title: Effects of low dose quercetin: cancer cell-specific inhibition of cell cycle progression.
abstract: Quercetin is a flavonoid present in many vegetables, fruits, and beverages. Due to its anti-oxidant, anti-tumor, and anti-inflammatory activity, quercetin has been studied extensively as a chemoprevention agent in several cancer models. Since most of these studies used higher doses of quercetin than clinically achievable, we focused on the effectiveness of physiologically relevant doses of quercetin. A low dose of quercetin exerted cancer cell-specific inhibition of proliferation and this inhibition resulted from cell cycle arrest at the G(1) phase. Quercetin induced p21 CDK inhibitor with a concomitant decrease of phosphorylation of pRb, which inhibits the G(1)/S cell cycle progression by trapping E2F1. A low dose of quercetin induced mild DNA damage and Chk2 activation, which is the main regulator of p21 expression by quercetin. In addition, quercetin down-regulated the cyclin B1 and CDK1, essential components of G(2)/M cell cycle progression. Inhibition of the recruitment of key transcription factor NF-Y to cyclin B1 gene promoter by quercetin led to transcriptional inhibition. This study proved that the chemo-preventive efficacy of a physiologically relevant dose of quercetin can be achievable through the inhibition of cell cycle progression.
authors.affiliation: Research Center for Molecular and Cellular Biology, Inha University, Incheon, Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Jeong
authors.forename: Jee Young
authors.initials: JY
authors.lastname: An
authors.forename: Yong Tae
authors.initials: YT
authors.lastname: Kwon
authors.forename: Juong G
authors.initials: JG
authors.lastname: Rhee
authors.forename: Yong J
authors.initials: YJ
authors.lastname: Lee
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D064447:Checkpoint Kinase 2; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism; D056744:Cyclin B1; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D011794:Quercetin; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase