Patterns of mRNA for epidermal growth factor receptor and keratin B-2 in normal cervical epithelium and in cervical intraepithelial neoplasia

Abstract

Patterns of epidermal growth factor receptor (EGFR) and keratin B-2 (KB2) mRNA localization were studied in samples of normal cervical squamous epithelium and in samples of cervical intraepithelial neoplasia (CIN). 35 S-Labeled EGFR and KB2 DNA probes were used for in situ hybridization on formalin-fixed tissue sections. Normal cervical squamous epithelium showed predominantly basal and parabasal expression of EGFR mRNA and suprabasal and midepithelial localization of KB2 mRNA. CIN lesions with moderate to severe dysplasia were generally characterized by continued expression of EGFR mRNA and decreased KB2 mRNA in midepithelial locations. Ratios of KB2 mRNA levels at the basal layer to KB2 mRNA levels at the midepithelial location were increased in moderate and severe dysplasia (CIN II and III) compared with normal epithelium ( P < .01). Ratios of EGFR mRNA levels at the midepithelial level to those of EGFR mRNA at the basal layer were increased in moderate to severe dysplasia compared with normal epithelium. These findings indicate a possible in vivo role of EGFR gene expression in normal and neoplastic proliferation and in prevention of differentiation of the cervical epithelium.