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很差，部分原因是 K-Ras 突变是人类肺癌中常见的基因改变，这些基因畸变可能会对放化疗的治疗反应产生负面影响。 Bcl2 是 Bcl2 家族的主要抗凋亡成员，可能作为这些基因突变激活的信号通路的下游生存底物。 K-Ras、电离辐射 (IR) 和 rapalog 抑制 mTOR 正向调节肺癌细胞或 NSCLC 患者中 Bcl2 的表达和/或磷酸化，这可能有助于开发新型小分子化合物来抵消 Bcl-2 的激活。由于 BH4 生存结构域是 Bcl2 所必需的，因此由 K-Ras 突变诱导的 IR 或 rapalog 应该逆转放射或 rapalog 耐药性，从而改善肺癌结果。抗凋亡功能，干扰 BH4 结构域的小分子代表了破坏 Bcl2 抗凋亡功能的新策略，我们选择 Bcl2 的 BH4 结构域作为对接位点，使用 UCSF DOCK 6.1 程序套件和 NCI 化学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，并根据功效和将它们命名为小分子 Bcl2 BH4 结构域拮抗剂（即 BDA）。由于在体内观察到 Bcl2 和 mTOR 水平升高，因此我们选择 BDA-366 作为进一步研究的主导药物，BDA-366 可以有效抑制肺癌，而不会产生明显的体内正常组织毒性。在癌细胞中，我们发现 BDA-366 或与 mTOR 抑制剂联合使用可能是克服放射或雷帕同源突变激活的 MEK/ERK1/2 耐药性的最佳策略。我们发现肿瘤组织中磷酸化 Bcl2 (pBcl2) 水平的升高与 NSCLC 患者的不良预后相关。我们发现 pBcl2 可能为 NSCLC 提供新的预测和预后生物标志物。已确定：(1) 确定 K-Ras 突变、放射或 mTOR 抑制是否以及如何正向调节 Bcl2 表达和磷酸化，从而导致人类肺癌的放射或雷帕霉素耐药性(2) 确定 K-Ras 突变与 Bcl2 磷酸化之间的关联，以及该关联是否定义了 NSCLC 的临床亚型；(3) 确定新型小分子 Bcl2 BH4 拮抗剂 (BDA-366) 失活的机制Bcl2 并诱导细胞凋亡。研究将测试 BDA-366 在耐药性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传导途径并确定。与肺癌治疗相关的新生物标志物预计将开发出一类新的药物，它可以克服非小细胞肺癌的放射和雷帕耐药性。