OPENING THE BLOOD-BRAIN BARRIER TO ANTITUMOR AGENTS

在目前的提案中，将使用单克隆抗体（IgG和F（ab '）2）。 结合靶向化疗药物的BBB破坏， 放射性核素和顺磁MRI试剂， 裸鼠皮下肿瘤。 在这些研究中，我们结合了 R 01提案早期获得的知识， 最近关于抗体递送和定位的信息， 治疗、毒性和抗体靶向的功效。 这些靶向 研究将集中在四个交付系统上。 首先，L 6抗体 与碱性磷酸酶结合的蛋白质将被递送至LX-1肿瘤 关于BBBD 随后，给予磷酸化的 化疗剂如磷酸丝裂霉素将被激活 主要是在肿瘤部位的细胞外碱性 与结合细胞的L 6抗体共价连接的磷酸酶 面 在第二种方法中，缀合至抗体的调节性抗体可以是抗肿瘤抗体。 评价阿霉素。 第三，使用有效的螯合系统 紧密结合放射性标记，定位和功效研究将 比较与L 6抗体螯合的γ-和β-发射体。 迄今 L 6抗体已经使用放射性碘标记或 免疫组织学 最后，使用相同的螯合系统 L 6抗体的放射性标记，顺磁性物质，如 钆，将被螯合以联合收割机结合MRI的空间分辨率 具有定位单克隆抗体的生物特异性， 如L 6。 与这些研究相关的是神经毒性试验 钆造影剂的解离性差异很大 constants. 在这次竞争性更新中要强调的第二个方面是 化疗药物的毒性和疗效， 之前、同时和之后无渗透性BBB破坏 体外放射治疗 两种毒性最小， 在我们的临床研究中， 甲氨蝶呤和环磷酰胺，最近还有卡铂的联合用药 和依托泊苷。 这些组合的疗效将在 我们的裸鼠肿瘤模型使用LX-1人肺癌。 在 此外，由于过去在测试神经毒性方面的成功， 在动物中中断施用化疗剂， 潜在的临床应用，我们将同样研究几种新的药物。 疗效将不仅通过生存期，而且通过肿瘤体积进行评价 通过组织学和系列MRI测量来评估 活体扫描 神经毒性测试有一个新的评价维度， 我们测量动物脑电图的能力。 我们的总体目标是 继续改进抗肿瘤剂和成像剂的递送， 脑肿瘤，最后，评估治疗效果 接近。 这一建议是为了响应 外科肿瘤学，是外科CREG的延续。

In the current proposal, monoclonal antibodies (IgG and F(ab')2) will be combined with BBB disruption to target chemotherapeutic drugs, radionuclides and paramagnetic MRI agents to intracerebral and subcutaneous tumor in nude rats. In these studies, we are combining knowledge obtained during the early years of this R01 proposal with more recent information on antibody delivery and localization to now evaluate therapy, toxicity, and efficacy with antibody targeting. These targeting studies will focus on four delivery systems. First, the L6 antibody conjugated to alkaline phosphatase will be delivered to the LX-1 tumor with BBBD. Subsequently, the administration of phosphorylated chemotherapeutic agents such as mitomycin phosphate will be activated primarily at the site of the tumor by the extracellular alkaline phosphatase covalently linked to the L6 antibody bound to the cell surface. In a second approach, a modulating antibody conjugated to adriamycin will be evaluated. Third, using an effective chelating system that tightly binds radiolabels, localization and efficacy studies will compare gamma- and beta-emitters chelated to the L6 antibody. To date the L6 antibody has been evaluated using either radioiodination or immunohistology. Finally, using the same chelating systems to attach radiolabels to the L6 antibody, paramagnetic substances, such as gadolinium, will be chelated to combine the spatial resolution of MRI with the biologic specificity of localizing monoclonal antibodies such as L6. Associated with these studies will be the neurotoxicity testing of gadolinium contrast agents with vastly differing dissociation constants. The second area to be emphasized in this competitive renewal is the toxicity and efficacy of chemotherapeutic agents administered with and without osmotic BBB disruption before, concomitant with and after external beam radiotherapy. The two least toxic and most efficacious chemotherapeutic combinations in our clinical studies have been methotrexate and cytoxan and more recently the combination of carboplatin and etoposide. The efficacy of these combinations will be evaluated in our nude rat tumor model using the LX-1 human lung carcinoma. In addition, because of past successes in testing the neurotoxicity of chemotherapeutic agents administered with disruption in animals for potential clinical use, we will similarly investigate several new agents. Efficacy will be evaluated not only by survival but also tumor volumetric measurements to assess response both histologically and by serial MRI in vivo scanning. Neurotoxicity testing has a new evaluation dimension in our ability to measure EEG in animals. Our overall objective is to continue to improve delivery of antitumor agents and imaging agents to brain tumors and, finally, to evaluate efficacy of therapeutic approaches. This proposal is in response to the program announcement in surgical oncology and is a continuation of a surgical CREG.