Role of sirtuin 6 in melanoma development and progression

黑色素瘤发病率正在迅速增加，预计2020年美国将有100，350例病例。此外，本发明还 黑色素瘤是退伍军人的一个重要问题，它是五种最常见的癌症之一 在退伍军人管理局癌症患者中恶性黑色素瘤是最致命的癌症之一，现有的 包括最近批准的BRAF抑制剂在内的治疗方法在黑色素瘤中尚未完全有效 由于获得性阻力。因此，需要新的基于目标的方法， 管理这个肿瘤。我们有一个正在进行的研究计划来定义sirtuins在以下方面的作用 黑素瘤哺乳动物sirtuins组成了一个由7个成员组成的家族（SIRT 1-SIRT 7），它们在哺乳动物中起关键作用。 在重要的细胞过程中发挥作用，并参与多种疾病，包括癌症。的作用 癌症中的SIRTs是复杂的，并且它们似乎具有取决于细胞环境的二分功能。最近 研究表明sirtuin 6（SIRT 6），一种主要的核蛋白，参与调节参与 基因转录、葡萄糖稳态、DNA修复和端粒完整性。SIRT 6已被发现 抑制肠和肝脏中的肿瘤发生。然而，SIRT 6在皮肤中也具有促增殖作用， 前列腺癌，表明其功能可能是组织和环境依赖性的。有趣的是，SIRT 6 还显示调节上皮-间质转化（EMT）并促进某些肿瘤的转移。 癌症类型。在最近的一项研究中，我们已经证明SIRT 6在人类黑色素瘤细胞中过表达， 通过shRNA介导的RNA干扰抑制SIRT 6， 反应（生长抑制、细胞周期交替、细胞迁移抑制、衰老和自噬 调节异常）。我们的初步数据和已发表的研究以及其他已发表的 研究为我们研究其作用和潜在治疗提供了强有力的科学前提 SIRT 6在黑色素瘤中的重要性，并支持我们提出的假设，即SIRT 6在黑色素瘤中起关键作用。 黑色素细胞转化和黑色素瘤进展以及与其他驱动途径一起，可以是 用于治疗黑色素瘤。提出了以下具体目标：1）界定 SIRT 6在黑色素瘤发生和进展中作用及其与关键黑色素瘤驱动因子的关联 采用组织微阵列（TMA）的途径，该组织微阵列由来自Veteran的回顾性黑素瘤组织创建 患者在这个目标中，我们将确定SIRT 6在黑色素瘤中的作用，以及它与黑色素瘤的关键性免疫反应的关系。 黑色素瘤驱动途径（RAS/RAF/MEK/ERK-和p16/细胞周期蛋白D-CDK 4/6-RB-途径）; 2）为了确定 SIRT 6在黑素瘤中的功能和机制意义。为此，我们将确定 CRISPR/Cas9介导的SIRT 6缺失对体外和体内黑素瘤细胞生长和进展的影响;以及 3)为了确定SIRT 6抑制单独和与其他有希望的治疗方法组合的治疗意义， 基于靶点的体内抗黑色素瘤模式。我们将使用小的细胞因子来确定SIRT 6抑制的效果。 单独的分子SIRT 6抑制剂和与其它临床相关的黑色素瘤疗法（BRAF）组合 抑制剂，维罗非尼;和MEK抑制剂，曲美替尼）对黑色素瘤发展、生长和转移的影响， Braf-Pten小鼠模型，和2）患者来源的异种移植物（PDX）。我们希望我们的研究能够定义这个角色， 机制和SIRT 6在黑色素瘤中的相互作用以及临床前环境中的新组合， 这可能对未来的临床研究有用。这可能最终导致小说的发展 黑色素瘤的诊断、预后和治疗方法。因此，我们建议的研究是相关的， 对退伍军人的医疗保健意义重大，符合退伍军人事务部的使命。

Melanoma incidences are increasing rapidly with 100,350 cases predicted in 2020 in the US. Further, melanoma is a significant problem in Veterans, and it is among the five most frequently diagnosed cancers among VA cancer patients. Malignant melanoma is one of the deadliest forms of cancer, and the existing therapeutics, including recently approved BRAF inhibitors, have not been fully effective in melanoma management due to acquired resistance. Therefore, novel target-based approaches are needed for the management of this neoplasm. We have an ongoing research program to define the role of sirtuins in melanoma. The mammalian sirtuins constitute a family of seven members (SIRT1 – SIRT7), which play critical roles in important cellular processes, and are involved in a variety of diseases, including cancer. The role of SIRTs in cancer is complex, and they appear to have dichotomous functions depending on cell context. Recent studies have implicated sirtuin 6 (SIRT6), a predominantly nuclear protein, in regulating pathways involved in gene transcription, glucose homeostasis, DNA repair and telomere integrity. SIRT6 has been found to suppress tumorigenesis in the intestine and liver. However, SIRT6 also has a pro-proliferative role in skin and prostate cancer, suggesting that its function may be tissue- and context- dependent. Interestingly, SIRT6 has also been shown to modulate epithelial-mesenchymal transition (EMT) and promote metastasis in certain cancer types. In a recent study, we have demonstrated that SIRT6 is overexpressed in human melanoma cells and tissues, and SIRT6 inhibition via shRNA-mediated RNA interference resulted in a marked antiproliferative response (growth inhibition, cell cycle alternation, inhibition of cell migration, senescence and autophagy dysregulation) in melanoma cells. Our preliminary data and published study together with other published research provide a strong scientific premise to our investigation into the role and potential therapeutic significance of SIRT6 in melanoma and supports our proposed hypothesis that SIRT6 plays a critical role in melanocytic transformation and melanoma progression and together with other driver pathways, can be therapeutically exploited for melanoma management. The following specific aims are proposed: 1) To define the role of SIRT6 in melanoma development and progression and its association with critical melanoma driver pathways employing a tissue microarray (TMA) created from retrospective melanoma tissues from Veteran patients. In this aim, we will determine the role of SIRT6 in melanoma as well as its association with critical melanoma driver pathways (RAS/RAF/MEK/ERK-, and p16/cyclin D-CDK4/6-RB- pathways); 2) To determine the functional and mechanistic significance of SIRT6 in melanoma. In this aim, we will determine the effect of CRISPR/Cas9 mediated SIRT6 deletion on growth and progression of melanoma cells in vitro and in vivo; and 3) To determine the therapeutic significance of SIRT6 inhibition alone and in combination with other promising target-based anti-melanoma modalities in vivo. We will determine the effects of SIRT6 inhibition using small molecule SIRT6 inhibitor alone and in combination with other clinically relevant melanoma therapies (BRAF inhibitor, Vemurafenib; and MEK inhibitor, Trametinib) on melanoma development, growth and metastasis in 1) Braf-Pten mouse model, and 2) patient-derived xenografts (PDX). We expect that our study will define the role, mechanism, and interactions of SIRT6 in melanoma as well as novel combinations in pre-clinical settings, which could be useful for future clinical investigations. This may ultimately lead to the development of novel diagnostic, prognostic, and therapeutic approaches for melanoma. Hence, our proposed study is relevant and significant to the health care of Veterans and is in line with the mission of the Department of Veteran Affairs.