雷公藤内酯醇对前列腺癌PC-3细胞中的白细胞介素8的表达调节作用

Role of triptolide in expression and regulation of interleukin-8 in prostate cancer PC-3 cells

目的探讨雷公藤内酯醇对前列腺癌PC-3细胞中白细胞介素8(IL-8)信号分子的表达影响。方法采用ELISA方法检测雷公藤内酯醇(10、30、50 nmol/L)处理后PC-3细胞分泌至培养基中的IL-8蛋白水平变化;采用qRTPCR方法检测雷公藤内酯醇(10、30、50 nmol/L)作用下IL-8的mRNA水平变化;构建IL-8的启动子荧光素酶报告基因,并转染至前列腺癌细胞中,使用双荧光素酶报告基因检测系统检测IL-8启动子活性在雷公藤内酯醇作用下的变化情况。采用Wester Blotting方法检测雷公藤内酯醇作用后细胞内的IL-8的两个受体(CXCR1和CXCR2)的表达变化情况。结果雷公藤内酯醇处理后,PC-3细胞分泌至培养基中的IL-8的蛋白量有显著下调,但IL-8的mRNA水平及其启动子活性均未发生改变。对IL-8的受体的蛋白水平检测结果表明,CXCR1和CXCR2受影响不显著。结论雷公藤内酯醇通过下调IL-8的分泌来下调IL-8信号的活性,该作用是对IL-8的转录后的蛋白水平的调控机制。

Objective To explore the influence of triptolide on expression of signal molecula interleukin-8（ IL-8） in prostate cancer PC-3 cells. Methods After PC-3 cells were treated with triptolide（ 10,30 and 50 nmol / L）,the ELISA assay was used to detect the changes of IL-8 secreted by PC-3 cells. The IL-8 mRNA change in PC-3 cells by triptolide（ 10,30 and 50 nmol / L） was determined by qRT-PCR assay. The p GL3-IL8 promoter reporter plasmid was constructed,and p GL3-IL8 and pRL-CMV were transfected into PC-3 cells,and the luciferase activity was investigated by dual-luciferase reporter assay. The protein levels of IL-8 receptors（ CXCR1 and CXCR2） were detected by Western Blotting assay. Results Triptolide decreased the secretion of IL-8 in PC-3 cells,but promoter activity and mRNA level showed no significant changes. The expressions of CXCR1 and CXCR2 did not change after triptolide treatment. Conclusion Triptolide can down regulate the IL-8 signaling activity by down regulating the secretion of IL-8 in PC-3 cells,and the mechanism might be a posttranscriptional protein level regulation.