Sorafenib is a kinase inhibitor that is used as a first-line therapy in advanced hepatocellular carcinoma (HCC) patients. However, the existence of sorafenib resistance has limited its therapeutic effect. Through RNA sequencing, we demonstrated that miR-138-1-3p was downregulated in sorafenib resistant HCC cell lines. This study aimed to investigate the role of miR-138-1-3p in sorafenib resistance of HCC. In this study, quantitative real-time PCR (qPCR) and Western Blot were utilized to detect the levels of PAK5 in sorafenib-resistant HCC cells and parental cells. The biological functions of miR-138-1-3p and PAK5 in sorafenib-resistant cells and their parental cells were explored by cell viability assays and flow cytometric analyses. The mechanisms for the involvement of PAK5 were examined via co-immunoprecipitation (co-IP), immunofluorescence, dual luciferase reporter assay and chromatin immunoprecipitation (ChIP). The effects of miR-138-1-3p and PAK5 on HCC sorafenib resistant characteristics were investigated by a xenotransplantation model. We detected significant down-regulation of miR-138-1-3p and up-regulation of PAK5 in sorafenib-resistance HCC cell lines. Mechanistic studies revealed that miR-138-1-3p reduced the protein expression of PAK5 by directly targeting the 3′-UTR of PAK5 mRNA. In addition, we verified that PAK5 enhanced the phosphorylation and nuclear translocation of β-catenin that increased the transcriptional activity of a multidrug resistance protein ABCB1. PAK5 contributed to the sorafenib resistant characteristics of HCC via β-catenin/ABCB1 signaling pathway. Our findings identified the correlation between miR-138-1-3p and PAK5 and the molecular mechanisms of PAK5-mediated sorafenib resistance in HCC, which provided a potential therapeutic target in advanced HCC patients.

中文翻译：

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MicroRNA-138-1-3p 通过靶向 PAK5 介导的 β-catenin/ABCB1 信号通路使索拉非尼对肝细胞癌敏感

索拉非尼是一种激酶抑制剂，用作晚期肝细胞癌 (HCC) 患者的一线治疗。然而，索拉非尼耐药的存在限制了其治疗效果。通过 RNA 测序，我们证明 miR-138-1-3p 在索拉非尼耐药的 HCC 细胞系中下调。本研究旨在探讨 miR-138-1-3p 在 HCC 索拉非尼耐药中的作用。在这项研究中，定量实时 PCR (qPCR) 和蛋白质印迹被用来检测索拉非尼耐药 HCC 细胞和亲本细胞中 PAK5 的水平。通过细胞活力测定和流式细胞术分析探索了 miR-138-1-3p 和 PAK5 在索拉非尼耐药细胞及其亲代细胞中的生物学功能。通过免疫共沉淀 (co-IP)、免疫荧光、双荧光素酶报告基因检测和染色质免疫沉淀 (ChIP)。通过异种移植模型研究了 miR-138-1-3p 和 PAK5 对 HCC 索拉非尼耐药特征的影响。我们在索拉非尼耐药的 HCC 细胞系中检测到 miR-138-1-3p 的显着下调和 PAK5 的上调。机制研究表明，miR-138-1-3p 通过直接靶向 PAK5 mRNA 的 3'-UTR 来降低 PAK5 的蛋白质表达。此外，我们证实 PAK5 增强了 β-catenin 的磷酸化和核转位，从而增加了多药耐药蛋白 ABCB1 的转录活性。PAK5 通过 β-catenin/ABCB1 信号通路促进 HCC 的索拉非尼耐药特征。