Study on the effect of brucine on cyclooxygenase 2 in non-small cell lung cancer cells / 中国癌症杂志

ABSTRACT

Background and purpose:Brucine is one of the active components from Strychnos nux vomica,with signifi cant analgesic,anti-inflammatory and platelet-aggregating inhibitory properties.Due to its cytotoxic effect,the anti-tumor effect of brucine has increasingly been appreciated.In this study,we investigated the impact of brucine on A549 cells proliferation,apoptosis as well as the underlying mechanisms.Methods:MTT assay was used to examine the cell viability,flow cytometric analysis and fluorescent microscope were applied to examine cell apoptosis,ELISA method was used to examine the effect of brucine on PGE2 release from A549 cells and RT-PCR analysis was used to measure mRNA content,western blotting analysis was used to measure protein expression and luciferase activity was detected to examine the effect of brucine on COX-2 promoter activity.Results:Brucine was able to suppress the proliferation of A549 cells and induce cell apoptosis to time-dependent and dose-dependent manner.To understand the mechanisms,COX-2 was identifi ed to be an important target molecule involved in the apoptosis induced by brucine because brucine could suppress the COX-2 mRNA,protein expressions as well as PGE2 release in A549 cells in a timedependent manner.Furthermore,overexpression of COX-2 abrogated brucine-induced cell apoptosis,in contrast,when A549 cells were transfected with COX-2 siRNA,the apoptotic effect of brucine was dramatically enhanced.Further analysis revealed that brucine was able to suppress COX-2 transcriptional activation.Conclusion:Brucine was able to induce lung cancer apoptosis via downregulation of COX-2.