title: Prostanoid EP1 receptor as the target of (-)-epigallocatechin-3-gallate in suppressing hepatocellular carcinoma cells in vitro.
abstract: OBJECTIVE
  To investigate the effects of (-)-epigallocatechin-3-gallate (EGCG), an active compound in green tea, on prostaglandin E(2) (PGE(2))-induced proliferation and migration, and the expression of prostanoid EP(1) receptors in hepatocellular carcinoma (HCC) cells.
  
  
  METHODS
  HCC cell line HepG2, human hepatoma cell lines MHCC-97L, MHCC-97H and human hepatocyte cell line L02 were used. Cell viability was analyzed using MTT assay. PGE(2) production was determined with immunoassay. Wound healing assay and transwell filter assay were employed to assess the extent of HCC cell migration. The expression of EP(1) receptor and Gq protein were examined using Western blot assay.
  
  
  RESULTS
  PGE(2) (4-40000 nmol/L) or the EP(1) receptor agonist ONO-DI-004 (400-4000 nmol/L) increased the viability and migration of HepG2 cells in concentration-dependent manners. EGCG (100 μg/mL) significantly inhibited the viability and migration of HepG2 cells induced by PGE(2) or ONO-DI-004. HepG2 cells secreted an abundant amount of PGE(2) into the medium, and EGCG (100 μg/mL) significantly inhibited the PGE(2)production and EP(1) receptor expression in HepG2 cells. EGCG (100 μg/mL) also inhibited the viability of MHCC-97L cells, but not that of MHCC-97H cells. Both EGCG (100 μg/mL) and EP(1) receptor antagonist ONO-8711 inhibited PGE(2) 4 μmol/L and ONO-DI-004 400 nmol/L-induced growth and migration of HepG2 cells. Both EGCG (100 μg/mL) and ONO-8711 210 nmol/L inhibited PGE(2)- and ONO-DI-004-induced EP(1) expression. EGCG and ONO-8711 had synergistic effects in inhibiting EP(1) receptor expression. PGE(2), ONO-DI-004, ONO-8711, and EGCG had no effects on Gq expression in HepG2 cells, respectively.
  
  
  CONCLUSIONS
  These findings suggest that the anti-HCC effects of EGCG might be mediated, at least partially, through the suppressing EP(1) receptor expression and PGE(2) production.
authors.affiliation: Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immunopharmacology of the Education Ministry of China, Hefei, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Jin
authors.forename: Yan
authors.initials: Y
authors.lastname: Chang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Yi-fu
authors.initials: YF
authors.lastname: He
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Hu
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.forename: Yu-jing
authors.initials: YJ
authors.lastname: Wu
mesh_terms: D000527:Alprostadil / Q000031:analogs & derivatives / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D015153:Blotting, Western; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology; D002208:Caproates / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000187:drug effects / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D007118:Immunoassay; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness; D058306:Receptors, Prostaglandin E, EP1 Subtype / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D001643:Bridged Bicyclo Compounds; D002208:Caproates; C122148:ONO 8711; C500045:ONO-DI-004; C545635:PTGER1 protein, human; D058306:Receptors, Prostaglandin E, EP1 Subtype; D002392:Catechin; C045651:epigallocatechin gallate; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D000527:Alprostadil; D015232:Dinoprostone