1,25-dihydroxyvitamin D3 induces biphasic NF-kappaB responses during HL-60 leukemia cells differentiation through protein induction and PI3K/Akt-dependent phosphorylation/degradation of IkappaB.
1,25-dihydroxyvitamin D(3) (VD(3)) induces differentiation in a number of leukemia cell lines and under various conditions is able to either stimulate or inhibit nuclear factor kappa B (NF-kappaB) activity. Here we report a time-dependent biphasic regulation of NF-kappaB in VD(3)-treated HL-60 leukemia cells. After VD(3) treatment there was an early approximately 4 h suppression and a late 8-72 h prolonged reactivation of NF-kappaB. The reactivation of NF-kappaB was concomitant with increased IKK activities, IKK-mediated IkappaBalpha phosphorylation, p65 phosphorylation at residues S276 and S536, p65 nuclear translocation and p65 recruitment to the NF-kappaB/vitamin D responsive element promoters. In parallel with NF-kappaB stimulation, there was an up-regulation of NF-kappaB controlled inflammatory and anti-apoptotic genes such as TNFalpha, IL-1beta and Bcl-xL. VD(3)-triggered reactivation of NF-kappaB was associated with PI3K/Akt phosphorylation. PI3K/Akt antagonists suppressed VD(3)-stimulated IkappaBalpha phosphorylation as well as NF-kappaB-controlled gene expression. The early approximately 4 h VD(3)-mediated NF-kappaB suppression coincided with a prolonged increase of IkappaBalpha protein which require de novo protein synthesis, lasted for as least 72 h and was insensitive to MAPK, IKK or PI3K/Akt inhibitors. Our data suggest a novel biphasic regulation of NF-kappaB in VD(3)-treated leukemia cells and our results may have provided the first molecular explanation for the contradictory observations reported on VD(3)-mediated immune-regulation.
Tse
Anfernee Kai-Wing
AK
Research & Development Division, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
Wan
Chi-Keung
CK
Shen
Xiao-Ling
XL
Zhu
Guo-Yuan
GY
Cheung
Hon-Yeung
HY
Yang
Mengsu
M
Fong
Wang-Fun
WF
D039481:CD11b Antigen / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation; D018922:HL-60 Cells; D006801:Humans; D020672:I-kappa B Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation; D051020:bcl-X Protein / Q000378:metabolism
D039481:CD11b Antigen; D002117:Calcitriol; D020672:I-kappa B Proteins; D053583:Interleukin-1beta; D016328:NF-kappa B; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D051020:bcl-X Protein; C494811:BCL2L1 protein, human