S.A.F.U. Department, Regina Elena Cancer Institute, (Via delle Messi d'Oro 156), Rome (00158), Italy.
J Transl Med. 2011 Jul 28;9:125. doi: 10.1186/1479-5876-9-125.
Nucleic acids designed to modulate the expression of target proteins remain a promising therapeutic strategy in several diseases, including cancer. However, clinical success is limited by the lack of efficient intracellular delivery. In this study we evaluated whether electroporation could increase the delivery of antisense oligodeoxynucleotides against bcl-2 (G3139) as well as the efficacy of combination chemotherapy in human melanoma xenografts.
Melanoma-bearing nude mice were treated i.v. with G3139 and/or cisplatin (DDP) followed by the application of trains of electric pulses to tumors. Western blot, immunohistochemistry and real-time PCR were performed to analyze protein and mRNA expression. The effect of electroporation on muscles was determined by histology, while tumor apoptosis and the proliferation index were analyzed by immunohistochemistry. Antisense oligodeoxynucleotides tumor accumulation was measured by FACS and confocal microscopy.
The G3139/Electroporation combined therapy produced a significant inhibition of tumor growth (TWI, more than 50%) accompanied by a marked tumor re-growth delay (TRD, about 20 days). The efficacy of this treatment was due to the higher G3139 uptake in tumor cells which led to a marked down-regulation of bcl-2 protein expression. Moreover, the G3139/EP combination treatment resulted in an enhanced apoptotic index and a decreased proliferation rate of tumors. Finally, an increased tumor response was observed after treatment with the triple combination G3139/DDP/EP, showing a TWI of about 75% and TRD of 30 days.
These results demonstrate that electroporation is an effective strategy to improve the delivery of antisense oligodeoxynucleotides within tumor cells in vivo and it may be instrumental in optimizing the response of melanoma to chemotherapy. The high response rate observed in this study suggest to apply this strategy for the treatment of melanoma patients.
设计用于调节靶蛋白表达的核酸仍然是几种疾病（包括癌症）的有前途的治疗策略。然而，临床成功率受到缺乏有效细胞内递药的限制。在这项研究中，我们评估了电穿孔是否可以增加针对 bcl-2（G3139）的反义寡脱氧核苷酸的递药，以及在人黑色素瘤异种移植瘤中联合化疗的疗效。
荷黑色素瘤裸鼠静脉内给予 G3139 和/或顺铂（DDP），然后对肿瘤应用电脉冲列车。通过 Western blot、免疫组织化学和实时 PCR 分析蛋白和 mRNA 表达。通过组织学确定电穿孔对肌肉的影响，通过免疫组织化学分析肿瘤细胞凋亡和增殖指数。通过流式细胞术和共聚焦显微镜测量反义寡脱氧核苷酸肿瘤积聚。
G3139/电穿孔联合治疗显著抑制肿瘤生长（TWI，超过 50%），并伴有明显的肿瘤再生长延迟（TRD，约 20 天）。这种治疗的疗效是由于肿瘤细胞中 G3139 的摄取增加，导致 bcl-2 蛋白表达明显下调。此外，G3139/EP 联合治疗导致肿瘤细胞凋亡指数增加和增殖率降低。最后，在 G3139/DDP/EP 三联治疗后观察到肿瘤反应增强，TWI 约为 75%，TRD 为 30 天。
这些结果表明，电穿孔是提高反义寡脱氧核苷酸在体内肿瘤细胞内递药的有效策略，可能有助于优化黑色素瘤对化疗的反应。本研究中观察到的高反应率提示应用该策略治疗黑色素瘤患者。
