Myofibroblasts constitute a significant component of the tumor microenvironment (TME) and play a pivotal role in the progression of hepatocellular carcinoma (HCC). Integrin α5 (ITGA5) is a crucial regulator in myofibroblasts of malignant tumors. Therefore, the potential of ITGA5 as a novel target for the therapeutic strategy of HCC should be investigated. Digital scanning and analysis of the HCC tissue microarray were performed to locate the distribution of ITGA5 and conduct the prognosis analysis. CRISPR Cas9-mediated ITGA5 knockout was performed to establish the ITGA5-KO myofibroblast cell line. Extracellular vesicles (EVs) derived from LX2 were extracted for the treatment of HCC cells. Subsequently, the sphere-forming ability and the stemness markers expression of the treated HCC cells were examined. An orthotopic HCC mouse model with fibrotic injury was constructed to test the outcomes of ITGA5-targeting therapy and its efficacy in the programmed death-ligand 1 (PD-L1) treatment. Co-immunoprecipitation/mass spectrometry and transcriptome data were integrated to delve into the mechanism. The tissue microarray results revealed that ITGA5 was highly enriched in the stromal myofibroblasts of HCC tissues and contributed to enhanced tumor progression and poor prognosis. Notably, ITGA5 transmission via extracellular vesicles (EVs) from myofibroblasts to HCC cells induced the acquisition of cancer stem cell-like properties. Mechanistically, ITGA5 directly bind to YES1, facilitating the activation of YES1 and its downstream pathways, thereby enhancing the stemness of HCC cells. Furthermore, the blockade of ITGA5 impeded tumor progression driven by ITGA5+ myofibroblasts and enhanced the efficacy of treatment with PD-L1 in a mouse model of HCC. Our findings elucidated a novel mechanism by which the EV-mediated transfer of ITGA5 from myofibroblasts to tumor cells augmented HCC stemness. ITGA5-targeting therapy helped prevent the progression of HCC and improved the efficacy of PD-L1 treatment.

中文翻译：

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肌成纤维细胞衍生的细胞外囊泡通过将 ITGA5 转移到肿瘤细胞来促进肝细胞癌的癌症干性


肌成纤维细胞构成肿瘤微环境 （TME） 的重要组成部分，在肝细胞癌 （HCC） 的进展中起关键作用。整合素 α5 （ITGA5） 是恶性肿瘤肌成纤维细胞的关键调节因子。因此，应研究 ITGA5 作为 HCC 治疗策略的新靶点的潜力。对 HCC 组织微阵列进行数字扫描和分析，以定位 ITGA5 的分布并进行预后分析。进行 CRISPR Cas9 介导的 ITGA5 敲除以建立 ITGA5-KO 肌成纤维细胞系。提取源自 LX2 的细胞外囊泡 （EVs） 用于治疗 HCC 细胞。随后，检查处理后的 HCC 细胞的球体形成能力和干性标志物表达。构建纤维化损伤的原位 HCC 小鼠模型，以测试 ITGA5 靶向治疗的结果及其在程序性死亡配体 1 （PD-L1） 治疗中的疗效。整合免疫共沉淀/质谱和转录组数据以深入研究其机制。组织微阵列结果显示，ITGA5 在 HCC 组织的基质肌成纤维细胞中高度富集，并导致肿瘤进展加剧和预后不良。值得注意的是，ITGA5 通过细胞外囊泡 （EV） 从肌成纤维细胞传递到 HCC 细胞诱导了癌症干细胞样特性的获得。从机制上讲，ITGA5 直接与 YES1 结合，促进 YES1 及其下游通路的激活，从而增强 HCC 细胞的干性。此外，ITGA5 的阻断阻碍了 ITGA5 + 肌成纤维细胞驱动的肿瘤进展，并增强了 PD-L1 治疗在 HCC 小鼠模型中的疗效。 我们的研究结果阐明了一种新的机制，即 EV 介导的 ITGA5 从肌成纤维细胞转移到肿瘤细胞增强了 HCC 干性。ITGA5 靶向治疗有助于预防 HCC 的进展并提高 PD-L1 治疗的疗效。