Toxicity of bacterial secreted cardiac protein on breast cancer cell line
MCF-7 breast cancer cell line was used for evaluating the anti-proliferative effects of expressed cardiac peptides. Briefly, 96 well microtiter plates were inoculated with 200
µL growth media containing a density of 2×105 cells and then incubated for 24h under 5% CO2 in humidified air. Bacteria bearing cardiac peptide construct and bacteria without construct were grow on LB agar media under hypoxic condition for 48h and then, the bacteria growth media were added to the cells. following 48h of exposure, 10 µL of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) (Sigma Aldrich) with the concentration of 0.05 mg/mL was added to the media. After 4 h incubation at 37°C, whole medium was removed and replaced with 200 µL DMSO to dissolve water-insoluble formazan salts. The Absorbance was then read at 570 nm using a 96-well plate spectrophotometer.