Hu Bo, Cheng Jian-Wen, Hu Jin-Wu, Li Hong, Ma Xiao-Lu, Tang Wei-Guo, Sun Yun-Fan, Guo Wei, Huang Ao, Zhou Kai-Qian, Gao Ping-Ting, Cao Ya, Qiu Shuang-Jian, Zhou Jian, Fan Jia, Yang Xin-Rong
Department of Liver Surgery and transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University; Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai 200032, P.R.China.
Key Laboratory for Computational Biology, CAS-MPG Partner Institute for Computing Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
J Cancer. 2019 Jun 24;10(17):3914-3925. doi: 10.7150/jca.31448. eCollection 2019.
Sorafenib, a multikinase inhibitor, is a new standard treatment for patients with advanced hepatocellular carcinoma (HCC). However, resistance to this regimen is frequently observed in clinical practice, and the molecular basis of this resistance remains largely unknown. Herein, the antitumor activity of sorafenib was assessed in 16 patient-derived xenograft (PDX) models of HCC. Gene expression analysis was conducted to identify factors that promote sorafenib resistance. Quantitative RT-PCR and immunoblotting were used to determine gene expression and activation of signaling pathways. Cell proliferation, clone formation, and transwell assays were conducted to evaluate drug-sensitivity, proliferation, and invasiveness, respectively. Kaplan-Meier analysis was used to evaluate the predictive power of biomarkers for sorafenib response. Differential gene expression analysis suggested that sorafenib resistance correlated with high karyopherin subunit alpha 3 (KPNA3) expression. Overexpression of KPNA3 in HCC cells enhanced tumor cell growth and invasiveness. Interestingly, KPNA3 was found to trigger epithelial-mesenchymal transition (EMT), a key process mediating drug resistance. On a mechanistic level, KPNA3 increased phosphorylation of AKT, which then phosphorylated ERK, and ultimately promoted TWIST expression to induce EMT and sorafenib resistance. Moreover, retrospective analysis revealed that HCC patients with low KPNA3 expression had remarkably longer survival after sorafenib treatment. Finally, we have identified a novel KPNA3-AKT-ERK-TWIST signaling cascade that promotes EMT and mediates sorafenib resistance in HCC. These findings suggest that KPNA3 is a promising biomarker for predicting patient responsiveness to sorafenib. Targeting KPNA3 may also contribute to resolving sorafenib resistance in HCC.
索拉非尼是一种多激酶抑制剂，是晚期肝细胞癌（HCC）患者的新的标准治疗药物。然而，在临床实践中经常观察到对该治疗方案的耐药性，而这种耐药性的分子基础在很大程度上仍然未知。在此，在16个源自患者的肝癌异种移植（PDX）模型中评估了索拉非尼的抗肿瘤活性。进行基因表达分析以确定促进索拉非尼耐药性的因素。使用定量RT-PCR和免疫印迹来确定基因表达和信号通路的激活。分别进行细胞增殖、克隆形成和Transwell试验以评估药物敏感性、增殖和侵袭性。使用Kaplan-Meier分析来评估生物标志物对索拉非尼反应的预测能力。差异基因表达分析表明，索拉非尼耐药性与核转运蛋白α3亚基（KPNA3）的高表达相关。HCC细胞中KPNA3的过表达增强了肿瘤细胞的生长和侵袭性。有趣的是，发现KPNA3触发上皮-间质转化（EMT），这是介导耐药性的关键过程。在机制层面上，KPNA3增加了AKT的磷酸化，然后AKT使ERK磷酸化，并最终促进TWIST表达以诱导EMT和索拉非尼耐药性。此外，回顾性分析显示，KPNA3表达低的HCC患者在索拉非尼治疗后的生存期明显更长。最后，我们确定了一种新的KPNA3-AKT-ERK-TWIST信号级联，该级联促进EMT并介导HCC中的索拉非尼耐药性。这些发现表明，KPNA3是预测患者对索拉非尼反应性的有前景的生物标志物。靶向KPNA3也可能有助于解决HCC中的索拉非尼耐药性问题。
