Functions and Activities of p53 and Mdm2 in Normal and Cancer Cells

P53和MDM2在正常细胞和癌细胞中的功能和活性 P53蛋白是动物和人类癌症的主要抑制因子，是一种DNA序列 数百个基因的特异性转录调节因子，其产物介导细胞 结果如细胞周期停滞、细胞死亡、衰老、代谢变化、DNA修复和 其他与肿瘤抑制相一致的。虽然这类过程的一个强有力的监管机构 承受各种形式的遗传毒性或致癌压力的细胞，如果允许其发挥作用的话 如果不加以控制，p53可能会对细胞和组织造成破坏，甚至是致命的。让P53保持在较低水平 因此，控制与允许它在需要时发挥作用一样重要。这两种蛋白质 在抑制P53中发挥最核心作用的是MDM2及其同系物MDMX。超过一半的人 所有人类恶性肿瘤(取决于肿瘤类型)都含有野生型p53，如果释放出来的话 来自MDM2/X，可能是一种有效的细胞抑制或细胞毒性抗肿瘤药物。然而，试剂 阻止MDM2与P53结合的多肽和小分子尚未完全被发现 被认为是有效的治疗剂。同样，临床上几乎没有有效的药物 抑制突变型P53的致癌活性。此外，增加证据文件的行数 MDM2和MDMX在可用于治疗的癌细胞中的P53非依赖性作用 和诊断目的。在这份申请中为一名杰出的调查员建议的工作 获奖之前，我们在国际和平研究所的实验室里做出了长期的贡献 P53、MDM2和MDMX一直延续至今。未来的计划建立在新的基础上 在PI的实验室中发现，并融入新技术，以获得更多全球和 关于P53/MDM轴的机械性信息。拟议的研究将延长最近的 与(I)MDM2降解P53的新机制和可能性有关的发现 这一发现可以导致新的疗法，防止MDM2降解野生型p53或 反过来促进癌基因突变型p53的MDM2降解，(Ii)一系列 CRISPR来源的细胞系具有独特的Li-Fraumeni综合征p53突变；(Iii)P53- MDM2和MDMX可能预防或支持肿瘤发生的独立作用，(Iv) 作为p53靶标的长的非编码RNA，可能在人类中提供新的生物标志物 癌症；(V)了解p53如何在体外和体内识别其位置的新方法，以及， (Vi)在单分子分辨率下研究野生型和突变型的定位 P53和MDM2在不同刺激后的表达。这一计划的长期目标有望导致 诊断和治疗散发性和遗传性癌症的新工具。

Functions and Activities of p53 and Mdm2 in Normal and Cancer Cells. The p53 protein, a major suppressor of cancer in animals and humans, is a DNA sequence specific regulator of transcription of hundreds of genes whose products mediate cellular outcomes such as cell cycle arrest, cell death, senescence, metabolic changes, DNA repair and others that are consistent with tumor suppression. While a potent regulator of such processes in cells undergoing various forms of genotoxic or oncogenic stress, if allowed to function unchecked, p53 can be damaging or even lethal to cells and tissues. Keeping p53 under tight control is therefore as important as allowing it to function when needed. The two proteins that play the most central role in suppressing p53 are Mdm2 and its homologue MdmX. Over half of all human malignancies (depending on the tumor type) harbor wild-type p53, which if released from Mdm2/X, might be effective as a cytostatic or cytotoxic anti-tumor agent. Yet reagents (peptides and small molecules) that prevent Mdm2 from binding to p53 have not yet been fully realized as effective therapeutic agents. Similarly, there few effective drugs in the clinic that prevent the oncogenic activities of mutant p53. Further, increasing lines of evidence document p53-independent roles of Mdm2 and MdmX in cancer cells that can be exploited for therapeutic and diagnostic purposes. The work proposed in this application for an Outstanding Investigator Award follows a long history of contributions in the laboratory of the PI to our understanding p53, Mdm2 and MdmX that continue to the present day. The plans going forward build on new findings in the PI's lab, and incorporate novel technologies in order to gain more global and mechanistic information about the p53/Mdm axis. The research proposed will extend recent discoveries related to (i) a novel mechanism by which Mdm2 degrades p53 and the possibility that this finding can lead to new therapeutics that prevent Mdm2 degradation of wild-type p53 or conversely facilitate Mdm2 degradation of oncogenic mutant forms of p53, (ii) a series of CRISPR-derived cell lines harboring unique Li-Fraumeni-Syndrome p53 mutations; (iii) p53- independent roles of Mdm2 and MdmX that may either prevent or support oncogenesis, (iv) long non-coding RNAs that are p53 targets and which may provide new biomarkers in human cancers; (v) new approaches to understand how p53 identifies its sites in vitro and in vivo and, (vi) examination at single molecule resolution the localization of wild-type and mutant forms of p53 and Mdm2 after different stimuli. The long term goals of this program will hopefully lead to new tools for diagnosis and treatment of sporadic and inherited cancers.