Increased expression of angiogenic factors in human colonic angiodysplasia.
OBJECTIVE
Angiodysplasia of the colon is a distinct vascular abnormality characterized by focal accumulation of ectatic vessels in the mucosa and submucosa. To investigate whether angiogenesis contributes to the pathogenesis of human colonic angiodysplasia, we examined the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), and its endothelial cell receptors flt-1 and KDR.


METHODS
Immunohistochemistry was performed in sections of specimens obtained from 18 patients with colonic angiodysplasia and from eight patients with colon cancer and its adjacent, histologically normal margins of resection. We used affinity-purified rabbit polyclonal antibodies and a streptoavidin-biotin peroxidase method.


RESULTS
We detected strong immunoreactivity for vascular endothelial growth factor, homogeneously distributed in the endothelial lining of blood vessels of all sizes in 16 (89%) specimens of colonic angiodysplasia and in seven (88%) patients with colon cancer. In contrast, very limited immunoreactivity was found in normal colon. Vascular staining for flt-1 was observed in eight (44%) and one (12.5%) of the colonic angiodysplasia or colon cancer specimens, respectively, but not in normal colon. Vascular immunoreactivity for basic fibroblast growth factor was observed in seven (39%) specimens from patients with colonic angiodysplasia, whereas either very limited or no immunostaining was found in sections from specimens of patients with colon cancer and its normal margins.


CONCLUSIONS
In human colonic angiodysplasia, increased expression of angiogenic factors is likely to play a pathogenic role.
Junquera
F
F
Pathology Department, Hospital General Vall d'Hebron, Autonomous University of Barcelona, Spain.
Saperas
E
E
de Torres
I
I
Vidal
M T
MT
Malagelada
J R
JR
D000230:Adenocarcinoma / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D016888:Angiodysplasia / Q000378:metabolism*; D000818:Animals; D016022:Case-Control Studies; D003106:Colon / Q000098:blood supply*; D003110:Colonic Neoplasms / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000096:biosynthesis*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis*; D006801:Humans; D007124:Immunoenzyme Techniques; D008222:Lymphokines / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis; D017978:Receptors, Growth Factor / Q000096:biosynthesis; D011975:Receptors, Mitogen / Q000096:biosynthesis; D040262:Receptors, Vascular Endothelial Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D017978:Receptors, Growth Factor; D011975:Receptors, Mitogen; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor