Endometrial Cancer Cells as Models to Study Uterine Receptivity

摘要

Endometrial estrogen and progesterone receptors mediate gene expression during the menstrual cycle' in all mammalian species. At the time of implantation, differential patterns of gene expression occur on both glandular and luminal (surface) epithelium. Glandular secretions appear to be essential for embryonic development and viability, whereas luminal epithelium may provide a site for attachment and subsequent invasion of the nascent embryo. We have characterized previously integrins and other extracellular matrix (ECM) molecules as differentiated markers of endometrial epithelium. Both luminal and glandular epithelium express constitutive alpha3beta1 and alpha6beta4 integrins and hormonally regulated alpha1beta1, alpha4beta1, alpha9beta1, and alphavbeta3. The glandular epithelium expresses hormonally regulated ECM glycoproteins, such as osteopontin. Luminal cells exhibit cycle-dependent patterns of other ct2fil and selectively express cytokeratin 13. Endometrial cancer cell lines have provided an excellent model to study normal endometrial epithelium. Of the many available cell lines, Ishikawa and ECC-1 cells maintain normal hormonal responsiveness to estrogen and progesterone, as well as to androgens. In this chapter, we review the potential of Ishikawa and ECC-1 cells as surrogate cells for normal endometrial epithelium and discuss their characteristics of glandular and luminal epithelia, respectively. Further characterization of these two cell lines may provide new insight into the mechanism of embryo implantation in humans and shed light on possible defects in endometrial receptivity.