Robertson M W, Wang M, Siegal G P, Rosenfeld M, Ashford R S, Alvarez R D, Garver R I, Curiel D T
Department of Obstetrics and Gynecology, University of Alabama at Birmingham, 35294, USA.
Cancer Gene Ther. 1998 Sep-Oct;5(5):331-6.
Molecular chemotherapy strategies have been developed for a number of epithelial malignancies based on selective delivery and expression of a toxin-encoding gene into the cancer cells. To date, these strategies have not been explored in the context of carcinoma of the cervix, despite the fact that a variety of factors suggest this as an appropriate disease for this gene therapy approach. One limitation in this respect is that appropriate tissue-specific promoters for selective toxin gene expression have not been defined for cervical carcinoma. In this regard, the secretory leukoprotease inhibitor (SLPI) gene has been shown to be constitutively expressed in many epithelial carcinoma cells including the uterine cervix. Thus, we investigated the utility of the SLPI gene as a tissue-specific promoter for regulatory control of the herpes simplex virus thymidine kinase gene for in vitro treatment of cervical carcinoma cells. For this analysis, a gene construct was derived with the herpes simplex virus thymidine kinase gene under regulatory control of the 5' upstream regions of the SLPI gene. Transient transduction of three human cervical carcinoma cell lines with the SLPI-thymidine kinase (TK) construct was followed by treatment with the prodrug ganciclovir. Crystal violet staining was subsequently used to assess cell viability. In this analysis, it was shown that the SLPI-TK construct directed TK-mediated killing in two of three tested cervical cell lines, with the two cell lines being positive for SLPI. In addition, mixing experiments established that cervical carcinoma cells could exhibit a bystander effect which potentially augments the efficacy of molecular chemotherapy approaches. These findings may allow for the development of efficacious, target-specific, toxin gene therapy strategies for cervical carcinoma in human patients.
基于将毒素编码基因选择性递送至癌细胞并使其表达，已经为多种上皮性恶性肿瘤开发了分子化疗策略。尽管有多种因素表明子宫颈癌适合采用这种基因治疗方法，但迄今为止，尚未在子宫颈癌的背景下探索这些策略。在这方面的一个限制是，尚未确定用于子宫颈癌选择性毒素基因表达的合适组织特异性启动子。在这方面，分泌型白细胞蛋白酶抑制剂（SLPI）基因已被证明在包括子宫颈在内的许多上皮癌细胞中组成性表达。因此，我们研究了SLPI基因作为组织特异性启动子对单纯疱疹病毒胸苷激酶基因进行调控以体外治疗子宫颈癌细胞的效用。为了进行此分析，构建了一种基因构建体，其中单纯疱疹病毒胸苷激酶基因受SLPI基因5'上游区域的调控。用SLPI-胸苷激酶（TK）构建体对三种人子宫颈癌细胞系进行瞬时转导，随后用前药更昔洛韦进行处理。随后使用结晶紫染色评估细胞活力。在此分析中，结果表明SLPI-TK构建体在三个测试的子宫颈细胞系中的两个中指导了TK介导的杀伤作用，这两个细胞系对SLPI呈阳性。此外，混合实验证实子宫颈癌细胞可表现出旁观者效应，这可能增强分子化疗方法的疗效。这些发现可能有助于为人类子宫颈癌患者开发有效的、靶向特异性的毒素基因治疗策略。
