title: Keratinization and the effect of vitamin A in aggregates of a squamous carcinoma cell line NBT II.
abstract: The terminal differentiation, keratinization, of a rat bladder tumor cell line, NBT II, occurred in multicellular aggregates. After aggregation, these cells did not undergo a round of mitosis before keratinization. 5-Bromodeoxyuridine added to the monolayer cell culture 2 days before aggregation completely prevented this differentiation; it was ineffective when added at the time of cell aggregation. Vitamin A prevented the keratinization of NBT II cells in aggregates but did not inhibit aggregate formation; it enhanced the number of cells engaged in DNA synthesis. This model appears to be very useful for analyzing the mechanisms of terminal differentiation and its modulation by vitamin A in tumor cells.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell; D002449:Cell Aggregation / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D003561:Cytarabine / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000096:biosynthesis; D007633:Keratins / Q000378:metabolism*; D008938:Mitosis; D051381:Rats; D001749:Urinary Bladder Neoplasms; D014801:Vitamin A / Q000494:pharmacology*
chemical_list: D004273:DNA, Neoplasm; D003561:Cytarabine; D014801:Vitamin A; D007633:Keratins; D001973:Bromodeoxyuridine