Leading-edge myofibroblasts in human colon cancer express plasminogen activator inhibitor-1.
Plasminogen activator inhibitor-1 (PAI-1) is up-regulated strongly in various cancer tissues, including colon cancer tissue. Highly specific rabbit polyclonal antibodies against PAI-1 were used for immunohistochemical localization of PAI-1 in 12 invasive colorectal adenocarcinomas. PAI-1 immunoreactivity was observed in endothelial cells of some vessels located in the submucosa and in several fibroblast-like cells located at the invasive front. No PAI-1 immunoreactivity was seen in cancer cells in any of the 12 cases. Double immunofluorescence using the PAI-1 antibodies together with antibodies against alpha-smooth muscle actin for myofibroblast/smooth muscle cells and CD34 for endothelial cells showed that more than 80% of the PAI-1-positive fibroblast-like cells in all 12 cases were myofibroblasts. In 4 of 12 cases, a few of the PAI-1-positive fibroblast-like cells in the invasive front were CD34+. We conclude that the majority of PAI-1-positive fibroblast-like cells located at the leading edge of the invasive colon cancers are myofibroblasts.
Finsen Laboratory, Copenhagen, Denmark.
Martin
M
Illemann
Ulla
U
Hansen
Hans Jørgen
HJ
Nielsen
Peter A
PA
Andreasen
Gunilla
G
Høyer-Hansen
Leif R
LR
Lund
Keld
K
Danø
Boye Schnack
BS
Nielsen
D000199:Actins / Q000378:metabolism; D000230:Adenocarcinoma / Q000098:blood supply / Q000378:metabolism / Q000473:pathology*; D018952:Antigens, CD34 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D003110:Colonic Neoplasms / Q000098:blood supply / Q000378:metabolism / Q000473:pathology*; D042783:Endothelial Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D032342:Muscle Cells / Q000378:metabolism* / Q000473:pathology; D009130:Muscle, Smooth / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis
D000199:Actins; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger