Association between Single Nucleotide Polymorphisms of Apoptosis and Cell Cycle Control Genes and the Risk of Cancer Development in Chronically Exposed People

The association between single nucleotide polymorphisms of genes involved in the cell cycle control ( ATM rs664677, MDM2 rs2279744, CDKN1A rs1801270) and apoptosis ( BCL-2 rs2279115, BAX rs4645878, TNF α rs361525, CASP8 rs1045485) and the risk of solid cancer development in people of various ethnicities exposed to chronic radiation is studied. The study included 915 residents of the Techa riverside settlements belonging to two ethnic groups the Slavs and the Turkic people who were affected by chronic exposure of a low dose rate in the low to medium dose range. Of them 310 people had solid cancers. Genotyping of polymorphic regions of the genes regulating the cell cycle and apoptosis was performed by the real-time PCR method. The study showed that the rs2279744*C allele of the MDM2 gene was associated with an increased risk of cancer development (OR = 2.29; 95% CI 1.23–4.28; p = 0.007), while the rs1801270*A allele of the CDKN1A gene showed a protective effect against cancer development (OR = 0.55; 95% CI 0.35–0.85; p = 0.01) in exposed individuals of the Turkic people. The combined effect of the identified polymorphisms and soft tissue exposure dose modifies statistically significantly the risk of cancer development in chronically exposed individuals of the Turkic ethnic group, with the greatest contribution being made by the carriage of the rs2279744*C allele of the MDM2 gene.