Effect of Chronic Radiation Exposure on Human microRNA Expression

Abstract

Relative expression of mature microRNA assessed in peripheral blood cells in persons chronically exposed to low-dose radiation in the long-term period. The study included people exposed in the 1950s on the Techa River (Southern Urals, Russia). The cumulative red bone marrow doses (RBM) of the persons in the main study group (33 persons) ranged from 77.7 to 2869.8 mGy (mean value – 698.5 mGy). The comparison group consisted of 30 people with RBM dose not exceeding 70 mGy over their lifetime. Reverse transcription of RNA samples was performed using specific stem-loop primers (“stem-loop”). Changes in the relative content of microRNA were assessed by real-time PCR on the CFX96 detection system (BioRad, USA). Statistical analysis of the results was performed using Mann–Whitney U-criterion. A significant increase in hsa-miR-125b, hsa-miR-181a, and hsa-miR-16-5p content was detected in exposed people after 60 years, and their expression was found to depend on the RBM dose.