Rapid and reversible inhibition of junctional communication by tumor promoters in a mouse cell line.
HEL-37 cells rapidly transferred microinjected fluorescein between contacting cells. This transfer was strongly inhibited by tumor-promoting phorbol esters and mezerein but not by non-promoting derivatives. The onset of the inhibition occurred after 5 to 10 min of exposure to the test compound and was complete within 20 min. Using a wash-off procedure, it was demonstrated that inhibition of dye transfer by phorbol-12, 13-dibutyrate was fully reversed by 100 min, after a lag of 40 to 60 min. The recovery of dye transfer competence was blocked by puromycin. Both 12-O-tetradecanoylphorbol-13-acetate and monensin caused elevated Na+ levels in HEL-37 cells, but the latter compound did not inhibit dye transfer. It was concluded that the promoter inhibition of transfer was not a consequence of Na+-induced increase in cytoplasmic Ca2+ concentration.
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology*; D002450:Cell Communication / Q000187:drug effects*; D002460:Cell Line; D004224:Diterpenes; D004817:Epidermis / Q000378:metabolism; D019793:Fluorescein; D005452:Fluoresceins / Q000378:metabolism; D051379:Mice; D008985:Monensin / Q000494:pharmacology; D010703:Phorbol Esters / Q000494:pharmacology; D011691:Puromycin / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism; D013729:Terpenes; D013997:Time Factors
D002273:Carcinogens; D004224:Diterpenes; D005452:Fluoresceins; D010703:Phorbol Esters; D013729:Terpenes; C011309:mezerein; D011691:Puromycin; D008985:Monensin; D012964:Sodium; D019793:Fluorescein