摘要
目的 探讨蛋白激酶C（PKC）活性对大肠癌多药耐药性的影响以及可能涉及的调控机制。方法 （1）以放射性32P,掺入法检测了在十字孢碱（SP）和佛波脂（PMA）作用下大肠癌耐药细胞LoVo/Adr中PKC活性的变化;（2）以流式细胞术检测了PKC活性对LoVo/Adr细胞摄入阿霉素的影响;（3）以RT-PCR法检测了PKC活性对LoVo/Adr细胞mdr1基因表达的影响。结果（1）PMA可双向调节LoVo/Adr细胞的PKC活性,SP对LoVo/Adr细胞胞浆和胞膜中的PKC活性均有显著的抑制效果;（2）在PMA作用30min时,LoVo/Adr细胞中阿霉素的摄入量显著减少,作用24h时,阿霉素摄入量显著增加;（3）PMA和SP均不影响mdr1基因的表达。结论 PKC可调控细胞的多药耐药性,但并非通过调节mdr1基因的mRNA水平而实现。
Objective To observe the effect of protein kinase C (PKC) on the multidrug resistance of multidrug-resistant colorec-tal cancer LoVo/Adr cells and explore the mechanism. Methods The changes of PKC activity in LoVo/Adr cells in response to treatment with staurosporine (SP) and phorbol-12-myristate-13-acetate (PMA) were detected by way of 32P incorporation. The effect of PKC on adriamycin uptake in LoVo/Adr cells was detected by flow cytometry. Reverse transcriptase-PCR was utilized to observe the effect of PKC on mdrl gene expression. Results PMA evinced bi-directional regulation of PKC activity in LoVo/Adr cells, and SP significantly inhibited membrane and cytosol fraction of PKC activity. Preincubation with PMA for 30 min caused the uptake of adriamycin to decrease significantly, but when the preincubation was prolonged to 24 h, significant increase occurred in adriamycin uptake. Neither PMA nor SP, however, could affect the expression of mdrl gene. Conclusion PKC regulates multidrug resistance of the cells through mechanisms other than regulation of mRNA level of mdrl gene.
出处
《第一军医大学学报》
CSCD
北大核心
2002年第7期626-628,共3页
Journal of First Military Medical University
