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.

头颈鳞状细胞癌（HNSCC）患者的总体 5 年生存率低于 50% 和~75% 的人类 HNSCC 病例的肿瘤抑制基因 p53 存在突变。 p53 突变是显示致癌活性的错义突变，与较差的致癌活性有很强的相关性。最近的证据表明突变型 p53 (mutp53) 在 HNSCC 患者的预后中具有稳定作用。肿瘤对其致癌活性至关重要，而其敲低则可减弱肿瘤的进展。关于野生型 p53 (wtp53) 的功能和调控的出版物有很多，但人们对此知之甚少控制肿瘤中 mutp53 水平的机制以及诱导 mutp53 降解的可行策略。该提案的目标是发现特异性降解 HNSCC 中 mutp53 的有效策略，为了阐明降低 mutp53 水平的潜在机制，我们进行了高水平的研究。对化学库进行通量筛选并鉴定出“他汀类药物”，这是一类抑制胆固醇的药物作为结构错误折叠的 mutp53 蛋白的降解诱导剂，他汀类药物显示出最小的影响。 wtp53 和 DNA 使 mutp53 与天然结构发生还原，但不还原 5-磷酸甲羟戊酸 (MVP)。甲羟戊酸 (MV) 途径中的其他代谢物，通过 CHIP 泛素连接酶触发 mutp53 降解他汀类药物还抑制 mutp53 与 DNAJA1（一种分子）的结合。事实上，mutp53 是 Hsp40 家族的伴侣，在错误折叠蛋白的重折叠中发挥作用。他汀类药物的降解可通过补充 MVP 以及 DNAJA1 过度表达而消除。数据表明 MVP 正向调节 DNAJA1-mutp53 结合，并且 DNAJA1 稳定错误折叠然而，目前尚不清楚 MVP 的减少如何导致 DNAJA1-mutp53 结合的抑制。我们的初步数据表明，甲羟戊酸激酶 (MVK) 的敲低可显着降低 MVP mutp53 的乙酰化增加，我们认为 MVP 还原后 mutp53 的乙酰化会抑制 mutp53-DNAJA1 结合，促进 mutp53 降解，从而抑制肿瘤，我们将对此进行测试。在目标 1 中，我们将建立 DNAJA1 在 HNSCC 细胞恶性进展中的作用。确定减少 MVP 导致 mutp53 与 DNAJA1 结合受到抑制的机制，以诱导 mutp53 降解和肿瘤抑制在目标 2 中，我们将检验 DNAJA1 促进的假设。 HNSCC 以错误折叠的 mutp53 依赖性方式进展。在目标 3 中，我们将描述潜在的特征。通过分子对接研究鉴定出 DNAJA1 抑制剂能够与 DNAJA1 结合，诱导这项研究的完成将揭示mutp53的降解，并降低HNSCC细胞的恶性特性。通过 MVP 和 DNAJA1 之间意想不到的功能联系实现 mutp53 稳定的新机制，并将本研究将 MV 通路和 DNAJA1 作为携带 mutp53 的癌症的新治疗靶点。还可能将 DNAJA1 抑制剂鉴定为可用于 HNSCC 治疗的潜在化合物。