title: Benzyl butyl phthalate induces migration, invasion, and angiogenesis of Huh7 hepatocellular carcinoma cells through nongenomic AhR/G-protein signaling.
abstract: BACKGROUND
  The widespread use of phthalates as plasticizers has raised public health concerns regarding their adverse effects, including an association with cancer. Although animal investigations have suggested an association between phthalate exposure and hepatocellular carcinoma, the mechanisms are unknown.
  
  
  METHODS
  The hepatocellular carcinoma cell line Huh7 was treated with benzyl butyl phthalate (BBP), and then analyzed by total internal reflection fluorescence microscopy, confocal microscopy and double immunogold transmission electron microscopy. Following BBP treatment, mRNA levels were measured by RT-PCR, protein levels were measured using western blot, and vascular endothelial growth factor levels were measured by an enzyme-linked immunosorbent assay. Cell migration and invasion assays were evaluated by transwell, and angiogenesis were performed by a tube formation assay. Nude mice were used to investigate metastasis and angiogenesis in vivo.
  
  
  RESULTS
  BBP affected hepatocellular carcinoma progression through the aryl hydrocarbon receptor (AhR) and that benzyl butyl phthalate (BBP) stimulated AhR at the cell surface, which then interacted with G proteins and triggered a downstream signaling cascade. BBP activated AhR through a nongenomic action involving G-protein signaling rather than the classical genomic AhR action. BBP treatment promoted cell migration and invasion in vitro and metastasis in vivo via the AhR/Gβ/PI3K/Akt/NF-κB pathway. In addition, BBP induced both in vitro and in vivo angiogenesis through the AhR/ERK/VEGF pathway.
  
  
  CONCLUSIONS
  These findings suggest a novel nongenomic AhR mechanism involving G-protein signaling induced by phthalates, which contributes to tumor progression of hepatocellular carcinoma.
authors: Cheng-Fang
authors: CF
authors: Tsai
authors: Tsung-Hua
authors: TH
authors: Hsieh
authors: Jau-Nan
authors: JN
authors: Lee
authors: Chia-Yi
authors: CY
authors: Hsu
authors: Yu-Chih
authors: YC
authors: Wang
authors: Feng-Jie
authors: FJ
authors: Lai
authors: Kung-Kai
authors: KK
authors: Kuo
authors: Hua-Lin
authors: HL
authors: Wu
authors: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 807, Taiwan. tsaieing@yahoo.com.
authors: Eing-Mei
authors: EM
authors: Tsai
authors: Po-Lin
authors: PL
authors: Kuo
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D016678:Genome; D057809:HEK293 Cells; D056945:Hep G2 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009361:Neoplasm Invasiveness / Q000473:pathology; D009368:Neoplasm Transplantation; D010795:Phthalic Acids / Q000633:toxicity*; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D010795:Phthalic Acids; D018336:Receptors, Aryl Hydrocarbon; D042461:Vascular Endothelial Growth Factor A; C111235:AHR protein, human; C467484:VEGFA protein, human; C027561:butylbenzyl phthalate