To investigate expression in c-myc gene by a chemical carcinogen benzo(a)pyrene(BP), human lymphoblast NC-37 cells were exposed to various concentrations of BP and the c-myc gene expression was evaluated by northern and slot blot hybridization methods...
To investigate expression in c-myc gene by a chemical carcinogen benzo(a)pyrene(BP), human lymphoblast NC-37 cells were exposed to various concentrations of BP and the c-myc gene expression was evaluated by northern and slot blot hybridization methods. When NC-37 cells exposed to BP of 0-4㎍/ml were treated with HindⅡ/XbaⅠ restriction enzyme, the c-myc genes were cut at the same region regardless of BP concentration. The site of cleavage by the restriction enzyme, HindⅡ/XbaⅠ was identical in the control, BP-treated and BP-washed cells. However, the m-RNA expression in slot blot hybridization appeared to be 4-5 times higher in BP-treated cells than in the control, and this effect was partially removed by washing the BP. When the DNA isolated from NC-37 cells exposed to various concentrations(0, 2, 4㎍/ml) of BP were amplified by polymerase chain reaction using a primer containing c-myc exon Ⅰ, the resulting DNA were of the same size in all groups. These results suggest that overexpression of c-myc oncogene may be required for the malignant transformation and maintenance in benzo(a)pyrene poisoned human lymphoblast NC-37 cells.