Binding of 20-[3H]-phorbol 2, 13-dibutyrate [( 3H] PDB) to intact human K 562 cells was characterized. Specific binding of [3H] PDB to K 562 cells at 20 degrees C or 37 degrees C reached a maximum within 15-20 min. Maximal specific [3H] PDB binding to K 562 cells was followed by a decline (down regulation) of radioacticity. This down regulation was temperature dependent; no loss of radioactivity occurred by 1 hour at 4 degrees C. When [3H] PDB binding was carried out a 4 degrees C, [3HDB bound to K 562 cells in a rapid, specific, and reversible manner. Phorbol esters which lack tumor-promoting activity, did not inhibit [3H] PDB binding. A Scatchard analysis was compatible with one class of binding sites, Kd = 50 nM and about 2 X 10(5) binding sites per cell. Human serum inhibited specific binding of [3H] PDB. The effect of several chemical compounds on [3H] PDB binding was also investigated. Most of the compounds tested such as butyrate, hemin, gamma-globulins, transferrin, insulin, EGF, and albumin failed to significantly affect the binding of [3H] PDB. In contrast, retinoic acid and quinacrine significantly affected the binding of [3H] PDB: retinoic acid induced a marked increase of [3H] PDB binding which was dose dependent; quinacrine induced a decrease of [3H] PDB binding, even at low concentration.
Characterization of phorbol esters binding to K 562 cells / F. Louache, J. L. Villeval, P. G. Pelicci, M. Rouis, M. Titeux, A. Henri, H. Rochant, P. Thomopoulos, U. Testa. - In: ANTICANCER RESEARCH. - ISSN 0250-7005. - 4:1-2(1984), pp. 33-9-39.
Characterization of phorbol esters binding to K 562 cells
P. G. Pelicci;
1984
Abstract
Binding of 20-[3H]-phorbol 2, 13-dibutyrate [( 3H] PDB) to intact human K 562 cells was characterized. Specific binding of [3H] PDB to K 562 cells at 20 degrees C or 37 degrees C reached a maximum within 15-20 min. Maximal specific [3H] PDB binding to K 562 cells was followed by a decline (down regulation) of radioacticity. This down regulation was temperature dependent; no loss of radioactivity occurred by 1 hour at 4 degrees C. When [3H] PDB binding was carried out a 4 degrees C, [3HDB bound to K 562 cells in a rapid, specific, and reversible manner. Phorbol esters which lack tumor-promoting activity, did not inhibit [3H] PDB binding. A Scatchard analysis was compatible with one class of binding sites, Kd = 50 nM and about 2 X 10(5) binding sites per cell. Human serum inhibited specific binding of [3H] PDB. The effect of several chemical compounds on [3H] PDB binding was also investigated. Most of the compounds tested such as butyrate, hemin, gamma-globulins, transferrin, insulin, EGF, and albumin failed to significantly affect the binding of [3H] PDB. In contrast, retinoic acid and quinacrine significantly affected the binding of [3H] PDB: retinoic acid induced a marked increase of [3H] PDB binding which was dose dependent; quinacrine induced a decrease of [3H] PDB binding, even at low concentration.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.