Quercetin is able to demethylate the p16INK4a gene promoter.
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.
Tan
Sainan
S
Reproductive and Genetic Center of the National Research Institute for Family Planning, Beijing, China.
Wang
Chong
C
Lu
Cailing
C
Zhao
Baojian
B
Cui
Yi
Y
Shi
Xinquan
X
Ma
Xu
X
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
D000975:Antioxidants; D019941:Cyclin-Dependent Kinase Inhibitor p16; D017931:DNA Primers; D011794:Quercetin