title: Comparing the expression of integrins αvβ3, αvβ5, αvβ6, αvβ8, fibronectin and fibrinogen in human brain metastases and their corresponding primary tumors.
abstract: OBJECTIVE
  To evaluate the expression of αv-series integrins in brain metastases. Inhibitors targeting these integrins are being tested for their therapeutic potential.
  
  
  METHODS
  The extracellular regions of the αvβ3, αvβ5, αvβ6, αvβ8, the cytoplasmic domain of β3, the αv-chain, and the ECM molecules fibronectin and fibrinogen were studied immunohistochemically in a series of 122 carcinoma and 60 melanomas metastatic to the central nervous system. In addition, 38 matched primary and metastatic tumors to the brain were compared directly.
  
  
  RESULTS
  The αv-subunit was generally moderately to highly expressed in most tumors. αvβ3 and cytoplasmic β3 were weakly to moderately detectable in metastatic renal cell carcinomas and melanomas, αvβ5 was prominently expressed in metastatic renal and colorectal carcinomas, αvβ6 was most abundantly detectable in metastatic lung adenocarcinomas, but absent in melanomas. The tumor associated vessels in CNS metastases consistently expressed αvβ3, αvβ5, αv-, fibronectin and fibrinogen, however, mostly at low levels, while αvβ6, αvβ8 were lacking in vasculature. The comparative analysis of 38 matched primary tumors and brain metastases showed comparable levels of expression only for αvβ3 and αvβ8, while αvβ6 and αvβ5 were higher in primaries.
  
  
  CONCLUSIONS
  We confirmed that integrin expression exhibits considerable heterogeneity according to tumor origin. αvβ5 is the most promising target for integrin targeted treatment in brain metastases.
authors.affiliation: Department of Neuropathology, Institute of Pathology and Neuropathology, University of Tübingen Tübingen 72076, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Schittenhelm
authors.forename: Annemarie
authors.initials: A
authors.lastname: Klein
authors.forename: Marcos S
authors.initials: MS
authors.lastname: Tatagiba
authors.forename: Richard
authors.initials: R
authors.lastname: Meyermann
authors.forename: Falko
authors.initials: F
authors.lastname: Fend
authors.forename: Simon L
authors.initials: SL
authors.lastname: Goodman
authors.forename: Bence
authors.initials: B
authors.lastname: Sipos
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D001932:Brain Neoplasms / Q000737:chemistry* / Q000556:secondary; D002277:Carcinoma / Q000737:chemistry* / Q000556:secondary; D005260:Female; D005340:Fibrinogen / Q000032:analysis*; D005353:Fibronectins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D039302:Integrin alphaVbeta3 / Q000032:analysis*; D016023:Integrins / Q000032:analysis*; D008297:Male; D008545:Melanoma / Q000737:chemistry* / Q000556:secondary; D011379:Prognosis; D019030:Receptors, Vitronectin / Q000032:analysis*; D012878:Skin Neoplasms / Q000737:chemistry* / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D005353:Fibronectins; D039302:Integrin alphaVbeta3; D016023:Integrins; D019030:Receptors, Vitronectin; C064660:integrin alphaVbeta5; C073878:integrin alphavbeta6; C403414:integrin alphavbeta8; D005340:Fibrinogen
keywords: Integrins; alphav; metastases; prognosis