Cytotoxicity effect of ICD-85 (Venom - derived peptides) on promyelocytic cancer cell lines (HL-60)

Our previous studies revealed an inhibitory effect of ICD-85; a venom derived peptide has been extracted by researchers of Razi vaccine and serum research institute, on breast cancer cell line (MDA-MB231). The present study was undertaken to evaluate the anti proliferative effect of HL60 cells. The effect of ICD-85 on proliferation of HL-60 cancer cells was determined using the MTT assay. A quantitative cytotoxicity assay based on the release of lactate dehydrogenase (LDH; EC 1.1.1.27) was performed 24 h after exposure to various concentrations of ICD-85. The morphological changes of ICD-85 treated HL-60 cancer cells were observed under electron microscope. ICD-85 induced marked concentration inhibition of cancer cell proliferation with an IC50 value of 0.04µg/ml following 24 h incubation. Electron microscopic findings of ICD-85 treated cells showed nuclear material condensation, endoplasmic reticulum dilation, mitochondria swelling or degradation, increased cytoplasmic vacuoles, reduction or disappearance in cytoplasmic process and decreased nuclear/cytoplasmic ratio. LDH determination of cultured media of HL60 cells exposed to various concentration of ICD-85 revealed no significant changes in LDH levels compared with untreated cells. The results of present study indicated that ICD-85 inhibited the cancer cell proliferation by inducing apoptosis rather than necrosis.