Celastrol decreases the level of Cyclin D1 and some Cdks. Following treatment, cells were incubated with indicated antibodies and the expressions of proteins were detected by FCM detailed in Methods. A: Celastrol induces reduction of Cyclin D1 in a dose-dependent manner. The left panel shows the histogram for FCM detection of Cyclin D1 expression with X-axis as fluorescence intensity and Y-axis representing cell number. The right panel shows the detected intensities of this protein. Each value represents the mean of three independent experiments. B: Effects of celastrol on Cdk4, Cdk6, and Cdk2 expressions. After exposure to 600 nM celastrol for 1 d, the proteins were detected by FCM. Y-axis represents the relative levels of each protein in different treatments, with the protein level in DMSO-control sample being set at 1.0. Each value is the mean of three independent experiments.