中文摘要：

目的探讨特异性抑制Hedgehog信号通路对人鳞状细胞癌（squamous cell carcinoma，SCC）细胞增殖抑制及诱导凋亡的作用。方法用Hedgehog信号通路的特异性抑制剂KAAD—cycloparnine处理Tca细胞，采用M1fr法观察KAAD—cyclopamine对Tca细胞增殖的影响，倒置显微镜下观察细胞形态，流式细胞仪测定细胞凋亡率和细胞周期的变化，凋亡率检测使用Annexin—V—FITC／PI双染法，细胞周期采用PI染色法。结果随着KAAD—cycloparnine作用时间的延长及浓度的增加，其对Tca细胞增殖的抑制作用增强（F=25．39，P〈0．01）。流式细胞仪检测显示：随着KAAD—cyclopamine浓度的增加，细胞凋亡率逐渐增加（F=43．67，P〈0．01）；细胞周期表现为G2／M期阻滞。结论KAAD—cyclopamine通过下调Hedgehog信号通路的活性，抑制人鳞状细胞癌Tca细胞增殖并促进其凋亡，诱导细胞发生G2／M期阻滞为其可能机制之一。

英文摘要：

Objective To study the effects of KAAD - cyclopamine, a specific inhibitor of Hedgehog signaling pathway, on the cell growth and apoptosis of Tcasquamous cell carcinoma cells. Methods Tca cells were treated with KAAD - cyclopamine at different concentrations and for different time. The inhibition of KAAD - cyclopamine on the cell growth of Tca cells was assessed by MTT assay. The morphological changes of the cells were observed under light microscopy. The phase distribution of the cell cycles and the apoptosis rate of Tca cells were evaluated by flow cytometery. Results KAAD - cyclopamine could inhibit the cell growth （ F = 49.92, P 〈 0.01 ） in a dose - dependent and time - dependent manner. The morphological microscopy revealed typical morphological features of the cells and the number of S phase and GE/M phase increased after treatment with KAAD - cyclopamine. The apoptosis rate in KAAD - cyclopamine - treated group was statistically higher than that in control group in a dose - de- pendent manner（F =43.67,P〈0.01）. Conclusion KAAD - cyclopamine,as a specific inhibitor of hedgehog signaling pathway, significantly inhibits the proliferation and induces the apoptosis in Tca, which may be involved in G2/M phase arrest.