1)中国医科大学生命科学学院,医学细胞生物学教育部重点实验室暨卫生部细胞生物学重点实验室,细胞生物学教研室,沈阳 110122;2)青岛大学附属妇女儿童医院病理科,青岛 266000;3)中国医科大学基础医学院干细胞与再生医学研究室,沈阳 110122
国家自然科学基金(81672920)资助项目。
1)Department of Molecular Cell Biology, Key Laboratory of Medical Cell Biology, Ministry of Education, Key Laboratory of Cell Biology, Ministry of Public Health, School of Life Sciences, China Medical University, Shenyang 110122, China;2)Department of Pathology, Women and Children’s Hospital Affiliated to Qingdao University, Qingdao 266000, China;3)Department of Stem Cells and Regenerative Medicine, School of Basic Medical Sciences, China Medical University, Shenyang 110122, China
This work was supported by a grant from The National Natural Science Foundation of China (81672920).
目的 探讨大肠癌LoVo细胞来源的外泌体(LoVo-Exos)对肿瘤血管生成的影响,并探讨其促血管生成的可能分子机制。方法 超速离心法提取LoVo-Exos,共聚焦显微镜观察其内化进入受体HUVEC细胞,体外管状形成实验分析LoVo-Exos对血管生成的影响;采用小鼠体内基质胶塞实验,分析LoVo-Exos对血管生成的影响。为探讨LoVo-Exos促血管生成的分子机制,蛋白质印迹(Western blot)分析LoVo-Exos携带磷酸化表皮生长因子受体(phosphorylated epidermal growth factor receptor,pEGFR)进入受体细胞。Western blot及酶联免疫吸附分析(ELISA)方法分析EGFR-ERK通路关键信号蛋白及下游血管生成核心分子表达情况,并观察敲减EGFR及细胞外调节蛋白激酶(extracellular regulatory protein kinase,ERK)抑制剂处理对血管生成的影响。结果 共聚焦显微镜观察到LoVo-Exos内化进入HUVEC内皮细胞;体外血管生成实验显示,LoVo-Exos能够显著促进HUVEC细胞管状结构的形成。小鼠皮下基质胶塞实验显示,LoVo-Exos能够促进血管样结构的形成。进一步研究发现,LoVo-Exos递送pEGFR到HUVEC中,激活EGFR-ERK通路,促进血管生成。分析LoVo-Exos对下游血管生成核心分子表达的影响,发现LoVo-Exos能够促进HUVEC细胞白介素-8(interleukin-8,IL-8)的分泌,敲减EGFR的LoVo-Exos中pEGFR水平降低,其对IL-8分泌的促进作用降低,且该促进作用能够被MEK1/2抑制剂U0126抑制。结论 LoVo-Exos能够在体内外促进血管生成,其可能机制为LoVo-Exos递送pEGFR到HUVEC中,通过EGFR-ERK途径上调IL-8分泌水平,从而促进HUVEC血管生成能力,为癌症的转移提供新机制。
Objective This study sought to investigate the impact of exosomes derived from LoVo cells (LoVo-Exos) in colorectal cancer (CRC) on tumor angiogenesis, as well as to elucidate the potential molecular mechanisms underlying their pro-angiogenic effects.Methods LoVo-Exos were isolated via ultracentrifugation, and their internalization into recipient human umbilical vein endothelial cells (HUVECs) was visualized using confocal microscopy. The influence of LoVo-Exos on angiogenesis was assessed through an in vitro tube formation assay. Additionally, the pro-angiogenic effects of LoVo-Exos were evaluated in vivo using a matrix gluing assay in mice. To investigate the molecular mechanisms through which LoVo-Exos facilitate angiogenesis, Western blot analysis was employed to examine the transfer of pEGFR by LoVo-Exos into recipient cells. Both Western blot and ELISA were utilized to assess the expression levels of key signaling proteins within the EGFR-ERK pathway, as well as the expression of downstream angiogenic core molecules. Furthermore, the impact of EGFR knockdown and ERK inhibitor treatment on angiogenesis was evaluated, with subsequent analysis of the expression of downstream angiogenic core molecules following these interventions.Results Confocal microscopy demonstrated the internalization of LoVo-Exos into HUVECs. In vitro angiogenesis assays further indicated that LoVo-Exos significantly enhanced the formation of tubular structures in HUVECs. Additionally, macroscopic examination of subcutaneous matrix plug formation in mice revealed a substantial increase in vascular-like structures within the matrix plugs following the administration of LoVo-Exos, compared to the PBS control group. Hematoxylin and eosin (HE) staining revealed the presence of erythrocyte-filled microvessels within the matrix plugs combined with LoVo-Exos. Furthermore, immunohistochemical analysis demonstrated the expression of the endothelial cell marker CD31 in these matrix plugs. The presence of CD31-positive cells in the LoVo-Exos-treated matrix plugs was associated with a significant enhancement in the formation of luminal structures. These findings suggest that LoVo-Exos facilitate the in vivo development of vascular-like structures. Subsequent investigations demonstrated that LoVo-Exos facilitated the delivery of pEGFR to HUVEC, thereby enhancing angiogenesis. Conversely, LoVo-Exos with EGFR knockdown exhibited a diminished capacity to promote angiogenesis, an effect that was further attenuated by the ERK phosphorylation inhibitor U0126. Western blot analysis assessing the activation of the EGFR-ERK signaling pathway in HUVEC indicated that LoVo-Exos augmented angiogenesis through the activation of this pathway. Furthermore, analysis of the impact of LoVo-Exos on the expression of downstream angiogenic core molecules revealed an increase in interleukin-8 (IL-8) secretion in HUVEC. The enhancement observed was diminished in LoVo-Exos following EGFR knockdown, and this reduction was counteracted by the ERK phosphorylation inhibitor U0126.Conclusion The underlying mechanism may involve the delivery of pEGFR in LoVo-Exos to HUVECs, leading to increased IL-8 secretion via the EGFR-ERK signaling pathway, thereby enhancing the angiogenic potential of HUVECs. This finding may offer new insights into the mechanisms underlying cancer metastasis.
程雅洁,周雪彤,王瑞,方瑾.大肠癌LoVo细胞源外泌体通过传递pEGFR促进血管生成的研究[J].生物化学与生物物理进展,2025,52(5):1229-1240
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