title: Matrix metalloproteinase-26 is present more frequently in squamous cell carcinomas of immunosuppressed compared with immunocompetent patients.
abstract: BACKGROUND
  Skin cancers are the most frequent malignancies in organ transplant recipients (OTRs). Squamous cell carcinomas (SCCs) occur 65-250 times more frequently in OTRs and tend to be aggressive in behavior. Because matrix metalloproteinases (MMPs) have a central role in tumorigenesis and invasion, we investigated the epithelial and stromal MMP and tissue inhibitor of MMP (TIMP) expression profile in SCCs of immunosuppressed (IS) compared with immunocompetent (IC) patients to determine if differences could explain the more aggressive behavior of SCCs in OTRs.
  
  
  METHODS
  Matched pairs from 20 SCCs of IS and IC patients were studied using immunohistochemistry for MMP-1, MMP-7, MMP-8, MMP-9, MMP-13 and MMP-26 and TIMP-1 and TIMP-3.
  
  
  RESULTS
  Among all MMPs studied, only staining for MMP-26 was significantly more intense in cancer cells of the post-transplant group compared with the IC group (p = 0.01), whereas MMP-9 expression was more abundant in stromal macrophages surrounding SCCs of IC patients (p = 0.02). MMP-26 expression in cancer cells (p = 0.04) and that of MMP-9 in neutrophils (p = 0.005) were more abundant in SCCs of patients using cyclosporine.
  
  
  CONCLUSIONS
  We conclude that MMP-26 and MMP-9 may contribute to the more aggressive behavior of SCCs in OTRs.
authors.affiliation: Department of Dermatology, Helsinki University Central Hospital and Biomedicum, University of Helsinki, Helsinki, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Kuivanen
authors.forename: Leila
authors.initials: L
authors.lastname: Jeskanen
authors.forename: Lauri
authors.initials: L
authors.lastname: Kyllönen
authors.forename: Keiichi
authors.initials: K
authors.lastname: Isaka
authors.forename: Ulpu
authors.initials: U
authors.lastname: Saarialho-Kere
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000276:immunology*; D006084:Graft Rejection / Q000517:prevention & control; D006801:Humans; D016867:Immunocompromised Host; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis; D053509:Matrix Metalloproteinase 13 / Q000096:biosynthesis; D020783:Matrix Metalloproteinase 7 / Q000096:biosynthesis; D020784:Matrix Metalloproteinase 8 / Q000096:biosynthesis; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D053505:Matrix Metalloproteinases, Secreted / Q000096:biosynthesis*; D008875:Middle Aged; D012878:Skin Neoplasms / Q000201:enzymology* / Q000276:immunology*; D019715:Tissue Inhibitor of Metalloproteinase-1; D019717:Tissue Inhibitor of Metalloproteinase-3
chemical_list: D007166:Immunosuppressive Agents; D019715:Tissue Inhibitor of Metalloproteinase-1; D019717:Tissue Inhibitor of Metalloproteinase-3; C410599:MMP26 protein, human; D053509:Matrix Metalloproteinase 13; D053505:Matrix Metalloproteinases, Secreted; D020783:Matrix Metalloproteinase 7; D020784:Matrix Metalloproteinase 8; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1