Spine venom of crown-of-thorns starfish (Acanthaster planci) induces antiproliferation and apoptosis of human melanoma cells (A375.S2).

The crown-of-thorns starfish (Acanthaster planci) is a venomous starfish. In this study, the extraction of A. planci spine venom (ASV) was performed by phosphate saline buffer, followed by assaying the cytotoxicity on human normal and tumor cells. It was found that human melanoma cells (A375.S2) were the most sensitive to the ASV solution. The cells, after incubation with ASV, significantly appeared to decrease cell viability and increase lactate dehydrogenase (LDH) release with a dose-dependent relationship. The extract of spine promoted loss of mitochondrial membrane potential (ΔΨm) and induced inter-nucleosomal DNA fragmentation in human melanoma cells. The cells exhibited apoptosis by using propidium iodide (PI) staining of DNA fragmentation; it was then determined by flow cytometry (sub-G1 peak). The molecular cytotoxicity of ASV was tested through evaluation of the apoptosis/necrosis ratio by double staining with annexin V and PI assay. The A. planci spine venom showed significant antiproliferation. The human melanoma cells revealed apoptosis at low dose (1.25 μg/ml), and necrosis occurred at high dose (5 μg/ml).