端粒酶核酶时间治疗肝癌裸鼠移植瘤研究

目的 探讨在端粒酶峰值时相与谷值时相施以端粒酶抑制剂治疗肝癌裸鼠移植瘤的疗效差异.方法 24只BALB/C裸鼠进行为期4 wk的LD12: 12节律同步化.移植肝癌细胞(SMMC-7721)于裸鼠以建立肝癌裸鼠移植瘤.在移植后 2 wk,瘤体内注射端粒酶抑制剂hTERT-5'RZ以治疗肝癌裸鼠移植瘤,注射时间点为9 HALO或21 HALO,持续2 wk.结果 21 HALO治疗组的肿瘤抑制率(65%)和端粒酶抑制率(90%)高于9 HALO治疗组的肿瘤抑制率(48%)和端粒酶抑制率(70%),差异具有统计学意义. 结论 在肿瘤DNA合成期注射以端粒酶为作用靶点的核酶能更好地抑制肝癌生长,具有更好的治疗效果.

Chronotherapy by Ribozyme Targeted to Telomerase in Nude Mice with a Transplanted Tumor: Model for Human Hepatic Cancer

Objective To investigate therapeutic autcomes of using telomerase inhibitors to treat cancer at the presumably most and least opportune circadian stages basing on our earlier study. Methods Twenty-four BALB/C nude mice were synchronized to a regimen of LD12:12 for 4 wk. Hepatic cancer cells (SMMC-7721) were implanted into both flanks of each mouse.Two weeks after transplantation,the hTERT-5'RZ was used to treat the hepatic cancer transplanted into the nude mice daily for two weeks,the injection times being either 9 or 21 HALO.Results The tumor inhibition ratio of mice treated at 21 HALO (65%) was statistically significantly higher than that of mice treated at 9 HALO (48%). Telomerase activity was also reduced to a greater extent in mice treated with hTERT-5'RZ at 21 than at 9 HALO, that was at the time of maximal circadian telomerase activity. Conclusion Injection of ribozyme targeted to telomerase during the tumor's DNA synthesis is associated with a better inhibition of tumor growth and a better therapeutic outcome in hepatic cancer.