title: [Role of poly (ADP-ribose) polymerase 1 in DNA methylation changes induced by hydroquinone in human bronchial epithelial cell].
abstract: OBJECTIVE
  To investigate the DNA methylation changes induced by hydroquinone (HQ) in human bronchial epithelial cells and to explore the role of poly (ADP-ribose) polymerase-l (PARP-l) in this process.
  
  
  METHODS
  Human bronchial epithelial 16HBE cells and PARP-l-deficient 16HBE cells (16HBE-shPARP-l cells) were exposed to HQ (10, 20, 40, 60, and 80 µmol/L) for 48h, while control cells were treated with an equal volume of PBS solution. The changes in genomic DNA methylation were investigated by high-performance capillary electrophoresis, and the expression levels of PARP-l and DNA methyltransferase 1 (DNMT1) were measured.
  
  
  RESULTS
  The percentages of methylated DNA of overall genome (mCpG%) in 16HBE and 16HBE-shPARP-l cells were 4.89%±0.07% and 9.53%±0.51%, respectively; after treatment with 5-aza-2'-deoxycytidine for 72 h, mCpG% decreased to 3.07±0.12% and 6.34%±0.3%, respectively. The one-way analysis of variance revealed significant differences in mCpG% between the cells exposed to different concentrations of HQ in both 16HBE and 16HBE-shPARP-l groups (F = 61.25, P < 0.01; F = 60.36, P < 0.01). For 16HBE cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-1 were 145.0%, 159.0%, 169.0%, 215.0%, and 236.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); for 16HBE-shPARP-l cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-l were 170.0%, 223.0%, 264.0%, 327.0%, and 320.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all). When the dose of HQ reached 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in 16HBE group were 114.0%, 126.0%, 136.0%, and 162.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); when the dose of HQ reached 10, 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in the 16HBE-shPARP-l group were 141.0%, 165.2%, 186.9%, 202.1%, and 217.3%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all).
  
  
  CONCLUSIONS
  HQ can induce hypomethylation in 16HBE cells, and PARP-1 can regulate DNA methylation in 16HBE cells by influencing the expression and activity of DNMT1.
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, Guangdong Province 518001, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sha
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, Guangdong Province 518001, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, Guangdong Province 518001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, Guangdong Province 518001, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, Guangdong Province 518001, China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D002478:Cells, Cultured; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004249:DNA Damage; D019175:DNA Methylation; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D006873:Hydroquinones / Q000633:toxicity*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*
chemical_list: D006873:Hydroquinones; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C031927:hydroquinone