Vertebral-specific activation of the CX3CL1/ICAM-1 signaling network mediates non-small-cell lung cancer spinal metastasis by engaging tumor cell-vertebral bone marrow endothelial cell interactions.
Vertebral-specific activation of the CX3CL1/ICAM-1 signaling network mediates non-small-cell lung cancer spinal metastasis by engaging tumor cell-vertebral bone marrow endothelial cell interactions.
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DOI：
10.7150/thno.54235
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发表时间：
2021
期刊：
影响因子：
12.4
通讯作者：
Zhang F
中科院分区：
文献类型：
--
作者：
Wang K;Jiang L;Hu A;Sun C;Zhou L;Huang Y;Chen Q;Dong J;Zhou X;Zhang F
研究背景：脊柱是非小细胞肺癌(NSCLC)最常见的转移部位之一，NSCLC的脊柱转移会导致严重后果。播散性癌细胞的转移性外渗包括增加侵袭性、粘附性和跨内皮细胞迁移是肿瘤转移的关键。本研究旨在基于C-X3-C基序趋化因子配体1-(CX3CL1)和细胞间黏附分子-1-(ICAM-1)介导的信号网络，探讨非小细胞肺癌脊柱转移的机制。方法：采用免疫组织化学、Western blotting和逆转录定量聚合酶链式反应检测CX3CL1/ICAM-1在不同脏器中的分布。通过Transwell、黏附和跨内皮细胞迁移实验评价CX3CL1/ICAM-1对NSCLC细胞体外侵袭、黏附和跨内皮细胞迁移的调节作用。NOD/SCID小鼠左心内注射NSCLC细胞建立自发性脊髓转移瘤模型。通过生物发光、微计算机断层扫描、免疫组织化学和组织学分析，验证CX3CL1/ICAM-1在体内对NSCLC脊柱转移的作用。结果：CX3CL1在椎骨中的表达明显高于四肢骨和肺组织，并与NSCLC的脊柱转移有关。从机制上讲，椎体骨髓内皮细胞通过CX3CL1信号介导的PI3K/AKT通路激活促进非小细胞肺癌细胞的侵袭。此外，我们还发现VBMEC通过CX3CL1/ICAM-1/LFA-1途径有效地诱导依赖ICAM-1的NSCLC细胞与血小板的黏附。同时，CX3CL1通过ICAM-1依赖的Src/gef-H1通路激活VBMECs的通透性，促进NSCLC细胞的跨内皮迁移。有趣的是，非小细胞肺癌细胞通过依赖于MAPK14/ADMA17的CX3CL1的释放和依赖于NF-κB的CX3CL1的合成来促进血管内皮细胞分泌CX3CL1。基于这些发现，我们揭示了循环中的NSCLC细胞和VBMEC之间由CX3CL1/ICAM-1信号介导的新的反馈循环。CX3CL1/ICAM-1介导的反馈循环在体内的进一步脱离显著限制了转移和延长小鼠的存活。结论：CX3CL1/ICAM-1信号介导的循环NSCLC细胞与VBMECs之间存在独特的反馈循环，这是NSCLC脊柱转移所必需的。这项工作为深入研究非小细胞肺癌脊柱转移的机制提供了新的视角，并为预防非小细胞肺癌脊柱转移提供了潜在的新靶点。
Rationale: The spine is one of the most common metastatic sites of non-small cell lung cancer (NSCLC), and NSCLC spinal metastasis results in serious consequences. Metastatic extravasation of disseminated cancer cells including increased invasiveness, adhesion and transendothelial migration is crucial for tumor metastasis. This study aimed to investigate the mechanisms underlying NSCLC spinal metastasis based on the C-X3-C motif chemokine ligand 1- (CX3CL1) and intercellular adhesion molecule-1- (ICAM-1) mediated signaling network. Methods: Immunohistochemistry, western blotting, and reverse transcription-quantitative PCR were conducted to detect the distribution of CX3CL1/ICAM-1 in different organs. Transwell, adhesion, and transendothelial migration assays were performed to evaluate the regulatory effects of CX3CL1/ICAM-1 on NSCLC cell invasion, adhesion, and transendothelial migration in vitro. A spontaneous spinal metastasis mouse model was established via injection of NSCLC cells into the left cardiac ventricle of NOD/SCID mice. The effects of CX3CL1/ICAM-1 on NSCLC spinal metastasis in vivo were validated using bioluminescent, micro-computerized tomography, immunohistochemistry and histological analyses. Results: CX3CL1 expression was specifically higher in vertebral bone compared with limb bones and lung tissue, and was associated with NSCLC spinal metastasis. Mechanically, vertebral bone marrow endothelial cells (VBMECs) enhanced NSCLC cell invasion via CX3CL1 signaling-mediated activation of the PI3K/AKT pathway. Furthermore, we found that VBMECs effectively induced ICAM-1-dependent NSCLC cell adhesion in coordination with platelets through the CX3CL1/ICAM-1/LFA-1 pathway. Meanwhile, CX3CL1 enhanced NSCLC cell transendothelial migration by increasing permeability of VBMECs via ICAM-1-dependent activation of the Src/GEF-H1 pathway. Interestingly, NSCLC cells were indicated to promote CX3CL1 secretion of VBMECs through MAPK14/ADMA17-dependent CX3CL1 release and NF-κB-dependent CX3CL1 synthesis. Based on these findings, we revealed a novel feedback cycle between circulating NSCLC cells and VBMECs mediated by CX3CL1/ICAM-1 signaling. Further disengagement of the CX3CL1/ICAM-1-mediated feedback cycle in vivo significantly restricted metastasis and prolonged mouse survival. Conclusions: Our results indicated a unique feedback cycle between circulating NSCLC cells and VBMECs mediated by CX3CL1/ICAM-1 signaling, which is necessary for NSCLC spinal metastasis. This work provides a new perspective for underlying the mechanisms of NSCLC spinal metastasis and indicates potential novel targets for the prevention of NSCLC spinal metastasis.