Synthesis and biochemical characteristics of nucleoproteins following a toxic dose of retinoic acid in cycling and differentiating HL-60 cells.
Exposure of HL-60 cells to 2 microM retinoic acid (RA), twice the dose necessary for differentiation, initiated rapid synthesis (2 h) of the nuclear stress proteins (SPs) e.g., 90, 70c, 70x, 22 (Mr x 10(-3)) during the G0 + G1 phase of the cell cycle as observed by polyacrylamide gel electrophoresis (PAGE). Synthesis of SPs was cell cycle correlated and not dependent on time-after-dosing, and all labeling disappeared from these proteins within 48 h of RA exposure. Stress proteins were not elicited with a 1 microM dose or less of retinoic acid. Non-stress nuclear proteins revealed changes in synthesis levels (e.g., actin, lamins, tubulins) which were cell cycle related and temporally associated with dosing. A major non-stress nuclear protein (Mr 120,000) which possessed an affinity for actin in binding assays, was cell cycle related in control cells, and was suppressed in synthesis in cells exposed to 2 microM retinoic acid. Two additional nuclear non-SPs 51 and 55 (Mr x 10(-3)) covalently bound the isotope [3H]retinoic acid, and their incorporation was cell cycle correlated during early periods of RA exposure. Except for the induction of SPs, the autoradiographs of nuclear proteins of RA dosed HL-60 cells, showed more quantitative than qualitative changes.
Department of Health and Human Services, Food and Drug Administration National Center for Toxicological Research, Jefferson, Arkansas 72079.
J L
JL
Pipkin
W G
WG
Hinson
J F
JF
Anson
H M
HM
Schol
L E
LE
Lyn-Cook
E R
ER
Burns
D A
DA
Casciano
D000199:Actins / Q000378:metabolism; D015415:Biomarkers; D002453:Cell Cycle; D002454:Cell Differentiation; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D009698:Nucleoproteins / Q000096:biosynthesis* / Q000302:isolation & purification; D011485:Protein Binding; D014212:Tretinoin / Q000633:toxicity*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D000199:Actins; D015415:Biomarkers; D006360:Heat-Shock Proteins; D009363:Neoplasm Proteins; D009698:Nucleoproteins; D014212:Tretinoin