L-securinine inhibits the proliferation of A549 lung cancer cells and promotes DKK1 promoter methylation

L-securinine is a natural product extracted and isolated from the leaf of dried Securinega suffruticosa. The aim of the present study was to explore the effects of Lsecurinine on proliferation, and the methylation profile of the dickkopf-related protein 1 (DKK1) gene in human lung cancer cells and fibroblasts. L-securinine was extracted, isolated and the structure was identified. The cytotoxicity of L-securinine in A549 cells was evaluated by Cell Counting Kit-8 assays. The expression and DNA methylation profile of DKK genes was analyzed by reverse transcription-quantitative polymerase chain reaction and bisulfite sequencing polymerase chain reaction, respectively. L-securinine inhibited the proliferation of lung cancer cells; the half-maximal inhibitory concentration values were 8.92, 4.73 and 3.81 mu g/ml, at 24, 36 and 48 h post-treatment, respectively. DKK1, 2 and 3 expression was significantly increased in A549 cells compared with HLF-a cells. L-securinine induced the downregulation of DKK1 in A549 cells in a dose-dependent manner and induced methylation changes at CpG sites in the DKK1 promoter region. L-securinine may be a potential anticancer drug that mediates its effects by altering DKK1 gene methylation.