Expression of vascular endothelial growth factor in canine mammary tumors.
Vascular endothelial growth factor (VEGF) is a dimeric protein that stimulates angiogenesis in vitro and in vivo by inducing endothelial cell proliferation and migration. In this immunohistochemical study, VEGF-immunolabeled cells were counted in a series of 10 benign and 40 malignant canine mammary tumors. The morphologic pattern of VEGF positivity (intensity of immunolabeling and VEGF granule size and distribution) was also evaluated. A low number of cells weakly positive for VEGF with few and small granules polarized to the luminal pole was detected in benign neoplasms. In contrast, in malignancies a high number of VEGF-positive cells had strong immunolabeling, often with large granules found diffusely in the cytoplasm. This level of immunolabeling was more pronounced in the less differentiated, more malignant phenotypes (grade 3). Macrophages, which can synthesize VEGF, were strongly positive. Stromal and myoepithelial cells were negative. VEGF data were correlated statistically with intratumoral microvessel density (number of newly formed microvessels) and both measures were greater in less differentiated malignant neoplasms, demonstrating that angiogenesis and malignancy increase together. VEGF appears to be a powerful angiogenic factor in canine mammary tumors.
Dipartimento di Patologia e Sanità Animale, Settore Anatomia Patologica, Facoltà di Medicina Veterinaria, Università di Napoli, Italia.
B
B
Restucci
S
S
Papparella
P
P
Maiolino
G
G
De Vico
D000818:Animals; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D016228:Endothelial Growth Factors / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry / Q000662:veterinary; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics; D008222:Lymphokines / Q000096:biosynthesis* / Q000235:genetics; D015674:Mammary Neoplasms, Animal / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors