title: Weak promotion of C3H/10T1/2 cell transformation by repeated treatments with formaldehyde.
abstract: C3H/10T 1/2 cells were treated with N-methyl-N'-nitro-N-nitrosoguanidine and then repeatedly exposed to formaldehyde (0.1 to 2.0 micrograms/ml). Exposure of N-methyl-N'-nitro-N-nitrosoguanidine-initiated cultures to formaldehyde concentrations of 0.5 or 1.0 micrograms/ml in a variety of treatment regimens resulted in focus formation in up to 9% of the treated dishes. Transformed foci were observed in 2% or less of the cultures treated with N-methyl-N'-nitro-N-nitrosoguanidine or formaldehyde alone. Formaldehyde thus appears to be only a weak tumor promoter for C3H/10T 1/2 cell transformation.
mesh_terms: D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced*; D003043:Cocarcinogenesis; D004622:Embryo, Mammalian; D005557:Formaldehyde / Q000633:toxicity*; D008748:Methylcholanthrene / Q000633:toxicity; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D051379:Mice
chemical_list: D008769:Methylnitronitrosoguanidine; D005557:Formaldehyde; D008748:Methylcholanthrene