title: Ezrin-expressing lung adenocarcinoma cells and podoplanin-positive fibroblasts form a malignant microenvironment.
abstract: OBJECTIVE
  Cancer cells and cancer-associated fibroblasts (CAFs) together create the tumor microenvironment, which affects malignant behavior. Lung adenocarcinomas with CAFs expressing podoplanin (PDPN) are clinically aggressive, but the molecular mechanism underlying this phenomenon has not been established. So we identified the characteristic immunophenotype of lung adenocarcinoma cells coexisting with PDPN-expressing CAFs (PDPN-CAFs) and examined how it relates to an aggressive clinicopathological outcome.
  
  
  METHODS
  We analyzed the clinicopathological characteristics of 119 adenocarcinomas with a uniform size (2-3 cm). The expression levels of ten invasiveness-related proteins which related to cell adhesion and invasiveness, such as Ezrin, were examined in cancer cells from PDPN-CAFs (+) cases and from PDPN-CAFs (-) cases (n = 20 each). To examine the functional importance of the identified protein on the invasion phenotype, we performed wound healing and a Matrigel invasion assay using shRNA-knockdown lung adenocarcinoma cells (PC-9).
  
  
  RESULTS
  The PDPN-CAFs (+) cases had significantly higher rates of node metastasis (p < 0.01) and vascular invasion (p < 0.01). The cancer cells from the PDPN-CAFs (+) cases also had a significantly higher staining score for Ezrin (p < 0.01) than those from the PDPN-CAFs (-) cases. The migration and invasion activities of the shEzrin-induced PC-9 cells were significantly lower than those of the control cells.
  
  
  CONCLUSIONS
  Our results indicated that within a tumor microenvironment composed of PDPN-CAFs, increased Ezrin expression in cancer cells might play a key role in the invasiveness of lung adenocarcinoma.
authors.affiliation: Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Suzuki
authors.forename: Genichiro
authors.initials: G
authors.lastname: Ishii
authors.forename: Rie
authors.initials: R
authors.lastname: Matsuwaki
authors.forename: Shinya
authors.initials: S
authors.lastname: Neri
authors.forename: Hiroko
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Chisako
authors.initials: C
authors.lastname: Yamauchi
authors.forename: Keiju
authors.initials: K
authors.lastname: Aokage
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hishida
authors.forename: Junji
authors.initials: J
authors.lastname: Yoshida
authors.forename: Mitsutomo
authors.initials: M
authors.lastname: Kohno
authors.forename: Kanji
authors.initials: K
authors.lastname: Nagai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002465:Cell Movement; D049109:Cell Proliferation; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D008207:Lymphatic Metastasis; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D011379:Prognosis; D014407:Tumor Cells, Cultured; D059016:Tumor Microenvironment; D014945:Wound Healing; D000099149:Ezrin; D000098853:Podoplanin
chemical_list: D014408:Biomarkers, Tumor; D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; D000099149:Ezrin; C117468:PDPN protein, human; D000098853:Podoplanin