Targeting Nucleotide Excision Repair Deficiency to Improve Bladder Sparing Treatment for Muscle Invasive Bladder Cancer

项目总结 器官保留治疗是多种实体肿瘤的标准治疗方法。对病人来说 肌肉浸润性膀胱癌(MIBC)、膀胱切除(根治性膀胱切除术)和保留膀胱 放化疗(CRT)是两种具有长期安全性和有效性的治疗方法。 数据；然而，这两种方法从未在随机试验中进行过比较。因此，这一决定 目前仅根据临床病理特征和患者/提供者进行手术入路 偏好。目前还没有可用的分子生物标记物来通知自由基之间的决定 膀胱切除和保留膀胱的CRT。我们之前的工作确定了~15%的MIBCs子集与体细胞 核苷酸切除修复基因ERCC2的改变。NER途径是一种高度保守的DNA 修复途径，修复由遗传毒素如紫外线照射和铂类药物引起的笨重的DNA加合物。 我们显示患有ERCC2突变肿瘤的MIBC患者对以顺铂为基础的药物的反应有所改善 化疗与MIBC患者合并野生型ERCC2肿瘤的比较和我们的功能工作 证明临床观察到的ERCC2突变不能支持正常的细胞内皮细胞 足以在临床前膀胱癌模型中增加顺铂的敏感性。然而， ERCC2突变对临床CRT方案的反应尚不清楚。这项提议的首要假设是 ERCC2突变导致NER缺乏症是否定义了具有独特生物学特性的膀胱癌的子集 特性和治疗脆弱性，包括对临床相关CRT方案的敏感性增加。这个 这里提出的工作目标是剖析导致NER独特属性的细胞机制 并明确NER缺乏对CRT反应的影响。在目标1中，我们将调查 ERCC2和其他NER通路基因突变与临床预后的关系 240例MIBC患者接受CRT治疗，完成合作组试验。我们将从功能上审问 观察到的NER基因改变在膀胱癌模型中的影响，我们将比较常见的 CRT方案在等基因NER-熟练/缺陷型人膀胱癌临床前模型中的应用在目标2中，我们 将确定NER缺乏对膀胱肿瘤微环境中免疫细胞亚群的影响 等基因NER-熟练/缺陷小鼠膀胱癌模型的建立及CD8+的作用 NER熟练和NER缺陷模型中T细胞对CRT的反应。我们还将表演转录 190例临床MIBC患者的临床资料，并将调查ERCC2突变状态与 免疫渗透的转录特征和临床结果。在目标3中，我们将调查CHK1 抑制作为诱导膀胱NER缺乏和增加对以顺铂为基础的治疗敏感性的策略 WT ERCC2的肿瘤。总之，这些整合的基因组和功能研究将定义 NER缺乏症作为MIBC保留膀胱治疗方法的生物标志物和治疗靶点。

PROJECT SUMMARY Organ-preserving therapy is the standard curative approach for numerous types of solid tumors. For patients with muscle-invasive bladder cancer (MIBC), bladder removal (radical cystectomy) and bladder-preserving chemoradiotherapy (CRT) are the two curative treatment approaches supported by long-term safety and efficacy data; however, these two approaches have never been compared in a randomized trial. Therefore, the decision between approaches is currently made based solely on clinical-pathologic features and patient/provider preference. There are currently no molecular biomarkers available to inform the decision between radical cystectomy and bladder-sparing CRT. Our previous work identified a subset of ~15% of MIBCs with somatic alterations in the nucleotide excision repair (NER) gene ERCC2. The NER pathway is a highly conserved DNA repair pathway that repairs bulky DNA adducts caused by genotoxins such as UV irradiation and platinum drugs. We showed that MIBC patients with ERCC2-mutant tumors have improved response to cisplatin-based chemotherapy compared to MIBC patients with wild-type (WT) ERCC2 tumors, and our functional work demonstrated that clinically observed ERCC2 mutations were unable to support normal cellular NER and were sufficient to confer increased cisplatin sensitivity in preclinical bladder cancer models. However, the impact of ERCC2 mutations on response to clinical CRT regimens is unknown. The overarching hypothesis of this proposal is that NER deficiency conferred by ERCC2 mutations define a subset of bladder tumors with unique biological properties and therapeutic vulnerabilities, including increased sensitivity to clinically relevant CRT regimens. The goal of work proposed here is to dissect the cellular mechanisms that contribute to the unique properties of NER deficient tumors and to define the impact of NER deficiency on CRT response. In Aim 1, we will investigate the association between mutations in ERCC2 and other NER pathway genes and clinical outcomes in a cohort of 240 MIBC patients treated with CRT on completed cooperative group trials. We will functionally interrogate the impact of observed NER gene alterations in bladder cancer models and we will compare the activity of commonly used CRT regimens in isogenic NER-proficient/deficient human bladder cancer preclinical models. In Aim 2, we will define the impact of NER deficiency on immune cell subsets in the bladder tumor microenvironment in two isogenic NER-proficient/deficient mouse bladder cancer models and we will investigate the contribution of CD8+ T cells to CRT response in the NER-proficient and NER-deficient models. We will also perform transcriptional profiling of 190 clinical MIBC cases and will investigate the relationship among ERCC2 mutation status, transcriptional signatures of immune infiltration, and clinical outcomes. In Aim 3, we will investigate CHK1 inhibition as a strategy to induce NER deficiency and increase sensitivity to cisplatin-based treatments in bladder tumors with WT ERCC2. Together, these integrated genomic and functional studies will define the impact of NER deficiency as a biomarker and therapeutic target in bladder-sparing treatment approaches for MIBC.