Treatment of Malignant Gliomas with 2-5A-anti-hTR

2-5A-抗 hTR 治疗恶性胶质瘤

• 批准号: 7068613
• 负责人: SEIJI KONDO
• 金额: $ 30.23万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7068613
• 关键词: RNA; antineoplastics; antisense nucleic acid; apoptosis; astrocytes; athymic mouse; carmustine; cisplatin; combination chemotherapy; drug delivery systems; enzyme inhibitors; gene expression; glioma; laboratory mouse; microarray technology; mitochondria; neoplasm /cancer chemotherapy; neoplasm /cancer genetics; neoplastic cell; nonhuman therapy evaluation; oligonucleotides; paclitaxel; pharmacokinetics; telomerase; telomere

DESCRIPTION (provided by applicant): Telomerase, a ribonucleoprotein enzyme, is detected in the vast majority of malignant gliomas, but not in normal brain tissues. In malignant gliomas, tumors with telomerase tend to have more malignant phenotype than those without telomerase. Therefore, our long-term goal is to explore a novel telomerase-targeting therapy for malignant gliomas. To inhibit telomerase function effectively, we have adopted the 2-5A (2', 5'-oligoadenylate) antisense system. 2-5A is a mediator of one pathway of interferon actions by activating RNase L, resulting in single-stranded RNA cleavage. By linking 2-5A to antisense, RNase L degrades the targeted RNA specifically and effectively. With the grant supported by NIH, we synthesized the antisense oligonucleotide against human telomerase RNA component (hTR) linked to 2-5A (2-5A-anti-hTR) and investigated its anti-tumor effect on malignant glioma cells. Treatment with 2-5A-anti-hTR for 4 days induced a massive apoptosis before a telomere length shortened critically. In contrast, normal cells such as astrocytes and fibroblasts lacking telomerase were insensitive to 2-5A-anti-hTR. Treatment of subcutaneous or intracerebral tumors in nude mice with intratumoral injections of 2-5A-anti-hTR was effective. Based on our previous results, we hypothesize that 2-5A-anti-hTR is a promising agent for the treatment of malignant gliomas expressing telomerase. However, the following questions remain to be answered. First, what molecular pathways play a key role in 2-5A-anti-hTR-induced apoptosis? Second, how can we enhance the effect of 2-5A-anti-hTR on intracerebral tumors? Third, which regimens based on 2-5A-anti-hTR show a significant combination effect on intracerebral tumors? The aim of this proposal is to address these issues. The specific aims are to: 1: Characterize the molecular pathways of 2-5A-anti-hTR-induced apoptosis. Using the microarray assay, we will identify which genes are involved in 2-5A-anti-hTR-induced cell death. We will also determine (i) the involvement of the mitochondria-associated cell death signaling pathways and (ii) the effect of 2-5A-anti-hTR on telomere 3' overhang or telomerase-positive astrocytes with or without tumorigenicity. 2: Define the effect of convection-enhanced drug delivery (CEDD) of 2-5A-anti-hTR on intracerebral tumors in nude mice. We will optimize CEDD and then compare the effect of CEDD and bolus injections of 2-5A-anti-hTR on intracerebral tumors. 3: Define the in vitro and in vivo effect of combination therapy based on 2-5A-anti-hTR. We will determine (i) the molecular pathways underlying the combination effect of 2-5A-anti-hTR and apoptosis-inducing agent (cisplatin, paclitaxel, or BCNU) and (ii) the effect of combination therapy on intracerebral tumors.

描述（由申请人提供）：在绝大多数恶性神经胶质瘤中检测到端粒酶，一种核糖核蛋白酶，但在正常的脑组织中未检测到。在恶性神经胶质瘤中，端粒酶的肿瘤往往比没有端粒酶的肿瘤具有更多的恶性表型。因此，我们的长期目标是探索针对恶性神经胶质瘤的新型端粒酶靶向疗法。为了有效抑制端粒酶功能，我们采用了2-5A（2'，5'-寡核苷酸）反义系统。 2-5a是通过激活RNASE L的一个干扰素作用途径的介体，导致单链RNA裂解。通过将2-5a与反义联系起来，RNase L特异性有效地降解了靶向的RNA。在NIH支持的赠款下，我们合成了与2-5A（2-5A-ANTI-HTR）相关的人端粒酶RNA成分（HTR）的反义寡核苷酸，并研究了其对恶性神经胶质瘤细胞的抗肿瘤作用。用2-5A-ANTI-HTR处理4天，在端粒长度缩短之前会诱导大量凋亡。相反，缺乏端粒酶的正常细胞（例如星形胶质细胞和成纤维细胞）对2-5A-ANTI-HTR不敏感。在2-5A-ANTI-HTR的肿瘤内注射裸鼠中的皮下或脑内肿瘤的治疗是有效的。根据我们先前的结果，我们假设2-5A-ANTI-HTR是治疗表达端粒酶恶性神经胶质瘤的有前途的药物。但是，以下问题仍有待回答。首先，哪些分子途径在2-5A-ANTI-HTR诱导的凋亡中起关键作用？第二，我们如何增强2-5A-ANTI-HTR对脑肿瘤的影响？第三，基于2-5A-ANTI-HTR的哪些方案对脑内肿瘤具有显着的组合作用？该提案的目的是解决这些问题。具体目的是：1：表征2-5A-ANTI-HTR诱导凋亡的分子途径。使用微阵列测定，我们将确定哪些基因与2-5A-ANTI-HTR诱导的细胞死亡有关。我们还将确定（i）与线粒体相关的细胞死亡信号通路的参与，以及（ii）2-5A-ANTI-HTR对具有或没有肿瘤性的端粒酶阳性星形胶质细胞的端粒3'Overhang或端粒酶阳性星形胶质细胞的影响。 2：定义2-5A-ANTI-HTR对流增强药物输送（CEDD）对裸鼠脑内肿瘤的影响。我们将优化CEDD，然后比较2-5A-ANTI-HTR对脑肿瘤的CEDD和注射剂的影响。 3：定义基于2-5A-ANTI-HTR的组合疗法的体外和体内效应。我们将确定（i）2-5A-ANTI-HTR和凋亡诱导剂（顺铂，紫杉醇或BCNU）和（ii）联合疗法对脑内肿瘤的作用的组合效应的分子途径。