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: 9335318
• 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/9335318
• 关键词: Animal Cancer 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; 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; Therapeutic; Therapeutic Intervention; Toxic effect; Tumor Tissue; cancer cell; cancer therapy; chemoradiation; in vivo; inhibitor/antagonist; lead chloride; mTOR Inhibitor; mTOR inhibition; member; mouse model; negative affect; 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)：肺癌患者的生存结果仍然非常差，部分原因是治疗抵抗。K-RAS突变是人类肺癌常见的基因改变之一。这些基因突变可能会对放化疗的治疗反应产生负面影响。Bcl2是bcl2家族中主要的抗凋亡成员，可能作为这些基因突变激活的信号通路(S)下游的生存底物。我们的初步数据表明，在肺癌细胞或NSCLC患者中，K-RAS、电离辐射(IR)和mTOR抑制的遗传改变正向调节Bcl2的表达和/或磷酸化，这可能有助于辐射抵抗。开发新的小分子化合物来对抗K-Ras突变、IR或Rapalog诱导的Bcl2的激活，将逆转放射或Rapalog的耐药性，从而改善肺癌的预后。由于BH4的存活结构域是Bcl2的S抗凋亡功能所必需的，干扰BH4结构域的小分子代表了一种新的策略来破坏Bcl2的抗凋亡功能。我们选择Bcl2的BH4结构域作为对接位点，利用UCSF dock 6.1程序套件和NCI化学文库数据库筛选小分子。我们鉴定了四个具有抗肺癌活性的化合物，并将它们命名为小分子BCl2 BH4结构域拮抗剂(即BDAS)。根据BDA-366的药效性和药物相似性，我们选择BDA-366作为进一步研究的先导。BDA-366在体内有效地抑制肺癌，没有明显的正常组织毒性。由于在对放射或雷帕洛格耐药的肺癌细胞中观察到bcl2和mTOR水平的增加，我们推测BDA-366或与mTOR抑制剂联合使用可能是克服放射或雷帕洛格耐药的最佳策略。K-RAS突变激活的MEK/ERK1/2可诱导Bcl2的磷酸化。我们发现，肿瘤组织中磷酸化Bcl2(PBcl2)水平的升高与NSCLC患者的预后不良有关。我们推测pBcl2可能在非小细胞肺癌中提供新的预测和预后的生物标志物。在这个建议中，已经确定了三个特定的目标：(1)确定K-RAS突变、辐射或mTOR抑制是否以及如何正向调节Bcl2的表达和磷酸化，从而导致对放射耐药或雷帕洛格耐药；(2)确定K-RAS突变(S)和Bcl2磷酸化之间的关联以及这种关联是否定义了非小细胞肺癌的临床亚群；(3)确定新的小分子Bcl2BH4拮抗剂(BDA-366)失活Bcl2并诱导细胞凋亡的机制。研究将在耐药肺癌和基因工程肺癌动物模型中测试BDA-366的效力。拟议的研究将发现新的遗传信号通路，并确定与肺癌治疗相关的新生物标记物。预计将开发一类新的药物，它可以克服非小细胞肺癌中的无线电和Rapalog抗性。