title: Erk1/2 activation in stromal fibroblasts from sporadic basal cell carcinomas.
abstract: BACKGROUND
  Constitutive activation of the Erk pathway can lead to oncogenic transformation. However, the Erk pathway is not activated in human basal cell carcinomas (BCCs); although in animal models, this seems to be important.
  
  
  OBJECTIVE
  To help understand the role of Erk activity in BCC formation.
  
  
  METHODS
  The authors assayed the specific levels of phosphorylated Erk by immunohistochemistry in BCCs and normal skin biopsies. They have also analyzed Erk activation by immunoblot in fibroblasts isolated from BCC.
  
  
  RESULTS
  By immunohistochemical analysis, the authors have observed that 10 of BCCs (56%) did not show phosphor-Erk staining in tumor masses and 7 (40%) showed a gradient staining exhibiting phospho-Erk only in the epidermal side of tumor masses. Remarkably, 15 BCC samples (83%) showed phospho-Erk accumulation in stroma. Six of the 9 independent cultures of dermal fibroblasts isolated from BCC maintained Erk activation "in vitro."
  
  
  CONCLUSIONS
  The authors propose that there is a specific cell-type regulation of Erk activity in BCC, and this feature may be relevant during BCC formation. Stroma region from BCCs showed Erk activation and reduced proliferation. Conversely, Erk activation is barely detectable in proliferative BCCs.
authors.affiliation: *Cell Cycle Unit, Institute of Biomedical Research of Lleida (IRB Lleida), Lleida, Spain; †Department of Medicine, University of Lleida, Lleida, Spain; ‡Department of Basic Medical Sciences, University of Lleida, Lleida, Spain; §Department of Pathology, Hospital Universitari Arnau de Vilanova, Lleida, Spain.
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Aguayo
authors.forename: Marta
authors.initials: M
authors.lastname: Rafel
authors.forename: Maria
authors.initials: M
authors.lastname: Santacana
authors.forename: Noel P
authors.initials: NP
authors.lastname: Fusté
authors.forename: Eloi
authors.initials: E
authors.lastname: Garí
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000201:enzymology*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D020935:MAP Kinase Signaling System; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000032:analysis / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000032:analysis / Q000378:metabolism*; D010766:Phosphorylation; D012867:Skin / Q000201:enzymology; D012878:Skin Neoplasms / Q000201:enzymology*; D014407:Tumor Cells, Cultured
chemical_list: D019394:Ki-67 Antigen; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3