Cyclin D₃ expression in HMC-1 cells down-regulated by treatment with IMD-0354. (A) Spontaneous expression of cyclins D₂, D₃, and E was detected in HMC-1 cells (right) by Western blotting. We used 3T3 cell lysate for positive control (left). (B) Cyclin D₃ expression in HMC-1 cells incubated with 1 μM IMD-0354 for various hours. (C) Cyclin D₃ expression in HMC-1 cells treated with various concentrations of IMD-0354 for 16 hours. (D) Spontaneously phosphorylated pRb was detected in HMC-1 cells with IMD-0354 for 16 hours. Results shown are representative of those of 3 different experiments.