title: Epigallocatechin-3-gallate regulates cell growth, cell cycle and phosphorylated nuclear factor-κB in human dermal fibroblasts.
abstract: OBJECTIVE
  To investigate the effects of (-)epigallocatechin-3-gallate (EGCG), the main polyphenol in green tea, on cell growth, cell cycle and phosphorylated nuclear factor-κB (pNF-κB) expression in neonatal human dermal fibroblasts (nHDFs).
  
  
  METHODS
  The proliferation and cell-cycle of nHDFs were determined using WST-8 cell growth assay and flow cytometry, respectively. The apoptosis was examined using DNA ladder and Annexin V-FITC assays. The expression levels of pNF-κB and cell cycle-related genes and proteins in nHDFs were measured using cDNA microarray analyses and Western blot. The cellular uptake of EGCG was examined using fluorescence (FITC)-labeled EGCG (FITC-EGCG) in combination with confocal microscopy.
  
  
  RESULTS
  The effect of EGCG on the growth of nHDFs depended on the concentration tested. At a low concentration (200 μmol/L), EGCG resulted in a slight decrease in the proportion of cells in the S and G(2)/M phases of cell cycle with a concomitant increase in the proportion of cells in G(0)/G(1) phase. At the higher doses (400 and 800 μmol/L), apoptosis was induced. The regulation of EGCG on the expression of pNF-κB was also concentration-dependent, whereas it did not affect the unphosphorylated NF-κB expression. cDNA microarray analysis showed that cell cycle-related genes were down-regulated by EGCG (200 μmol/L). The expression of cyclins A/B and cyclin-dependent kinase 1 was reversibly regulated by EGCG (200 μmol/L). FITC-EGCG was found to be internalized into the cytoplasm and translocated into the nucleus of nHDFs.
  
  
  CONCLUSIONS
  EGCG, through uptake into cytoplasm, reversibly regulated the cell growth and expression of cell cycle-related proteins and genes in normal fibroblasts.
authors.affiliation: Department of Nanomedical Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 609-735, Korea.
authors.forename: Dong-wook
authors.initials: DW
authors.lastname: Han
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Lee
authors.forename: Hak Hee
authors.initials: HH
authors.lastname: Kim
authors.forename: Suong-hyu
authors.initials: SH
authors.lastname: Hyon
authors.forename: Jong-chul
authors.initials: JC
authors.lastname: Park
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D028241:Camellia sinensis / Q000737:chemistry; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation / Q000187:drug effects; D012867:Skin / Q000166:cytology / Q000187:drug effects
chemical_list: D000975:Antioxidants; D016328:NF-kappa B; D002392:Catechin; C045651:epigallocatechin gallate