Pickart, M.A., S. J. Liliensiek, A. Aumock, K. N. Reagans, P. M. Harari, and B. L. Allen-Hoffmann. Use of Green Fluorescent Protein in a Human Organotypic Stratifying Squamous Epithelium for Molecular and Pharmacological Studies of Normal and Malignant Epithelial Growth. The Toxicologist 1999. 48(1S): 76. Abstract #355.

We have developed a novel organotypic in vitro model for the study of normal and malignant human squamous epithelial cell proliferation and pharmacological response. This model utilizes expression of green fluorescent protein (GFP) in transfected epithelial cells to identify and isolate cells within an organotypic stratifying squamous epithelium. Prototypic non-malignant and malignant cell lines, BC-1-Ep/SL and SCC13y, respectively, have been developed which stably express GFP. GFP-labeled SCC13y cells (GFP13y) grown in mixed cultures with unlabeled BC-1-Ep/SL cells, do not appear to effect the normal stratification of BC-1-Ep/SL cells in organotypic cultures. Individual and groups of GFP13y cells are visualized in frozen standard skin differentiation and proliferation markers such as involucrin and PCNA. Data observed in studies using confocal microscopy and flow cytometry are also presented which demonstrate the growth of GP13Y cells over a period of 5-15 days in organotypic culture. This model has potential broad use with all types of stratified epithelia and associated tumors (oral cavity, cervix, trachea, cornea) and melanoma. We believe it is a particularly valuable to screen for efficacy of pharmacological agents on normal and malignant epithelia cultured in a context which maintains the cell interactions present in functioning human epithelial tissue. By entirely reconstructing human epithelial cell growth within a tissue-like environment, epithelial cell growth characteristics can be monitored in a physiologically relevant context. Preliminary data characterizing the radiation response and antiproliferative response of a set of standard chemotherapeutic agents are described herein. We believe this approach may provide a more accurate assessment of epithelial cell proliferation kinetic and prove to be a valuable tool for the pharmacological studies.