维甲酸诱导的人大肠癌细胞凋亡

本研究应用光镜、电镜技术、DNA凝胶电泳、流式细胞术及末端脱氧核苷酰转移酶原位标记(TUNEL法),观察全反式维甲酸ATRA诱导的人大肠癌CCL229细胞凋亡特征。RA诱导CCL229细胞凋亡,光、电镜下观察到凋亡小体形成等典型的形态学改变,琼脂糖凝胶电泳上呈现特征性的DNA ladder,DNA直方图上显示亚二倍体峰。10-8mol/L-105mol/L范围内,RA诱导CCL229细胞凋亡表现出时间和剂量依赖性。

COLORECTAL CARCINOMA CELL APOPTOSIS INDUCED BY ALL-TRANS RETINOIC ACID

An in vitro model of apoptosis in human colorectal carcinoma cells was developed to study the mode and mechanisms of cell death induced by treatment with all-trans retinoic acid (ATRA). ATRA was found to induce pronounced morphological changes characteristic of apoptosis and extensive DNA fragmentation in the CCL229 cell line 12 hrs after treatment. Morphological examination by fluorescence and electron microscopy showed cells with chromatin condensation and margination, nuclear fragmentation,cell shrinkage,and the presence of "apoptotic bodies". Degradation of the nuclear DNA of apoptotic cells was demonstrated by visualization of "DNA ladders" on gel electrophoresis. Moreover,DNA flow cytofluorimetric analysis and TdT-mediated in situ nick end labeling of DNA breaks also demonstrated that apoptosis induced by ATRA was dose-and time-dependent. In addition,RA-treatment of CCL 229 cells resulted in morphological maturation prior to apoptosis,which suggest that the mode of,cell death in cultures of terminally differentiated CCL 229 cells is that of apoptosis.