Objective To evaluate the effects of occupational exposure to radiation during interventional procedures on DNA methylation, DNA methylation related enzymes, and methylation metabolites.
Methods The exposure group was composed of 120 radiologists who had been engaged in interventional treatment for more than three years, and the control group included 120 non-interventional radiologists matched for sex and age (±threes years) with the exposure group. Total methylation rate of DNA and expression levels of DNA methyltransferase (Dnmt) and homocysteine (Hcy) in fasting venous blood samples were detected and compared by high performance liquid chromatography and enzyme-linked assay, respectively. The relationships of DNA methylation related indicators with annual effective individual dose and working age for interventional radiology were analyzed by partial correlation analysis and analysis of covariance. The effects of individual dose, working age for interventional radiology, age, and other factors on the methylation levels of the subjects were analyzed by multi-factor linear regression.
Results The expression levels of Dnmt(0.064±0.043) U/mL and Hcy(10.37±3.92) μmol/L in the exposure group were higher than those in the control group(0.047±0.035)×103 U/L and (9.32±3.90) μmol/L (P < 0.05); however, the total DNA methylation rate was not statistically different between the two groupsexposure group:(8.10±1.53)% vs control group:(8.47±1.41)% (P > 0.05). Annual effective individual dose in the exposure group was positively correlated with Dnmt (r=0.671, P=0.00), but not correlated with other indicators. The results of multi-factor analysis showed that age and working age for interventional radiology were important factors affecting DNA methylation levels of interventional radiologists (standardized partial regression coefficients were -0.182 and -0.198, respectively, Ps < 0.01).
Conclusion Occupational exposure to interventional treatment relevant radiation may affect the expression of related enzymes and metabolites in the process of DNA methylation, but has little effect on the DNA methylation of interventional radiologists.
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