目的：分析丁酸钠对HT-29结肠癌细胞p53三个主要靶基因（p21waf1，bax和gadd45）的调控，并探讨其作用机制。方法：HT-29细胞常规培养在含有和不含有丁酸钠的培养液中。分别用MTT和流式细胞仪(flow cytometry,FCM) 检测细胞增殖和细胞周期分布，通过形态学观察、亚G1峰的检测和AnnexinV-FITC 双标记观察细胞凋亡情况；RT-PCR和Western blot分别检测丁酸钠对p21waf1，bax和gadd45三种基因mRNA和蛋白表达水平的影响。结果：丁酸钠以剂量和时间依赖的方式抑制HT-29细胞增殖和诱导凋亡，并阻滞细胞于G1期。RT-PCR 和Western blot结果显示丁酸钠可以促进p21waf1和bax基因mRNA和蛋白的表达，而对gadd45基因的表达无明显影响。结论：2.5 mmol/L以上浓度的丁酸钠可以抑制HT-29细胞增殖并诱导凋亡，该作用可能通过上调p21waf1和bax基因表达而实现。

Objective: To investigate the regulatory effects of sodium butyrate onp53 target genes (p21waf1, bax,and gadd45) in HT-29 colorectal cancer cells and the related mechanisms. Methods: HT-29 cells were cultured in the absence or presence of sodium butyrate. The cell proliferation and cell cycle were studied by MTT and FCM, respectively. Apoptosis was assessed by observing cell morphology, percentage of sub-G1 cells and AnnexinV-FITC. The effects of sodium butyrate on transcription of p21waf1, bax and gadd45 were analyzed by RT-PCR and Western blot. Results: Sodium butyrate inhibited proliferation and induced apoptosis of HT-29 cells in a time- and dose-dependent manner, and it blocked HT-29 cell at G1 phase. Sodium butyrate stimulated p21waf1 and bax expression both at mRNA and protein level in HT-29 cells, but had little effect on the transcription of gadd45. Conclusion: Sodium butyrate can inhibit proliferation and induce apoptosis of HT-29 cells, which might be through up-regulating p21waf1 and -bax-expression both at mRNA and protein levels.

济南市科技局立项课题(济科合2002第13号)