Targeting oncogenes for hepatocellular carcinoma

摘要 肝细胞癌是第五大常见癌症，也是第二大常见病因。 在世界范围内，与癌症相关的死亡人数很多，但对晚期疾病没有有效的治疗方法。目前的建议 重点介绍了两种相互作用的蛋白质，AEG-1和SND1，它们是真正的肝癌癌基因。AEG-1 和SND1协同增加RNA诱导的沉默复合体(RISC)活性，其中AEG-1起 支架蛋白和SND1起核酸酶的作用。然而，我们在认识上存在着一种差距 (S)驱动AEG-1和SND1协同致癌功能的机制(S)。在原代肝细胞中，AEG- AEG-1主要定位于细胞核，而在肝癌细胞AEG-1主要定位于内质 网状(ER)膜。初步结果表明，AEG-1的致癌功能需要内质网锚定。 内质网锚定的AEG-1与分泌和膜蛋白编码的mRNAs特异性结合，以促进其 翻译。对SND1RNA相互作用组的分析也确定了膜蛋白编码的mRNAs。共同-- 定位研究表明，AEG-1和SND1均位于肝癌细胞的ER膜上。两个AEG-1 和SNd1激活核因子-κB，内质网锚定的AEG-1作为上游信号分子的平台 核因子-κB途径，在核因子-κB的激活中起着重要作用。SND1的激活机制 核因子-κB尚不清楚。我们假设在转化的肝细胞中，AEG-1从细胞核移位 并锚定到ER膜上，在那里招募SND1，两者通过调节相互作用促进肝癌 RISC中mRNAs的转录后调控、膜蛋白的翻译调控和激活 在核转录因子κB中，AEG-1和SND1AEG-1相互需要才能发挥最佳功能，可能不发挥致癌活性 单独及联合抑制AEG-1和SND1可能是治疗肝癌的有效策略。 实验旨在使用新的小鼠模型和有针对性的 为AEG-1和SND1提供siRNA的纳米复合体。这项建议将有助于实现我们的长期目标 识别调控肝癌发病机制的关键因素并将其转化为新的开发 和有效的靶向治疗。这项建议的直接目标是深入了解 AEG-1和SND1促进肝细胞癌的分子机制及联合治疗策略评价 在小鼠模型中抑制AEG-1和SND1作为一种潜在的治疗方法。因此，该提案既有 机理和治疗意义及创新。成功完成拟议的研究将 为开发治疗学建立新的目标，并为有针对性的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.