Fig. 5. Inhibition of CDK4/6-Rb pathway by palbociclib decreases cell proliferation and induces cell cycle arrest in human synovial sarcomas.

Human synovial sarcoma SYO-1 and Fuji cells were treated with increasing concentrations of palbociclib for the indicated time, and cell proliferation and growth was determined subsequently. a, b Cell viability was determined by MTT assays after palbociclib exposure for 2, 4, and 6 days. The cell cycle of SYO-1 and Fuji cells was assessed after exposure to palbociclib (1 µM) for 24 h by flow cytometry analysis. Representative images of cell cycle distribution in SYO-1 (c) and Fuji (d) cells with or without palbociclib treatment. Cell numbers in different cell cycle phases were counted. Different cell cycle phase rates were also analyzed. *P < 0.05, **P < 0.01 compared with the cell only group