Hu Haitian, Li Xuan, Xu Zhanao, Tao Yuwei, Zhao Luyang, You Huiwen, Xu Guoyuan, Zhang Tengjiang, Zhang Yuan, Fan Huijuan, Wang Xuxiang, Chen Wenjing, Lin Christopher G, Zheng Hanqiu
Center for Cancer Biology, School of Basic Medical Sciences, Tsinghua University, Beijing, 100084, China.
SXMU-Tsinghua Collaborative Innovation Center for Frontier Medicine, Shanxi Medical University, Taiyuan, Shanxi Province, 030001, China.
EBioMedicine. 2025 Jan;111:105503. doi: 10.1016/j.ebiom.2024.105503. Epub 2024 Dec 13.
Lung metastasis is a critical and often fatal progression in cancer patients, with monocyte-derived macrophages (Mo-macs) playing multifaceted roles in this process. Despite the recognized importance of Mac-macs, most studies focus on these cells themselves, while the precise mechanisms through which tumor cells manipulate Mo-macs to promote metastasis remain poorly understood.
We developed an in vivo CRISPR screening system to identify genes involved in macrophage-dependent metastasis by depleting Mo-macs. Osteoprotegerin (OPG) was identified as the factor significantly enhances lung metastasis. We validated its function in lung metastasis by modulating the expression of OPG in an array of cell lines and performed spontaneous and experimental lung metastasis assays. Genetically engineered mice were utilized to confirm the role of RANKL-RANK signaling in OPG-mediated metastasis. Additionally, we employed different neutralizing antibodies to elucidate the roles of Mo-macs and NK cells and inhibitor to clarify the role of CXCL10 signaling.
Employing in vivo screening techniques, we elucidate the role of OPG, a protein secreted by cancer cells, in driving lung metastasis, contingent upon regulating Mo-mac activity. OPG blocks the signaling cascade between receptor activator of nuclear factor kappa-B ligand (RANKL) and its receptor RANK on Mo-macs, thereby hindering Mo-macs from secreting CXCL10, a chemokine crucial for recruiting natural killer (NK) cells that help control lung metastasis. Moreover, we observe an enrichment of OPG amplifications in metastatic cancer patients, and elevated levels of OPG expression in lung metastatic sites compared to paired primary breast cancer samples.
Our work revealed that OPG works as a lung metastasis promoting factor by blocking the RANKL-RANK-CXCL10 axis to drive the paucity of NK cells, which could be a therapeutic target for lung metastatic cancer patients.
The full list of funding supporting this study can be found in the Acknowledgements section.
肺转移是癌症患者病情发展的关键阶段，且往往是致命的，单核细胞衍生的巨噬细胞（Mo - 巨噬细胞）在此过程中发挥着多方面作用。尽管人们认识到巨噬细胞的重要性，但大多数研究聚焦于这些细胞本身，而肿瘤细胞操纵Mo - 巨噬细胞促进转移的精确机制仍知之甚少。
我们开发了一种体内CRISPR筛选系统，通过消耗Mo - 巨噬细胞来鉴定参与巨噬细胞依赖性转移的基因。骨保护素（OPG）被确定为显著增强肺转移的因子。我们通过调节一系列细胞系中OPG的表达来验证其在肺转移中的功能，并进行了自发性和实验性肺转移实验。利用基因工程小鼠来证实RANKL - RANK信号通路在OPG介导的转移中的作用。此外，我们使用不同的中和抗体来阐明Mo - 巨噬细胞和NK细胞的作用，并用抑制剂来阐明CXCL10信号通路的作用。
利用体内筛选技术，我们阐明了癌细胞分泌的蛋白质OPG在驱动肺转移中的作用，这取决于对Mo - 巨噬细胞活性的调节。OPG阻断了Mo - 巨噬细胞上核因子κB受体活化因子配体（RANKL）与其受体RANK之间的信号级联，从而阻碍Mo - 巨噬细胞分泌CXCL10，CXCL10是一种对招募有助于控制肺转移的自然杀伤（NK）细胞至关重要的趋化因子。此外，我们观察到转移性癌症患者中OPG扩增富集，与配对的原发性乳腺癌样本相比，肺转移部位的OPG表达水平升高。
我们的研究表明，OPG通过阻断RANKL - RANK - CXCL10轴发挥肺转移促进因子的作用，导致NK细胞缺乏，这可能是肺转移性癌症患者的一个治疗靶点。
支持本研究的完整资金列表可在致谢部分找到。
