Mechanisms of mutant p53 reactivation

突变体 p53 重新激活的机制

基本信息

批准号：
10719196
负责人：
Peter Kaiser
金额：
$ 49.81万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-10 至 2028-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10719196
关键词：
Academia Affect Alleles Amino Acids Animal Model Apoptosis Binding Bioinformatics Biological Biology Biophysics Biotechnology Cancer Patient Cell Cycle Arrest Cell Proliferation Cells Chemicals Clinic Clinical Trials Collection Crystallography DNA DNA Binding DNA Binding Domain Development Diagnosis Exposure to Future Gene Expression Genes Genetic Genetic Induction Genetic study Goals Human In Vitro Knowledge Length Malignant Neoplasms Malignant neoplasm of lung Malignant neoplasm of ovary Malignant neoplasm of pancreas Mass Spectrum Analysis Missense Mutation Molecular Molecular Conformation Mutate Mutation Oxidation-Reduction Pathway interactions Pharmaceutical Preparations Pharmacologic Substance Positioning Attribute Process Property Proteins Reporting Series Site Structure Structure-Activity Relationship System TP53 gene Testing Therapeutic Tumor Suppression Tumor Suppressor Proteins United States cancer cell cancer therapy crosslink drug development drug-like compound experience experimental study gain of function in vivo inhibitor mutant novel therapeutic intervention pharmacologic prevent programs reconstitution small molecule success targeted cancer therapy therapeutic protein therapeutic target tool translational therapeutics triple-negative invasive breast carcinoma tumor tumor growth tumor progression

项目摘要

PROJECT SUMMARY The tumor suppressor protein p53 is the most frequently mutated protein in human cancers. About 600,000 new cancer patients in the United States are diagnosed each year with tumors expressing mutated p53. Most of the mutations are missense mutations that affect one of six hotspot sites in the p53 DNA binding domain. These cancers express full length p53 that has lost tumor suppressor activity, but has acquired gain-of-function oncomorphic properties that provide selective advantage to cancer cells. The large number of affected cancers make p53 an exquisite target for cancer therapy. However, therapeutic approaches require reactivation of mutated p53. Developing “reactivation or corrector drugs” is challenging in itself, but further complicated by very limited experience in pharma, biotech, and academia in this domain. These challenges in exploring novel therapeutic approaches by developing p53 corrector drugs have led to very slow, and limited success in clinical trials with proposed p53 reactivator compounds. It recently emerged that several of the reported compounds are likely not acting on mutant p53 in vivo, but rather exploit redox- sensitivity of cells expressing p53 mutants. Development of bona fide p53 mutant corrector drugs that bind p53 and restore a wild-type like conformation/activity in p53 cancer mutants, thus remains a central goal with potentially very high impact. To achieve this goal mechanistic understanding of the p53 cancer mutant reactivation process is essential, but currently mostly lacking due to the lack of genuine p53 corrector molecules with the exception of compounds developed specifically for the relatively rare p53-Y220C allele. We have extensively studied genetic and pharmacological p53 reactivation. We found that Intragenic rescue mutations and small molecules we are developing induce a similar conformational change and stabilize an active conformation of p53 hotspot mutants. Although reactivation mutations have no direct therapeutic potential, they help in our understanding of p53 mutant reactivation mechanisms and can guide corrector drug development. Using information obtained from reactivating second-site mutations, we have developed tool compounds that bind mutant p53 and thereby restore DNA binding activity of mutant p53 in a reconstituted purified in vitro system. p53 target genes are induced when cells harboring p53 hotspot mutants are exposed to these compounds. Furthermore, cell proliferation is halted and apoptosis is induced in a p53 mutant dependent manner. Importantly, growth of tumors carrying p53 mutants is blocked by this compound series in animal models. Tumors lacking p53 or expressing wild-type p53 are not affected by such treatment. These compounds provide strong support for feasibility to develop drug-like molecules that act as genuine p53 mutant correctors. We now propose to use these tool compounds as well as well-characterized rescue mutations to develop detailed molecular understanding of the reactivation process for p53 hotspot mutants. Findings from these studies will be essential to jump start the development of chemically diverse p53 corrector drugs.

项目概要肿瘤抑制蛋白 p53 是人类癌症中最常见的突变蛋白，约有 600,000 种。美国每年都有新的癌症患者被诊断患有表达 p53 突变的肿瘤。其中的突变是错义突变，影响 p53 DNA 结合域中的六个热点位点之一。这些癌症表达全长 p53，其已失去肿瘤抑制活性，但已获得功能获得为癌细胞提供选择性优势的肿瘤形态特性。大量的癌症患者使 p53 成为癌症治疗的绝佳靶点。方法需要重新激活突变的 p53，开发“重新激活或校正药物”具有挑战性。其本身，但由于制药、生物技术和学术界在该领域的经验非常有限而变得更加复杂。通过开发 p53 校正药物来探索新的治疗方法所面临的这些挑战导致最近出现的 p53 重激活剂化合物的临床试验进展缓慢且成功有限。一些报道的化合物可能不会在体内作用于突变型 p53，而是利用氧化还原作用表达 p53 突变体的细胞的敏感性开发结合 p53 的真正的 p53 突变体校正药物。并恢复 p53 癌症突变体中野生型的构象/活性，因此仍然是一个中心目标为了实现这一目标，对 p53 癌症突变体的机制了解可能会产生非常大的影响。重新激活过程是必要的，但目前由于缺乏真正的p53校正器而大多缺乏分子，但专门为相对罕见的 p53-Y220C 等位基因开发的化合物除外。我们主要研究了基因和药理学p53重新激活，我们发现了基因内拯救。我们正在开发的突变和小分子会诱导类似的构象变化并稳定 p53热点突变体的活性构象虽然重新激活突变没有直接的治疗作用。潜力，它们有助于我们理解 p53 突变体重新激活机制，并可以指导校正药物利用从重新激活第二位点突变中获得的信息，我们开发了工具。结合突变体 p53 并恢复突变体 p53 的 DNA 结合活性的化合物，从而重建当含有 p53 热点突变体的细胞暴露时，纯化的体外系统会诱导 p53 靶基因。此外，p53 突变体中的细胞增殖被停止并诱导细胞凋亡。重要的是，携带 p53 突变体的肿瘤生长被该化合物系列阻断。缺乏 p53 或表达野生型 p53 的动物模型不受此类治疗的影响。化合物为开发充当真正的p53突变体的药物样分子的可行性提供了强有力的支持我们现在建议使用这些工具化合物以及充分表征的救援突变来对 p53 热点突变体的重新激活过程进行详细的分子理解。这些研究对于快速开发化学多样化的 p53 校正药物至关重要。