Targeting oncogenes for hepatocellular carcinoma

总结 肝细胞癌（HCC）是第五大常见癌症和第二大常见病因。 全球癌症相关死亡人数最多，但对晚期疾病尚无有效治疗方法。现时的建议 重点关注两个相互作用的蛋白质，AEG-1和SND 1，它们作为HCC的真正癌基因发挥作用。AEG-1 和SND 1合作增加RNA诱导的沉默复合物（RISC）活性，其中AEG-1作为一种抑制剂发挥作用。 支架蛋白和SND 1起核酸酶的作用。然而，我们的理解存在知识差距 AEG-1和SND 1协同致癌功能的机制。在原代肝细胞中， AEG-1主要定位于细胞核中，而在HCC细胞中AEG-1主要定位于内质网中。 内质网（ER）膜。初步结果表明ER锚定是AEG-1致癌功能所必需的。 ER锚定的AEG-1特异性结合分泌和膜蛋白编码mRNA，以促进其表达。 翻译. SND 1 RNA相互作用组的分析还鉴定了膜蛋白编码mRNA。共- 定位研究表明AEG-1和SND 1均位于HCC细胞的ER膜上。AEG-1 和SND 1激活NF-κB。ER锚定的AEG-1作为一个平台， NF-κB通路中起重要作用，因此在NF-κB活化中起重要作用。SND 1激活的机制 NF-κB未知。我们推测在转化的肝细胞中，AEG-1从细胞核转位 并锚定在ER膜上，在那里它招募SND 1，两者通过调节 RISC中mRNA的转录后调节、膜蛋白的翻译调节和活化 NF-κB、AEG-1和SND 1相互依赖以实现最佳功能，可能不发挥致癌活性 联合抑制AEG-1和SND 1可能是治疗肝癌的有效策略。 实验设计成使用新的小鼠模型和靶向药物来询问这些假设。 递送AEG-1和SND 1的siRNA的纳米复合物。这一建议将有助于实现我们的长期目标， 确定调节HCC发病机制的关键参与者，并将这些知识转化为新的 和有效的靶向治疗。该建议的直接目标是深入了解 AEG-1和SND 1促进HCC的分子机制，并评估AEG-1和SND 1促进HCC的组合策略。 在小鼠模型中抑制AEG-1和SND 1作为潜在的治疗剂。因此，该提案既有 机制和治疗意义和创新。成功完成拟议的研究将 为开发治疗药物建立新的靶点，并为靶向方案提供临床前证据。

Summary Hepatocellular carcinoma (HCC), the fifth most common cancer and the second most common cause of cancer-related deaths worldwide, has no effective treatment for advanced disease. The present proposal focuses on two interacting proteins, AEG-1 and SND1, which function as bona fide oncogenes for HCC. AEG-1 and SND1 cooperate to increase RNA-induced silencing complex (RISC) activity where AEG-1 functions as a scaffold protein and SND1 functions as a nuclease. However, there is a gap of knowledge in our understanding of the mechanism(s) driving AEG-1 and SND1 cooperative oncogenic functions. In primary hepatocytes, AEG- 1 is predominantly localized in the nucleus, while in HCC cells AEG-1 is primarily localized in the endoplasmic reticulum (ER) membrane. Preliminary results indicate ER-anchoring is required for AEG-1 oncogenic function. ER-anchored AEG-1 binds specifically to secretory and membrane protein-encoding mRNAs to facilitate their translation. Analysis of SND1 RNA-interactome also identifies membrane protein-encoding mRNAs. Co- localization studies show that both AEG-1 and SND1 are located on ER membrane in HCC cells. Both AEG-1 and SND1 activate NF-κB. ER-anchored AEG-1 functions as a platform for upstream signaling molecules of NF-κB pathway and thus plays an essential role in NF-κB activation. The mechanism by which SND1 activates NF-κB is not known. We hypothesize that in transformed hepatocytes, AEG-1 translocates from the nucleus and anchors into the ER membrane where it recruits SND1 and both cooperate to promote HCC by modulating post-transcriptional regulation of mRNAs in RISC, translational regulation of membrane proteins and activation of NF-κB, AEG-1 and SND1 require each other for optimum functioning and might not exert oncogenic activity alone, and combinatorial inhibition of AEG-1 and SND1 might be an effective therapeutic strategy for HCC. Experiments are designed to interrogate these hypotheses using novel mouse models and targeted nanoplexes delivering siRNA for AEG-1 and SND1. This proposal will contribute to our long-term objectives of identifying key players regulating HCC pathogenesis and translating this knowledge into development of novel and effective targeted therapies. The immediate objective of the proposal is in-depth understanding of the molecular mechanisms by which AEG-1 and SND1 promote HCC and evaluate a combinatorial strategy of inhibiting AEG-1 and SND1 in a mouse model as a potential therapeutic. Thus the proposal has both mechanistic and therapeutic significance and innovation. Successful completion of the proposed studies will establish new targets for developing therapeutics and provide pre-clinical evidence for a targeted protocol.