Triethylenetetramine Synergizes with Pharmacologic Ascorbic Acid in Hydrogen Peroxide Mediated Selective Toxicity to Breast Cancer Cell

Figure 4

Asc/TETA induces H₂O₂-dependent RAS downregulation and apoptosis in MCF-7 cells. MCF-7 cells were treated with 1 mM Asc, 10 μM TETA, 1 mM Asc/10 μM TETA, 5 mM NAC, or 1 mM Asc/10 μM TETA and 5 mM NAC, respectively, for 4 hours. (a) ROS generation in MCF-7 cells was examined by H2DCF staining; (b) MCF-7 cells were treated with 1 mM Asc/10 μM TETA, 3 mM Asc/30 μM TETA, or 3 mM Asc/30 μM TETA with 5 mM NAC for 12 hours. RAS expression and H3 acetylation were assessed by western blotting; (c) MCF-7 cells were treated with 1 mM Asc/10 μM TETA for 6, 12, and 24 hours, respectively; RAS expression and H3 acetylation were assessed by western blotting; (d) MCF-7 cells were treated with 1 mM Asc, 10 μM TETA, 5 mM NAC, 1 mM Asc/10 μM TETA, or 1 mM Asc/10 μM TETA plus NAC for 12 hours; cell viability was measured with MTT assay, , . Experiment was repeated three times.

(a)

(b)

(c)

(d)