5-氟尿嘧啶诱导人大肠癌多药耐药细胞株及细胞凋亡的实验研究

5-Flourouracil-induced apoptosis in multi-drug resistance human colorectal cancer cell lines

目的:研究5-氟尿嘧啶(5-FU)诱导LOVO细胞凋亡,探讨人大肠癌多药耐药机制。方法:用噻唑蓝(MTT)法、光镜及电镜、DNA凝胶电泳和原位DNA末端转移酶标记法,分别对耐药细胞株LOVO/5-FU细胞及敏感细胞株LOVO细胞进行5-FU诱导细胞凋亡的实验研究。结果:LOVO/5-FU细胞存活率明显高于LOVO细胞,光镜和电镜观察凋亡形态学改变,凋亡细胞DNA凝胶电泳可以出现梯形(ladder)凋亡带,LOVO细胞原位DNA末端转移酶标记阳性率高于LOVO/5-FU。结论:(1)5-FU诱导人大肠癌LOVO细胞凋亡,有明显的时间和剂量效应。(2)在相同条件下,耐药细胞株LOVO/5-FU与敏感细胞株LOVO相比,前者凋亡受到抑制。(3)细胞凋亡对研究大肠癌LOVO细胞多药耐药机制,克服化疗产生的多药耐药及逆转多药耐药具有重要的临床价值。

Objective To study 5-flourouracil（5-FU）-induced apoptosis of LOVO cells and explore the mechanism of multi-drug resistance in human colorectal cancer. Methods MTT assay, optical microscopy, electron microscopy, DNA agarose gel electrophoresis, and in situ DNA nick end-labeling were used to detect the apoptosis in the drug resistant LOVO/ 5-FU and sensitive LOVO cells. Results The survival rate of LOVO/5-FU cells was significantly higher than that of LOVO cells. The morphological changes of apoptotie cell in both cell lines were observed using both optical and electron microscopy. A ladder-like apoptofic band was shown by agarose gel electrophoresis. The positive rate of in situ DNA nick end-labeling in LOVO cells was higher than that in LOVO/5-FU cells. Conclusions （1） 5-FU induces the apoptosis of human colorectal cancer LOVO cells in a characteristic dose- and time-dependant manner. （2） The apoptosis in the drug resistant LOVO/5-FU cells was much less than that in sensitive LOVO cells under the same condition. （3） Apoptasis may play an important role in studying the mechanism of multi-drug resistance in human colorectal cancer LOVO cells and preventing the development of multi-drug resistance induced by chemotherapy as well as eliminating this multi-drug resistance.