Department of Hepatobiliary Surgery, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China.
Gannan Medical University, Ganzhou, Jiangxi, China.
Cell Biol Int. 2021 Sep;45(9):1906-1916. doi: 10.1002/cbin.11625. Epub 2021 May 16.
Sorafenib was the first systemic therapy approved by the Food and Drug Administration to treat advanced hepatocellular carcinoma (HCC). However, sorafenib therapy is frequently accompanied by drug resistance. We aimed to explore the mechanisms of sorafenib resistance and provide feasible solutions to increase the response to sorafenib in patients with advanced HCC. The expression profile of discoidin domain receptor 2 (DDR2) in HCC tissues and cells was detected using quantitative real-time PCR (qPCR) and western blotting assays. The effects of DDR2 on sorafenib resistance were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation, TdT-mediated dUTP nick end labeling, and flow cytometry assays. The effect of DDR2 on the nuclear factor kappa B (NF-κB) signaling pathway was evaluated by luciferase reporter, immunofluorescence, qPCR and flow cytometry assays. We demonstrated that DDR2 expression was dramatically upregulated in sorafenib-resistant HCC tissues relative to sensitive tissues. Downregulation of DDR2 sensitized HCC cell lines to sorafenib cytotoxicity. Further analysis showed that DDR2 could increase the nuclear location of REL proto-oncogene, a NF-κB subunit, to mediate NF-κB signaling. Blocking NF-κB signaling using the NF-κB signaling inhibitor, bardoxolone methyl, increased the response of HCC cells to sorafenib. Further analysis showed that DNA amplification of DDR2 is an important mechanism leading to DDR2 overexpression in HCC. Our results demonstrated that DDR2 is a potential therapeutic target in patients with HCC, and targeting DDR2 represents a promising approach to increase sorafenib sensitivity in patients with HCC.
索拉非尼是食品和药物管理局批准的第一种用于治疗晚期肝细胞癌（HCC）的系统治疗药物。然而，索拉非尼治疗常常伴随着耐药性。我们旨在探讨索拉非尼耐药的机制，并提供可行的解决方案，以增加晚期 HCC 患者对索拉非尼的反应。采用实时定量 PCR（qPCR）和 Western blot 检测 HCC 组织和细胞中 discoidin 域受体 2（DDR2）的表达谱。采用 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）、集落形成、TdT 介导的 dUTP 缺口末端标记和流式细胞术检测 DDR2 对索拉非尼耐药的影响。通过荧光素酶报告、免疫荧光、qPCR 和流式细胞术评估 DDR2 对核因子 kappa B（NF-κB）信号通路的影响。我们证明，与敏感组织相比，索拉非尼耐药 HCC 组织中 DDR2 的表达明显上调。DDR2 下调使 HCC 细胞系对索拉非尼的细胞毒性更敏感。进一步分析表明，DDR2 可以增加 REL 原癌基因，NF-κB 亚基的核定位，以介导 NF-κB 信号。使用 NF-κB 信号抑制剂 bardoxolone methyl 阻断 NF-κB 信号可增加 HCC 细胞对索拉非尼的反应。进一步分析表明，DDR2 的 DNA 扩增是导致 HCC 中 DDR2 过表达的重要机制。我们的结果表明，DDR2 是 HCC 患者的潜在治疗靶点，靶向 DDR2 代表了增加 HCC 患者对索拉非尼敏感性的一种有前途的方法。
