Developing corrector small molecules for reactivation of mutant p53 in cancer

项目总结 抑癌蛋白P53是人类癌症中最常见的突变蛋白。约600,000 美国每年都有新的癌症患者被诊断出患有表达突变的p53的肿瘤。多数 在与p53相关的突变中，有一种是影响DNA中六个热点位置之一的错义突变 结合结构域。这些癌症表达全长的P53，它已经失去了肿瘤抑制活性，但获得了 为癌细胞提供选择性优势的功能获得性肿瘤形态特性。 针对P53的治疗方法具有挑战性，需要重新激活突变的P53。发展中 这种重新激活或纠正药物由于在制药、生物技术和药物方面的经验有限而进一步复杂化。 在这一领域的学术界。这些通过开发p53来探索新的治疗方法的挑战 校正药物在临床试验中的成功非常缓慢，而且有限，建议的P53再激活因子 化合物。然而，人们可以辩称，真正的p53校正药物尚未在临床上进行测试， 因为在体内，可用的化合物(即APR-246和其他硫醇活性分子)很可能不是 作用于突变型p53，而不是利用表达突变型p53的细胞的氧化还原敏感性。发展中的 结合P53并恢复P53野生型构象/活性的真P53突变校正药物 因此，癌症突变者仍然是一个具有潜在非常高影响的关键目标。 我们已经开发出一种小分子系列，它能结合突变型p53的L1/S3口袋，从而恢复 体外重组纯化系统中突变型P53的DNA结合活性。这些结果反映在 含p53热点突变体的细胞暴露于这些化合物后对p53靶基因表达的诱导作用 化合物。此外，依赖于p53突变的细胞增殖受阻并诱导细胞凋亡。 举止。重要的是，携带p53突变体的实体肿瘤在动物体内被该化合物系列所阻断。 模特们。缺乏P53或表达野生型P53的肿瘤不受这种治疗的影响。这些 化合物为开发可修复肿瘤的类药物分子的可行性提供了强有力的支持 P53热点突变体中的抑制子活性。然而，这些化合物在细胞内的微摩尔范围内起作用。 需要改进培养系统和活性，以产生用于药物开发的先导化合物。我们 提出两种并行的方法来实现这一目标。 这项提议将为突变型p53校正药物的开发产生有前途的先导化合物。

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 associated with p53 are missense mutations that affect one of six hotspot sites in the DNA binding domain. These cancers express full length p53 that has lost tumor suppressor activity, but acquired gain-of-function oncomorphic properties that provide selective advantage to cancer cells. Therapeutic approaches targeting p53 are challenging and require reactivation of mutated p53. Developing such reactivation or corrector drugs is 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. However, one can argue that genuine p53 corrector drugs have not yet been tested in the clinic, because in vivo the available compounds (i.e. APR-246 and other thiol reactive molecules) are most likely not acting on mutant p53, but rather exploit redox-sensitivity of cells expressing p53 mutants. Development of genuine p53 mutant corrector drugs that bind p53 and restore a wild-type like conformation/activity in p53 cancer mutants, thus remains a crucial goal with potentially very high impact. We have developed a small molecule series that binds the L1/S3 pocket of mutant p53 and thereby restores DNA binding activity of mutant p53 in a reconstituted purified in vitro system. These results are reflected in induction of p53 target gene expression 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 solid 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 can restore tumor suppressor activity in p53 hotspot mutants. However, these compounds act in the low micromolar range in cell culture systems and activity needs to be improved to generate lead compounds for drug development. We propose two parallel approaches to achieve this goal. This proposal will generate promising lead compounds for mutant p53 corrector drug development.