title: [Tumor microenvironment elicits primary resistance to afatinib through HGF secretion].
abstract: OBJECTIVE
  To observe the effects of hepatocyte growth factor (HGF) derived from tumor microenvironment and/or afatinib on the growth of human lung adenocarcinoma H1975 cells and explore the potential mechanisms by which HGF induces primary resistance to afatinib.
  
  
  METHODS
  The effects of HGF, TGF-α and afatinib on the growth of H1975 cells were evaluated by MTT assay. The HGF concentrations of normal human fetal lung fibroblasts MRC-5 cells and human lung adenocarcinoma H1975 cells co-cultured or separately cultured were determined by ELISA assay. Western blot was used to detect the expressions of EGFR and Met signal pathway-related proteins and epithelial-mesenchymal transition (EMT) markers in H1975 cells treated with HGF and/or afatinib.
  
  
  RESULTS
  The MTT assay showed that H1975 cells were hyposensitive to afatinib in the presence of HGF. The ELISA assay showed that HGF production by H1975 cells was less than 0.1 ng/2.0×10(6) cells, but HGF production by MRC-5 cells was (151.37 ± 2.07)ng/2.0×10(6) cells incubated for 48 h. When H1975 cells and MRC-5 cells were co-cultured for 72 h, the concentration of HGF in the culture supernatant was (61.13 ± 16.21)ng/ml. In the presence of HGF, the expression of p-Met, p-Akt and p-ERK proteins in the H1975 cells was markedly up-regulated. afatinib inhibited p-EGFR, but did not affect the expression of p-Met, p-Akt and p-ERK proteins. In the presence of afatinib, HGF up-regulated the expression of vimentin and down-regulated the expression of E-cadherin.
  
  
  CONCLUSIONS
  HGF secreted by stromal cells in the tumor micro-environment may confer resistance to afatinib in H1975 cells by activation of the Met/PI3K/Akt and Met/MAPK/ERK signaling pathways, and is involved in the epithelial-mesenchymal transition process.
authors.affiliation: Department of Oncology, Longhua Hospital Affiliated to Shanghai University of TCM, Shanghai 200032, China.
authors.forename: Xiao-hong
authors.initials: XH
authors.lastname: Kang
authors.affiliation: Department of Oncology, Longhua Hospital Affiliated to Shanghai University of TCM, Shanghai 200032, China.
authors.forename: Li-fang
authors.initials: LF
authors.lastname: Wang
authors.affiliation: Department of Oncology, Longhua Hospital Affiliated to Shanghai University of TCM, Shanghai 200032, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cao
authors.affiliation: Department of Oncology, Longhua Hospital Affiliated to Shanghai University of TCM, Shanghai 200032, China.
authors.forename: Fang-tian
authors.initials: FT
authors.lastname: Fan
authors.affiliation: Department of Oncology, Longhua Hospital Affiliated to Shanghai University of TCM, Shanghai 200032, China. Email: xuzhenye1947@126.com.
authors.forename: Zhen-ye
authors.initials: ZY
authors.lastname: Xu
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000077716:Afatinib; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition; D066246:ErbB Receptors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D017228:Hepatocyte Growth Factor / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008168:Lung / Q000166:cytology; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D016211:Transforming Growth Factor alpha / Q000494:pharmacology; D059016:Tumor Microenvironment; D014746:Vimentin / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D015820:Cadherins; D011799:Quinazolines; D016211:Transforming Growth Factor alpha; D014746:Vimentin; D000077716:Afatinib; D017228:Hepatocyte Growth Factor; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met; D051057:Proto-Oncogene Proteins c-akt