Figure A10.
High hemin concentration correlates with an escape from the senescence of SW480 cells. SW480 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 the cells were cultured in a drug-free medium for 4 days. (A) Evaluation of metabolic activity assayed by MTT metabolism. (B) Quantification of the percentage of cells in the subG1 phase (with DNA content < 2C). Cell cycle analysis was performed with the use of Cell Cycle Analysis Kit (Sigma) and flow cytometry. (C) Activity of SA-β-Galactosidase enzyme in UNT and IRINO-treated cells subjected to hemin. Detection of the enzyme was performed on cytospined cells. Representative photos were acquired using light microscopy. Original magnification 200×, scale bar 50 μM. (D) Quantification of SA-β-Gal positive cells after treatment with hemin. (E,F) Quantification of the percentage of cells in the G0/G1 (E) or G2/M phases (F). Cell cycle analysis was performed with MuseTM Cell Cycle Reagent and flow cytometry. Each bar represents mean ± SEM, n ≥ 3. * p < 0.05, ** p < 0.01, *** p < 0.001—hemin concentration vs. 0.