Role of DNA methylation in the adaptive responses induced in a human B lymphoblast cell line by long-term low-dose exposures to γ-rays and cadmium

Publication date: October 2014 Source:Mutation Research/Genetic Toxicology and Environmental Mutagenesis, Volume 773 Author(s): Shuang Ye , Dexiao Yuan , Yuexia Xie , Yan Pan , Chunlin Shao The possible involvement of epigenetic factors in health risks due to exposures to environmental toxicants and ionizing radiation is poorly understood. We have tested the hypothesis that DNA methylation contributes to the adaptive response (AR) to ionizing radiation or Cd. Human B lymphoblast cells HMy2.CIR were irradiated (0.032Gy γ-rays) three times per week for 4 weeks or exposed to CdCl2 (0.005, 0.01, or 0.1μM) for 3 months, and then challenged with a high dose of Cd (50 or 100μM) or γ-rays (2Gy). Long-term low-dose radiation (LDR) or long-term low-dose Cd exposure induced AR against challenging doses of Cd and irradiation, respectively. When the primed cells were treated with 5-aza-2′-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, the ARs were eliminated. These results indicate that DNA methylation is involved in the induction of AR in HMy2.CIR cells.
Source: Mutation Research Genetic Toxicology and Environmental Mutagenesis - Category: Genetics & Stem Cells Source Type: research