The cytotoxic activities of 7-isopentenyloxycoumarin on 5637 cells via induction of apoptosis and cell cycle arrest in G2/M stage

Background: Bladder cancer is the second common malignancy of genitourinary tract, and transitional cell carcinomas (TCCs) account for 90% of all bladder cancers. Due to acquired resistance of TCC cells to a wide range of chemotherapeutic agents, there is always a need for search on new compounds for treatment of these cancers. Coumarins represent a group of natural compounds, which some of them have exerted valuable anti-tumor activities. The current study was designed to evaluate anti-tumor properties and mechanism of action of 7-isopentenyloxycoumarin, a prenyloxycoumarin, on 5637 cells (a TCC cell line). Results: MTT results revealed that the cytotoxic effects of 7-isopentenyloxycoumarin on 5637 cancerous cells were more prominent in comparison to HDF-1 normal cells. This coumarin increased the amount of chromatin condensation and DNA damage in 5637 cells by 58 and 33%, respectively. The results also indicated that it can induce apoptosis most probably via activation of caspase-3 in these cells. Moreover, propidium iodide staining revealed that 7-isopentenyloxycoumarin induced cell cycle arrest at G2/M stage, after 24 h of treatment. Conclusion: Our results indicated that 7-isopentenyloxycoumarin had selective toxic effects on this bladder cancer cell line and promoted its effects by apoptosis induction and cell cycle arrest. This coumarin can be considered for further studies to reveal its exact mechanism of action and also its anti-cancer effects in vivo.