Project 4: FTO Inhibition to Enhance the Therapeutic Index of Radiotherapy

摘要（项目4） 放射治疗是许多实体瘤的标准治疗方法，包括宫颈癌、非小细胞肺癌（NSCLC） 癌症和头颈癌。虽然在大部分患者中有效，但局部失败仍然是一个问题。 患者发病率和死亡率的重要原因。一个有吸引力的策略，放射增敏肿瘤是靶向 癌症特异性谷氨酰胺代谢重编程，因为该途径支持肿瘤生长、存活、氧化 应激反应和DNA损伤修复。RNA去甲基化酶FTO正在成为一种治疗靶点， 癌症治疗，因为它在几种癌症中过表达和致癌，包括宫颈癌、非小细胞肺癌、 癌症（NSCLC）和头颈癌。然而，FTO以前没有被探索为目标， 肿瘤放射增敏初步研究表明，FTO抑制可减少肿瘤生长和存活 在体外和体内。在分子水平上，FTO抑制降低了SLC 1A 5的表达和谷氨酰胺的摄取。 癌细胞重要的是，FTO抑制使宫颈癌和KEAP 1突变型NSCLC癌细胞放射增敏。这 一项提案将检验这一假设，即抑制RNA去甲基化酶脂肪量和肥胖相关 (FTO)将通过抑制肿瘤细胞的增殖来提高放射治疗在实体瘤中的治疗指数。 谷氨酰胺代谢目的1将确定FTO抑制与FTO抑制联合的抗肿瘤作用。 使用遗传学和药理学方法对一系列实体瘤癌症进行放射治疗。目标2确定是否 FTO抑制通过降低谷氨酰胺代谢、氧化还原和抗氧化能力来增强癌细胞中的辐射反应。 应激和/或DNA损伤修复反应。目标3将测试 FTO抑制不会影响产生辐射的正常组织的辐射敏感性的假设- 在治疗宫颈、NSCLC和HNSCC肿瘤时诱导毒性。FTO抑制的急性和晚期效应 骨髓、肠（与项目1合作）、唾液腺和口腔中的辐射反应 粘膜（与项目2合作）和肺（与项目3合作）将使用以下模型进行分析： 在成年小鼠中的整体条件性FTO失活。与项目1、2和3一起，该项目将调查 FTO在肿瘤和正常组织放射反应中的作用，目的是确定FTO在肿瘤和正常组织放射反应中的作用。 基于FTO的放射增敏剂的治疗潜力。除了确定肿瘤类型， 有效和安全地治疗FTO抑制，他们将使用最先进的分析工具来研究 作用机制。这些目标的成功完成将1）确定FTO是一个表转录调控因子 2）提供临床前数据支持FTO作为一种抗肿瘤药物， 安全有效的分子靶点，以放射增敏肿瘤; 3）提供概念验证研究，以证明 靶向FTO脱甲基酶活性小分子可使肿瘤放射增敏。

Abstract (Project 4) Radiation therapy is a standard treatment for many solid tumors including cervical, non-small cell lung (NSCLC) cancer, and head and neck cancer. While effective in a large proportion of patients, local failure remains a significant cause of patient morbidity and mortality. An attractive strategy to radiosensitize tumors is targeting cancer-specific glutamine metabolic reprogramming as this pathway supports tumor growth, survival, oxidative stress responses and DNA damage repair. The RNA demethylase FTO is emerging as a therapeutic target for cancer therapy as it is overexpressed and oncogenic in several cancers including cervical, non-small cell lung cancer (NSCLC), and head and neck cancers. However, FTO has not previously been explored as a target for tumor radiosensitization. Preliminary studies demonstrate that FTO inhibition reduces tumor growth and survival in vitro and in vivo. At the molecular level, FTO inhibition reduces SLC1A5 expression and glutamine uptake in cancer cells. Importantly, FTO inhibition radiosensitizes cervical and KEAP1 mutant NSCLC cancer cells. This proposal will test the hypothesis that inhibition the RNA demethylase fat-mass and obesity-associated (FTO) will enhance the therapeutic index of radiotherapy in solid tumors through the inhibition of glutamine metabolism. Aim 1 will determine the anti-tumor effects of FTO inhibition in combination with radiation on a range of solid tumors cancers using genetic and pharmacologic approaches. Aim 2 determine if FTO inhibition enhances the radiation response in cancer cells by reducing glutamine metabolism, oxidative stress and/or DNA damage repair responses using knockdown and gain of function approaches. Aim 3 will test the hypothesis that FTO inhibition will not impact the radiation sensitivity of normal tissues that develop radiation- induced toxicity when treating cervical, NSCLC and HNSCC tumors. The acute and late effects of FTO inhibition on the radiation response in the bone marrow, intestine (collaboration with Project 1), salivary gland and oral mucosa (collaboration with Project 2), and lung (collaboration with Project 3) will be analyzed using models of global conditional FTO inactivation in adult mice. Together with Projects 1, 2 and 3 this project will investigate the role of FTO in both the tumor and normal tissue radiation response with the goal of ascertaining the therapeutic potential of FTO-based radiosensitizers. In addition to determining the tumor types that can be effectively and safely treated with FTO inhibition, they will use cutting edge analytical tools to study the mechanism of action. Successful completion of these aims will 1) identify FTO is an epitranscriptomic regulator of cancer cell glutamine metabolism and oxidative stress; 2) provide the preclinical data to support FTO as a safe and effective molecular target to radiosensitize tumors; 3) provide proof of concept studies to demonstrate that small molecule targeting of FTO demethylase activity can radiosensitize tumors.