Effects of cyclophosphamide on proliferation and viability of malignant HN5 cell line and comparing with embryonic fibroblast cells

Background: One of the major causes of death in the world is cancer and therefore any study in the field of cancer biology is of great importance. Head and neck cancers represent approximately 2-5% of neoplasms which is higher in some countries. The most appropriate therapy for various cancers is identifying effective and efficient ways that contribute to initiation of apoptosis. Cyclophosphamide is an alkylating agent that stops the replication of DNA and then, it stops the cell proliferation and viability. Therefore, cyclophosphamide is used to treat various types of cancer. In this study we evaluate the cytotoxic effects of cyclophosphamide on viability of (head and neck cancer cells) HN5 cell line and compare it with fibroblast cells as noncancerous cells. Methods: This experimental study was done in cell and developmental laboratory in faculty of science, Shahid Chamran University of Ahvaz in Spring of 2016. HN5 cell line and embryonic fibroblast cells were grown in DMEM supplemented with 10% fetal bovine serum (FBS), penicillin/streptomycin (100 U/ml, 100 &micro;g/ml) at 37 &deg;C, then the effects of different concentrations of cyclophosphamide on cell viability was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. 4',6-diamidino-2-phenylindole (DAPI) staining was performed to determine the proportion of apoptotic cells by manually counting pyknotic nuclei. According to standard procedures from day 13 embryos of outbred strains naval medical research institute (NMRI), fibroblast cells were isolated. In this study HN5 cell line and fibroblasts were exposed to cytostatics for 72 hours. Results: Various concentrations of cyclophosphamide were effective in cytotoxicity of HN5 cancer and fibroblast cells. A significant cytotoxicity was observed with the examined concentration of 1 &micro;g/ml of cyclophosphamide with 50% in 3th day and P< 0.001. Interestingly, at low concentrations, cyclophosphamide was more toxic than at higher concentrations. Conclusion: Totally cyclophosphamide had low toxicity effects on both of the cell lines but the toxicity effects of cyclophosphamide on HN5 were significantly greater than fibroblast cells. These results indicate that cyclophosphamide can be a potential anticancer agent