内脂素调控CD4+T细胞介导的免疫微环境促进子宫内膜癌进展的机制研究

The mechanism of endometrial cancer (EC) progression remains unclear, and the relative mechanism of tumor immunity in endometrial cancer is a focus in recent years. Our previous studies in vivo and in vitro demonstrated that visfatin, a new type of adipokines, not only promoted EC cells proliferation and inhibited EC cells apoptosis through PI3K and MAPK pathways, but also promoted the proliferation of CD4+T cells which positively correlated with the level of visfatin in EC tissue. However, there are few studies about how visfatin regulates the differentiation, activation and cytokine secretion of CD4+T cells subsets becoming a special regional immune microenvironment of EC which leads to the progression of EC. This project will explore the mechanism of EC in three aspects. First, we plan to detect the level and function of CD4+ T cells subsets and the cytokines which they secret respectively in peripheral blood and tumor tissue, and then analyze the correlation between them and visfatin, also between them and poor biological behavior of EC. Second, we will co-culture CD4+T cells and EC cells in vitro to demonstrate the effect of visfatin on the migration, differentiation and activation of CD4+ T cells subsets and the changes of cytokines secreted by each subsets.Third, we will establish a mouse model of EC, to explore whether visfatin can promote EC progression through influencing CD4+ T cells subsets and their respective cytokines. This study is of great significance on illustrating the mechanism of EC progression, and providing theoretical basis for the immunotherapy of EC.

子宫内膜癌（EC）进展机制不清，肿瘤免疫在EC中的相关机制是近年EC研究的热点问题。前期体内外研究发现新型脂肪因子内脂素除通过PI3K及MAPK通路影响EC的增殖、凋亡外，还与CD4+T细胞的浸润呈正相关，且内脂素可促进CD4+T细胞增殖，然而内脂素如何调控CD4+T细胞亚群分化、激活及分泌细胞因子，形成EC特有的区域免疫微环境网络，促进EC进展目前研究甚少。本课题拟从：1)观察临床外周血及肿瘤组织标本CD4+T细胞亚群数量及其分泌的细胞因子与内脂素的相关性、与EC不良预后的关系；2）体外实验通过CD4+T细胞与EC细胞共培养阐明内脂素对CD4+T细胞亚群迁移、分化、激活的影响及分泌的细胞因子变化，影响EC恶性表型；3）体内实验通过建立EC小鼠模型，探讨内脂素是否通过影响CD4+T细胞亚群及各亚群分泌的细胞因子促进EC进展。本研究有助于提高对EC进展机制的认识,为EC免疫治疗提供理论基础。

子宫内膜癌（EC）发病与高血压、肥胖和糖尿病密切相关，课题组前期系列研究发现胰岛素抵抗是上述代谢紊乱的共同致病基础，与EC发生发展相关，同时发现胰岛素作为细胞因子促进EC进展的新机制。内脂素作为与胰岛素抵抗相关的脂肪因子，可通过PI3K及MAPK通路作用于EC细胞，促进EC细胞增殖、抑制凋亡。此外内脂素还与免疫微环境中CD4+T细胞的浸润呈正相关，但具体关联机制仍然不清。因此本课题旨在进一步探索内脂素调控CD4+T细胞介导的免疫微环境促进EC进展的新机制。本研究发现：①临床外周血及组织标本中Th1占CD4+T细胞的比例在正常、不典型增生、EC组中逐渐降低，且与血清内脂素水平呈负相关；Th2、Th17、Treg和Th22占CD4+T细胞的比例在三组中逐渐升高，且与血清内脂素水平呈正相关，以Th17细胞最为明显。②体外实验证实内脂素能够促进Th0细胞向EC细胞的趋化和Naïve CD4+T细胞向Th17细胞的分化过程，同时可促进EC相关CD4+T细胞对EC细胞生物学行为的影响，进一步将研究重点聚焦在Th17细胞分泌的主要细胞因子IL-17和IL-22上。内脂素可通过激活NF-κB通路上调EC细胞IL-17的表达，IL-17和IL-22可通过MAPK和PI3K通路促进EC的增殖、迁移侵袭。③体内实验发现内脂素、IL-17和IL-22促进EC移植瘤生长，同时IL-17和IL-22抑制剂可拮抗内脂素的促EC进展作用。本研究提示内脂素可通过调控Th0细胞的趋化及EC免疫微环境中CD4+T向TH17细胞的分化过程，并在细胞因子IL-17和IL-22的介导下发挥促癌作用，进而形成EC特有的区域免疫微环境网络。本课题执行期间发表文章14篇，其中SCI 6篇，培养博硕士生12名，国内外学术会议交流15次，圆满达到预期效果。本研究对EC发病机制的认识有了新的提高，为EC的靶向治疗提供了新的方向。