Shen Wen-Jing, Dai Dong-Qiu, Teng Yue, Liu Jie
Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang 110001, China.
Zhonghua Yi Xue Za Zhi. 2008 Apr 29;88(17):1192-6.
To investigate the effects of sodium butyrate (NaB), a histone deacetylase inhibitor (HDACI), on the proliferation of human gastric cancer cells and the expression of p16, an important negative-regulatory factor of the cell cycle G1.
Human gastric cancer cells of the lines SGC7901 and BGC823 were cultured in RPMI1640 medium and treated with NaB of different concentrations: 5 x10(-4), 1 x 10(-3), 3 x 10(-3), and 5 x 10(-3) mol/L for 24 h or 72 h. MTT assay, flow cytometry, and annexin V-fluorescein isothiocyanate staining were performed to analyze the cell proliferation activity, cell cycle, and apoptotic rate. RT- PCR, Western blotting, and methylation-specific PCR (MSP) were used to detect the e mRNA and protein expression and methylation state of p16 gene respectively.
Exposure to different concentrations of NaB inhibited the growth of the SGC7901 and BGC823 cells. Treated with NaB of the concentrations of 1 x 10(-3), 3 x 10(-3), and 5 x 10(-3) mol/L respectively for 72 h, the numbers of the SGC7901 and BGC823 cells at G0/G1 stage increased significantly and those at S stage decreased significantly (all P <0.01), which showed that the cell cycle was blocked at G1 phase. The apoptosis rates of the SGC7901 and BGC823 cells treated with NaB of different concentrations for 72 h all increased significantly (all P <0.01). P16 was expressed in the SGC7901 and BGC823 cells at low levels, and hypermethylation was detected in its promoter region in both cells before the treatment of NaB. After treated with NaB the mRNA and protein expressions of p16 gene were increased in both cells.
NaB inhibits the growth of human gastric cancer cells by blocking cell cycles, inducing apoptosis and upregulating the expression of p16 gene by increasing acetylation and reducing methylation.
探讨组蛋白去乙酰化酶抑制剂（HDACI）丁酸钠（NaB）对人胃癌细胞增殖及细胞周期G1期重要负调控因子p16表达的影响。
将人胃癌细胞系SGC7901和BGC823培养于RPMI1640培养基中，分别用5×10⁻⁴、1×10⁻³、3×10⁻³和5×10⁻³mol/L不同浓度的NaB处理24小时或72小时。采用MTT法、流式细胞术和膜联蛋白V-异硫氰酸荧光素染色分析细胞增殖活性、细胞周期和凋亡率。分别用RT-PCR、蛋白质印迹法和甲基化特异性PCR（MSP）检测p16基因的mRNA和蛋白表达及甲基化状态。
不同浓度的NaB处理可抑制SGC7901和BGC823细胞的生长。分别用1×10⁻³、3×10⁻³和5×10⁻³mol/L浓度的NaB处理72小时后，SGC7901和BGC823细胞处于G0/G1期的数量显著增加，处于S期的数量显著减少（均P<0.01），表明细胞周期阻滞于G1期。不同浓度的NaB处理72小时后，SGC7901和BGC823细胞的凋亡率均显著增加（均P<0.01）。SGC7901和BGC823细胞中p16表达水平较低，在NaB处理前，两细胞中其启动子区域均检测到高甲基化。NaB处理后，两细胞中p16基因的mRNA和蛋白表达均增加。
NaB通过阻滞细胞周期、诱导凋亡以及增加乙酰化和减少甲基化上调p16基因表达，从而抑制人胃癌细胞生长。
