Figure 1.

Hemin influences the activity of senescent HCT116 cells. (A) The scheme of the experiment. HCT116 colon cancer cells were subjected to 2.5 μM of irinotecan (IRINO) and 1, 10, or 100 μM of hemin. After 24 h, the medium was changed and cells were cultured in a drug-free medium for 4 days. (B) Expression of antioxidative enzymes in untreated (UNT) and IRINO-treated cells subjected to hemin in different concentrations. Representative blots show levels of catalase, GPx-1, and HO-1 proteins. GAPDH acts as loading control; (C) Evaluation of metabolic activity assayed by MTT assay; (D) Evaluation of cell number. Cell number was counted using Bürker’s chamber. (E) Quantification of the percentage of cells in the subG1 phase (with DNA content < 2C). Cell cycle analysis was performed with the use of Muse^TM Cell Cycle Reagent and flow cytometry. Each bar represents mean ± SEM, n ≥ 3.