Targeting Apoptosis Signaling in Breast Cancer Cells

靶向乳腺癌细胞中的凋亡信号传导

• 批准号: 6872479
• 负责人: KAPIL BHALLA
• 金额: $ 26.73万
• 依托单位: H. LEE MOFFITT CANCER CTR & RES INST
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6872479
• 关键词: BCL2 gene /protein; Bax gene /protein; RNA interference; RNase protection assay; apoptosis; athymic mouse; biological signal transduction; breast neoplasms; cell growth regulation; clinical research; clinical trials; combination cancer therapy; combination chemotherapy; confocal scanning microscopy; drug screening /evaluation; epothilon; flavopiridol; human subject; human therapy evaluation; immunocytochemistry; neoplasm /cancer classification /staging; paclitaxel; patient oriented research; phosphorylation; protein kinase; protein structure function; survivin

DESCRIPTION (provided by applicant): Tubulin polymerizing agents (TPA) taxotere and Epothilone B (EpoB) are highly active drugs against human breast cancer. Intracellularly, these agents bind to beta tubulin, promote microtubule bundling and induce mitotic arrest, which triggers the intrinsic (mitochondrial) pathway of apoptosis. However, the molecular mechanisms that link TPA-induced microtubular damage and mitotic arrest to the mitochondrial release of the death promoters, e.g., cytochrome c (cyt c), Smac and Omi/HtrA2, which promote the activation of effector caspases involved in apoptosis, remain to be elucidated. Survivin is a member of the antiapoptotic IAP family, and Bim is a BH3-only pro-apoptotic member of the Bcl-2 family of proteins; both are associated with the microtubules of the mitotic spindle. While downregulation of survivin levels induces apoptosis and sensitizes cancer cells to TPA, microtubule damage induces Bim to translocate to the mitochondria and neutralize the anti-apoptotic activity of Bcl-2/Bcl-XL. Recently, exposure to flavopiridol (FP), which depletes the levels of IAP and some Bcl-2 family members, following treatment with TPA has been shown to enhance TPA induced apoptosis. The working hypothesis of this project is that the strategies that downregulate survivin levels and/or function, or reduce the level and/or function of the antiapoptotic Bcl-2 and IAP proteins, would potentiate TPA-induced apoptosis as well as improve the clinical response of TPA + FP-based therapy of breast cancer. The specific aims of the project are: 1) To determine the role of survivin and Aurora 2 kinase during TPA-induced in vitro mitotic arrest and apoptosis of human breast cancer cells. 2) To determine the role of Bim and Bcl-2 family of proteins as therapeutic targets in potentiating TPA-induced in vitro mitochondrial signaling for apoptosis in breast cancer cells. 3) To determine the effects of in vitro modulation of the levels and activity of the IAP family of proteins on TPA-induced apoptosis in human breast cancer cells. 4) To determine the predictive value of the expression of survivin, Bim, Aurora 2 kinase, Bcl-2 and IAP family of proteins for the clinical response to treatment with the sequential combination of taxotere and flavopiridol in patients with stage IV breast cancers. These translational studies would elucidate the molecular determinants that are not only predictors of response to TPA + FP but may also be promising therapeutic targets in novel treatments of human breast cancer.

描述（由申请人提供）：微管蛋白聚合剂（TPA）taxotere和epothilone B（EPOB）是针对人类乳腺癌的高活性药物。细胞内这些药物与β微管蛋白结合，促进微管捆绑并诱导有丝分裂停滞，从而触发凋亡的内在（线粒体）途径。然而，将TPA诱导的微管损伤和有丝分裂停滞连接到死亡启动子的线粒体释放的分子机制，例如，细胞色素C（Cyt C），SMAC和OMI/HTRA2，促进涉及效应caspases涉及的效应caspases的激活，仍然是供应，仍然是供应的。 Survivin是抗凋亡IAP家族的成员，BIM是BCl-2蛋白质家族的仅BH3促凋亡成员。两者都与有丝分裂主轴的微管有关。虽然存活水平的下调诱导凋亡并使癌细胞对TPA敏感，但微管损伤会诱导BIM转移到线粒体上，并中和Bcl-2/bcl-XL的抗凋亡活性。最近，在用TPA治疗后，暴露于耗尽IAP和某些BCL-2家族成员水平的黄素蛋白醇（FP）可增强TPA诱导的细胞凋亡。该项目的工作假设是，降低抗凋亡抗凋亡Bcl-2和IAP蛋白的水平和/或功能的策略将增强TPA诱导的细胞凋亡，并改善基于TPA + FP的乳腺癌治疗的临床反应。该项目的具体目的是：1）确定在TPA诱导的体外有丝分裂停滞和人类乳腺癌细胞凋亡过程中的源性和Aurora 2激酶的作用。 2）确定BIM和BCl-2蛋白质作为治疗靶标在增强TPA诱导的体外线粒体信号中对乳腺癌细胞凋亡的作用。 3）确定IAP家族蛋白质水平和活性的体外调节对人类乳腺癌细胞中TPA诱导的凋亡的影响。 4）为了确定Survivin，BIM，Aurora 2激酶，Bcl-2和IAP家族的表达的预测价值，以便在IV期乳腺癌患者中与分类犬和黄酮醇的顺序组合进行治疗的临床反应。这些翻译研究将阐明分子决定因素，这些决定因素不仅是对TPA + FP反应的预测指标，而且在人类乳腺癌的新型治疗方法中也可能是有希望的治疗靶标。