Applied and Functional Genomics Laboratory, National Centre of Excellence in Molecular Biology, University of Punjab, Lahore 53700, Pakistan.
Virol J. 2011 Apr 1;8:155. doi: 10.1186/1743-422X-8-155.
Hepatitis C virus (HCV) Core protein is thought to trigger activation of multiple signaling pathways and play a significant role in the alteration of cellular gene expression responsible for HCV pathogenesis leading to hepatocellular carcinoma (HCC). However, the exact molecular mechanism of HCV genome specific pathogenesis remains unclear. We examined the in vitro effects of HCV Core protein of HCV genotype 3a and 1a on the cellular genes involved in oxidative stress and angiogenesis. We also studied the ability of HCV Core and Cox-2 siRNA either alone or in combination to inhibit viral replication and cell proliferation in HCV serum infected Huh-7 cells.
Over expression of Core gene of HCV 3a genotype showed stronger effect in regulating RNA and protein levels of Cox-2, iNOS, VEGF, p-Akt as compared to HCV-1a Core in hepatocellular carcinoma cell line Huh-7 accompanied by enhanced PGE2 release and cell proliferation. We also observed higher expression levels of above genes in HCV 3a patient's blood and biopsy samples. Interestingly, the Core and Cox-2-specific siRNAs down regulated the Core 3a-enhanced expression of Cox-2, iNOS, VEGF, p-Akt. Furthermore, the combined siRNA treatment also showed a dramatic reduction in viral titer and expression of these genes in HCV serum-infected Huh-7 cells. Taken together, these results demonstrated a differential response by HCV 3a genotype in HCV-induced pathogenesis, which may be due to Core and host factor Cox-2 individually or in combination.
Collectively, these studies not only suggest a genotype-specific interaction between key players of HCV pathogenesis but also may represent combined viral and host gene silencing as a potential therapeutic strategy.
丙型肝炎病毒 (HCV) 核心蛋白被认为可以触发多条信号通路的激活，并在改变与 HCV 发病机制相关的细胞基因表达方面发挥重要作用，导致肝细胞癌 (HCC)。然而，HCV 基因组特定发病机制的确切分子机制仍不清楚。我们研究了 HCV 基因型 3a 和 1a 的核心蛋白在体外对涉及氧化应激和血管生成的细胞基因的影响。我们还研究了 HCV 核心和 Cox-2 siRNA 单独或联合抑制 HCV 感染血清中的 Huh-7 细胞中病毒复制和细胞增殖的能力。
与 HCV-1a 核心相比，HCV 3a 基因型的核心基因过表达在调节肝癌细胞系 Huh-7 中的 Cox-2、iNOS、VEGF、p-Akt 的 RNA 和蛋白水平方面表现出更强的作用，并伴有 PGE2 释放和细胞增殖增强。我们还观察到 HCV 3a 患者的血液和活检样本中上述基因的表达水平较高。有趣的是，核心和 Cox-2 特异性 siRNA 下调了核心 3a 增强的 Cox-2、iNOS、VEGF、p-Akt 表达。此外，联合 siRNA 治疗还显示出 HCV 感染血清中的 Huh-7 细胞中病毒滴度和这些基因表达的显著降低。总之，这些结果表明 HCV 3a 基因型在 HCV 诱导的发病机制中表现出不同的反应，这可能是由于核心和宿主因子 Cox-2 单独或联合作用所致。
总之，这些研究不仅表明 HCV 发病机制中的关键因素之间存在基因型特异性相互作用，还可能代表联合病毒和宿主基因沉默作为一种潜在的治疗策略。
