Figure 5.

TSA treatment does not affect p21^CIP1 repression by c-Myc. (A) Effect of TSA on basal p21^CIP1 promoter activity. NIH 3T3 p21^CIP1 reporter lines infected with vector only were left untreated (−TSA) or treated with 500 ng/ml TSA overnight (+TSA). Cells were analyzed for luciferase activity 24 hr after plating and normalized by standard protein assay. Fold luciferase activity was determined as compared to untreated cells for each line. Error bars represent standard deviation of the average of duplicate readings from four independent stable clones. (B) Effect of TSA on repression of the p21^CIP1 promoter by c-Myc. NIH 3T3 p21^CIP1 reporter lines infected with either empty retroviral vector (white bars) or c-Myc expression vector (dark bars) were left untreated (−TSA) or treated with 500 ng/ml TSA overnight (+TSA). Cells were analyzed for luciferase activity after treatment and normalized by standard protein assay. Fold luciferase activity was determined as compared to untreated vector only lines. Error bars represent standard deviation of the average of duplicate readings for four independent clones.