Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca, Spain.
National Institute for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Carlos III National Health Institute, Madrid, Spain.
Hepatology. 2019 Oct;70(4):1246-1261. doi: 10.1002/hep.30656. Epub 2019 May 20.
Although the multi-tyrosine kinase inhibitor sorafenib is useful in the treatment of several cancers, cholangiocarcinoma (CCA) is refractory to this drug. Among other mechanisms of chemoresistance, impaired uptake through human organic cation transporter type 1 (hOCT1) (gene SLC22A1) has been suggested. Here we have investigated the events accounting for this phenotypic characteristic and have evaluated the interest of selective gene therapy strategies to overcome this limitation. Gene expression and DNA methylation of SLC22A1 were analyzed using intrahepatic (iCCA) and extrahepatic (eCCA) biopsies (Copenhagen and Salamanca cohorts; n = 132) and The Cancer Genome Atlas (TCGA)-CHOL (n = 36). Decreased hOCT1 mRNA correlated with hypermethylation status of the SLC22A1 promoter. Treatment of CCA cells with decitabine (demethylating agent) or butyrate (histone deacetylase inhibitor) restored hOCT1 expression and increased sorafenib uptake. MicroRNAs able to induce hOCT1 mRNA decay were analyzed in paired samples of TCGA-CHOL (n = 9) and Copenhagen (n = 57) cohorts. Consistent up-regulation in tumor tissue was found for miR-141 and miR-330. High proportion of aberrant hOCT1 mRNA splicing in CCA was also seen. Lentiviral-mediated transduction of eCCA (EGI-1 and TFK-1) and iCCA (HuCCT1) cells with hOCT1 enhanced sorafenib uptake and cytotoxic effects. In chemically induced CCA in rats, reduced rOct1 expression was accompanied by impaired sorafenib uptake. In xenograft models of eCCA cells implanted in mouse liver, poor response to sorafenib was observed. However, tumor growth was markedly reduced by cotreatment with sorafenib and adenoviral vectors encoding hOCT1 under the control of the BIRC5 promoter, a gene highly up-regulated in CCA. Conclusion: The reason for impaired hOCT1-mediated sorafenib uptake by CCA is multifactorial. Gene therapy capable of selectively inducing hOCT1 in tumor cells can be considered a potentially useful chemosensitization strategy to improve the response of CCA to sorafenib.
尽管多酪氨酸激酶抑制剂索拉非尼在治疗几种癌症方面很有效，但胆管癌（CCA）对此药物有抗性。在其他化学抗性机制中，已有人提出通过人有机阳离子转运体 1（hOCT1）（基因 SLC22A1）摄取减少。在这里，我们研究了导致这种表型特征的事件，并评估了选择性基因治疗策略克服这种局限性的意义。使用肝内（iCCA）和肝外（eCCA）活检（哥本哈根和萨拉曼卡队列；n=132）和癌症基因组图谱（TCGA-CHOL）（n=36）分析 SLC22A1 的基因表达和 DNA 甲基化。hOCT1mRNA 的减少与 SLC22A1 启动子的高甲基化状态相关。用地西他滨（去甲基化剂）或丁酸盐（组蛋白去乙酰化酶抑制剂）处理 CCA 细胞可恢复 hOCT1 表达并增加索拉非尼摄取。在 TCGA-CHOL（n=9）和哥本哈根（n=57）队列的配对样本中分析了能够诱导 hOCT1mRNA 降解的 microRNA。在肿瘤组织中发现 miR-141 和 miR-330 一致上调。在 CCA 中也观察到 hOCT1 异常 mRNA 剪接的高比例。用 hOCT1 转导 eCCA（EGI-1 和 TFK-1）和 iCCA（HuCCT1）细胞的慢病毒转导增强了索拉非尼摄取和细胞毒性作用。在大鼠化学诱导的 CCA 中，rOct1 表达减少伴随着索拉非尼摄取减少。在植入小鼠肝脏的 eCCA 细胞的异种移植模型中，观察到对索拉非尼的反应不佳。然而，通过用sorafenib 和编码 hOCT1 的腺病毒载体共同处理，sorafenib 的肿瘤生长明显减少，后者由 BIRC5 基因（在 CCA 中高度上调）控制。结论：CCA 中 hOCT1 介导的 sorafenib 摄取减少的原因是多因素的。能够选择性诱导肿瘤细胞中 hOCT1 的基因治疗可以被认为是一种潜在有用的化疗增敏策略，以提高 CCA 对 sorafenib 的反应。
