肝癌中CXCR4阳性内皮细胞介导的调节性T细胞浸润对治疗的影响与机制

Our recent study discovered the presence of blood vessels encapsulating tumor cell cluster (VETC), a distinct vascular pattern in hepatocellular carcinoma (HCC), which was significantly associated with poor patient prognosis and metastasis. We also showed that the chemokine receptor CXCR4 was specifically expressed on the tumor vascular endothelial cells (EC) and promoted the formation of VETC structure in HCC. Further study revealed that the expression of CXCR4 in EC (CXCR4+ EC) was regulated by the inflammatory cytokines within tumor microenvironment (TME), which then regulated the infiltration of regulatory T cells (Treg cells) via paracrine signaling. But the underlying mechanism of this regulation and its treatment significance remains unclear. Our research group intends to combine clinical samples, in vitro experiments and animal models: 1. To clarify the relationship between the CXCR4+ EC of VETC and the infiltration of different types of immune cells; 2. To elucidate the molecular mechanism of CXCR4+ EC in regulating Treg cell infiltration; 3. To block the downstream signaling pathway of CXCR4 in EC in order to rescue its regulatory effect on immunosuppressive TME; 4. To explore the optimization of anti-angiogenesis and immunotherapy combination treatment strategy and its underlying clinical significance. Therefore, these results will not only help to reveal the new mechanism of vascular regulation of immunosuppressive TME, but also provide the theoretical basis and concepts of combining anti-angiogenesis and immunotherapy in HCC treatment.

我们前期工作发现肝癌中存在的包绕肿瘤细胞团的特殊微血管网络结构（VETC）与患者预后和血行转移密切相关。CXCR4分子能特异性表达在肝癌血管内皮细胞（EC）上，并能促进VETC形成。进一步研究发现，CXCR4+ EC不仅受到微环境中的炎症因子调控，还可通过旁分泌效应促进调节性T细胞（Treg）在肿瘤中的浸润，但具体的调控机制和治疗意义尚不清楚。本课题拟结合临床样本、体外实验和小鼠模型：1）明确肝癌VETC结构中CXCR4的表达与不同功能类型免疫细胞浸润的关系；2）以Treg细胞为主要对象，研究激活EC的CXCR4信号通路对不同免疫细胞浸润和功能的具体调控机制；3）阻断相关分子通路对于肿瘤免疫微环境的影响和干预策略；4）探讨联合抗血管生成和免疫治疗方案的优化和潜在临床应用价值。所得结果不仅有助于揭示内皮细胞主动调控免疫微环境的新机制，还可为临床上联合治疗方案的设计提供新思路和理论依据。

我们前期的研究结果显示肿瘤组织中CXCR4+血管内皮细胞会形成特殊的血管结构（包绕肿瘤细胞团的特殊微血管网络结构）并调控Treg细胞的浸润。进一步的研究发现CXCR4+血管内皮细胞周围包饶大量周细胞，但该现象在肿瘤中的意义尚不清楚。为探究这一问题，我们利用磁珠联合流式分选的方法分离出了肿瘤组中的周细胞，对其进行功能研究发现肿瘤周细胞的血管支持功能缺陷。代谢分析显示HK2驱动的糖酵解代谢在肿瘤肿瘤周细胞中异常激活，这种活化进一步导致ROCK2-MLC2通路激活，引起周细胞收缩能力增强，最终导致血管功能紊乱。通过对临床资料的分析我们发现HK2阳性周细胞可以预测肿瘤预后。抑制周细胞HK2的功能可以提高化疗药物的递送效率，抑制肿瘤生长。上述研究成果揭示了糖代谢在周细胞调控血管功能过程中的作用，为提高化疗效率提供新思路。