title: Could the increase in natural killer activity induced by the tumor-promoting agent TPA depend on the TPA-adherent, nonphagocytic mononuclear cells?
abstract: The tumor-promoting agent phorbol-12-myristate-13-acetate (TPA) has been studied for its effects upon Natural Killer (NK) activity. The removal of phagocytic cells prior to incubation of the effectors with TPA resulted in a dose-dependent increase in NK activity in accordance with the results of other workers. When total mononuclear cells were exposed to TPA and used as effector cells, no clear-cut results were obtained, in contrast to the suppression of NK activity already described in this situation. This lack of suppression could be due to the way effector cells are recovered after TPA incubation, since it was found that there was an enrichment of NK activity among cells which adhered after TPA treatment.
authors.affiliation: Centro de Pesquisa Básica, Instituto Nacional de Câncer, Rio de Janeiro, Brasil.
authors.forename: L
authors.initials: L
authors.lastname: De-La-Rocque
authors.forename: V M
authors.initials: VM
authors.lastname: Marques-Silva
authors.forename: V M
authors.initials: VM
authors.lastname: Rumjanek
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D013755:Tetradecanoylphorbol Acetate