Control of mutant p53 stability via the mevalonate pathway-DNAJA1 axis

通过甲羟戊酸途径-DNAJA1 轴控制突变体 p53 的稳定性

基本信息

批准号：
10339474
负责人：
Tomoo Iwakuma
金额：
$ 34.28万
依托单位：
CHILDREN'S MERCY HOSP (KANSAS CITY, MO)
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-01 至 2024-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10339474
关键词：
Acetylation Affect Apoptosis Attenuated Binding Cells Cholesterol DNA DNA Binding Domain Data Docking EP300 gene Family Goals Head and Neck Squamous Cell Carcinoma Human Immunohistochemistry In Vitro Knock-out Link Lipids Lysine Malignant - descriptor Malignant Epithelial Cell Malignant Neoplasms Maps Mass Spectrum Analysis Mevalonate kinase Missense Mutation Molecular Molecular Chaperones Molecular Conformation Mutate Mutation Oncogenic Pathway interactions Patients Pharmaceutical Preparations Play Production Prognosis Proliferation Marker Property Protein Isoprenylation Proteins Publications Regulation Role Signal Pathway Structure Supplementation Survival Rate TP53 gene Testing Tissues Tumor Suppression Xenograft procedure base cancer addiction cancer cell gain of function high throughput screening improved in vivo inhibitor inorganic phosphate knock-down mevalonate misfolded protein mouse model mutant new therapeutic target novel overexpression patient prognosis small molecule libraries therapeutic target tumor tumor progression ubiquitin ligase virtual screening

项目摘要

The overall 5-year survival rate of patients with head and neck squamous cell carcinoma (HNSCC) is less than 50%, and ~75% of human HNSCC cases have mutations in the tumor suppressor p53. The vast majority of p53 mutations are missense mutations that show oncogenic activities, with strong correlation with poor prognosis in patients with HNSCC. Recent evidence indicates that stabilization of mutant p53 (mutp53) in tumors is crucial for its oncogenic activities, while its knockdown attenuates tumor progression. Although there are numerous publications on the function and regulation of wild-type p53 (wtp53), little is known about mechanisms controlling mutp53 levels in tumors and the workable strategies that induce mutp53 degradation. The goal of this proposal is to discover efficient strategies to specifically degrade mutp53 in HNSCC and elucidate the underlying mechanisms. To identify compounds that reduce mutp53 levels, we performed high throughput screening of chemical libraries and identified “statins”, a class of drugs that inhibit cholesterol production, as degradation inducers of structurally misfolded mutp53 proteins. Statins showed minimal effects on wtp53 and DNA contact mutp53 with native structure. Reduction in mevalonte-5-phosphate (MVP), but not other metabolites in the mevalonate (MV) pathway, triggered mutp53 degradation by CHIP ubiquitin ligase in a protein prenylation-independent manner. Statins also inhibited binding of mutp53 to DNAJA1, a molecular chaperone of the Hsp40 family which plays a role in refolding of misfolded proteins. Indeed, mutp53 degradation by statins was nullified by MVP supplementation, as well as by DNAJA1 overexpression. These data suggest that MVP positively regulates the DNAJA1-mutp53 binding and that DNAJA1 stabilizes misfolded mutp53. However, it is still unclear how reduced MVP leads to inhibition of DNAJA1-mutp53 binding. Based on our compelling preliminary data showing that reduction in MVP by knockdown of mevalonate kinase (MVK) increased acetylation of mutp53, we hypothesize that acetylation of mutp53 upon MVP reduction inhibits the mutp53-DNAJA1 binding, which promotes mutp53 degradation, leading to tumor suppression. We will test this hypothesis and establish the role of DNAJA1 in the malignant progression of HNSCC cells. In Aim 1, we will determine the mechanism by which reduced MVP leads to inhibited binding of mutp53 with DNAJA1 to induce mutp53 degradation and tumor suppression. In Aim 2, we will test the hypothesis that DNAJA1 promotes HNSCC progression in a misfolded mutp53-dependent manner. In Aim 3, we will characterize potential DNAJA1 inhibitors identified through molecular docking studies for their abilities to bind to DNAJA1, induce mutp53 degradation, and reduce the malignant properties of HNSCC cells. Completion of this study will reveal a novel mechanism of mutp53 stabilization via unexpected functional link between MVP and DNAJA1 and will establish the MV pathway and DNAJA1 as novel therapeutic targets for mutp53-carrying cancers. This study may also identify a DNAJA1 inhibitor as a potential compound that can be used for HNSCC therapy.

头部和颈部鳞状细胞癌（HNSCC）患者的总体5年生存率小于 50％，约75％的人类HNSCC病例在肿瘤抑制p53中具有突变。绝大多数 p53突变是表现出致癌活性的错义突变，与较差的相关性很强 HNSCC患者的预后。最近的证据表明，突变体p53（mutp53）在肿瘤对于其致癌活性至关重要，而其敲低可减轻肿瘤的进展。虽然那里关于野生型P53（WTP53）功能和调节的许多出版物，对控制肿瘤中MATP53水平的机制以及诱导MUTP53降解的工作策略。该提案的目的是发现有效的策略，以在HNSCC和HNSCC和阐明基本机制。为了识别降低MUTP53水平的化合物，我们表现较高化学文库的吞吐量筛查并确定了“汀类药物”，这是一种抑制胆固醇的药物生产，作为结构错误折叠的MUTP53蛋白的降解影响者。他汀类药物的影响很小在具有天然结构的WTP53和DNA接触MUTP53上。减少5-磷酸盐（MVP），但不减少甲氯酯（MV）途径中的其他代谢产物，通过芯片泛素连接酶在A中触发了MUTP53 蛋白质前原化的非依赖性方式。他汀类药物还抑制了Mutp53与DNAJA1的结合，DNAJA1是分子 HSP40家族的伴侣，在重折叠错误折叠的蛋白质中起作用。的确，mutp53 他汀类药物的降解因补充MVP以及DNAJA1的过表达而无效。这些数据表明MVP积极调节DNAJA1-MUTP53结合，并且DNAJA1稳定了错误折叠 mutp53。但是，尚不清楚MVP减少如何导致DNAJA1-MUTP53结合的抑制。基于我们引人注目的初步数据，表明通过敲低甲龙酸酯激酶（MVK）减少MVP Mutp53的乙酰化增加，我们假设MVP减少后MUTP53的乙酰化抑制了 MUTP53-DNAJA1结合，促进MUTP53降解，导致肿瘤抑制。我们将测试这个假设并确定DNAJA1在HNSCC细胞的恶性进展中的作用。在AIM 1中，我们将确定减少MVP导致MUTP53与DNAJA1抑制结合的机制 MUTP53降解和肿瘤抑制。在AIM 2中，我们将测试DNAJA1促进的假设 HNSCC以错误折叠的MUTP53依赖性方式进展。在AIM 3中，我们将表征潜力 DNAJA1抑制剂通过分子对接研究鉴定出其与DNAJA1结合的能力，诱导 MUTP53降解，并降低HNSCC细胞的恶性特性。这项研究的完成将揭示通过MVP和DNAJA1之间的意外功能联系，MUTP53稳定的新型机制，将会建立MV途径和DNAJA1作为携带Mutp53携带癌症的新型治疗靶标。这项研究还可以将DNAJA1抑制剂识别为可用于HNSCC治疗的潜在化合物。