Is Estrogen a Cellular Signal for Female Genital Tract Epithelium?
In vivo, the vagina and uterus, and their respective epithelial linings, are considered to be estrogen target structures. As a result of classical endocrinological studies, their dependence on estrogen for growth and differentiation is considered axiomatic. In vitro, primary cultures of epithelial cells from the vagina and uterus, grown in collagen gel matrix in a serum-free medium, proliferate independently of the presence of added estrogen. Addition of estrogen to these primary cultures does not stimulate epithelial cell proliferation, even in suboptimal conditions, but rather retards their growth. The estrogen receptor system of these cultured cells appears to be functionally intact, and the cells respond to estrogen addition by specific product synthesis (progestin receptors). Thus, estrogen has a direct modulative effect on cultured vaginal and uterine epithelia, but estrogen is not a directly-acting mitogen for these cells. It appears that stromal and possibly organismal factors are essential synergists and/or mediators for estrogen’s well-known mitogenic effect on female genital epithelia in vivo. Several alternative pathways for estrogen action on female genital epithelia are suggested.
KeywordsAlbumin Estrogen Trypsin Stratification Luminal
Unable to display preview. Download preview PDF.
- 4.Cunha, G.R. and Fujii, H., Stromal-parenchymal interactions in normal and abnormal development of the genital tract, In: Developmental Effects of Diethylstilbestrol (DES) in Pregnancy, A.L. Herbst and H.A. Bern, (eds.), Thieme-Stratton, New York (1981).Google Scholar
- 5.Gilchrest, B.A., Karassik, R.L., Wilkins, L.M., Vrabel, M.A., and Maciag, T., Autocrine and paracrine growth stimulation of cells derived from human skin, J. Cell. Physiol., 117:235–240.Google Scholar
- 7.Iguchi, T., Uchima, F.-D.A., Ostrander, P.L., Hamamoto, S.T., and Bern, H.A., Proliferation of normal mouse uterine luminal epithelial cells in serum-free collagen gel culture, Proc. Japan Acad., 61B:292 (1985).Google Scholar
- 14.Sirbasku, D.A., Ikeda, T., and Danielpour, D., Characterization of endocrine and autocrine mammary tumor cell growth factors, In: Growth and Differentiation of Cells in Defined Environment, H. Murakami., (eds.), Springer-Verlag, Berlin (1985).Google Scholar
- 18.Tsai, P.-S., Estrogen modulation of growth of mouse vaginal epithelium in cell and organ cultures, M.A. thesis in Zoology, University of California, Berkeley (1989).Google Scholar
- 19.Uchima, F.-D.A., Unpublished.Google Scholar