IKKβ activates p53 to promote cancer cell adaptation to glutamine deprivation

a HT1080 transduced with control (Ctrl) or IKKβ shRNA were cultured in glutamine-free medium for 24 and 48？h. Cell viability was assessed by PI exclusion. Cell lysate was collected for western blotting with the indicated antibodies. b Western blot analysis of wild-type (WT), Ikkα？/？ or Ikkβ？/？ MEFs and HT1080 cells transiently transfected with siRNA against scrambled control, IKKα, or IKKβ cultured in complete and glutamine (Gln)-free medium 24h and cell lysate was used for immunoblotting using the antibodies indicated. c Wild-type and Ikkβ？/？ MEFs were cultured in complete (Comp) or glutamine-free (No Gln) media overnight and mRNA was extracted for qPCR analysis of p53-target genes. d HT1080 cells transiently transfected with siRNA against scrambled control or IKKβ were cultured in complete or glutamine-free media overnight. mRNA was extracted, and expression of p53-target genes was determined using qPCR. a, c, and d represent means？±？s.d. of triplicates from three independent experiments (*p？<？0.05, **p？<？0.01, ***p？<？0.001 using Student’s t-test