Enhancement of BALB/c 3T3 cells transformation by 1,2-dibromoethane promoting effect.
Two of the most representative halogenated aliphatic hydrocarbons, 1,2-dibromoethane and 1,1,2,2-tetrachloroethane, were tested in the two-stage cell transformation model for analysing the promoting ability. Both of these compounds had previously been found to exert genotoxic effects, probably acting as moderate initiators. BALB/c 3T3 cells were initiated with subtransforming doses of N-methyl-N-nitro-N-nitrosoguanidine or 3-methylcholanthrene and then exposed to a chronic treatment with different non-transforming dosages of the two haloalkanes. 1,1,2,2-Tetrachloroethane did not exert any promoting activity in that system. By contrast, significant promoting effects by 1,2-dibromoethane were observed both in cells treated with N-methyl-N-nitro-N-nitrosoguanidine and in cells treated with 3-methylcholanthrene. Promotion of the transformation process initiated with 3-methylcholanthrene was detectable when confluent cells in the chemical-treated plates were replated in the level-II amplification test. This experimental procedure allowed cells to perform further rounds of replications and transformed foci to became detectable. Results gave evidence for a promoting role of 1,2-dibromoethane in multistep carcinogenesis, probably responsible for the higher oncogenic ability of this compound with respect to 1,1,2,2-tetrachloroethane.
Colacci
A
A
Istituto Nazionale per la Ricerca sul Cancro (IST)-Genova, Biotechnology Satellite Unit Bologna, Italy.
Vaccari
M
M
Perocco
P
P
Da Vià
C
C
Silingardi
P
P
Manzini
E
E
Horn
W
W
Grilli
S
S
D016475:3T3 Cells / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004980:Ethane / Q000031:analogs & derivatives* / Q000633:toxicity; D015946:Ethylene Dibromide / Q000633:toxicity*; D006843:Hydrocarbons, Chlorinated / Q000633:toxicity*; D008769:Methylnitronitrosoguanidine; D051379:Mice; D013755:Tetradecanoylphorbol Acetate
D002273:Carcinogens; D006843:Hydrocarbons, Chlorinated; D008769:Methylnitronitrosoguanidine; C015530:1,1,2,2-tetrachloroethane; D015946:Ethylene Dibromide; D004980:Ethane; D013755:Tetradecanoylphorbol Acetate