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

项目摘要 与其他肿瘤抑制因子相比，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质（“mutp 53”）的DNA结合结构域。的研究计划 Ute Moll博士的实验室生成了新的小鼠模型，明确证明了某些热点 错义突变型p53蛋白不仅丧失了其肿瘤抑制功能，而且获得了广泛的致癌增益， 功能性（GOF）活性（“mutp 53 GOF”）。我们的人源化p53 R248 Q敲入小鼠（“Q”小鼠）提供了 长期寻求的令人信服的表型，所有自发产生的肿瘤类型的发病更快， 与p53缺失的同窝仔相比，存活率更短。重要的是，我们的发现转化为人类癌症。在李- Fraumeni患者携带p53生殖系突变，Q等位基因显著加速肿瘤发作10.5 与p53 null样Li-Fraumeni患者相比，此外，TCGA数据 表明携带特异性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， p53突变是功能无效的。GOF导致恶性进展，增殖增加， 侵袭、转移、化学抗性、间质重塑和重编程代谢。如中央 翻译进展，我们的实验室还确定，这些小鼠发展了强烈的可利用依赖性， mutp 53的持续高表达对肿瘤的生长、维持和转移起作用。我们发现基因 或药理学（通过Hsp 90抑制剂）切除原位淋巴瘤和结直肠癌中的mutp 53 在不同热点GOF基因敲入小鼠中引发强烈的细胞毒性，转化为肿瘤消退， 侵袭和生存的主要增益，即使在没有野生型p53。我的研究建立在这些强大的 临床前和临床发现，以进一步探索mutp 53 GOF及其在更广泛的癌症背景下的可利用性。 考虑到TP 53突变在所有癌症类型中的异常高频率， 与广泛的癌症患者群体高度相关。作为摩尔实验室的研究员，我 积极开展两方面的研究。1)我一直在领导一项研究， 在其他主要散发性癌中mutp 53消融的研究， 胰腺癌2)我设计并表征了一种新的“wtp 53到mutp 53开关”小鼠品系， 使用时间分辨ChIPseq/single鉴定mutp 53 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。我的最终目标是确定新的治疗靶点， mutp 53癌症。除了进行实验室研究以解决这些生物学和翻译问题外， 我的职责包括培养博士后、研究生和本科生;技术开发 并监督实验室的基础设施和大型小鼠群。我还管理与 其他各组

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.