中文摘要：

目的：探讨γ-分泌酶抑制剂DAPT对成牙骨质细胞株OCCM30的Notch信号通路是否有抑制作用,及对成牙骨质细胞增殖活性的影响,并初步探讨其作用机制。方法：γ-分泌酶抑制剂DAPT作用于OCCM30细胞,分别培养2、4、6d,采用RT-PCR检测Notch信号通路下游基因（Hes-1、Hey-1）和细胞周期相关基因（Cyclin D、Cyclin E）的表达,采用流式细胞术检测DAPT对OCCM30细胞周期的影响;DAPT作用于OCCM30细胞后,连续培养8d,采用CCK-8法测定细胞增殖活性。结果：实验组Hes-1、Hey-1、Cyclin D、Cyclin E mRNA的表达下降,G1/G0期细胞百分比增高,与对照组相比差异有统计学意义（P〈0.05）;第2~8天,实验组细胞增殖活性（A450值）显著降低,呈浓度依赖性,且与对照组相比差异有统计学意义（P〈0.05）。结论：DAPT能有效抑制成牙骨质细胞株OCCM30的Notch信号通路,抑制OCCM30细胞的增殖活性,其机制可能与DAPT下调细胞周期相关基因（Cyclin D、Cyclin E）表达有关。

英文摘要：

Objective： To clarify whether DAPT （a γ-secretase inhibitor） could inhibit the Notch signaling path- way in the cementoblast OCCM30. To investigate the impact of DAPT on the proliferation of the cementohIast and the mechanism behind. Methods： The OCCM30 cells were cultured with γ-secretase inhibitor DAPT. On day 2, 4 and 6, RT- PCR was conducted to detect the expression of the Notch signaling pathway genes （Hes- 1 and Hey- 1） and cell cycle related genes （Cyclin D and Cyclin E） and flow cytometry was used to investigate the impact of DAPT on the cell cycle of OCCM30. On day 8, the CCK-8 was carried out for the detection Of the proliferative ac- tivity of the OCCM30. Results： Compared to the control group, the expression level of Hes-1, Hey-1, Cyclin D and Cycin E in the experimental groups decreased （P〈0.05） while the G1/G0 cell proportion increased （P~0.05）. From day 2 to day 8, the proliferative activity of the ceils in the experimental groups decreased significantly （P〈0. 05）. The proliferative activity of the OCCM30 in the higher DAPT concentration group was lower than that in the lower DAPT concentration group, both of which were significantly lower than the control group （P〈0.05）. Conclu- sion： DAPT effectively inhibited the proliferative activity of the OCCM30. The mechanism behind that could be the inhibitory effect of the DAPT on the Notch signaling pathway, down--regulating the expression of the cell--cycle related genes.