Novel inhibitors of oncogenic p53 mutants for lung cancer therapy.

项目摘要 功能获得性（GOF）p53突变在所有类型的化疗和放疗耐药的难治性肿瘤中非常常见。 预后差的肺癌。内源性突变型p53的缺失消除了肿瘤的致瘤表型， 许多人肺癌细胞系。因此，特异性抑制癌基因的小分子抑制剂， GOF p53的功能应该对许多肺癌患者具有癌细胞特异性的有效影响。 使用肺癌细胞的全基因组分析，我们追踪了GOF p53的致癌特性， 转录激活细胞增殖基因表达的能力。我们公布的基因数据显示， 反式激活缺陷型GOF p53在肺癌细胞的肿瘤形成和增殖中有缺陷。这里我们 我建议测试一个假设，即GOF p53特异性转录激活（GOF）的小分子抑制剂 p53 TAIn）特异性抑制肺癌细胞和具有GOF p53突变的肿瘤的增殖。我们的短- 我们的目标是在肺癌的细胞和动物模型中检验这一假设。我们的长期目标是翻译 我们的发现用于人类肺癌的新型靶向治疗。 为了支持我们的假设，我们的初步研究已经确定了新的小分子抑制剂（GOF p53 TAIns）特异性抑制GOF p53驱动的转录激活，保留野生型（WT）p53- 诱导转录和基础转录。初步实验鉴定了GOF p53 TAIns， 用GOF p53抑制肺癌细胞的生长，超过p53缺失的肺癌细胞或用WT抑制肺癌细胞的生长 53. GOF p53 TAIns之一，Gloxazone，特异性抑制GOF p53诱导的转录和细胞生长， 并且另外特异性抑制来自具有突变型p53的肺癌细胞异种移植物的肿瘤生长， 而不是WT p53。将通过以下具体目标进一步检验所提出的假设： 目的1：检查鉴定的GOF p53 TAIns特异性抑制GOF p53诱导的GAF的能力。 肺癌细胞的生长诱导细胞死亡。跨越不同亚型的人肺癌细胞系（非 小细胞，小细胞，鳞状细胞），具有或不具有各种GOF p53突变（a），匹配的基因编辑的 具有GOF p53、WT p53和p53无效等位基因的肺癌细胞系（B），和从原发性或非原发性肺癌中分离的肿瘤细胞， 将使用传代的患者肺癌样品（c）。GOF p53 TAIns改变GOF p53稳定性的能力 并将开始分析选定化合物的生长抑制机制。 目的2：检查鉴定的GOF p53 TAIns特异性抑制GOF p53驱动的 肿瘤生长和诱导肿瘤细胞死亡。三种小鼠模型，肿瘤来自（a） 皮下或原位植入的肺癌细胞异种移植物，和（B）患者来源的异种移植物 (PDX)和（c）诱导型GOF p53依赖性肺癌小鼠 模型将被检查。

Project Summary Gain-of-function (GOF) p53 mutations are very frequent in all types of chemo- and radio-resistant intractable lung cancers with poor prognosis. Depletion of endogenous mutant p53 eliminates the tumorigenic phenotype of many human lung cancer cell lines. Therefore, small molecule inhibitors that specifically inactivate the oncogenic function of GOF p53 should have a cancer cell-specific efficient impact on many lung cancer patients. Using genome wide analyses of lung cancer cells, we have traced the oncogenic properties of GOF p53 to its ability to transcriptionally activate expression of cell proliferative genes. Our published genetic data showed that transactivation deficient GOF p53 is defective in tumor formation and proliferation of lung cancer cells. Here we propose to test a hypothesis that small molecule inhibitors of GOF p53-specific transcriptional activation (GOF p53TAIn) specifically inhibit proliferation of lung cancer cells and tumors with GOF p53 mutation. Our short- term goal is to test this hypothesis in cellular and animal models of lung cancer. Our long-term goal is to translate our findings into novel targeted therapies for human lung cancer. In support of our hypothesis, our preliminary studies have identified novel small molecule inhibitors (GOF p53TAIns) that specifically inhibit GOF p53-driven transcriptional activation sparing Wild-type (WT) p53- induced transcription and basal transcription. Pilot experiments identified GOF p53TAIns that preferentially inhibited growth of lung cancer cells with GOF p53, over p53-null lung cancer cells or lung cancer cells with WT 53. One of the GOF p53TAIns, Gloxazone, specifically inhibits GOF p53-induced transcription and cell growth, and in addition specifically inhibits growth of tumors from xenografts of lung cancer cells with mutant p53 but not from that of WT p53. The proposed hypothesis will be further tested via the following specific aims: Aim 1: Examine identified GOF p53TAIns for their ability to specifically inhibit GOF p53-induced growth of lung cancer cells inducing cell death. Human lung cancer cell lines spanning different subtypes (non- small cell, small cell, squamous cell) with or without various GOF p53 mutation (a), matched sets of gene-edited lung cancer cell lines with GOF p53, WT p53 and p53-null alleles (b), and tumor cells isolated from primary or passaged patient lung cancer samples (c) will be employed. Ability of GOF p53TAIns to alter GOF p53 stability will be determined and analysis of mechanism of growth inhibition for selected compounds will be initiated. Aim 2: Examine identified GOF p53TAIns for their ability to specifically inhibit GOF p53-driven tumor growth and induce tumor cell death using mouse models. Three mouse models, tumors from (a) xenograft of lung cancer cells, implanted subcutaneously or orthotopically, and (b) patient-derived xenografts (PDX) in immunocompromised mice will be used and (c) inducible GOF p53-dependent lung cancer mouse models will be examined.