Targeting CDKs with Roscovitine Increases Sensitivity to DNA Damaging Drugs of Human Osteosarcoma Cells - Fig 4

<p><b>Effects on cell cycle of doxorubicin (DX), cisplatin (CDDP) and roscovitine (ROS)</b>, used either alone or in combination, in the human osteosarcoma cell lines U-2OS and Saos-2 and their variants resistant to DX or CDDP. Cell cycle phase distribution was determined by flow cytometry after bromodeoxyuridine (BrdU) incorporation and propidium iodide counterstaining. The intensity of propidium iodide fluorescence (representative for the DNA content) was plotted on the X axis. The intensity of the incorporated BrdU fluorescence (representative for the DNA synthesis) was plotted on the Y axis. Legend: CTR, control cells cultured in drug-free medium; DX, CDDP, ROS, cells treated with their respective IC50 dosages of each drug for 24 h (DX and CDDP) or 48 h (ROS); DX>ROS and CDDP>ROS, cells sequentially treated with their respective IC50 dosages of DX or CDDP for 24 h followed by treatment with the IC50 concentration of ROS for 48 h.