Lee Christine M, Lo Hui-Wen, Shao Ru-Ping, Wang Shao-Chun, Xia Weiya, Gershenson David M, Hung Mien-Chie
Department of Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Cancer Res. 2004 Mar 1;64(5):1788-93. doi: 10.1158/0008-5472.can-03-2551.
Gene therapy provides a novel treatment approach to cancer patients. Ideally, expression of therapeutic genes driven by cancer-specific promoters would only target tumors resulting in minimal toxicity to normal tissues. While there is a need of more effective and tolerable treatments for ovarian cancer patients, we aimed to identify gene promoters with high activity in ovarian tumors that can be potentially used in gene therapy to drive the expression of a therapeutic gene in tumors. To identify such promoters, a literature search was performed to reveal genes that are preferentially expressed in ovarian cancer compared with normal ovarian tissue. We found that the ceruloplasmin promoter drove up to 30-fold higher luciferase expression in ovarian cancer cells compared with immortalized normal cells. Furthermore, deletion studies revealed an activator protein-1 (AP-1) site in the ceruloplasmin promoter to be critical for optimal ceruloplasmin promoter activity. Ceruloplasmin promoter activity was significantly activated by 1-O-tetradecanoyl phorbol-13-acetate, a c-jun activator, and conversely suppressed by SP600125, a c-jun inhibitor. Consistently, the ceruloplasmin AP-1 site was specifically recognized by c-jun both in vitro and in vivo. Immunohistochemical analyses of human ovarian cancer specimens showed a direct correlation (r = 0.7, P = 0.007) between expression levels of c-jun and ceruloplasmin. In nude mice carrying SKOV3.ip1 xenografts, the ceruloplasmin promoter demonstrated significantly higher activities in tumors compared with normal organs. Together, these results suggest that the ceruloplasmin promoter activity is significantly enhanced in ovarian cancer and therefore may be exploited as a promising cancer-specific promoter in developing new gene therapy strategies for ovarian cancer.
基因治疗为癌症患者提供了一种新的治疗方法。理想情况下，由癌症特异性启动子驱动的治疗基因表达只会靶向肿瘤，对正常组织产生最小的毒性。虽然卵巢癌患者需要更有效且耐受性更好的治疗方法，但我们旨在鉴定在卵巢肿瘤中具有高活性的基因启动子，这些启动子可能用于基因治疗，以驱动治疗基因在肿瘤中的表达。为了鉴定此类启动子，我们进行了文献检索，以揭示与正常卵巢组织相比在卵巢癌中优先表达的基因。我们发现，与永生化正常细胞相比，铜蓝蛋白启动子在卵巢癌细胞中驱动的荧光素酶表达高达30倍。此外，缺失研究表明铜蓝蛋白启动子中的一个活化蛋白-1（AP-1）位点对于最佳的铜蓝蛋白启动子活性至关重要。1-O-十四酰佛波醇-13-乙酸酯（一种c-jun激活剂）可显著激活铜蓝蛋白启动子活性，相反，c-jun抑制剂SP600125可抑制该活性。一致地，铜蓝蛋白AP-1位点在体外和体内均被c-jun特异性识别。对人卵巢癌标本的免疫组织化学分析显示，c-jun和铜蓝蛋白的表达水平之间存在直接相关性（r = 0.7，P = 0.007）。在携带SKOV3.ip1异种移植物的裸鼠中，与正常器官相比，铜蓝蛋白启动子在肿瘤中的活性显著更高。总之，这些结果表明铜蓝蛋白启动子活性在卵巢癌中显著增强，因此在开发新的卵巢癌基因治疗策略中可能被用作有前景的癌症特异性启动子。
