Effects of cisplatin and/or UV-C on HER2 and EGFR in human colorectal cancer cells. SW480, DLD-1, HT29 and HCT116 cells were first exposed to the indicated doses of UV-C (0 J/m² or 10 J/m²), and then treated with/without 10 μM of cisplatin for the indicated periods. Protein extracts were then harvested and examine by Western blotting using anti-HER2, anti-EGFR and anti-GAPDH antibodies. The lower line graphs show quantification data for the protein levels of HER2 and EGFR, after normalization to GAPDH, respectively. Bars designate SD of triplicate assay. The asterisks (* and **) indicate significant decrease (p < 0.05) as compared to the corresponding controls, respectively.