title: Activities of potential tumour marker enzymes during induced differentiation in HL-60 and U-937 cells.
abstract: HL-60 and U-937 cells were used as models to assess the involvement of the enzymes of thymidine metabolism in differentiation. Both cell types showed decreased thymidine kinase and thymidylate synthase but increased thymidine phosphorylase activities in response to the induction of differentiation by dimethylsulfoxide and 12-O-tetradecanoylphorbol 13-acetate. This was accompanied by a greater than three-fold increase in the stimulation of superoxide production in both cell lines. Thymidylate synthase and thymidine kinase activities were noted as potential markers of leukaemic cell proliferation while thymidine phosphorylase and superoxide production correlated well with differentiated phenotypes. Prolonged treatment of U-937 by 12-O-tetradecanoylphorbol 13-acetate resulted in a marked de-differentiation, indicating overstimulation of one or more of the isoforms of protein kinase C.
authors.affiliation: School of Biomedical Sciences, University of Ulster, Coleraine, Co. Londonderry, Northern Ireland, UK.
authors.forename: P B
authors.initials: PB
authors.lastname: Mullan
authors.forename: P G
authors.initials: PG
authors.lastname: McKenna
authors.forename: V J
authors.initials: VJ
authors.lastname: McKelvey-Martin
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D004798:Enzymes / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D013936:Thymidine / Q000378:metabolism; D020298:U937 Cells
chemical_list: D014408:Biomarkers, Tumor; D004798:Enzymes; D013936:Thymidine