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.
Department of Veterinary Pathology, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada.
A N
AN
Al-Dissi
D M
DM
Haines
B
B
Singh
B A
BA
Kidney
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