Abstract: ObjectiveTo study mRNA expression of c-myc,c-fos and N-ras oncogenes in kidney tissue of rats administrated with melamine for 28 days.MethodsFive male and 5 female SD rats in every experimental group were administrated with three doses of melamine(low,middle,and high dose)by gavage,respectively,for 28 days.After melamine treatment the animals were sacrificed and the kidneys were taken out for detection of mRNA expression of c-myc,c-fos and N-ras with fluorescent quantitative PCR assay.ResultsMelamine induced a significant increase in mRNA expression of c-myc,cfos and N-ras at low,middle,and high dose.The relative levels of c-myc expression in groups treated with three doses of melamine were 156%-339% higher than that of the control.Meanwhile,c-fos mRNA levels increased by 234%-403% in groups treated with three doses of melamine,and N-ras mRNA levels increased by 265%-1 208% in groups treated with three doses of melamine.ConclusionMelamine could induce a significant increase in mRNA expression of c-myc,c-fos and N-ras in kidney tissue when rats were treated with subacute administration of melamine.The findings indicate that melamine might be a potential carcinogen.