EN
Carcinogenesis is often associated with the uncontrolled cell division cycle that leads to the growth and development of cancer. In this study we analyzed the occurrence of MAP2K1 gene polymorphism, which is described as a cell division regulator, in a group of dogs with diagnosed adenocarcinoma and aged group of animals. In this study, blood samples were obtained from 22 female dogs diagnosed with mammary tumors. Moreover, blood samples from geriatric (> 5 to 10-years-old; n = 15), mature adult (> 2 to 5-years-old; n = 10) and young (from 1 to 2-years-old; n = 11) dogs were also collected. 36 bitches diagnosed because of other reasons served as controls. After Sanger sequencing analysis, 15 single nucleotide variations were identified, of which 3 were situated in exons (exon 2, 7 and 11) and the remaining 12 were localized in splice regions of introns. We also observed differences in genotype and allele frequencies between tumor and control groups for heterozygote and for an alternative allele for 3 polymorphisms (c.G267T, g.T72562C, g.T75728C). Moreover, we found higher prevalence of the alternative alleles and/or alternative homozygotes solely in the most advanced age subgroup in comparison with the other two subgroups for two pair of variations: g.A71023G and g.T72440C; g.T75757C and c.C1179T. Although the results in many cases were not statistically significant, we observed different patterns of genetic segregation of alleles in control and tumor-affected subjects, which may serve as a risk factor of cancer occurrence in the investigated group. Moreover, g.T75757C and c.C1179T polymorphisms may be recognized as markers of aging in dogs.