Vanadate enhances transformation of bovine papillomavirus DNA-transfected C3H/10T1/2 cells.
Bovine papillomavirus (BPV) DNA-transfected C3H/10T1/2 cells respond to tumor promoters by enhanced production of transformed foci. Vanadate, a suspected carcinogen, is a mitogen, generates active oxygen species and alters phosphorylation of proteins. We investigated whether vanadate would enhance transformation of BPV DNA-transfected C3H/10T1/2 cells. Transformed foci in BPV DNA transfected C3H/10T1/2 cells exposed continuously to vanadate for 21 days increased in a dose-dependent manner to 50-fold at 4 microM vanadate. This increase was not due to enhanced uptake of BPV DNA post transfection. Neither catalase nor superoxide dismutase inhibited the vanadate-mediated increase in transformed foci but this does not necessarily rule out the involvement of intracellular active oxygen species. At vanadate concentrations greater than 6 microM, cells lost adherence to the Petri plates. We conclude that vanadate is capable of enhancing BPV DNA-mediated cell transformation. Possible mechanisms may involve active oxygen species or altered patterns of protein phosphorylation.
Kowalski
L A
LA
Epidemiology and Cancer Prevention, B.C. Cancer Research Centre, Vancouver, Canada.
Tsang
S S
SS
Davison
A J
AJ
D000818:Animals; D002374:Catalase / Q000494:pharmacology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral / Q000187:drug effects*; D004279:DNA, Viral; D051379:Mice; D008809:Mice, Inbred C3H; D027383:Papillomaviridae / Q000235:genetics*; D013482:Superoxide Dismutase / Q000494:pharmacology; D014162:Transfection; D014412:Tumor Virus Infections; D014638:Vanadates / Q000494:pharmacology*
D004279:DNA, Viral; D014638:Vanadates; D002374:Catalase; D013482:Superoxide Dismutase