title: Evidence that phosphatidylinositol 3-kinase and p70S6K protein are involved in differentiation of HL-60 cells induced by calcitriol.
abstract: 1,25-dihydroxyvitamin D3 (calcitriol) is not only an antirachitic agent, but also a well known regulator of cell differentiation. HL-60 promyelocytic leukemia cells differentiate to monocytes upon treatment with calcitriol. We describe here, that PI3-K inhibitors are able to block the differentiation induced by calcitriol in HL-60 cells. Also the downstream effector of PI3-K, p70S6K ribosomal protein kinase seems to be involved in HL-60 cell differentiation. PKC alpha and PKC delta are activated and translocated to the nucleus upon exposure of cells to calcitriol. However in our experiments the inhibition of PKC did not result in an inhibition of calcitriol induced differentiation of HL-60 cells. On the contrary, the use of thapsigargin, caused the differentiation process to stop.
authors.affiliation: Department of Tumor Immunology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Wroclaw, Poland. marcinko@immuno.pan.wroc.pl
authors.forename: E
authors.initials: E
authors.lastname: Marcinkowska
authors.forename: A
authors.initials: A
authors.lastname: Wiedlocha
authors.forename: C
authors.initials: C
authors.lastname: Radzikowski
mesh_terms: D015415:Biomarkers; D018845:CD11 Antigens / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018922:HL-60 Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019893:Ribosomal Protein S6 Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D018845:CD11 Antigens; D002117:Calcitriol; D002120:Calcium Channel Agonists; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D004791:Enzyme Inhibitors; D007211:Indoles; D018950:Lipopolysaccharide Receptors; D008301:Maleimides; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C; D019893:Ribosomal Protein S6 Kinases; D019284:Thapsigargin; C070515:bisindolylmaleimide I