In vitro differentiation of epithelial cells from cervical neoplasias resembles in vivo lesions.

Cell lines derived from cervical neoplasias, as well as cells from normal cervix and neonatal foreskin were examined in an in vitro culture system (raft system) that allows for stratification and differentiation of epithelial cells at an air-liquid interface. Epithelial cells from human foreskin and ectocervix were observed to differentiate in a manner histologically similar to normal epithelium in vivo as indicated by a single layer of basal cells with a defined mid and upper zone. In contrast, cells expanded from cervical squamous carcinoma explants showed total absence of normal differentiation in the raft system with numerous cells in the upper portion of the stratum exhibiting mitotic figures. Cell cultures derived from low grade cervical intraepithelial neoplasia and condyloma acuminata exhibited partial differentiation in addition to perinuclear clearing, binucleate cells and individual cell keratinization. These studies show that in the raft system, cultured cells derived from tissue biopsies can duplicate many of the histological features observed in cervical neoplasias. In addition, epithelial cells derived from normal fetal ectocervix and electroporated with cloned human papillomavirus (HPV) type 16 DNA exhibited abnormal differentiation patterns similar to those of cervical intraepithelial neoplasia in vivo. This model system will thus be useful for examining the effects of HPV infection on epithelial maturation and for investigating the role of other factors in the progression of cervical malignancies.