Cells closely resembling epithelia constitute the first specific cell type in a mammalian embryo. Many other cell types emerge via epithelial-mesenchymal differentiation. The transcription factors and signal transduction pathways involved in this differentiation are being elucidated. I have previously reported (Frisch, 1991) that adenovirus E1a is a tumor suppressor gene in certain human cell lines. In the present report, I demonstrate that E1a expression caused diverse human tumor cells (rhabdomyosarcoma, fibrosarcoma, melanoma, osteosarcoma) and fibroblasts to assume at least two of the following epithelial characteristics: (a) epithelioid morphology; (b) epithelial-type intercellular adhesion proteins localized to newly formed junctional complexes; (c) keratin-containing intermediate filaments; and (d) down-regulation of non-epithelial genes. E1a thus appeared to partially convert diverse human tumor cells into an epithelial phenotype. This provides a new system for molecular analysis of epithelial-mesenchymal interconversions. This effect may also contribute to E1a's tumor suppression activity, possibly through sensitization to anoikis (Frisch, S.M., and H. Francis, 1994. J. Cell Biol. 124:619-626).
Article| November 15 1994
E1a induces the expression of epithelial characteristics.
S M Frisch
La Jolla Cancer Research Foundation, La Jolla, California 92037.
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1994) 127 (4): 1085–1096.
S M Frisch; E1a induces the expression of epithelial characteristics.. J Cell Biol 15 November 1994; 127 (4): 1085–1096. doi: https://doi.org/10.1083/jcb.127.4.1085
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