摘要
目的 探讨细胞内基本p2 1水平和被应急反应诱导的p2 1,在大肠肿瘤细胞DLD1对化学治疗、放射治疗和基因治疗所诱发的细胞凋亡中的作用和机制。方法 建立受IPTG控制表达p2 1大肠肿瘤细胞系DLD1 p2 1,用阿霉素、X射线和暂时性转染p5 3基因的方法处理表达和不表达p2 1的两种DLD1细胞 ,观察其细胞形态、DNA片段化和测定细胞的生存率 ;并用放射性同位素标记进入S期细胞来显示细胞周期和凋亡间的关系。结果 (1)p2 1不仅能以p5 3依赖性方式产生 ,而且还能以p5 3非依赖性方式产生。 (2 )细胞内基本的p2 1在抗细胞凋亡中发挥着主要作用 ,而相反 ,应急产生的p2 1几乎不在抗细胞凋亡中发挥作用。凋亡细胞数分别为 9%对 5 5 %、12 %对 6 5 %和 7%对 5 9%。结论 在抗细胞凋亡作用中 ,基本的p2 1比应急产生的p2
Objective To investigate the role of basal expression p21 and stress stimulated p21 in preventing apoptosis of human colorectal carcinoma cells DLD1 after treatment of adriamycin, roentgenotherapy and gene therapy of p53. Methods A human colorectal carcinoma cell line DLD1 whose p21 expression can be controlled by isopropyl β D thiogalactoside (IPTG) was established. The morphology, DNA fragmentation and survival rates of two kinds of DLD1 cells expressing or not expressing p21 were observed after treatment with adriamycin, X ray and transient transfection of p53. The cells in S stage were incubated with thymidine so as to examine the relationship between apoptosis and cell cycle. Results (1) p21 may be one of the most important stress stimulated proteins in the cells, which can be induced by the p53 dependent pathway and the p53 independent pathway as well. (2) Basal expression of p21 plays an important antiapoptosis role in carcinoma cells after stress treatment. In contrast, stress stimulated p21 plays a minor role in preventing apoptosis. Conclusion Basal expression of p21 plays a more important antiapoptosis role than stress stimulated p21 in carcinoma cells.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2001年第21期1330-1332,共3页
National Medical Journal of China
