Alkaline phosphatase activity during sphinganine potentiation of retinoic acid-induced differentiation of human promyelocytic leukemia cell line, HL-60.
Sphinganine (SP) pre-treatment potentiated the retinoic acid (RA)-induced (4-96h exposures) differentiation and increase of alkaline phosphatase (ALP) activity. A higher percentage of SP pre-treated cells in RA exposures resembled mature myelocytes or granulocytes; greater increase in ALP activity was observed. In cells exposed to RA alone for only a period of 24h, the ALP activity could still increase and reach a similar maximum ALP activity (8.5-10.0 units/mg protein) at 48h as it was under continuous RA treatment. In all cells with longer exposures (24-96h) to RA, SP pre-treatment increased ALP activity to more or less the same higher maximum (14.0-15.5 units/mg protein). SP, added 24h before or concomitantly, but not 24 nor 48h after the addition of RA, could potentiate the RA-induced differentiation and increase of ALP activity.
Department of Pharmacology, Chang Gung Medical College, Taiwan, R.O.C.
L L
LL
Wei
E K
EK
Hui
J S
JS
Wei
W F
WF
Tzeng
B Y
BY
Yung
D000469:Alkaline Phosphatase / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D004357:Drug Synergism; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D014212:Tretinoin; D000469:Alkaline Phosphatase; D013110:Sphingosine; C005682:safingol