移植于裸鼠的人鼻咽癌细胞DNA合成生物节律的初步研究

目的：探讨鼻咽癌细胞DNA合成的生物节律为临床制订鼻咽癌时辰化疗方案提供必要的参数。方法：BALB/C裸小鼠15只，置于积控的独立光照系统中（12h光照，12h黑暗）中同步化至少3周。然后双侧腋下接种人鼻咽低分化鳞癌细胞裸小鼠移植瘤CNE-2，成瘤后按灯亮后3、9、15、21h（即3、9、15、21 HALO）的时间点取瘤块，制成单个细胞悬液，固定，染色后流式细胞仪侧DNA含量。用SPSS软件系统ANOVA法检验各期细胞在4个时间点差异的显著性，用Cosinor法考察G1、S、G2/M期细胞在24h的分布是否符合余弦函数。结果：G1、S、G2/M期细胞在3、9、15、21 HALO的分布随时间变化有显著性差异，G1、G2/M期细胞变化符合余弦节律。结论：移植于裸鼠的人鼻咽癌细胞的DNA合成随昼夜交替呈节律性变化。

Circadian Rhythms of DNA Synthesis in Human Nasopharyngeal Carcinoma Cells Transplanted in Nude Mice

Objective： The circadian rhythm of DNA synthesis in nasopharyngeal carcinoma (NPC) cells was investigated so that to provide necessary data for making clinical chrono-chemotherapy schedule of NPC. Methods： Fifteen BALB/c mice were synchronized with an alternative lighting regimen with 12 hours for light and 12 hours for dark (12∶ 12 LD) at least 3 weeks. Human nasopharyngeal poorly differentiated squamous cell carcinoma(CNE-2) cells were implanted into both flanks of each mouse. Ten days after transplantation, sampling from tumor was conducted in the 3, 9, 15, 21 hours after light onset (HALO). Single cell suspension was obtained and stained with propidium iodide. The cellular DNA content was measured by flow cytometry. Data were documented by ANOVA and Cosinor analysis. Results： The proportion of tumor cells in Phage G1,S,G2-M varied according to circadian time with statistical significance. The distribution curves of Phage G1 and Phage G2-M fit for Cosinor changes. Conclusion： DNA synthesis of human nasopharyngeal poorly differentiated squamous cell carcinoma(CNE-2) cells trausplanted in nude mice varies according to circadian rhythm.