title: The effects of 5-bromodeoxyuridine on cyclic AMP levels and cytoskeletal organization in malignant melanoma cells.
abstract: 5-Bromodeoxyuridine (BUdR) causes mouse melanoma cells to develop a flattened morphology and simultaneously adhere tenaceously to the substratum on which they are growing. Experiments were done to determine if these events are coupled to increases in cAMP levels and to rearrangements in the cells' cytoskeleton. Cyclic AMP assays revealed that cell flattening and the increase in adhesive properties caused by BUdR is not accompanied by an increase in the cellular concentration of cyclic AMP. However, electron micrographs of cells grown in the presence of BUdR show a striking increase in the number of organized microtubules and microfilaments. Colchicine binding revealed no difference in the amount of tubulin present in untreated or BUdR-treated cells indicating that the increase in the number of microtubules is due to the polymerization of pre-existing tubulin subunits. These results are discussed in light of possible similar mechanisms of action of BUdR and cyclic AMP in regulating the organization of microtubules and microfilaments and the role these structures play in altering cell morphology and adhesive properties.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D003078:Colchicine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects* / Q000648:ultrastructure; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology; D008545:Melanoma / Q000378:metabolism / Q000648:ultrastructure*; D051379:Mice; D008854:Microscopy, Electron; D008870:Microtubules / Q000187:drug effects*; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000648:ultrastructure; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; D009074:Melanocyte-Stimulating Hormones; D000242:Cyclic AMP; D001973:Bromodeoxyuridine; D003078:Colchicine