Mutant p53 gain-of-function as an actionable target in cancer therapy

项目摘要 与其他抑癌基因相比，人类癌症中75%的P53改变是错义突变 产生异常稳定的突变蛋白的DNA结合域(‘mutP53’)。的研究计划 单位主任Ute Moll博士的实验室产生了新的老鼠模型，明确证明了某些热点 错义突变的P53蛋白不仅失去了抑癌功能，而且获得了广泛的致癌收益- 功能外(GOF)活动(‘mup53GOF’)。我们的人源化p53R248Q敲门小鼠(‘Q’小鼠)提供了 长期寻求引人注目的表型，所有自发发生的肿瘤类型起病更快，显著 与p53null产仔相比，存活时间更短。重要的是，我们的发现转化为人类癌症。在李- 携带p53胚系突变的Fraumeni患者，Q等位基因显著加速肿瘤发病10.5 与p53ull样Li-Fraumeni患者相比，该基因突变可导致更高的死亡率。此外，TCGA数据 提示携带特定GOF等位基因的散发性癌症患者的死亡率高于携带GOF等位基因的患者 功能上为零的P53突变。GOF促进了恶性进展，增加了增殖， 侵袭、转移、化疗耐药、间质重塑和重新编程代谢。作为中心 翻译方面的进展，我们的实验室还证实这些小鼠对 突变型P53的持续高表达与肿瘤的生长、维持和转移有关。我们证明了基因 或药物(通过Hsp90抑制剂)消融原发淋巴瘤和结直肠癌中的突变P53 在不同热点GOF敲击小鼠中触发强烈的细胞毒性，转化为肿瘤消退，抑制 侵袭性和主要的生存收益，即使在没有野生型p53的情况下也是如此。我的研究建立在这些强有力的基础上 临床前和临床结果，以进一步探索mup53GOF及其在更广泛的癌症背景下的可利用性。 鉴于TP53突变在所有癌症类型中的异常高频率，这一治疗概念是 与广泛的癌症患者群体高度相关。作为Moll实验室的研究调查员，我是 积极开展两个领域的研究。1)我一直在领导评估治疗潜力的研究 在其他主要散发性癌中应用突变P53消融的研究 胰腺癌。2)设计并鉴定了一种新的‘wtP53转MtP53开关’小鼠品系，并领导了工作 应用时间分辨ChIPseq/Single技术研究突变P53基因GOF驱动的体内肿瘤形成的分子基础 细胞RNAseq和功能蛋白质组分析。我的最终目标是找到新的治疗靶点 突变的P53癌。除了进行工作台研究来解决这些生物和翻译问题外， 我的职责包括培养博士后、研究生和本科生；技术开发 负责实验室基础设施和大型老鼠聚居地的组织和监督。我还管理与 其他团体。

Project Summary In contrast to other tumor suppressors, 75% of p53 alterations in human cancers are missense mutations in the DNA-binding domain that generate abnormally stabilized mutant proteins (‘mutp53’). The research program of Unit Director Dr. Ute Moll’s laboratory generated new mouse models that definitively proved that certain hotspot missense mutant p53 proteins not only lose their tumor suppressor function, but acquire broad oncogenic gain- of-function (GOF) activities (‘mutp53GOF’). Our humanized p53R248Q knockin mice (’Q’ mice) provided the long-sought compelling phenotype of faster onset of all spontaneously arising tumor types and significantly shorter survival compared to p53null littermates. Importantly, our finding translates to human cancers. In Li- Fraumeni patients harboring p53 germline mutations, the Q allele dramatically accelerates tumor onset by 10.5 years and leads to increased mortality compared to p53null-like Li-Fraumeni patients. Moreover, TCGA data suggest that sporadic cancer patients harboring specific GOF alleles have higher death rates than patients with p53 mutations that are functionally null. GOF contributes to malignant progression with increased proliferation, invasion, metastasis, chemoresistance, stroma remodeling and reprogrammed metabolism. As central translational progress, our lab also established that these mice develop strong exploitable dependency on continued high expression of mutp53 for tumor growth, maintenance and metastasis. We showed that genetic or pharmacologic (via Hsp90 inhibitors) ablation of mutp53 in autochthonous lymphomas and colorectal cancers triggers strong cytotoxicity in different hotspot GOF knockin mice, translating to tumor regression, inhibition of invasion and major gains in survival, even in the absence of wildtype p53. My research builds on these strong pre-clinical and clinical findings to further explore mutp53GOF and its exploitability in a broader cancer context. Given the exceptionally high frequency of TP53 mutations across all cancer types, this therapeutic concept is highly relevant for a wide population of cancer patients. As a research Investigator in the Moll laboratory, I am actively pursuing two areas of research. 1) I have been leading research on evaluating the therapeutic potential of mutp53 ablation in other major sporadic carcinomas by testing autochthonous mouse models of liver and pancreatic cancer. 2) I designed and characterized a new ‘wtp53 to mutp53 switch’ mouse strain and I lead work identifying the molecular basis of mutp53 GOF-driven tumor formation in vivo using time-resolved ChIPseq/single cell RNAseq and functional proteome analyses. My ultimate goal is to identify novel therapeutic targets for mutp53 cancers. In addition to performing bench research to address these biologic and translational questions, my responsibilities include training of postdocs, graduate and undergraduate students; technology development for the group and oversight of the lab's infrastructure and large mouse colony. I also manage collaborations with other groups.