Inducible systems for studying liver tumor mainenance in vivo

摘要 肝细胞癌是第五大常见癌症，也是导致癌症死亡的第三大原因。 全世界。然而，肝细胞癌发生的分子遗传学仍不甚清楚。 肝细胞癌的治疗选择非常有限，而且通常无效。只有一个选项可以用于 治疗晚期肝癌(索拉非尼)，平均只延长三个月的生命！因此， 对肝癌的新见解将导致新的治疗方法，这是一种迫切的未得到满足的需求。不断增长的 另一方面，对肝癌分子发病机制的了解确实为新的治疗策略打开了大门。 靶向治疗。流体动力导入结合流体动力注射与睡美人 通过体细胞整合实现基因的长期表达。由于其灵活性和高效率，它具有 现在，越来越多的人被用来建立研究肝癌发生的小鼠模型。 然而，到目前为止，还没有为这项技术建立起可诱导的系统。放大和 C-Myc癌基因过度表达是肝细胞癌中最常见的遗传事件之一 C-Myc被认为是肝细胞癌重要的致癌基因。确实过度表达了 小鼠肝脏c-Myc促进低分化肝细胞癌的形成。最近，我们发现， 消融mTORC1的独特成分Raptor显著抑制c-Myc诱导的肝癌 体内发育。然而，目前尚不清楚c-Myc肝细胞癌的维持和修复是否需要mTORC1。 MTORC1抑制是否导致肝细胞癌消退。在本应用程序中，我们假设mTORC1为 C-Myc维持所需；在肿瘤形成后删除Raptor将导致肿瘤消退。在这 R03小规模应用，我们将建立一种高效的可诱导Cre系统，用于流体动力转染(目标1)。 然后，我们将应用这项技术在体内删除c-Myc诱导的肝癌肿瘤中的Raptor，目标是研究 维持c-Myc肝细胞癌是否需要mTORC1复合体(目标2)。总之，这是一个 自给式 符合R03小型研究项目描述和范围的研究项目。它有助于 开发一种强大的研究技术，可以用来描述基因或 肝细胞癌维持的途径。这类研究的结果对于确定基因或 肝细胞癌的治疗途径。

Abstract Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death worldwide. However, molecular genetics underlying HCC development remain to be poorly understood. Treatment options for HCC are very limited and in general ineffective. There is only a single option for treatment of advanced HCC (Sorafenib) which prolongs life by an average of just three months! Consequently, there is a pressing unmet need for new insights on HCC that will lead to new therapies. The growing understanding of molecular pathogenesis of HCC, on the other hand, does open the door for novel strategy of targeted therapy. Hydrodynamic transfection combines hydrodynamic injection together with sleeping beauty mediated somatic integration for long term gene expression. Because of its flexibility and high efficiency, it has now becoming increasingly popular to be used to generate murine models for studying hepatocarcinogenesis. However, so far few inducible systems have been established for this technology. Amplification and overexpression of c-Myc oncogene is one of the most frequently observed genetic events during HCC pathogenesis; and c-Myc is considered to be an important driver oncogene for HCC. Indeed overexpression of c-Myc in mouse liver promotes the formation of poorly differentiated HCC. Recently, we discovered that ablation of Raptor, the unique component of mTORC1, significantly suppressed c-Myc driven HCC development in vivo. However, it is not clear whether mTORC1 is required for c-Myc HCC maintenance and whether inhibition of mTORC1 leads to HCC regression. In this application, we hypothesize that mTORC1 is required for c-Myc maintenance; and deleting Raptor after tumor formation will lead to tumor regression. In this R03 small application, we will establish an efficient inducible Cre system for hydrodynamic transfection (Aim 1). We will then apply the technology to delete Raptor in c-Myc induced HCC tumors in vivo with the goal to study whether mTORC1 complex is required for maintaining c-Myc HCC (Aim 2). Altogether, this is a self-contained research projects which fits well with the description and scope of a R03 small research project. It assists to develop a powerful research technology which can be used to characterize the requirement of a gene or pathway for HCC maintenance. The results from such studies are critical for establishing the gene or pathway for the treatment of HCC.