title: Upregulation of cancer-associated myofibroblasts by TGF-β from scirrhous gastric carcinoma cells.
abstract: BACKGROUND
  Myofibroblasts in the cancer microenvironment have recently been implicated in tumour growth and metastasis of gastric cancer. However, the mechanisms responsible for the regulation of myofibroblasts in cancer-associated fibroblasts (CAFs) remain unclear. This study was performed to clarify the mechanisms for regulation of myofibroblasts in gastric cancer microenvironment.
  
  
  METHODS
  Two CAFs (CaF-29 and CaF-33) from the tumoural gastric wall and a normal fibroblast (NF-29) from the nontumoural gastric wall, 4 human gastric cancer cell lines from scirrhous gastric cancer (OCUM-2MD3 and OCUM-12), and non-scirrhous gastric cancer (MKN-45 and MKN-74) were used. Immunofluorescence microscopy by triple-immunofluorescence labelling (α-SMA, vimentin, and DAPI) was performed to determine the presence of α-SMA-positive myofibroblasts. Real-time RT-PCR was performed to examine α-SMA mRNA expression.
  
  
  RESULTS
  Immunofluorescence microscopy showed that the frequency of myofibroblasts in CaF-29 was greater than that in NF-29. The number of myofibroblasts in gastric fibroblasts gradually decreased with serial passages. Transforming growth factor-β (TGF-β) significantly increased the α-SMA expression level of CAFs. Conditioned medium from OCUM-2MD3 or OCUM-12 cells upregulated the α-SMA expression level of CAFs, but that from MKN-45 or MKN-74 cells did not. The α-SMA upregulation effect of conditioned medium from OCUM-2MD3 or OCUM-12 cells was significantly decreased by an anti-TGF-β antibody or Smad2 siRNA.
  
  
  CONCLUSIONS
  Transforming growth factor-β from scirrhous gastric carcinoma cells upregulates the number of myofibroblasts in CAFs.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fuyuhiro
authors.forename: M
authors.initials: M
authors.lastname: Yashiro
authors.forename: S
authors.initials: S
authors.lastname: Noda
authors.forename: S
authors.initials: S
authors.lastname: Kashiwagi
authors.forename: J
authors.initials: J
authors.lastname: Matsuoka
authors.forename: Y
authors.initials: Y
authors.lastname: Doi
authors.forename: Y
authors.initials: Y
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Sawada
authors.forename: K
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D002293:Adenocarcinoma, Scirrhous / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D015153:Blotting, Western; D017077:Culture Media, Conditioned / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051899:Smad2 Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D017077:Culture Media, Conditioned; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D016212:Transforming Growth Factor beta