Mechanisms of mutant p53 reactivation

突变体 p53 重新激活的机制

• 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
• 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

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.

项目摘要 肿瘤抑制蛋白p53是人类癌症中最常见的突变蛋白。约60万 每年在美国，新的癌症患者被诊断出表达突变p53的肿瘤。最多 这些突变是影响p53 DNA结合域中六个热点位点之一的错义突变。 这些癌症表达了失去肿瘤抑制活性的全长p53，但获得了功能的收益 对癌细胞的选择性优势的oncomorphic特性。 大量受影响的癌症使P53成为癌症治疗的独家靶标。但是，治疗 方法需要重新激活突变的p53。开发“重新激活或矫正药物”在 本身，但由于在该领域的制药，生物技术和学术界的经验非常有限的经验而变得更加复杂。 通过开发p53校正药物来探索新型热方法的这些挑战已导致 在提出的p53反抗器化合物的临床试验中，非常慢，成功的成功。它最近出现了 几种报告的化合物可能不对体内突变体p53作用，而是利用氧化还原 表达p53突变体的细胞的敏感性。真正的p53突变纠正药物结合p53的开发 并恢复p53癌症突变体中的野生型构象/活性，因此仍然是一个核心目标 可能很高的影响。为了实现对p53癌症突变体的目标机械理解 重新激活过程是必不可少的，但目前由于缺乏真正的p53校正器而缺乏重新激活的过程 除了专门为相对罕见的p53-Y220C等位基因开发的化合物外，分子。 我们已经进行了广泛研究的遗传和药物p53重新激活。我们发现基因内救援 突变和小分子我们正在发展影响类似的构象变化并稳定 p53热点突变体的主动构象。尽管重新激活突变没有直接治疗 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 发展。使用从重新激活第二站点突​​变获得的信息，我们开发了工具 结合突变体p53的化合物，从而恢复重构中突变体p53的DNA结合活性 纯化体外系统。当携带p53热点突变体的细胞暴露时诱导p53靶基因 到这些化合物。此外，细胞增殖停止并在p53突变体中诱导凋亡 依赖方式。重要的是，携带p53突变体的肿瘤的生长被该化合物系列所阻断 动物模型。缺乏p53或表达野生型p53的肿瘤不受这种治疗的影响。这些 化合物为开发具有真正p53突变体的药物样分子的可行性提供了强有力的支持 校正器。现在，我们建议使用这些工具化合物以及特定的救援突变 开发了对p53热点突变体重新激活过程的详细分子理解。来自 这些研究对于开始开发化学潜水p53校正药物至关重要。