MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
J Antimicrob Chemother. 2015 Jul;70(7):2013-23. doi: 10.1093/jac/dkv077. Epub 2015 Apr 8.
Hepatitis C virus (HCV) infects hepatocytes and causes liver damage. The aim of this study was to identify new classes of host-targeting anti-HCV compounds that may provide novel approaches for antiviral treatment regimens.
Cell culture-derived HCV (HCVcc), replicons and pseudoparticles were used in combination with high-throughput screening, reporter gene assays and cytotoxicity and signalling pathway analyses.
A small-molecule inhibitor of HCV, N-(cyclopropyl(phenyl)methyl)thieno[2,3-d]pyrimidin-4-amine, designated IB-32, was identified by screening a compound library with a Jc1-luc HCVcc assay. By using various virus models, HCV replication was identified as the predominant step of IB-32's action. IB-32 inhibited HCVcc (genotype 2a) and HCV replicons (genotype 1b) at low nanomolar ranges (with IC50s of 40 ± 8 and 100 ± 15 nM, respectively). IB-32 was found to be non-toxic when tested against a panel of human cell lines in vitro at the effective antiviral dose. Mechanistically, IB-32 strongly inhibited STAT3 (Tyr705) phosphorylation, a necessary cellular factor for HCV replication and a pivotal therapeutic target for multiple cancers. Furthermore, the inhibition of HCV replication by IB-32 was augmented in cells with STAT3 knockdown. In contrast, the inhibitory effect of IB-32 was attenuated in cells overexpressing a constitutively active form of STAT3.
The results presented here identify a promising STAT3-targeting anti-HCV therapeutic candidate. This novel small molecule could be further optimized and developed for use as both an antiviral and an anti-cancer drug.
丙型肝炎病毒（HCV）感染肝细胞并导致肝损伤。本研究旨在鉴定新的宿主靶向抗 HCV 化合物，这些化合物可能为抗病毒治疗方案提供新的方法。
使用细胞培养衍生的 HCV（HCVcc）、复制子和假病毒颗粒，结合高通量筛选、报告基因检测以及细胞毒性和信号通路分析。
通过使用 Jc1-luc HCVcc 测定法筛选化合物文库，鉴定出 HCV 的小分子抑制剂 N-(环丙基(苯基)甲基)噻吩并[2,3-d]嘧啶-4-胺，命名为 IB-32。通过使用各种病毒模型，鉴定出 HCV 复制是 IB-32 作用的主要步骤。IB-32 在低纳摩尔范围内抑制 HCVcc（基因型 2a）和 HCV 复制子（基因型 1b）（IC50 分别为 40±8 和 100±15 nM）。在体外针对人细胞系进行的有效抗病毒剂量的测试中，IB-32 被发现无细胞毒性。在机制上，IB-32 强烈抑制 STAT3（Tyr705）磷酸化，这是 HCV 复制所必需的细胞因子，也是多种癌症的关键治疗靶点。此外，在 STAT3 敲低的细胞中，IB-32 抑制 HCV 复制的作用增强。相比之下，在过表达组成型激活形式的 STAT3 的细胞中，IB-32 的抑制作用减弱。
本研究结果鉴定出一种有前途的 STAT3 靶向抗 HCV 治疗候选物。这种新型小分子可以进一步优化和开发，用作抗病毒和抗癌药物。
