γ-H2AX induced by linear alkylbenzene sulfonates is due to deoxyribonuclease-1 translocation to the nucleus via actin disruption.
Phosphorylation of histone H2AX (γ-H2AX) occurs following formation of DNA double strand breaks (DSBs). Other types of DNA damage also generate DSBs through DNA replication and repair, leading to the production of γ-H2AX. In the present study, we demonstrated that linear alkylbenzene sulfonates (LAS), the most widely used and non-genotoxic anionic surfactants, could generate γ-H2AX via a novel pathway. Breast adenocarcinoma MCF-7 cells were treated with five kinds of LAS with alkyl chains ranging from 10 to 14 carbon units (C10-C14LAS). The generation of DSBs and subsequent production of γ-H2AX increased in a manner that depended on the number of carbon units in LAS. γ-H2AX could also be generated with non-cytotoxic doses of LAS and was independent of the cell cycle, indicating the non-apoptotic and DNA replication-independent formation of DSBs. The generation of γ-H2AX could be attenuated by EGTA and ZnCl2, deoxyribonuclease-1 (DNase I) inhibitors, as well as by the knockdown of DNase I. LAS weakened the interaction between DNase I and actin, and the enhanced release of DNase I was dependent on the number of carbon units in LAS. DNase I released by the LAS treatment translocated to the nucleus, in which DNase I attacked DNA and generated γ-H2AX. These results suggested that the LAS-induced generation of γ-H2AX could be attributed to the translocation of DNase I to the nucleus through the disruption of actin, and not to LAS-induced DNA damage.
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Xiaoxu
X
Zhao
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Tatsushi
T
Toyooka
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Toru
T
Kubota
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
Guang
G
Yang
Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan. Electronic address: ibuki@u-shizuoka-ken.ac.jp.
Yuko
Y
Ibuki
D017738:Alkanesulfonic Acids / Q000009:adverse effects*; D002453:Cell Cycle / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects; D003850:Deoxyribonuclease I / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D014178:Translocation, Genetic
D017738:Alkanesulfonic Acids; C468783:H2AX protein, human; D006657:Histones; D009124:Muscle Proteins; D017382:Reactive Oxygen Species; C030641:alkylbenzyl sulfonic acid; C097585:DNASE1L1 protein, human; D003850:Deoxyribonuclease I
Actin; DNA double strand breaks; Deoxyribonuclease-1; Linear alkylbenzene sulfonates; γ-H2AX