中文摘要：

目的探讨二噁英（TCDD）对调控成骨肉瘤细胞（SaOS-2）凋亡和胰岛素样生长因子结合蛋白6（insulin—like growth factor binding protein 6，IGFBP-6）基因表达的影响。方法应用1×10^9、1×10^-8、1×10^-7mol／L浓度的TCDD作用于SaOS-2细胞株，采用四甲基偶氮噻唑蓝（MTT）法检测TCDD对SaOS-2细胞增殖能力的影响，流式细胞仪检测SaOS-2细胞株细胞凋亡率，采用对硝基酚磷酸盐法测定SaOS-2细胞内碱性磷酸酶（ALP）的活力，采用反转录-聚合酶链反应（RT—PCR）半定量分析SaOS-2中IGFBP-6 mRNA的表达，采用Western印迹杂交鉴定SaOS-2中IGFBP-6蛋白的表达。结果在1×10^-9、1×10^-8、1×10^-7mol／LTCDD浓度下SaOS-2的增殖指数分别为18．4±4．5、22．5±3．6、29．4±4．2。SaOS-2 ALP的活力分别为1．12±0．28、1．58±0．14、1．96±0．17U／mg Pro，均高于对照组；且1×10^-7、1×10^-8mol／L组与对照组比较，差异有统计学意义（P〈0．05）；1×10^-7mol／LTCDD浓度组的细胞凋亡率明显低于对照组，差异有统计学意义（P〈0．05）。3个不同浓度组的mRNA表达和1×10^-7mol／LTCDD组蛋白的表达均明显低于对照组，差异有统计学意义（P〈0．05）。结论低浓度的TCDD对SaOS-2的凋亡代谢具有拮抗作用。TCDD对SaOS-2内IGFBP-6基因表达的抑制效应，可能是TCDD参与骨肿瘤发生及生长的作用机制之一。

英文摘要：

Objective To investigate the effect of the environmental carcinogenic factor-TCDD （2,3,7,8-tetrachlorodibenzo-p-dioxin） on cell apoptosis and gene regulation of insulin-like growth factor binding protein 6 （IGFBP-6） in osteogenic sarcoma （SaOS-2） cells. Methods The SaOS-2 cells were cultured with TCDD （ 1 ×10^-9, 1 ×10^-8,1 ×10^-7mol/L） for 24 hours. The MTT reduction assay and flow cytometry were used to measure the cell proliferation and the cell apoptosis in TCDD-treated SaOS-2 cells. The Nitrophenol phosphate salt method was used to measure activity of alkaline phosphatase （ALP） in SaOS-2 cells. The IGFBP-6 mRNA and protein in SaOS-2 cells were detected by reverse transcription polymerase chain reaction （RT-PCR） and western blotting analysis. Results SaOS-2 cell proliferation was up-regulated with TCDD （ 1 ×10^-9,1 ×10^-8,and 1×10^-7mol/L） about 20% ,47% and 93%（ 18.4±4.5,22.5±3.6 and 29.4±4.2） ,respectively. The synthesis of ALP was up-regulated about 28% ,95% ,and 142%（ 1.12±0.28, 1.58±0.14 and 1.96±0.17） ,respectively（P〈0.05 ）. The cell apoptosis was down-regulated in dose-dependent biological manner about 5%, 26% and 52% ,respectively （P〈0.05）. The expression of IGFBP-6 mRNA and protein was decreased in 1×10^-7mol/L TCDD-treated SaOS-2 cells about 76% and 72%（P〈0.05）. Conclusion TCDD at low concentration may have the negative effect on cell apoptosis and down-regulation on gene expression of IGFBP-6 in SaOS-2 cells.