PROTEOLYTIC CONTROL OF GLIOBLASTOMA

胶质母细胞瘤的蛋白水解控制

• 批准号: 7105562
• 负责人: SWAPAN K. RAY
• 金额: $ 21.39万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7105562
• 关键词: 13 cis retinoate; BCL2 gene /protein; apoptosis; astrocytoma; athymic mouse; calpain; cell differentiation; cell growth regulation; combination chemotherapy; cysteine endopeptidases; cytotoxicity; enzyme activity; flow cytometry; gel electrophoresis; immunofluorescence technique; interferon gamma; mitochondria; neoplasm /cancer chemotherapy; neoplastic growth; nonhuman therapy evaluation; paclitaxel; polymerase chain reaction; proteolysis; retinoids; telomerase; terminal nick end labeling

DESCRIPTION (provided by applicant): Although glioblastomas are the most malignant and common brain tumors, effective treatment strategies remain a challenge. Since current treatments are ineffective, further therapeutic approaches for this deadly disease are needed. This proposal aims to develop a dual approach to control the growth of glioblastoma by promoting differentiation and enhancing apoptosis. This can be achieved by down regulation of telomerase activity and activation of proteolysis. Preliminary results indicate that interferon-gamma (IFN-gamma) and taxol (TXL) induce modest amounts of apoptosis or programmed cell death (PCD) in human (T98G and U87MG) and rat (C6) glioblastoma cell lines. The differentiating agents, all-trans-retinoic acid (ATRA) and 13-cis-retinoic acid (13-CRA), induce differentiation and also down regulate telomerase activity in glioblastoma cells. Retinoid-treated glioblastoma cells become more sensitive to IFN-gamma or TXL for apoptosis. We hypothesize that (1) IFN-gamma or TXL activates cysteine proteases (e.g., calpain and caspase-3) by modulating levels and functions of Bcl-2 family members, (2) ATRA and 13-CRA induce differentiation and down regulate telomerase activity and Bcl-2 level and increase cell sensitivity to IFN-gamma or TXL for apoptosis, and (3) treatment of glioblastoma in animal models with a retinoid and IFN-(. or a retinoid and TXL will down regulate telomerase and enhance apoptosis. The central hypothesis of this proposal is that down regulation of telomerase activity and activation of proteolysis may effectively control glioblastoma growth. The main objective is to strategically use two treatment systems: ATRA or 13-CRA followed by IFN-gamma or TXL. To achieve this objective, the following will be examined: Specific Aim 1: Proteolysis by calpain and caspase-3 in apoptosis of glioblastoma cells exposed to IFN-gamma or TXL. Specific Aim 2: The ability of ATRA or 13-CRA to down regulate telomerase activity and Bcl-2 levels enhancing apoptosis in glioblastoma subsequently treated with IFN-gamma or TXL. Specific Aim 3: The efficacy of the combination of a retinoid and IFN-gamma or a retinoid and TXL for proteolytic control of glioblastoma in animal models. A novel technique of "combined TUNEL and double-immunofluorescent labeling" to simultaneously detect apoptosis and specific proteolysis in glioblastoma will be used. Success of our therapeutic strategy in in vitro and animal models may form a basis for treatment of glioblastoma in humans.

描述（由申请人提供）：尽管胶质母细胞瘤是最恶性和最常见的脑肿瘤，但有效的治疗策略仍然是一个挑战。由于目前的治疗方法无效，因此需要针对这种致命疾病采取进一步的治疗方法。该提案旨在开发一种通过促进分化和增强细胞凋亡来控制胶质母细胞瘤生长的双重方法。这可以通过下调端粒酶活性和激活蛋白水解来实现。初步结果表明，干扰素-γ (IFN-γ) 和紫杉​​醇 (TXL) 在人（T98G 和 U87MG）和大鼠（C6）胶质母细胞瘤细胞系中诱导适量的细胞凋亡或程序性细胞死亡 (PCD)。分化剂全反式视黄酸 (ATRA) 和 13-顺式视黄酸 (13-CRA) 可诱导胶质母细胞瘤细胞分化并下调端粒酶活性。经类视黄醇处理的胶质母细胞瘤细胞对 IFN-γ 或 TXL 更敏感，可导致细胞凋亡。我们假设 (1) IFN-gamma 或 TXL 通过调节 Bcl-2 家族成员的水平和功能来激活半胱氨酸蛋白酶（例如钙蛋白酶和 caspase-3），(2) ATRA 和 13-CRA 诱导分化并下调端粒酶活性和 Bcl-2 水平并增加细胞对 IFN-γ 或 TXL 的敏感性以促进细胞凋亡，以及 (3) 用类视黄醇治疗动物模型中的胶质母细胞瘤和IFN-(.或类维生素A和TXL将下调端粒酶并增强细胞凋亡。该提案的中心假设是端粒酶活性的下调和蛋白水解的激活可以有效控制胶质母细胞瘤的生长。主要目标是战略性地使用两种治疗系统：ATRA 或 13-CRA，然后是 IFN-gamma 或 TXL 为了实现这一目标，将检查以下内容： 具体目标 1：暴露于 IFN-gamma 或 TXL 的胶质母细胞瘤细胞凋亡过程中钙蛋白酶和 caspase-3 的蛋白水解作用。 具体目标 2：ATRA 或 13-CRA 下调端粒酶活性和 Bcl-2 水平的能力，增强随后用 IFN-γ 或 TXL 治疗的胶质母细胞瘤的细胞凋亡。 具体目标 3：类维生素A与IFN-γ或类维生素A与TXL的组合在动物模型中对胶质母细胞瘤的蛋白水解控制的功效。 将使用“结合TUNEL和双重免疫荧光标记”的新技术来同时检测胶质母细胞瘤中的细胞凋亡和特异性蛋白水解。我们的治疗策略在体外和动物模型中的成功可能为人类胶质母细胞瘤的治疗奠定基础。