DMSO exhibits similar cytotoxicity effects to thalidomide in mouse breast cancer cells

The purpose of this study was to evaluate the cytotoxic effect of thalidomide on 4T1 and 4THMpc mouse breast cancer cell lines. Mouse breast cancer cells (4T1) and cells derived from metastatic lesions (4THMpc) were treated with various doses of thalidomide [10(-2)-100 µM dissolved in dimethyl sulfoxide (DMSO) as recommended] and 1.4 µM DMSO (maximum DMSO concentration in the highest thalidomide dose) as a DMSO control against the untreated control groups. MTT was used to evaluate the cytotoxic effects of the treatments. Therefore, we investigated the role of thalidomide on apoptosis. A fluorometric EnzChek caspase-3 enzyme activity assay kit was used to evaluate the apoptotic effects of thalidomide. Thalidomide dissolved in DMSO exhibited cytotoxic effects on 4T1 and 4THMpc cells compared to the control groups incubated without any supplement. Treatment with thalidomide resulted in apoptosis of mouse breast cancer cells in a time- and dose-dependent manner as demonstrated by caspase-3 enzyme activity. However, DMSO alone suppressed cell proliferation more effectively than thalidomide. In cultured mouse breast cancer cells the inhibitory effect of thalidomide may be partially attributed to the solvent DMSO alone.