p53-Independent Cell Death Signaling by Mitomycin DNA Adducts

描述（由申请人提供）：需要确定独立于p53诱导细胞死亡的药物和途径，这一点值得高度关注。当p53和其他凋亡途径失活时，诱导癌细胞死亡是具有挑战性的，并且需要诱导不需要肿瘤抑制因子p53的细胞死亡途径的化疗药物，因为至少50%的癌症缺乏功能性p53途径。我们发表了不同的丝裂霉素（烷基化剂）激活p53依赖性和p53非依赖性细胞死亡。我们看到丝裂霉素衍生物10-十氨甲酰丝裂霉素C（DMC），而不是丝裂霉素C（MC），可以快速激活p53非依赖性细胞死亡途径，缺乏凋亡死亡的标志物。DMC诱导的细胞死亡是用于鉴定诱导p53非依赖性细胞死亡途径（例如坏死和自噬）的靶标的良好模型。我们的中心假设是，DMC引起p53非依赖性细胞死亡，由于特定的DNA加合物的形成和阐明的途径（S）将使有效的药物设计参数。确定DMC诱导细胞死亡的机制是该提案的重点，并且将是开发药物以战略性地诱导许多缺乏功能性p53通路的癌症细胞死亡的第一步。尽管p53非依赖性细胞死亡的重要性，很少有人知道这些途径的激活。提出了四个目标，将使用具有诱导型p53及其同基因对（无p53）的人癌细胞系来检查细胞死亡信号中的p53依赖性和独立性，以及C. elegans作为临床前模型系统。(1)鉴定在存在和不存在p53的情况下细胞死亡所需的由DMC和MC激活和/或抑制的人信号转导途径。(2)分析DMC和MC DNA加合物在体外和体内在存在和不存在p53的情况下募集DNA修复蛋白的能力。(3)比较分析p53通路和自噬通路对化疗DNA损伤诱导的C. elegans线虫and human人cell细胞systems系统. (4)为我的实验室研究获得R 01资金。 关于如何靶向p53非依赖性细胞死亡的知识存在空白。了解p53非依赖性细胞死亡途径的信号机制将有助于将药物靶向缺乏功能性p53的癌症患者。

DESCRIPTION (provided by applicant): The need to identify drugs and pathways that induce cell death independently of p53 deserves substantial attention. Induction of cancer cell death is challenging when p53 and other apoptotic pathways are inactivated, and requires chemotherapeutics that induce cell death pathways that do not require the tumor suppressor p53, as at least 50 percent of cancers lack a functional p53 pathway. We published that different mitomycins, which are alkylating agents, activate p53-dependent and p53-independent cell death. We see the mitomycin derivative 10-decarbamyl mitomycin C (DMC), as opposed to mitomycin C (MC), can rapidly activate a p53-independent cell death pathway which lacks markers of apoptotic death. DMC-induced cell death is a good model for identifying targets for the induction of p53-independent cell death pathways, such as necrosis and autophagy. Our central hypothesis is that DMC provokes p53-independent cell death due to specific DNA adducts formed and that elucidating the pathway(s) will enable efficient drug design parameters. Identifying the mechanisms by which DMC induces cell death is the focus of this proposal and will be a first step toward developing drugs to strategically induce cell death for the many cancers lacking functional p53 pathways. Despite the importance of p53-independent cell death, little is known about the activation of such pathways. Four aims are proposed that will use a human cancer cell line with inducible p53 and its isogenic pair (without p53) to examine p53 dependency and independency in cell death signaling, and C. elegans to serve as a preclinical model system. (1) Identify the human signal transduction pathways required for cell death in the presence and absence of p53 that are activated and/or repressed by DMC and MC. (2) Analyze the ability of DMC and MC DNA adducts in vitro and in vivo to recruit DNA repair proteins in the presence and absence of p53. (3) Perform comparative analysis of the influence of the p53 pathway and the autophagy pathway on the chemotherapeutic DNA damage-induced cell death in C. elegans and human cell systems. (4) Obtain R01 funding for my laboratory research. There is a gap in knowledge as to how to target for p53-independent cell death. Knowledge of the signaling mechanisms for p53-independent cell death pathways will help in targeting drugs to patients who have cancers that lack functional p53.