Figure 4 | Oncogene

Figure 4

From: Transcriptional activation of cyclooxygenase-2 by tumor suppressor p53 requires nuclear factor-kappaB

Figure 4

p53-dependent induction of cyclooxygenase-2 (Cox-2) in response to daunomycin. (a) p53-dependent increase in Cox-2 protein after treatment with daunomycin. HCT116 and HCT116 E6 cells were treated with daunomycin (2 μ M, for indicated times). Cyclooxygenase-2 and p53 proteins were detected by Western blot using β-actin as loading control. (b) p53-dependent COX-2 promoter activation in response to daunomycin. HCT116 and HCT116 E6 cells were co-transfected with COX-2-LUC reporter and RSV-βGAL as transfection control. Six hours after transfection, cells were exposed to daunomycin (24 h). LUC activity was expressed as fold induction normalized to βGAL. (c) Recruitment of p53 and NF-kappaB on COX-2 promoter in response to daunomycin. Cross-linked chromatin from HCT116 cells exposed or not exposed to daunomycin (1 μ M, 24 h) was immunoprecipitated with antibodies to p53, NF-kappaB or control antibody as negative control, and analysed by polymerase chain reaction with primers for WAF-1 and COX-2 promoter sequences. Input: non-precipitated cross-linked chromatin.