ANAEROBE MEDIATED ANTICANCER GENE THERAPY

描述：本申请描述了一种新的目标方法 针对肿瘤的化疗药物。它是基于能力的 某些专性厌氧菌的孢子能够萌发和繁殖 选择性地位于实体瘤常见的缺氧区/坏死区。这个 正在开发的假说是因为这些缺氧/坏死区 是实体肿瘤所特有的，而且因为专性肿瘤的增殖 厌氧菌只出现在肿瘤中，然后表达的任何蛋白质 细菌只会出现在肿瘤中。这种选择性表达可以 用于前药的靶向激活。据信，这一点 Strategy有可能在靶向上更具肿瘤特异性 比目前正在调查的任何其他战略都要好。此应用程序将 使用基因工程菌株乙酰丁酸梭菌作为 靶向载体表达能够激活特定前体药物的酶。 在第一种情况下，梭状芽胞杆菌将被改造为表达E. 代谢单功能烷基化的大肠杆菌硝基还原酶 试剂CB1954和与双官能团烷基化试剂相近的类似物 毒性是母体化合物的10(4)到10(5)倍。初步 研究表明，这种硝基还原酶可以在 在小鼠肿瘤中选择性地以活性形式存在。在第二个系统中， 梭状芽孢杆菌将表达能够代谢的β-葡萄糖苷酸酶 选定抗癌药物的葡萄糖醛酸化结合物，包括 阿霉素前体药物。尽管将使用的前药将应用于 从系统上讲，有毒的代谢物应该只在肿瘤中产生。 这项申请是由两个实验室共同努力的，具有广泛的 分子生物学和药理学专业知识。

DESCRIPTION: The present application describes a novel approach to target chemotherapeutic drugs specifically to tumors. It is based on the ability of spores of certain obligate anaerobes to germinate and proliferate selectively in the hypoxic/necrotic regions common to solid tumors. The hypothesis being developed is that because these hypoxic/necrotic regions are unique to solid tumors and because the proliferation of the obligate anaerobes only occurs in the tumor, then any proteins expressed by the bacteria will be present only in the tumor. This selective expression can be used for targeted activation of prodrugs. It is believed that this strategy has the potential of being more tumor-specific in its targeting than any other strategy presently being investigated. This application will use a genetically engineered strain of Clostridium acetobutylicum as the targeting vector to express enzymes capable of activating specific prodrugs. In the first case, the Clostridium species will be engineered to express E. coli-derived nitroreductase which metabolizes the monofunctional alkylating agent CB1954 and close analogs to bifunctional alkylating agents that are 10(4) to 10(5) times more toxic than the parent compound. Preliminary studies have demonstrated that this nitroreductase can be expressed in active form selectively in mouse tumors. In the second system, the Clostridium will express beta-glucuronidase which is capable of metabolizing glucuronidated conjugates of selected anticancer drugs, including a doxorubicin prodrug. Although the prodrugs to be used will be applied systemically, the toxic metabolites should be generated solely in the tumor. The application is a joint effort of two laboratories with extensive molecular biology and pharmacological expertise.