The in Vitro Interaction of Intraepithelial Neoplasia, Normal Epithelium, and Fibroblasts from the Adult Human Uterine Cervix1

The interaction of tissue-cultured cells derived from normal squamous epithelium, normal connective tissue, and intraepithelial neoplasia of the adult human uterine cervix was studied using phase-contrast time-lapse cinematography. The fibroblasts exhibited typical, passive, contact inhibition to other fibroblasts but not to the normal epithelial cells or cells from intraepithelial neoplasia. The normal epithelial cells grew as an adherent sheet and exhibited an active type of contact inhibition with other nor mal cells but no contact inhibition in association with fibroblasts or neoplastic cells. The cells derived from intraepithelial neoplasia behaved in a manner intermediate between those derived from normal epithelium and those derived from invasive carcinoma. In these cells there was a striking lack of adhesiveness and an absence of contact inhibition, but no actual invasion of normal epithelium or fibroblasts was observed, and the cells remained essentially as a monolayer. It was suggested that the term "contact inhibition" not be used alone in describing these