Targeting RNF114 for Cancer Therapy and Targeted Protein Degradation

天然产品一直是抗癌治疗药物的丰富来源，包括广泛使用的 乳腺癌药物紫杉醇由太平洋红豆杉树皮产生，通过靶向微管蛋白来损害 乳腺癌的致病性。虽然有无数的天然产品来自植物，微生物和 其他已被证明具有抗癌活性的生物，大多数的作用机制 人们对这些天然产物仍然知之甚少。其中一种天然产物是尼姆波利特，一种三萜类化合物。 从印楝树或印楝树中提取，已被许多团体证明具有抗癌活性 针对多种不同类型的癌症，包括乳腺癌、肝细胞癌、结肠癌、 和肾细胞癌。虽然这种天然产品具有令人信服的抗癌特性，但直接 人们对目标仍然知之甚少。我使用了一种名为Activity的创新化学蛋白质组平台- 基于蛋白质图谱(ABPP)，它使用基于反应性的化学探针来绘制反应性， 复杂蛋白质组中的功能性和可药物热点，以定位蛋白质组范围内的可配基 针对乳腺癌细胞中抗癌天然产物尼姆波利特的热点。我的初选 使用ABPP的数据表明，尼博利特选择性地靶向231MFP中E3泛素连接酶RNF114上的C8 三阴性乳腺癌(TNBC)细胞，导致肿瘤抑制基因p21泛素化受损 通过RNF114识别其蛋白质底物的能力受损。这反过来又会导致 P21水平升高，导致乳腺癌细胞致病性受损。在这个提案中，我将使用 创新的化学生物学方法确定宁波利特和安慰剂的抗癌机制 将RNF114描述为癌症治疗和靶向蛋白质降解应用的靶点。

Natural products have been a prolific source of therapeutics for combatting cancers, including the widely-used breast cancer drug taxol produced by the bark of the Pacific yew that acts through targeting tubulin to impair breast cancer pathogenicity. While there are countless natural products derived from plants, microbes, and other living organisms that have been shown to exert anti-cancer activity, the mechanism of action of most of these natural products remain poorly understood. One such natural product is nimbolide, a triterpenoid obtained from Azadirachta indica or neem, that has been shown by many groups to exert anti-cancer activity against multiple different types of cancers, including breast cancers, hepatocellular carcinomas, colon cancers, and renal cell carcinomas. While this natural product possesses compelling anti-cancer properties, the direct targets remain poorly understood. I have used an innovative chemoproteomic platform termed activity- based protein profiling (ABPP), which uses reactivity-based chemical probes to map reactive, functional, and druggable hotspots in complex proteomes, to map the proteome-wide ligandable hotspots targeted by the anti-cancer natural product nimbolide in breast cancer cells. My preliminary data using ABPP indicate that nimbolide selectively targets C8 on the E3 ubiquitin ligase RNF114 in 231MFP triple-negative breast cancer (TNBC) cells, leading to impaired ubiquitination of the tumor suppressor p21 through an impairment in the ability of RNF114 to recognize its protein substrates. This in-turn leads to an elevation in p21 levels, leading to impaired breast cancer cell pathogenicity. In this proposal, I will use innovative chemical biology approaches to determine the anti-cancer mechanisms of nimbolide and characterize RNF114 as a target for cancer therapy and for targeted protein degradation applications.