Godbey W T, Atala Anthony
Laboratory for Cellular Therapeutics and Tissue Engineering, Harvard Medical School, The Children's Hospital, Boston, MA 02115, USA.
Gene Ther. 2003 Aug;10(17):1519-27. doi: 10.1038/sj.gt.3302012.
The principle of promoter-targeted gene delivery was used to direct the expression of reporter genes and inducible caspases to Cox-2-overexpressing cancer cells. The polycation poly(ethylenimine) was used in unmodified form to nonvirally deliver genes into cells, and targeting was achieved at the transcriptional level. Results demonstrated that reporter expression was reduced by an average of 89.8% in normal cells and cell lines not overexpressing Cox-2 when the strong cytomegalovirus promoter was replaced with the human Cox-2 promoter in delivered plasmids. Cocultures of normal and Cox-2-overexpressing cancer cells showed less than 0.5% reporter expression in normal fibroblast cells but over 35% reporter expression in PC3 prostate cancer cells. This targeting method was then used to direct the expression of inducible forms of caspases 3 and 9 to Cox-2-overexpressing cancer cells of the bladder and prostate. Following activation of the resulting caspase pro-forms, cells underwent apoptosis as evidenced by DNA fragmentation and cytoskeletal degradation. This result was also observed in cells resistant to apoptosis in terms of TNF-alpha initiation. Such directed apoptosis could eventually serve as a treatment for an entire class of Cox-2-overexpressing carcinomas.
启动子靶向基因递送原理被用于将报告基因和可诱导的半胱天冬酶的表达导向过表达Cox-2的癌细胞。聚阳离子聚乙烯亚胺以未修饰的形式用于非病毒地将基因递送至细胞，并且靶向作用在转录水平实现。结果表明，当在递送的质粒中用人类Cox-2启动子替换强巨细胞病毒启动子时，在未过表达Cox-2的正常细胞和细胞系中，报告基因的表达平均降低了89.8%。正常细胞与过表达Cox-2的癌细胞共培养显示，正常成纤维细胞中报告基因的表达低于0.5%，但在PC3前列腺癌细胞中报告基因的表达超过35%。然后使用这种靶向方法将可诱导形式的半胱天冬酶3和9的表达导向膀胱和前列腺的过表达Cox-2的癌细胞。在所得半胱天冬酶前体形式被激活后，细胞发生凋亡，DNA片段化和细胞骨架降解证明了这一点。在对TNF-α启动的凋亡具有抗性的细胞中也观察到了这一结果。这种定向凋亡最终可作为一类过表达Cox-2的癌症的一种治疗方法。
