中文摘要：

目的：探讨曲古抑菌素A（TSA）对人结肠癌细胞株Colo205组蛋白乙酰化及ING1bmRNA表达的影响。方法：培养人结肠癌细胞株Colo205，对照组（A组）不加TSA干预，实验组分3组（B、c、D组），分别应用组蛋白去乙酰化酶（HDACs）抑制剂TSA50、100、200μg/L的浓度作用于人结肠癌细胞株Colo205，24h后用染色质免疫沉淀（ChIP）方法检测4组Colo205细胞乙酰化组蛋白H3结合的DNA情况，以了解抑癌基因ING1b相关组蛋白H3乙酰化的变化，并用逆转录聚合酶链反应（RT—PCR）方法检测INGIbmRNA的表达，均用实时定量PCR方法分析。结果：A组人结肠癌细胞株Colo205组蛋白H3乙酰化水平及ING1bmRNACt值为23．25±0．08和23．32±0．05，经TSA干预后，C、D组组蛋白H3乙酰化水平较A组增加（P〈0．05），2-△△Ct。值分别为4．21和4．38，ING1bmRNA表达亦比A组高（P〈0．05），2-△△Ct、值分别为4．52和4．62，组蛋白H3乙酰化水平及INGlbmRNA表达c、D组间无显著性差异（P〉0．05），组蛋白H3乙酰化水平及ING1bmRNA表达B组与A组比较无显著性差异（P〉0．05），2-△△Ct。值分别为1．12和1．33。同时观察到C、D组Colo205细胞较A、B组细胞生长明显受抑制。结论：人结肠癌细胞株Colo205组蛋白去乙酰化可能是导致基因ING1b表达沉默的主要原因之一，100μg/L的TSA能较好地提高组蛋白乙酰化水平，并有效地激活去乙酰化所致ING1b基因转录，诱导该基因表达，从而抑制肿瘤细胞生长。

英文摘要：

Objective： To investigate the effect of Trichostatin A （TSA） on histone acetylation and expression of INGlb mRNA in Colo205 human colon cancer cell line. Methods： Human colon cancer Colo205 cells were cultured and divided into 4 groups. Cells in the control group （group A） was treated without TSA. In the other three groups, cells were treated with 3 different concentrations of TSA： 501Jg/L （group B）, 100μg/L （group C）, and 200pg/L （group D）. At 24 hours after treatment, the level of histone H3 acetylation was analyzed by chromatin immunoprecipitation （CHIP） and the expression of INGlb mRNA was detected by RT-PCR with qPCR. The growth of Colo205 human colon cancer ceils in group C and D was obviously inhibited compared with that in group A and B. Results： The Ct value of histone H3 acetylation and mRNA expression of INGlb in group A were 23.25± 0.08 and 23.32±0.05, respectively. After treatment with TSA, the 2-△△Ct value of histone H3 acetylation in group B, C, and D were 1.12, 4.2t and 4.38, respectively. The level of histone H3 acetylation in group C and D was increased more compared with that in group A （P〈0.05） and there was no difference between group B and group A （P〉0.05）. The 2-△△Ct value of the expression of INGlb mRNA in group B, C and D were 1.33, 4.52 and 4.62, respectively. The expression of INGlb mRNA in group C and D were more than that in group A （P〈0.05）. Group B and group A had a similar level of INGlb mRNA expression （P〉0.05）. Conclusion： The histone acetylation is probably responsible for INGlb expression silencing in Coto205 human colon cell line. TSA at 100μg/L can increase the level of acetylation and activate the gene transcription which is silenced by low level of acetylation and induce the expression of gene, inhibiting the growth of tumor cells.