Vascular endothelial growth factor. Expression in human vulvar neoplastic and nonneoplastic tissues

To investigate the expression of vascular endothelial growth factor (VEGF) in human vulvar neoplastic and nonneoplastic tissues.

Specimens were collected at the Vulvovaginal Clinic, Department of Obstetrics and Gynecology, University of Milan. Human vulvar neoplastic and nonneoplastic tissues were dissected and frozen immediately at -80 degrees C until RNA extraction. Five micrograms of total RNA from each sample was denatured and transferred to nitrocellulose and nylon membranes for dot blot hybridization with labeled [alpha-32P]dCTP cDNA probe for VEGF.

Messenger RNA encoding VEGF was detected in all tissues studied. VEGF mRNA was highly expressed in vulvar epithelial neoplasia (VIN) associated with human papillomavirus infection and minimally expressed in invasive squamous cells carcinoma of the vulva. Nonneoplastic lesions, such as chronic inflammation, lichen sclerosus, lichen planus, squamous hyperplasia and squamous papilloma, were also assessed, and none had a significant difference in VEGF mRNA expression.

The prominence of VEGF mRNA levels in particular cases of VIN demonstrated that VEGF may be involved in promoting a new vascular network as a basic condition for the progression or at least self-maintenance of those lesions.