Adenovirus Replication-Competent Anti-Cancer Vector

描述（由申请人提供）：我们已经开发了几种用于癌症基因治疗的肿瘤特异性和组织特异性复制能力腺病毒（Ad）载体。一种名为KD3的载体在E1A基因上发生了突变，使得KD3不能在“正常”细胞中复制和破坏。然而，KD3可以在癌细胞中复制，因为它们有一个有利于KD3复制的微环境。KD3能有效地裂解细胞并在细胞间传播，因为它过度表达一种叫做ADP的蛋白质，这种蛋白质能促进细胞的裂解。第二种名为GZ3的载体与KD3完全相同，只是它具有野生型E1A基因。GZ3具有很强的细胞溶解作用，但它不是肿瘤特异性的，不能以目前的形式用于治疗癌症。在过去的一年里，我们继续尝试开发治疗癌症的最佳载体。我们构建了新的载体，分别命名为KD3-COL和GZ3-COL，其中E4启动子被命名为col的结肠癌特异性启动子所取代。这些Ad载体在结肠癌细胞中复制，而不是在其他类型的细胞中复制。我们还构建了端粒酶的TERT启动子取代E4启动子的KD3-TERT和GZ3-TERT载体。这些载体应该在端粒酶阳性的癌细胞中复制，而不是在正常细胞中复制。我们还构建了KD3的一个版本，它分泌一种诱导凋亡的蛋白质，而不妨碍载体的复制。该载体通过两种机制破坏肿瘤：载体裂解复制和感染细胞周围未感染细胞的凋亡。有希望的是，分泌的蛋白质可能能够诱导已经转移的肿瘤细胞凋亡。我们提出在细胞培养中对KD3-COL、GZ3-COL、KD3-TERT、GZ3-TERT和凋亡诱导载体进行表征，主要目的是确定它们对癌细胞的特异性以及它们在这些细胞中复制和扩散的能力。他们还将评估他们破坏或抑制免疫缺陷裸鼠体内人类癌细胞生长的能力。将对这些肿瘤的生长、病理和支持载体复制的能力进行检查。将研究这些媒介的毒性和在小鼠中的分布。

DESCRIPTION (provided by applicant): We have developed several tumor-specific and tissue-specific replication-competent adenoviruses (Ad) vectors for cancer gene therapy. One vector, named KD3, has a mutation in the E1A gene such that KD3 cannot replicate in, and destroy, "normal" cells. However, KD3 can replicate in cancer cells because they have a microenvironment conducive to KD3 replication. KD3 is efficient in lysing cells and spreading from cell-to-cell, because it overexpresses a protein named ADP which enhances cell lysis. A second vector, named GZ3, is identical to KD3 except it has a wild-type E1A gene. GZ3 is very cytolytic, but it is not tumor-specific and could not be used in its present form to treat cancer. In the past year, we have continued in our attempt to develop optimal vectors to treat cancer. We have constructed new vectors, named KD3-COL and GZ3-COL, where the E4 promoter is replaced by a colon cancer-specific promoter named COL. These Ad vectors replicate in colon cancer cells but not other types of cells. We have also constructed vectors named KD3-TERT and GZ3-TERT, which have the E4 promoter replaced by the TERT promoter for telomerase. These vectors should replicate in telomerase-positive cancer cells but not in normal cells. We have also constructed a version of KD3 that secretes an apoptosis-inducing protein without precluding the replication of the vector. This vector should destroy tumors by two mechanisms, vector lytic replication and apoptosis of uninfected cells surrounding the infected cells. Hopefully, the secreted protein may be able to induce apoptosis in tumors that have metastasized. We propose to characterize KD3-COL, GZ3-COL, KD3-TERT, GZ3-TERT, and the apoptosis-inducing vector in cell culture, with the primary aim of ascertaining their specificity to cancer cells together with their ability to replicate and spread in these cells. They will also be evaluated for their ability to destroy or suppress the growth of human cancer cells in immunodeficient nude mice. These tumors will be examined with respect to their growth, pathology, and ability to support vector replication. The toxicity and distribution of these vectors in mice will be studied. PROPOSED COMMERCIAL APPLICATION: Cancer is the second leading cause of death in the USA. The adenovirus anti-cancer vectors that wwe have developed are expected to provide effective treatment of many different types of cancers, including colon and prostate. Accordingly, the market potential is extremely large.