A phospholipase A2 of Daboia siamensis venom suppressed expression of genes and proteins in MAPK pathway

High mortality rate of Melanoma is due to poor response to radiotherapy and chemotherapy. A phospholipase A(2) (PLA(2)) of Daboia siamensis venom has been reported to inhibit melanoma cells. The aim of this study is to evaluate the effects of dssPLA(2) on gene and protein expression of MAPKs (Mitrogen-activated protien kinases) in melanoma cells. The mRNA and protein were determined by quantitative real-time PCR and western blotting to detect the expression levels of MEK1, MEK2, BRAF V600E and ERK1/2. Results indicated that 0.25 mu g/ml of dssPLA(2) reduced the mRNA expression level of these genes in a time dependent manner. Interestingly, at 48 h, the mRNA expression level of all genes was extremely decreased compared with untreated cells in the same condition. Whereas, the protein level of MEK1, MEK2, BRAF V600E and ERK1/2 were clearly reduced after dssPLA(2) incubation. Our results show that dssPLA(2) is a strong inhibitor to MAPK genes at 48 h.