Shapovalova Mariya, Davydova Julia, Henzler Christine, Daniel Mark, Dehm Scott M, Warlick Christopher A, LeBeau Aaron M
Department of Pharmacology, University of Minnesota, Minneapolis 55455, MN, USA.
Department of Surgery, University of Minnesota, Minneapolis 55455, MN, USA.
Oncotarget. 2018 Nov 30;9(94):36693-36704. doi: 10.18632/oncotarget.26401.
The metabolic protein alpha-methylacyl-CoA racemase (AMACR) is significantly overexpressed in prostate cancer compared to the normal prostate and other non-malignant tissue. Though an attractive target, there are no reports in the literature on leveraging the expression of AMACR for the molecular imaging of prostate cancer. Here, we used a molecular-genetic imaging strategy to exploit the transcriptional specificity of the AMACR promoter for the detection of prostate cancer using the reporter gene luciferase. We performed a stepwise truncation of the promoter and identified a 565 base pair minimal promoter for AMACR that retained both high activity and specificity. Following identification of the minimal promoter for AMACR, we used an advanced two-step transcriptional amplification system to maximize the promoter output. We showed that our optimized AMACR promoter can drive expression of luciferase for molecular imaging in subcutaneous xenograft models of androgen receptor-positive and androgen receptor-negative prostate cancer using a non-replicative adenovirus for gene delivery. Our results provide evidence that the AMACR promoter can be exploited to drive the cancer-specific expression of reporter genes and potentially even be incorporated into conditionally replicative adenoviruses for oncolytic therapy and other applications.
与正常前列腺组织及其他非恶性组织相比，代谢蛋白α-甲基酰基辅酶A消旋酶（AMACR）在前列腺癌中显著过表达。尽管它是一个有吸引力的靶点，但文献中尚无利用AMACR表达进行前列腺癌分子成像的报道。在此，我们采用分子遗传成像策略，利用AMACR启动子的转录特异性，通过报告基因荧光素酶来检测前列腺癌。我们对启动子进行了逐步截短，确定了一个565个碱基对的AMACR最小启动子，它兼具高活性和特异性。在确定AMACR最小启动子后，我们使用先进的两步转录扩增系统来最大化启动子输出。我们证明，在雄激素受体阳性和雄激素受体阴性前列腺癌的皮下异种移植模型中，我们优化后的AMACR启动子能够驱动荧光素酶表达用于分子成像，采用非复制型腺病毒进行基因递送。我们的结果表明，AMACR启动子可用于驱动报告基因的癌症特异性表达，甚至有可能被纳入条件性复制腺病毒用于溶瘤治疗及其他应用。
