长明显受到抑制，伴随TAM浸润显著降低，提示P2Y6与TAM的功能及肿瘤密切相关。本课题拟探讨：肺癌P2Y6的高表达与TAM浸润及极化的相互关系；P2Y6参与调控TAM功能的信号网络和分子机制，筛选调控所涉及的关键蛋白；探讨P2Y6通过调控TAM的相关免疫功能在肺癌发生、发展及转移中的作用。即从动物整体、细胞和分子三个层面阐述P2Y6通过调控TAM免疫功能及在肺癌中的作用。揭示作为危险信号的核苷酸与肿瘤微环境间的联系，为肺癌免疫治疗策略提供新的思路。

嘌呤类受体P2Y6在骨骼、心血管、内分泌、免疫等系统中发挥重要作用，但在肿瘤免疫调控方面的功能和机制尚待阐明。本课题从动物整体 、细胞和分子三个层面对P2Y6介导的巨噬细胞在肿瘤免疫调控方面展开了系统研究。首先，课题通过临床肿瘤数据库分析发现P2Y6在肺癌、黑色素瘤、乳腺癌等多种肿瘤组织中呈现高表达，并与肺癌患者的不良预后呈正相关。然后，课题利用P2Y6敲除小鼠构建了肿瘤模型并对肿瘤组织中的免疫细胞进行了详细分析，结果显示P2Y6敲除的小鼠肿瘤组织中M1型巨噬细胞比例显著上调，而不影响其他免疫细胞的浸润比例。同时，课题在体外对巨噬细胞分化和成熟过程中受体表达、UDP释放进行检测，结果表明随着巨噬细胞的成熟，P2Y6受体的表达以及UDP的释放均显著提高，但是P2Y6敲除小鼠中Ly6C+细胞比例和脾脏中F4/80+细胞比例没有显著变化。进一步分析并揭示了UDP/P2Y6对于巨噬细胞中多种细胞因子和趋化因子的表达调控机制，结果显示UDP/P2Y6信号轴可以通过调控ERK磷酸化来促进MCP-1的表达，进而参与肿瘤微环境的调控。P2Y6的缺失或者抑制可以有效提高单核细胞向抗肿瘤的M1型巨噬细胞分化，改变肿瘤免疫微环境，显著抑制肿瘤的发生、发展。本课题的研究进一步拓展了UDP/P2Y6在巨噬细胞介导的免疫调控中的重要作用，为基于嘌呤受体信号的抗肿瘤药物研发和临床肿瘤治疗奠定了理论基础。