A Role of Bit1 in the Apoptosis Resistance, Anoikis Insensitvity, and Chemoresist

Bit1 在细胞凋亡抵抗、失巢凋亡不敏感性和化疗抵抗中的作用

• 批准号: 8224157
• 负责人: Hector Ramos Biliran
• 金额: $ 36.29万
• 依托单位: XAVIER UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-28 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8224157
• 关键词: Address; Anchorage-Independent Growth; Anoikis; Apoptosis; Apoptotic; Attenuated; Bypass; Cancer Biology; Cancer cell line; Caspase; Cell Death; Cell Death Induction; Cell-Matrix Junction; Cells; DNA Damage; Data; Defect; Disabled Persons; Disease; Distant; Down-Regulation; Ectopic Expression; Etoposide; Exhibits; Figs - dietary; Genetic Transcription; Goals; Heat-Shock Proteins 70; Human; Induction of Apoptosis; Integrins; Lung; Lung Neoplasms; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of lung; Mediating; Mitochondria; Molecular; Molecular Analysis; Neoplasm Metastasis; Non-Small-Cell Lung Carcinoma; Oncogenes; Organ; Outcome Study; Pathway interactions; Pharmaceutical Preparations; Phenotype; Predisposition; Principal Investigator; Proteins; Publishing; Radiation; Regulation; Relative (related person); Research; Resistance; Role; Signal Pathway; Signal Transduction; Small Interfering RNA; Stimulus; Structure of parenchyma of lung; Testing; Therapeutic; Tissues; apoptosis inducing factor; base; cancer cell; cancer therapy; chemotherapeutic agent; chemotherapy; combat; inhibitor/antagonist; insight; mortality; new therapeutic target; novel; outcome forecast; overexpression; programs; response; restoration; small hairpin RNA; tool; undergraduate student

DESCRIPTION (provided by applicant): Non-small cell lung cancer (NSCLC) is a highly aggressive form of malignancy that is associated with metastasis and poor response to chemotherapy. Non-small cell lung cancer cells exhibit high resistance to undergo apoptosis, at least in part due to a disabled apoptotic machinery. In particular, partial defects in the caspase-dependent pathway in NSCLC cells conferred resistance to apoptosis induced by DNA-damaging agents such as etoposide or 3-radiation (9,14). Hence, a major therapeutic avenue in combating the aggressiveness and chemotherapy resistance of NSCLC is through effective induction of apoptosis by the alternative caspase-independent cell death pathway. The goal of this project is to address the critical barrier to NSCLC treatment by obtaining the information needed to understand the role of the novel caspase- independent anoikis effector, Bcl2-inhibitor of transcription (Bit1), in the apoptosis resistance and malignant transformation of NSCLC cells. Several observations indicate the nonfunctionality of the Bit1 pathway in lung cancer: i) Bit1 expression is significantly suppressed in various types of NSCLC tissue relative to counterpart normal lung tissue (Fig. 1A and 1B) and ii) an inhibitor of Bit1 function, TLE1, functions as a lung specific oncogene and is overexpressed in human lung tumors (1). While ectopic expression of cytoplasmic localized Bit1 in the NSCLC cell line NCI-H460 induces apoptosis (Fig 1D-F), restoration of mitochondrial localized Bit1 in H460 cells enhances anoikis sensitivity and attenuates anchorage independent growth and resistance to etoposide-induced apoptosis (Fig. 2). Based on the published data and our preliminary results, our objective is to test the hypothesis that malignant NSCLC cells are likely to bypass the Bit1 apoptotic pathway to become anoikis resistant and anchorage-independent, and that activation of the Bit1 pathway may be effective in inducing apoptosis and attenuating the aggressive phenotypes in NSCLC cells. The specific aims are: 1) to examine the regulation and relevance of the Bit1 apoptosis pathway in the survival and apoptotic resistance of NSCLC cells, 2) to test the hypothesis that the Bit1 apoptotic pathway regulates the aggressive phenotypes of NSCLC cells by alteration of mitochondrial Bit1 expression and its impact on anoikis resistance, anchorage- independent growth potential, or chemoresistance of NSCLC cells, and 3) to understand and dissect the apoptotic machinery in NSCLC using Bit1 as a tool. The outcome of this study will delineate the importance of the suppression or blockage of the Bit1 apoptotic pathway in the acquisition of anoikis resistance and anchorage-independence by the NSCLC. We believe that activation of the caspase-independent cell death pathway via the Bit1 apoptotic function will result in a successful eradication of chemoresistance in NSCLC. Thus, Bit-1 may serve as a novel therapeutic target for the treatment of this aggressive cancer. PHS398 (Rev. 5/01) Page Continuation Format Page PUBLIC HEALTH RELEVANCE: A Role of Bit1 in the Apoptosis Resistance, Anoikis Insensitivity, and Chemoresistance in Non-small cell lung cancer (NSCLC) Cells Non-small cell lung cancer (NSCLC) is a highly aggressive disease with poor prognosis and high mortality. The dismal prognosis is in part due to its resistance to conventional chemotherapy and its propensity to disseminate to distant organs. To circumvent the aggressiveness and chemoresistance of NSCLC, it is imperative to identify novel cell death pathway(s) that may enhance the apoptotic sensitivity of NSCLC cells.

描述（由申请人提供）：非小细胞肺癌（NSCLC）是一种高度侵略性的恶性肿瘤，与转移和对化学疗法的反应不佳有关。非小细胞肺癌细胞表现出对凋亡的耐药性，至少部分是由于残疾人凋亡机制。特别是，NSCLC细胞中caspase依赖性途径的部分缺陷赋予了对DNA受损剂（如依托泊苷或3辐射）诱导的凋亡的抗性（9,14）。因此，打击NSCLC的侵略性和化学疗法抗性的主要治疗途径是通过有效诱导替代性caspase无关的细胞死亡途径诱导凋亡。该项目的目的是通过了解新型caspase-Independed-nippdion-anoikis效应子，转录的BCL2抑制剂（BIT1）在凋亡耐药性和NSCLC细胞的恶性转化中所需的信息来解决NSCLC治疗的关键障碍。几个观察结果表明肺癌中比特1途径的无功能：i）在各种类型的NSCLC组织中，BIT1表达相对于对应的正常肺组织（图1A和1B）和II）BIT1功能，TLE1的抑制剂TLE1，TLE1的抑制剂，作为肺特异性oncogene and compersection and tle1（1B）在人类lung oneclassected（1）中（1）。 NSCLC细胞系NCI-H460在NSCLC细胞系NCI-H460中的异位表达诱导凋亡（图1D-F），而H460细胞中线粒体局部局部BIT1的恢复增强了Anoikis敏感性，并增强了锚固的生长，并导致对依托莫皮固定型的锚固型的锚固型帕普（Etoposide）的抗性（图）（图2）。根据已发布的数据和我们的初步结果，我们的目标是检验以下假设：恶性NSCLC细胞可能会绕过Bit1凋亡途径，使其具有耐药性和锚固独立性，并且BIT1途径的激活可能有效地诱导凋亡和诱导NSClccemplective phactimate insclccypepes in nsclccypece。具体目的是：1）检查BIT1凋亡途径在NSCLC细胞的生存和凋亡抗性中的调节和相关性，2）测试以下假说：Bit1凋亡途径调节NSCLC细胞的积极表达及其对线粒体的抗性的影响，或者是对线粒体的抗性的变化，或者是对Minochrial sanceriss of Anoiikis sancorise sandoreiks sandoreiks sandoreike sandoreike sandoreike sandoreike sandoreike sancor的抗性， NSCLC单元格和3）使用BIT1作为工具来理解NSCLC中的凋亡机械。这项研究的结果将描述Bit1凋亡途径抑制或阻塞在获得NSCLC抗厌氧菌抗性和锚固独立性时的重要性。我们认为，通过BIT1凋亡功能激活与caspase非依赖性细胞死亡通路将导致NSCLC中的化学耐药性成功地消除。因此，BIT-1可以作为治疗这种攻击性癌症的新型治疗靶标。 PHS398（Rev. 5/01）页面延续格式页面 公共卫生相关性：BIT1在非小细胞肺癌（NSCLC）细胞非小细胞肺癌（NSCLC）中的凋亡耐药性，不敏感性和化学抗性中的作用是一种高度积极的疾病，预后较差，死亡率很高。令人沮丧的预后部分是由于其对常规化学疗法的抵抗力及其传播到远处器官的倾向。为了避免NSCLC的侵略性和化学抗性，必须鉴定出可能增强NSCLC细胞凋亡灵敏度的新型细胞死亡途径。