Association of GNAS, RABL6, and RHOD gene methylation levels with chronic external γ-ray exposure dose

Introduction. The expansion of human fields of activity where ionizing radiation is used (nuclear energy, military affairs, nuclear medicine) poses the task of assessing the individual radiosensitivity of persons in contact or planning to associate their professional activities with the radiation factor.

Aim: To evaluate the degree of methylation of the GNAS, RABL6, RHOD genes and its association with the dose of chronic external radiation and the frequency of chromosomal aberrations in workers of the Siberian Chemical Plant who were exposed to radiation during their professional activities.

Material and Methods. The sample was made up of personnel of the Siberian Chemical Plant, who in the course of their professional activities were not exposed (control group, n = 38) or were exposed (study group, n = 98) to chronic exposure to ionizing radiation at doses from 10 to 656 mSv. The degree of gene methylation was assessed using real-time methyl-sensitive PCR. The frequency of chromosomal aberrations was assessed using a routine cytogenetic method without karyotyping, using Giems dye.

Results. It was found that the degree of methylation of GNAS, RABL6 and RHOD between the control group and the study group did not differ statistically (р > 0.05). However, it is noted that women are older than men in both groups. The frequency of dicentric chromosomes in women in the study group is lower, which may be explained by their lower age compared to the control group and (or) exposure to gamma radiation in “small” doses. There was no correlation of the degree of methylation of the studied genes with an external radiation dose of 10–656 mSv and the frequency of chromosomal aberrations in men.

Conclusion. An additional study of the degree of methylation of GNAS, RABL6 and RHOD at high doses of external exposure to gamma radiation is likely to confirm or deny the absence of a dose dependence of the degree of methylation of these genes.

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