Modulation of implantation-associated integrin expression but not uteroglobin by steroid hormones in an endometrial cell line

In order to test the hypothesis that integrin and uteroglobin (UG) expression in cultured endometrial cells are affected by hormone treatment, Ishikawa-CH endometrial cancer cells were cultured and exposed to oestradiol or oestradiol and progesterone regimens and assayed using immunohistochemistry. We evaluated the intensity of immunohistochemical staining for the integrin monomers α_v and β₁, the dimers α_vβ₃ and α_vβ₆, and for the secretory protein uteroglobin under various experimental conditions. Cells grown in control media stained positively for the integrin monomers α_vand β₃ the dimer α_vβ₃, and for UG. Oestradiol and sequential oestradiol/progesterone reversibly suppressed staining for the dimer α_vβ₃. Hormone treatment had no effect on the staining of the β₁ and α_v monomers or UG. The α_vβ₆ dimer antibody did not stain under any experimental treatment conditions. These data indicate that expression of the integrin complex α_vβ₃ is reversibly suppressed by oestradiol in Ishikawa cells and that these cells may be a good model for studying hormone-driven molecular changes in endometrium.