Modulation of Bcl2 BH4 and mTOR in lung cancer therapeutics

肺癌治疗中 Bcl2、BH4 和 mTOR 的调节

• 批准号: 9150648
• 负责人: Xingming Deng
• 金额: $ 35.69万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-25 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9150648
• 关键词: Affect; Animal Model; Apoptosis; Apoptotic; BCL2 gene; BH4 Domain; Biological Markers; Cancer Patient; Clinical; DNA Sequence Alteration; Data; Databases; Development; Docking; FRAP1 gene; Family; Genetic; Genetic Engineering; Human; In Vitro; Investigation; Ionizing radiation; KRAS2 gene; Lead; Lung Neoplasms; MAPK3 gene; MEKs; Malignant neoplasm of lung; Modeling; Mutation; Names; New Agents; Non-Small-Cell Lung Carcinoma; Normal tissue morphology; Outcome; Patients; Pharmaceutical Preparations; Phosphorylation; Prognostic Marker; Public Health; Radiation; Radiation therapy; Radio; Radioresistance; Ras/Raf; Resistance; Signal Pathway; Signal Transduction; Site; Staging; Therapeutic; Therapeutic Intervention; Toxic effect; Tumor Tissue; cancer cell; cancer therapy; chemoradiation; in vivo; inhibitor/antagonist; mTOR Inhibitor; mTOR inhibition; member; mouse model; novel; novel strategies; outcome forecast; potency testing; predictive marker; programs; public health relevance; small molecule; small molecule libraries; survival outcome; tetrahydrobiopterin; therapeutic target; therapy resistant; treatment response; tumor; tumor growth

 DESCRIPTION (provided by applicant): Survival outcomes remain very poor for lung cancer patients, in part due to treatment resistance. K-Ras mutations are among the common genetic alterations in human lung cancer. These genetic aberrations may negatively affect treatment response to chemoradiotherapy. Bcl2 is the major anti-apoptotic member of the Bcl2 family that may act as downstream survival substrates of these genetic mutations-activated signaling pathway(s). Our preliminary data indicate that genetic alterations in K-Ras, ionizing radiation (IR) and mTOR inhibition by rapalog positively regulate expression and/or phosphorylation of Bcl2 in lung cancer cells or NSCLC patients, which could contribute to radioresistance. Development of novel small molecule compounds to counteract activation of Bcl-2 induced by K-Ras mutations, IR or rapalog should reverse radio- or rapalog resistance leading to improvement of lung cancer outcome. Since the BH4 survival domain is required for Bcl2's antiapoptotic function, small molecules that interfere with the BH4 domain represent a novel strategy to disrupt the antiapoptotic function of Bcl2. We chose the BH4 domain of Bcl2 as docking site to screen small molecules using the UCSF DOCK 6.1 program suite and the NCI chemical library database. We identified four compounds with activity against lung cancer and named them small molecule Bcl2 BH4 domain antagonists (i.e. BDAs). According to the potency and drug-likeness, we chose BDA-366 as the lead for further investigation in this proposal. BDA-366 potently represses lung cancer without significant normal tissue toxicity in vivo. Since increased levels of Bcl2 and mTOR were observed in radio- or rapalog resistant lung cancer cells, we hypothesize that BDA-366 or in combination with mTOR inhibitor may represent an optimal strategy for overcoming radio- or rapalog resistance. K-Ras mutations-activated MEK/ERK1/2 can induce phosphorylation of Bcl2. We found that increased levels of phospho-Bcl2 (pBcl2) in tumor tissues are associated with poor prognosis of NSCLC patients. We hypothesize that pBcl2 may provide new predictive and prognostic biomarker in NSCLC. In this proposal, three specific aims have been identified: (1) To determine whether and how K-Ras mutations, radiation or mTOR inhibition positively regulate Bcl2 expression and phosphorylation leading to radio- or rapalog resistance in human lung cancer cells; (2) To determine the association between K-Ras mutation(s) and Bcl2 phosphorylation and whether this association defines clinical subsets of NSCLC; (3) To determine mechanism by which novel small molecule Bcl2 BH4 antagonist (BDA-366) inactivates Bcl2 and induces apoptosis. Studies will test the potency of BDA-366 in the resistant lung cancer and the genetically engineered lung cancer animal models. Proposed studies will uncover novel genetic signaling pathways and identify new biomarker relevant for lung cancer treatment. It is expected that a new class of novel agents will be developed, which can overcome both radio- and rapalog resistances in NSCLC.

 描述（由申请人提供）：肺癌患者的生存结局仍然非常差，部分原因是治疗抵抗。K-Ras突变是人类肺癌中常见的遗传改变之一。这些遗传畸变可能会对放化疗的治疗反应产生负面影响。Bcl 2是Bcl 2家族的主要抗凋亡成员，其可以充当这些遗传突变激活的信号传导途径的下游存活底物。我们的初步数据表明，K-Ras基因的改变，电离辐射（IR）和mTOR抑制雷帕霉素积极调节表达和/或Bcl 2的磷酸化在肺癌细胞或NSCLC患者，这可能有助于辐射抗性。开发新的小分子化合物来抵消由K-Ras突变、IR或雷帕霉素诱导的Bcl-2活化，应该逆转放射性或雷帕霉素抗性，从而改善肺癌的结果。由于BH 4存活结构域是Bcl 2抗凋亡功能所必需的，因此干扰BH 4结构域的小分子代表了破坏Bcl 2抗凋亡功能的新策略。我们选择Bcl 2的BH 4结构域作为对接位点，使用UCSF DOCK 6.1程序套件和NCI化学文库数据库筛选小分子。我们鉴定了四种具有抗肺癌活性的化合物，并将它们命名为小分子Bcl 2 BH 4结构域拮抗剂（即，BDA）。根据效价和药物相似性，我们选择BDA-366作为本方案中进一步研究的先导。BDA-366在体内有效抑制肺癌而没有显著的正常组织毒性。由于在放射性或雷帕霉素抗性肺癌细胞中观察到Bcl 2和mTOR水平增加，我们假设BDA-366或与mTOR抑制剂组合可能代表克服放射性或雷帕霉素抗性的最佳策略。K-Ras突变激活的MEK/ERK 1/2可诱导Bcl 2磷酸化。我们发现肿瘤组织中磷酸化Bcl 2（pBcl 2）水平的升高与NSCLC患者的不良预后相关。我们假设pBcl 2可能为NSCLC提供新的预测和预后生物标志物。在该提案中，已经确定了三个具体目标：（1）确定K-Ras突变、辐射或mTOR抑制是否以及如何正调控Bcl 2表达和磷酸化，从而导致人肺癌细胞中的放射性或放射性抗性;（2）确定K-Ras突变和Bcl 2磷酸化之间的关联，以及这种关联是否定义了NSCLC的临床子集;（3）探讨新型小分子Bcl 2-BH 4拮抗剂（BDA-366）对Bcl 2的失活及诱导细胞凋亡的作用机制。研究将测试BDA-366在耐药肺癌和基因工程肺癌动物模型中的效力。拟议的研究将揭示新的遗传信号通路，并确定与肺癌治疗相关的新生物标志物。预计将开发一类新的新型药物，其可以克服NSCLC的放射性和放射性耐药性。