TUMOR-TARGETING SALMONELLA EXPRESSING TUMOR-SELECTIVE CYTOTOXIC PROTEINS IN COMBINATION WITH PROTEASE INHIBITORS

项目摘要/摘要 与其他抗癌药物输送系统相比，肿瘤靶向细菌具有许多优势， 包括从远距离接种部位靶向多个肿瘤，选择性肿瘤内复制， 高度的衰减和安全性，以及在体内直接表达抗癌蛋白的能力 肿瘤。值得注意的是，减毒沙门氏菌在实体瘤中的分布水平至少是实体肿瘤的1000倍 比其他组织更大。人体临床研究已证实静脉注射的安全性 接种减毒沙门氏菌突变体VNP20009，建立耐受多剂量，并已 显示肿瘤靶向在某些患者中发生。然而，没有观察到抗肿瘤活性， 即使在沙门氏菌被证实在其肿瘤中定植的患者中也是如此。我们假设 人类临床试验中缺乏抗肿瘤效果的问题可以通过工程抗肿瘤来克服 诱导细胞凋亡(程序性细胞死亡)的细胞毒蛋白，能够选择性地杀死肿瘤 细胞，这些蛋白质杀死癌细胞的能力可以通过阻断它们的 通过共表达的蛋白水解酶抑制物来降解肿瘤蛋白。具体目标是 旨在测试在最初的SC3资助期产生的小鼠肿瘤选择性毒素 癌症的模型。具体目标也是针对个体的生成和分析 VNP20009表达的防止蛋白水解物降解的蛋白酶抑制剂组合 治疗性蛋白与肿瘤靶向增强抗肿瘤沙门氏菌载体的研制 活动。将单独和结合分析表达肿瘤细胞靶向毒素的VNP20009 使用细菌与小鼠肿瘤相互作用的光学成像的一种或多种蛋白酶抑制剂 高度侵袭性乳腺癌的模型。预计结果将表明该计划的有效性 靶向毒素及单独应用蛋白酶抑制剂和联合应用毒素的效果(S)。 这些结果有可能在不增加其毒性的情况下改善VNP20009，因此 可能导致在人类身上进行翻译研究。 。

PROJECT SUMMARY/ABSTRACT Tumor-targeting bacteria offer a number of advantages over other cancer drug delivery systems, including targeting of multiple tumors from a distant inoculation site, selective intratumoral replication, a high degree of attenuation and safety, and the ability to express anti-cancer proteins directly within the tumor. Remarkably, attenuated Salmonella localize within solid tumors at levels at least 1000 times greater than other tissues. Human clinical studies have validated the safety of intravenously administered attenuated Salmonella mutant VNP20009, established tolerated multiple doses, and have shown that tumor targeting occurs in some patients. However, no anti-tumor activity was observed, even in patients in whom the Salmonella were verified to have colonized their tumors. We hypothesize that the lack of antitumor efficacy in the human clinical trials can be overcome by engineering antitumor apoptosis (programmed cell death) -inducing cytotoxic proteins that are able to selectively kill tumor cells, and that the ability of these proteins to kill cancer cells can be enhanced by blocking their degradation by tumor proteases through co-expression of protease inhibitors. The specific aims are designed to test the tumor-selective toxin generated during the initial SC3 funding period in murine models of cancer. The specific aims are also directed toward generation and analysis of individual protease inhibitor combinations expressed by VNP20009 in order to prevent proteolytic degradation of the therapeutic protein and develop tumor-targeted Salmonella vectors with enhanced antitumor activity. VNP20009 expressing a tumor-cell targeted toxin will be analyzed alone and in combination with one or more protease inhibitors using optical imaging of the bacterial interaction with murine tumor models of highly aggressive breast cancer. The results are expected to indicate the effectiveness of the targeted toxin and the effect(s) of the protease inhibitors alone and in combination with the toxin. These results have the potential to improve VNP20009 without increasing its toxicity, and therefore could lead to translational studies in humans. .