title: Quercetin is able to demethylate the p16INK4a gene promoter.
abstract: BACKGROUND
  Quercetin is a flavonoid found ubiquitously in nature. Studies in vitro and in vivo have suggested that quercetin may have a protective role against colon cancer.
  
  
  METHODS
  We selected the human colon cancer cell line RKO to investigate the effects of quercetin in vitro. RKO cells were treated with different concentrations of quercetin.
  
  
  RESULTS
  In comparison to the control, quercetin was able to inhibit the growth of RKO cells, as measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Untreated RKO cells demonstrated almost complete methylation of the p16INK4a gene. Hypermethylation of the p16INK4a gene was successfully reversed after 120 h of treatment with quercetin. Expression of the p16INK4a gene was restored in a concentration-dependent manner.
  
  
  CONCLUSIONS
  All these data suggest that quercetin has antitumor properties, probably via demethylation of the p16INK4a gene promoter.
authors.affiliation: Reproductive and Genetic Center of the National Research Institute for Family Planning, Beijing, China.
authors.forename: Sainan
authors.initials: S
authors.lastname: Tan
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Cailing
authors.initials: C
authors.lastname: Lu
authors.forename: Baojian
authors.initials: B
authors.lastname: Zhao
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.forename: Xinquan
authors.initials: X
authors.lastname: Shi
authors.forename: Xu
authors.initials: X
authors.lastname: Ma
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001483:Base Sequence; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics*; D019175:DNA Methylation; D017931:DNA Primers; D004305:Dose-Response Relationship, Drug; D006801:Humans; D011401:Promoter Regions, Genetic; D011794:Quercetin / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D000975:Antioxidants; D019941:Cyclin-Dependent Kinase Inhibitor p16; D017931:DNA Primers; D011794:Quercetin