Down regulation of specific binding of (20-/sup 3/H)phorbol 12,13-dibutyrate and phorbol ester-induced differentiation of human promyelocytic leukemia cells

Journal Article · Sun Mar 01 00:00:00 EST 1981 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.78.3.1722· OSTI ID:6396281

Solanki, V; Slaga, T J; Callaham, M; Huberman, E

Binding of (20-/sup 3/H)phorbol 12,13-dibutyrate ((/sup 3/H)PDB) to intact human promyelocytic leukemia cells susceptible (HL-60) or resistant (R-35) to phorbol ester-induced differentiation was characterized. Specific binding of (/sup 3/H)PDB to both HL-60 and R-35 cells at 37/sup 0/C reached a maximum within 15 to 20 min. Maximal specific (/sup 3/H)PDB binding to HL-60 cells was followed by a decline (down regulation) of radioactivity. This down regulation was temperature dependent, because no loss of radiolabel occurred by 1 hr at 4/sup 0/C. The down regulation of bound (/sup 3/H)PDB seen in HL-60 cells at 37/sup 0/C was not observed with R-35 cells. Prior exposure of the HL-60 cells but not of R-35 cells to 1 ..mu..M phorbol 12-myristate 13-acetate for 90 min at 37/sup 0/C caused a marked reduction in the specific binding of (/sup 3/H)PDB. When (/sup 3/H)PDB binding was carried out at 4/sup 0/C, (/sup 3/H)PDB bound to both cell types in a rapid, specific, and reversible manner. At equilibrium, HL-60 and R-35 cells were found to contain almost the same number of binding sites, which had dissociation constants of about 50 nM, indicating that the failure of R-35 cells to undergo PDB-induced differentiation was not associated with any change in the affinity or in the number of (/sup 3/H)PDB binding sites. These results indicate that the down regulation of specific (/sup 3/H)PDB binding may be a crucial early event in the control of phorbol ester-induced terminal differentiation in HL-60 cells. Furthermore, we suggest that such down regulation may be involved in other cellular and biochemical effects of phorbol diester tumor promoters.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6396281
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 78:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELL DIFFERENTIATION
BIOLOGICAL MODELS
LEUKEMOGENESIS
PHORBOL ESTERS
TOXICITY
TRITIUM COMPOUNDS
LEUKEMIA
LEUKOCYTES
LYSOZYME
TUMOR CELLS
ANIMAL CELLS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARCINOGENESIS
CARCINOGENS
DISEASES
ENZYMES
ESTERS
GLYCOSYL HYDROLASES
HEMIC DISEASES
HYDROLASES
LABELLED COMPOUNDS
MATERIALS
NEOPLASMS
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
PATHOGENESIS
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