Immunohistochemical expression of vascular endothelial growth factor and vascular endothelial growth factor receptor associated with tumor cell proliferation in canine cutaneous squamous cell carcinomas and trichoepitheliomas.
The expression of 5 markers associated with angiogenesis was studied in canine squamous cell carcinomas (SCCs) (n = 19) and canine trichoepitheliomas (TCPs) (n = 24). SCCs were assigned histologic grades, and tissue sections from both tumor types were immunohistochemially stained for the expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGFR-2), as well as intratumoral microvessel density (iMVD), tumor proliferation index (PI), and tumor apoptotic index (AI), using antibodies against VEGF, VEGFR-2, von Willebrand's factor, Ki-67 antigen, and the terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate end-labeling method (TUNEL), respectively. VEGF and VEGFR-2 were detected in 17/19 (89.4%) and 19/19 (100%) SCCs and in 17/24 (70.8%) and 20/24 (83.3%) TCPs, respectively. In SCCs, there was substantial correlation between histologic grade and PI (r = 0.51); and moderate correlation between VEGF and histologic grade (r = 0.43), VEGFR-2 and histologic grade (r = 0.47), VEGF and PI (r = 0.47), and VEGFR-2 and PI (r = 0.47) (Spearman rank correlation coefficient). In TCPs, there was substantial correlation between VEGF and PI (r = 0.51) and a moderate correlation between VEGFR-2 and iMVD (r = 0.36). The median iMVD of SCCs (15.5) was significantly higher than the median iMVD of TCPs (9.05) (P value < .05). It was concluded that VEGF and VEGFR-2 may promote tumor cell proliferation in TCPs and SCCs. An autocrine pathway for VEGF probably operates in canine SCCs and TCPs, as VEGF and VEGFR-2 expression was found in most tumors and was associated with evidence for tumor cell proliferation.
Al-Dissi
A N
AN
Department of Veterinary Pathology, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada.
Haines
D M
DM
Singh
B
B
Kidney
B A
BA
D000818:Animals; D015415:Biomarkers; D002277:Carcinoma / Q000098:blood supply / Q000378:metabolism / Q000662:veterinary*; D002294:Carcinoma, Squamous Cell / Q000098:blood supply / Q000378:metabolism / Q000662:veterinary*; D049109:Cell Proliferation; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D005786:Gene Expression Regulation; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000662:veterinary; D040262:Receptors, Vascular Endothelial Growth Factor / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*; D014841:von Willebrand Factor / Q000378:metabolism
D015415:Biomarkers; D019394:Ki-67 Antigen; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; D040262:Receptors, Vascular Endothelial Growth Factor