Basing on Multifactor Dimensionality Reduction method we showed that polymorphic variants p.Q399R (rs25487, XRCC1) and p.P72R (rs1042522, TP53) correlated with increased risk of breast cancer for women from the Kyrgyz Republic and the Republic of Belarus. Cohort for investigation included patients with clinically verified breast cancer: 117 women from the Kyrgyz Republic (nationality - Kyrgyz) and 169 - of the Republic of Belarus (nationality - Belarusians). Group for comparison included (healthy patients without history of cancer pathology at the time of blood sampling) 102 patients from the Kyrgyz Republic, 185 - from the Republic of Belarus. Respectively genotyping of polymorphic variants p.Q399R (rs25487, XRCC1) and p.P72R (rs1042522, TP53) was done by PCR-RFLP. Analysis of the intergenic interactions conducted with MDR 3.0.2 software. Both ethnic groups showed an increase of breast cancer risk in the presence of alleles for SNPs Gln p.Q399R (XRCC1) in the heterozygous state: for the group “Kyrgyz” - OR=2,78 (95% CI=[1,60-4,82]), p=0,001; for the group “Belarusians” - OR=1,85 (95% СІ=[1Д1-2,82], p=0,004. Carriers with combination of alleles Gln (p.Q399R, XRCC1) and Pro (p.P72R, TP53) showed statistically significance increases of breast cancer risk as for patients from the Kyrgyz Republic (OR=2,89, 95% CI=[1,33-6,31]), so as for patients from the Republic of Belarus (OR=3,01, 95% CI=[0,79-11,56]).

Aim: We studied the intergenic interactions and the contribution of polymorphic loci p.Arg72Pro (gene TP53), p.Gln399Arg (gene XRCC1), p.Arg194Trp (gene XRCC1), g.4682G>A (gene TNFa), p.Val353Ala (gene HMMR), p.14+309T>G (gene MDM2), g.38444T>G (gene PALB2) in the formation of predisposition to breast cancer (ВС) in women of Kyrgyz nationality. Material and method: The study included 103 women of the Kyrgyz ethnic group with the morphologically verified diagnosis of BC and 102 women without cancer and chronic diseases. Genotyping of single-nucleotide polymorphisms (SNPs) was performed using PCR-RFLP. Analysis of the intergenic interactions conducted with MDR 3.0.2 software. Results: Heterozygous genotype Gln/Arg of gene XRCC1 (ОR=3,15; 95% CI 1,78-5,58), the combination of Arg/Gln // Arg/Pro of genes XRCC1 (p.Gln399Arg) / TP53 (p.Arg72Pro) (OR=3,21; 95% CI 1,21-8,47), Arg/Gln // T/T of genes XRCC1 (p.Gln399Arg) / MDM2 (o.14+309T>G) (OR=3,18; 95% CI 0,99-10,7), Arg/Gln // G/G and Arg/Gln // G/A of genes XRCC1 (p.Gln399Arg) / TNFa (g.4682G>A) (OR=3,84; 95% CI 1,847,90) and (OR=3,91 95% CI 1,29-8,51 respectively), Arg/Gln // T/T of genes XRCC1 (p.Gln399Arg) / PALB2 (p.Thr1100=) (OR=2,92; 95% CI 1,59-5,37), as well as Arg/Gln // Arg/Arg and Arg/Gln // Arg/Trp for polymorphic loci p.Gln399Arg and p.Arg194Trp of gene XRCC1 (OR=2,48; 95% CI 1,12-5,19 and 0R=2,90, 95% CI 1,04-8,12 respectively) were associated with BC in Kyrgyz women. Conclusions: The results of the present study suggest that combinations of variants of ТP53, XRCC1, TNFa, HMMR, MDM2 и PALB2 genes may contribute to the genetic susceptibility of BC in Kyrgyz women.

Aim. Allele frequency and genotype distribution in the cervical cancer group were compared with those of the control group to determine whether polymorphism Arg72Pro of Р53 gene elevates the susceptibility of Kyrgyz women to cervical cancer (CC). Materials and Methods. A total of 102 women (mean age 53,5±10 years) of Kyrgyz nationality with cervical cancer were recruited into the study and 102 healthy women were used as the control group (mean age 46,5±8,5 years). The diagnosis of cervical cancer was confirmed histologically. 88 % (90/102) of women with cervical cancer were human papillomavirus (HPV) positive. 17 % (15/90) specimens were positive for HPV type 16, 48 % (43/90) were positive for HPV type 18 and 35 % (32/90) were positive both HPV - 16/18. Presence of human papillomavirus DNA types 16 and 18 was analyzed by polymerase chain reaction with hybridization-fluorescence detection. The Arg72Pro polymorphisms of the P53 gene were determined by the PCR-RFLP method. Results. No significant difference was found between genotype distributions in the cervical cancer patients and the control group (χ2=1,24; р=0,54). However, the Arg72Arg genotype and Arg72 allele was significantly more frequent in women with cervical cancers infected with HPV than in the control group (χ2=7,25; р=0,027 for для genotype, χ2=6,83; р=0,009 for allele). Women who are HIV positive and having the Arg72 allele had 1,94 fold (OR=1,94 [1,20-3,15]; р=0,009) higher risk of developing CC compared with subjects carrying neither of these alleles. HPV positive women carrying the genotype Arg72Arg had 1,85 fold (OR=1,85 [1,03-3,32]; р=0,027) higher risk of CC. Conclusion. The Arg72Arg genotype of р53 gene in HIV positive women from Kyrgyz Republic may represent a potential risk factor for the development of cervical cancer.