中文摘要：

目的：观察诱导分化剂笨乙酸（Phenylacetate，PA）抑制结直肠癌细胞HCT-8增殖过程中C-myc基因表达的变化，方法：应用噻唑蓝（MTT）比色法，以1．0、2．0、3．0、4．0、5．0mmol／L的PA作用于HCT-8细胞，分别于24、48、72h对细胞增殖进行检测．应用原位分子杂交方法观察应用PA后对HCT-8细胞C-myc mRNA表达的情况。结果：1．0．5．0mmol／LPA作用HCT-8细胞24-72h．随着PA浓度的增加或作用时间的延长，细胞生长抑制率明显增加，PA作用24h为5．1％～24.3％．48h为16．7％～72．3％．72h为30．2％～93．4％PA治疗后HCT-8细胞C-myc mRNA阳性表达率为（12．05±7．92）％，显著低于非治疗组中的阳性率（55．15±21．64）％（P〈0．01）。结论：PA可有效抑制结直肠癌HCT-8细胞的增殖．PA对C-myc基因具有明显的抑制作用

英文摘要：

Objective： To observe the changes in C-myc mRNA expression in HCT-8 colorectal carcinoma cells treated with phenylacetate （PA）. Methods： HCT-8 cells were cultured in the presence of PA at 1.0, 2.0, 3.0, 4.0, and 5.0 mmol/L The cellular proliferation inhibitory ratio was evaluated by MTT assay 24h, 48h, and 72h later, and C-myc mHNA expression in the HCT-8 cell line was detected by an in situ hybridization test. Results： With increased PA concentration and extended ct, hure time, the inhibitory rate of tumor cell growth was notably increased. The inhibitory rates were 5.1%-24.3%, 16.7%-72.3%, and 30.2%-93.4% in cells cuhured for 24h, 48h, and 72h, respectively. The expression rate of C-myc was lower in cells cultured in PA than that in cells cuhured without PA, with a significant difference （P〈0.05）. Conclusion： PA can downregulate C-myc mRNA expression and inhibit the growth of colorectal carcinoma cells.