NES1基因联合188Re内放射治疗前列腺癌的实验研究

For those patients suffered with the androgen-independent prostate cancer (AIPC) is still lack of effective treatment methods currently. Our previous study demonstrated: ①the role of normal epithelial cell specific -1 (NES1) gene as a tumor suppressor gene in AIPC cell line (PC3); ②the down-regulation of Bcl-2 expression and the apoptosis promotion in NES1 over-expressed PC3 cell line. On this basis, we intend to go a step further to demonstrate the mechanism of Bcl-2 controlled by NES1 in PC3 cell line, and to explore the relative signal pathway, in the purpose of revealing the molecular mechanism of NES1 in PC3 inhibition. In view of recent literatures, which reported the radiosensitizing effects of Bcl-2 down-regulated on radiotherapy for prostate cancer, this study aims to utilize the dual-gene expressed PC3 cell line, stably transfected by recombinant NES1-IRES-hNIS lentivirus, and the PC3 xenograft nude mice model, to explore the multiple anti-tumor effects of apoptosis promotion and 188Re internal radiosensitizing in the result of Bcl-2 down-regulated, via combining over-expressed NES1 gene therapy and 188Re internal radiotherapy mediated by human sodium iodidesymporter (hNIS); besides, to synchronously monitor NES1 gene expression and evaluate curative therapeutic effects in vivo through the hNIS reporter gene imaging. This study is in the purpose of establishing the theoretical basis for future AIPC multimodal therapy scheme that integrates the combined treatments and therapeutic monitoring synchronously.

目前对于雄激素非依赖前列腺癌(AIPC)尚缺乏有效治疗方法。本课题组前期研究表明正常上皮细胞特异性-1（NES1）基因在AIPC细胞株（PC3）中为抑癌基因，过表达NES1可下调癌基因Bcl-2表达，促进肿瘤细胞凋亡。据此，我们拟进一步阐明NES1在PC3中下调Bcl-2的机制及相关信号通路，从而揭示NES1对PC3的抑癌机制。最新研究显示下调Bcl-2对前列腺癌放疗具有增敏作用，本研究拟利用已制备的重组双基因NES1-IRES-hNIS慢病毒稳转获得的双基因表达PC3细胞及其荷瘤裸鼠模型，探究过表达NES1下调Bcl-2促凋亡联合人钠碘同向转运体（hNIS）介导188Re的内放射治疗对肿瘤促凋亡、内放疗增敏的多重抑癌作用，同时hNIS作为报告基因显像在体动态评估疗效，为今后AIPC联合治疗与疗效监测同步的多模态治疗方案提供理论依据。

目前对于雄激素非依赖前列腺癌(AIPC)尚缺乏有效治疗方法。本课题组前期研究表明正常上皮细胞特异性-1（NES1）基因在AIPC细胞株（PC3）中为抑癌基因，过表达NES1可下调癌基因Bcl-2表达，通过TUNEL实验检测发现NES1促进肿瘤细胞凋亡。考虑到肿瘤存在“Warburg效应”，我们通过18F-FDG Micro PET/CT显像检测了PC3-NES1移植瘤的糖代谢水平，发现过表达NES1基因后，PC3细胞移植瘤的糖代谢能力下降， qPCR、Western Blot和免疫组化检测提示HK-2表达下调。为了更好地研究NES1如何调控Bcl-2和HK-2分子的表达，我们把PC3-NES1细胞株分别过表达Bcl-2和HK-2基因，发现两组PC3-NES1细胞的增殖活性得到增强，Western Blot提示过表达Bcl-2后，HK-2及NES1分子表达增强；过表达HK-2后，Bcl-2和NES1分子表达也增强，这提示我们可能存在一个上调NES1表达负性调控Bcl-2和HK-2表达的关系，而Bcl-2和HK-2之间可能存在协同调控的关系。最新研究显示下调Bcl-2对前列腺癌放疗具有增敏作用，本研究构建重组双基因NES1-IRES-hNIS慢病毒稳转获得的双基因表达PC3细胞及其荷瘤裸鼠模型，利用过表达NES1下调Bcl-2促凋亡及人钠碘同向转运体（hNIS）介导131I的内放射治疗，达到促进肿瘤凋亡、内放疗增敏的多重抑癌作用，同时hNIS作为报告基因显像监测基因治疗的可行性，通过体内增殖显像验证了基因联合内放射治疗的有效性，活体评价疗效，为今后AIPC联合治疗与疗效监测同步的多模态治疗方案提供了理论依据。