Unraveling the molecular control of a pro-metastatic regulatory network in melanoma

 描述(申请人提供)：拟议的跨学科研究计划结合了分子、生化、遗传学、人类病理学和动物功能研究，以描述已发现通过代表不同突变亚型的广泛黑色素瘤来调控转移进展的促转移调控网络。我们已发表的工作表明，在大多数人类黑色素瘤中，三个促进转移的microRNAs(miR-1908、miR-199a5p和miR-199a3p)的过度表达通过直接靶向ApoE基因和热休克因子DNAJA4来推动转移定植(Pencheva等人，Cell，2012；Pencheva，Buss等人，Cell，2014)。APOE和DNAJA4被发现有力地抑制了转移定植和血管生成。我们之前发表的和未发表的大量工作支持这些基因及其网络在人类转移进展中的强大和临床病理验证的作用。自我们最初发表论文以来，独立研究人员通过证明载脂蛋白E基因抑制乳腺癌转移以及人类载脂蛋白E4基因多态增加男性和女性死于恶性肿瘤的可能性，进一步支持了载脂蛋白E在癌症进展中的作用。总体而言，这些发现确立了载脂蛋白E是转移进展和肿瘤血管生成的有效和双重调节因子。因此，需要更深入地了解调控载脂蛋白E在癌症中的上游机制、其对肿瘤血管生成的下游作用机制(S)、其治疗潜力以及载脂蛋白E基因多态变异对癌症的影响。目前的建议旨在回答对癌症和转移生物学具有重要意义的四个主要问题：(I)DNAJA4热休克因子对载脂蛋白E上游调控的机制是什么？(Ii)载脂蛋白E与内皮LRP8受体的结合如何抑制血管生成？(Iii)我们能否建立一个由ApoE基因失活驱动的黑色素瘤转移进展的遗传模型，并使用该模型来测试ApoE多肽模拟物的抗转移效果？以及(Iv)普遍存在的人类载脂蛋白E4基因多态性是否推动了小鼠黑色素瘤的转移进展。ApoE失活驱动的基因启动的黑色素瘤转移进展模型的开发是创新的，可能会有益于影响科学、医疗和制药界-使我们能够在免疫熟练的模型中测试和开发ApoE多肽疗法。发现一种未知的转录后机制来调节载脂蛋白E，这是一种与痴呆和心血管疾病有关的基因，也可能具有广泛的科学和临床影响，并揭示载脂蛋白E治疗激活的另一条途径。测试ApoE-LRP8对乳腺癌和肺癌血管生成抑制的影响也可以扩大ApoE治疗的范围和影响到这些流行的癌症。

 DESCRIPTION (provided by applicant): The proposed inter-disciplinary research plan combines molecular, biochemical, genetic, human pathologic, and animal functional studies to characterize a pro-metastatic regulatory network that has been found to regulate metastatic progression by a broad range of melanomas representing diverse mutational subtypes. Our published work has revealed that in the majority of human melanomas, over-expression of three pro-metastatic microRNAs (miR-1908, miR-199a5p, and miR-199a3p) drives metastatic colonization through direct targeting of ApoE gene and the heat-shock factor DNAJA4 (Pencheva et al., Cell, 2012; Pencheva, Buss et al., Cell, 2014). ApoE and DNAJA4 were found to robustly suppress metastatic colonization and angiogenesis. Our extensive previously published and unpublished work supports a robust and clinico-pathologically validated role for these genes and their network in human metastatic progression. Since our original publications, independent investigators have provided further support of a role for ApoE in cancer progression by demonstrating that the ApoE gene suppresses breast cancer metastasis and that the human ApoE4 polymorphism increases the likelihood of death from malignancy in men and women. These findings as a whole establish ApoE as a potent and dual regulator of metastatic progression and tumor angiogenesis. Thus, an enhanced understanding of the upstream mechanisms that regulate ApoE in cancer, its downstream mechanism(s) of action on tumor angiogenesis, its therapeutic potential, and the impact of ApoE polymorphic variants on cancer is required. The current proposal aims to answer four major questions of great significance to cancer and metastasis biology: (i) what is the mechanism of upstream regulation of ApoE by the DNAJA4 heat-shock factor? (ii) How does the binding of ApoE to the endothelial LRP8 receptor suppress angiogenesis? (iii) Could we develop a genetic model of melanoma metastatic progression driven by genetic inactivation of ApoE and use this model to test the anti-metastatic efficacy of an ApoE peptide mimetic? and (iv) does the prevalent human ApoE4 polymorphism drive mouse melanoma metastatic progression. The development of an ApoE inactivation driven genetically initiated model of melanoma metastatic progression is innovative and could beneficially impact the scientific, medical, and pharmaceutical communities-allowing us to test and develop ApoE peptide therapy in an immunoproficient model. Discovery of an unexplored post- transcriptional mechanism that regulates ApoE, a gene implicated in dementia and cardiovascular disease could also have broad scientific and clinical impact and reveal another avenue for therapeutic activation of ApoE. Testing the impact of angiogenic suppression of breast and lung cancer by ApoE- LRP8 could broaden the scope and impact of ApoE therapy to these prevalent cancers as well.