Human papilloma virus (HPV)-E6/E7 and epidermal growth factor receptor (EGF-R) protein levels in cervical cancer and cervical intraepithelial neoplasia (CIN).

Abstract

About 90% of cervical cancers and advanced cervical intraepithelial neoplasia (CIN II/III) are squamous epithelial cells with mRNA for human papillomavirus (HPV)16 and 18 and up-regulated epidermal growth factor receptor (EGF-R). Since presence of proteins rather than mRNA may be truly indicative of active infection or disease progression, establishing reliable methods for quantifying these proteins in cervical biopsies is important. We have established an objective semi-quantitative immunofluorescent antibody assay to reliably assess the levels of HPV-E6/E7 and EGF-R proteins in the cervical biopsies from 12 normal women, five women with CIN I, 15 with CIN II/III and ten with cervical cancer. HPV-E6/E7 and EGF-R, when present, were specific to para-basal, basal and squamous epithelial cells (negative in stromal cells). Nine of ten women with cervical cancer and 15 (14 CIN II/III; 1 CIN I) of 20 women with CIN were positive for HPV-E6/E7. All 12 controls were HPV-negative. The controls and six women with CIN (four with CIN I) negative for HPV had low levels of EGF-R. The only exception was one woman with cervical cancer negative for HPV, with high levels of EGF-R. Levels of HPV-E6/E7 and EGF-R were significantly higher (P < 0.001 vs. controls) in women with advanced CIN II and III (P< 0.05 vs. controls in CIN I) and cervical cancer. The HPV-E6/E7 and EGF-R levels correlated significantly (r = 18.98; P < 0.001, by linear regression analysis). We have established a highly specific and sensitive semi-quantitative immunofluorescent antibody assay for measuring levels of HPV-E6/E7 proteins and EGF-R in archival cervical biopsies. Our data suggest an association between HPV-E6/E7 and EGF-R.