METHODS: By using single-cell RNA transcriptomics data of 11 cases of primary and liver metastasis UM, we analyzed the endothelial cell status. In addition, we analyzed and validated ECs in the in vitro model and collected clinical specimens. Subsequently, we explored the impact of endothelial dysfunction on UM cell migration and explored the mechanisms responsible for the endothelial cell abnormalities and the reasons for their peripheral effects.
RESULTS: UM metastasis has a significantly higher percentage of vascular endothelial cells compared to in situ tumors, and endothelial cells in metastasis show significant senescence. Senescent endothelial cells in metastatic tumors showed significant Krüppel-like factor 4 (KLF4) upregulation, overexpression of KLF4 in normal endothelial cells induced senescence, and knockdown of KLF4 in senescent endothelium inhibited senescence, suggesting that KLF4 is a driver gene for endothelial senescence. KLF4-induced endothelial senescence drove tumor cell migration through a senescence-associated secretory phenotype (SASP), of which the most important component of the effector was CXCL12 (C-X-C motif chemokine ligand 12), and participated in the composition of the immunosuppressive microenvironment.
CONCLUSIONS: This study provides an undesirable insight of senescent endothelial cells in promoting UM metastasis.
方法:利用11例原发性和肝转移UM的单细胞RNA转录组学数据,我们分析了内皮细胞状态.此外,我们在体外模型中分析和验证了ECs,并收集了临床标本.随后,我们探讨了内皮功能障碍对UM细胞迁移的影响,并探讨了内皮细胞异常的机制及其外周效应的原因.
结果:与原位肿瘤相比,UM转移的血管内皮细胞百分比明显更高,转移中的内皮细胞表现出明显的衰老。转移性肿瘤中的衰老内皮细胞显示出显着的Krüppel样因子4(KLF4)上调,在正常内皮细胞中过度表达KLF4诱导衰老,衰老内皮中KLF4的敲除抑制衰老,提示KLF4是内皮衰老的驱动基因。KLF4诱导的内皮衰老通过衰老相关分泌表型(SASP)驱动肿瘤细胞迁移,其中效应物的最重要成分是CXCL12(C-X-C基序趋化因子配体12),并参与了免疫抑制微环境的组成。
结论:本研究提供了衰老内皮细胞促进UM转移的不良见解。