Brain Tumor Animal Therapeutics Core (Scientific Cores)

自2004年成立以来，NOB实验室与制药公司和学术机构以及NCI开发治疗计划合作，在临床前和临床开发了许多新的抗胶质瘤药物。开发管道的第一步是通过ABTC筛选代理。ABTC提供专业服务，使用标准皮下和立体定向颅内模型在体外和体内筛选这些药物。自2005年以来，大量抗胶质瘤药物被筛选出来。其中，25种新药物显示出足够的前景，值得通过ABTC进行扩展评估。这些扩展研究涉及基于立体定向的颅内模型，研究各种剂量和给药方案以及新药与其他药物的联合试验。此外，ABTC还提供给药时间表以及新药与其他药物的联合试验。此外，ABTC还为NOB内外的其他研究人员提供实验和技术支持，以评估新开发的治疗方法。例如，干细胞因子（SCF）在胶质瘤血管生成中的作用; Notch-1在胶质瘤细胞存活和增殖中的作用; stathmin在恶性胶质瘤对DNA烷化剂的体内抗性中的作用。核心已经产生了RNA的基因表达谱使用微阵列技术从给定的神经胶质瘤细胞系处理特定类别的代理。一旦识别出与抗肿瘤活性相对应的特征模式，则可以/将设计临床试验以在活检/手术之前立即向脑肿瘤患者施用这些药剂中的一种，以尝试并在临床上识别类似的遗传特征。与NOB实验室和基因组核心团队合作，正在ABTC内测试的所有化合物的所有胶质瘤细胞系和GIC/GSC中生成基因表达特征。此外，已经在ABTC内的动物模型中评价了许多较新的药物递送技术，包括颈动脉内给药、有或没有选择性或总体血脑屏障破坏的递送、对流递送等。许多新型抗肿瘤治疗剂将具有细胞抑制而非细胞毒性特性。在小型早期临床试验中评估这些药物中哪一种将在人体中具有生物活性是一项挑战，因为标准反应标准是基于细胞毒性反应的测定。可用于评价真正的细胞生长抑制剂的活性的唯一真正有效的临床参数是患者存活或肿瘤无进展存活。然而，这些在小规模的早期临床试验中并不是筛选药物活性的有用参数。因此，如果可以确定生物活性的替代标志物，则可以利用这些作为筛选具有很少或没有临床活性的药物的早期终点。为此，ABTC正在积极努力开发可用于临床试验和验证的药物抗肿瘤活性的替代标志物，其中包括三个主要领域：1）成像; 2）基因表达谱; 3）蛋白质组学/血清标志物。例如，与NOB、NINDS和实验成像科学临床中心项目的研究人员合作，非侵入性MR成像已被用于对体内磁性标记的内皮祖细胞进行成像，以直接识别胶质瘤模型中的血管发生。最后，ABTC存储了来自用每种新化合物治疗的动物的代表性肿瘤、组织和血清样品，期望可以发现药物活性、肿瘤活性和/或一些肿瘤生物学过程（即血管生成）的新候选组织和/或基于血清的蛋白质标志物，这将是未来验证此类声明的宝贵临床前资源。NOB的一个主要努力是开发人类神经胶质瘤细胞系，在生物学和分子学上更接近原发性人类神经胶质瘤的模型。ABTC积极参与从NIH手术的每个胶质瘤患者的新鲜手术标本中产生原代人脑胶质瘤细胞系和GIC/GSC系。ABTC的工作人员与癌症干细胞生物学家密切合作，研究这些细胞系和动物异种移植物的生长、繁殖和特征。ABTC使用这些充分表征的细胞系作为两大类药物的筛选; 1）使用更常规的已建立的胶质瘤细胞系从体外和体内筛选的第一水平中筛选出最有前途的药物; 2）靶向可能不能被标准胶质瘤细胞系的生物学很好地代表但在GIC/GSC中再现的途径的药物。这些细胞的实验室专业知识，以及不同GIC/GSC系的大量资源，是NCI和制药/生物技术界之间潜在合作伙伴关系的有力诱惑，因为他们越来越认识到标准癌细胞系的局限性和癌症干细胞更好地代表人类疾病的前景。ABTC成功的证据是，我们已经启动了11项临床试验，这是NOB内进行的转化工作的直接结果，所有这些临床试验都在ABTC内进行了临床前动物研究。更重要的是，我们已经通过ABTC临床前筛选计划确定了12种化合物，这些化合物已经在NIH进行了临床试验（AZD 6918，RO 4929097，AXD 8005，MLN-518，ZD 6474，LY 317615，舒尼替尼，CC 5013，Talampanel）。在吉尔伯特博士的新领导下，ABTC正在扩大转化研究，如实验免疫治疗和代谢靶向治疗。

Since established in 2004, the NOB Lab has collaborated with pharmaceutical companies and academic institutions, and the NCI Developmental Therapeutics Program in the preclinical and clinical development of a number of new anti-glioma agents. The first step in the development pipeline is screening of the agent through the ABTC. The ABTC provides the professional service for screening these agents both in vitro and in vivo using both standard subcutaneous and stereotactic intracranial models. Since 2005, a large number of anti-glioma agents have been screened. Of those, 25 new agents showed significant enough promise to warrant extended evaluation through the ABTC. These extended studies involved stereotactic-based intracranial models looking at various dose and administration schedules as well as combination trials of the new drug with other agents. Furthermore, ABTC provides administration schedules as well as combination trials of the new drug with other agents. Furthermore, ABTC provides experimental and technical support to other investigators both within and outside of the NOB for evaluating newly developed therapeutics. For example, the role of stem cell factor (SCF) in glioma angiogenesis; Notch-1 in glioma cell survival and proliferation; stathmin in the resistance of malignant gliomas to DNA alkylating agents in vivo. The core has generated the RNA for gene expression profiles using microarray technology from given glioma cell lines treated with a specific class of agents. Once characteristic patterns are identified that correspond with anti-tumor activity, then clinical trials can/will be devised to administer one of these agents to patients with brain tumors immediately prior to biopsy/surgery in order to attempt and identify a similar genetic profile clinically. In collaboration with the NOB Lab and the Genomic Core team, gene expression signatures are being generated in all of glioma cell lines and GIC/GSCs for all compounds tested within the ABTC. In addition, a number of newer drug delivery technologies including intra-carotid administration, delivery with or without selective or gross blood-brain barrier disruption, convection delivery, etc. have been evaluated in animal models within the ABTC. Many of the new classes of anti-tumor therapeutics will have cytostatic rather than cytotoxic properties. Evaluating which of these agents will have biologic activity in humans in small, early clinical trials are a challenge since the standard response criteria are based on the determination of cytotoxic responses. The only truly valid clinical parameter available for evaluating the activity of a truly cytostatic agent is patient survival or tumor progression-free survival. These, however, are not useful parameters for screening drug activity in small, early phase clinical trials. Thus, if surrogate markers of biologic activity could be identified, one could utilize these as early endpoints for screening out agents with little or no clinical activity. Toward that end, the ABTC is actively working to develop surrogate markers of drug anti-tumor activity that can be utilized and validated in clinical trials, which includes three major areas: 1) Imaging; 2) Gene expression profiling; 3) Proteinomics/Serum markers. For example, in collaboration with investigators in NOB, NINDS and the Clinical Centers program of experimental imaging science, noninvasive MR imaging has been used to image magnetically labeled endothelial progenitor cells in vivo to directly identify vasculogenesis in a glioma model. Finally, the ABTC stores representative tumor, tissue and serum samples from animals treated with each new compound tested with the expectations that new candidate tissue and/or serum-based protein markers of drug activity, tumor activity and/or some tumor biological process (i.e. angiogenesis) may be found. This will be an invaluable preclinical resource for validating such claims in the future. A major effort of the NOB is to develop human glioma cell lines that more closely model primary human gliomas both biologically and molecularly. The ABTC is actively involved in the generation of primary human glioma cell lines and GIC/GSC lines from fresh surgical specimens for every glioma patient operated on at the NIH. The ABTC staff works closely with the cancer stem cell biologists for the growth, propagation and characterization of each of these cell lines and animal xenografts. The ABTC uses these well-characterized cell lines as screens for two major categories of drugs; 1) The most promising drugs from the first levels of in vitro and in vivo screens using the more conventional established glioma cell lines; 2) drugs that target pathways that may not be well represented by the biology of standard glioma cell lines but are reproduced in the GIC/GSCs. The laboratory expertise with these cells, and the large resources of different GIC/GSC lines, are a potent enticement for potential partnerships between NCI and the pharmaceutical/biotechnology community given their growing appreciation of the limitation of standard cancer cell lines and the promise of cancer stem cells for better representing the human disease. Evidence of the success of the ABTC is the fact that we have activated 11 clinical trials as a direct result of translational work performed within the NOB, all of which had preclinical animal studies performed within the ABTC. Even more to the point, we have identified 12 compounds solely through the ABTC preclinical screening program that have since been brought forward to clinical trials at the NIH (AZD6918, RO4929097, AXD8005, MLN-518, ZD6474, LY317615, Sunitinib, CC5013, Talampanel). Under the new leadership of Dr. Gilbert, ABTC is extending the translational studies, such as experimental immunotherapeutics and metabolic targeting therapeutics.