No abstract

To examine the sex steroid-dependent growth mechanisms of the human endometrium, the expression of steroid receptor coactivators [steroid receptor coactivator-1 (SRC-1) and p300/CREB-binding protein (p300/CBP)] and corepressors (nuclear receptor corepressor and silencing mediator for retinoid and thyroid hormone receptors) was examined by immunohistochemistry, using 50 samples of normal endometria, and was compared with that of estrogen receptors (ER), progesterone receptors (PR), and proliferation marker Ki-67. In addition, actual binding of the coactivators to ER or PR was analyzed by immunoprecipitation. The expression of SRC-1 was diffusely observed in glandular and stromal cells in the proliferative phase and drastically decreased in the secretory phase. Such change in the expression pattern of SRC-1 resembled that of ER, PR, and Ki-67. On the other hand, p300/CBP expression was relatively constant throughout the menstrual cycle, with slight predominance in the proliferative phase. The expression of corepressors nuclear receptor corepressor and silencing mediator for retinoid and thyroid hormone receptors was focal in the endometrium. Immunoprecipitation, using tissue samples of both proliferative and secretory phases, revealed the complex formation between the coactivators and receptors. Binding of SRC-1 to ER was observed in the proliferative (but not in the secretory) endometrium. In contrast, binding p300/CBP to ER was noted in the endometria of both phases. Complex formation between p300/CBP and PR was noted in the secretory endometrium, whereas that between SRC-1 and PR was not apparent. Accordingly, we showed the expression pattern of steroid receptor coactivators and corepressors in the normal endometrium. Cyclic change in the expression of SRC-1 during the menstrual cycle might be important in the estrogen-action for the glandular and stromal cells.

Thin palladium membranes of different thicknesses were prepared on sol‐gel derived mesoporous γ‐alumina/α‐alumina and yttria‐stabilized zirconia/α‐alumina supports by a method combining sputter deposition and electroless plating. The effect of metal‐support interface on hydrogen transport permeation properties was investigated by comparing hydrogen permeation data for these membranes measured under different conditions. Hydrogen permeation fluxes for the Pd/γ‐Al2O3/α‐Al2O3 membranes are significantly smaller than those for the Pd/YSZ/α‐Al2O3 membranes under similar conditions. As the palladium membrane thickness increases, the difference in permeation fluxes between these two groups of membranes decreases and the pressure exponent for permeation flux approaches 0.5 from 1. Analysis of the permeation data with a permeation model shows that both groups of membranes have similar hydrogen permeability for bulk diffusion, but the Pd/γ‐Al2O3/α‐Al2O3 membranes exhibit a much lower surface reaction rate constant with higher activation energy, due possibly to the formation of Pd‐Al alloy, than the Pd/YSZ/α‐Al2O3 membranes. © 2009 American Institute of Chemical Engineers AIChE J, 2009

To examine estrogen-induced growth mechanisms of endometrial carcinoma, we investigated the estrogen-induced activation of the mitogen-activated protein kinase (MAPK) pathway and cell cycle regulators. Estradiol (E 2 ) treatment at concentrations of 10 K8 M and 10 K6 M to estrogen receptor (ER)-positive endometrial carcinoma Ishikawa cells for 24 h resulted in increased cell proliferation by 20% and 28% respectively. The E 2 -induced proliferation was associated with the activation of extracellular signal-regulated kinase (MAPK)3/1 and up-regulation of cyclin D1 and E, which were suppressed by the addition of an MAP2K inhibitor (U0126) or an ER antagonist (ICI 182 780). Then, our screening for estrogen-inducible growth factors identified that IGF1 was up-regulated remarkably by E 2 . Immunoprecipitation using conditioned medium of Ishikawa cells after E 2 treatment confirmed the E 2 -induced secretion of IGF1 protein. Treatment with recombinant IGF1 stimulated cell proliferation in a dose-dependent fashion, in association with MAPK3/1 phosphorylation and up-regulation of cyclin D1 and E. These IGF1-induced responses were suppressed by treatment with MAP2K inhibitor or anti-IGF1 receptor antibody. Immunohistochemical staining confirmed the expression of activated MAPK3/1 in normal proliferative phase endometria and endometrial carcinomas, indicating the involvement of this pathway in actively proliferating endometrial tissues in vivo. These findings suggest that E 2 -induced proliferation of endometrial carcinoma cells is mediated by the MAPK3/1 pathway via autocrine stimulation of IGF1.

Although endometriosis is primarily benign, it has been identified as a risk factor for endometriosis-associated ovarian cancer (EAOC). Genetic alterations in ARID1A, PTEN, and PIK3CA have been reported in EAOC; however, an appropriate EAOC animal model has yet to be established. Therefore, the present study aimed to create an EAOC mouse model by transplanting uterine pieces from donor mice, in which Arid1a and/or Pten was conditionally knocked out (KO) in Pax8-expressing endometrial cells by the administration of doxycycline (DOX), onto the ovarian surface or peritoneum of recipient mice. Two weeks after transplantation, gene KO was induced by DOX and endometriotic lesions were thereafter removed. The induction of only Arid1a KO did not cause any histological changes in the endometriotic cysts of recipients. In contrast, the induction of only Pten KO evoked a stratified architecture and nuclear atypia in the epithelial lining of all endometriotic cysts, histologically corresponding to atypical endometriosis. The induction of Arid1a; Pten double-KO evoked papillary and cribriform structures with nuclear atypia in the lining of 42 and 50% of peritoneal and ovarian endometriotic cysts, respectively, which were histologically similar to EAOC. These results indicate that this mouse model is useful for investigating the mechanisms underlying the development of EAOC and the related microenvironment.