Fig. 3

Thieno[2,3-b]pyridine induces G2/M cell cycle arrest but not DNA damage. MDA-MB-231 breast cancer cells treated by derivative 3 (1 μM) or camptothecin (1 μM) for 24 h. a The effect of DNA damage was shown as relative measure of γH2AX abundance in the MDA-MB-231 breast cancer cells. Cellular immunofluorescence (anti-γ-H2AX antibody; y-axis) is plotted against DNA content (propidium iodide staining; x-axis). The top half (marked by dashed line) represents high γ-H2AX phosphorylation and the proportion of the total is indicated. b The cell cycle proportions of MDA-MB-231 treated by derivative 3 (1 μM) or camptothecin (1 μM) for 24 h. Population of G2/M phase was significantly increased by derivative 3. c Immunoblot for the phosphorylated γ-H2AX in the MDA-MB-231 breast cancer cell line. Actin was used as a loading control