Hexabromocyclododecane-induced Genotoxicity in Cultured Human Breast Cells through DNA Damage

To investigate the genotoxicity and reveal the potential toxicological mechanisms of Hexabromocyclododecane (HBCD), human breast cells HBL-100 were exposed to a sequence of HBCD concentrations (0, 5, 10, and 50 mg/L) for 24 h. With a series of zymology and molecular biology methods, we found that HBCD induced dose-dependent oxidative stress on HBL-100 DNA. As revealed in qRT-PCR, activated prognostic factor ATM down-regulated tumor suppressor gene BRCA1 and prompted DNA repair genes hOGG1 and hMTH1 expression in lower concentrations of HBCD (< 10 mg/L). However, DNA repair were inhibited as well as cell proliferation rate by higher concentrations of HBCD (50 mg/L). The results inferred that the genotoxicity of HBCD was dose-dependent and related to DNA repair pathway.