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Query: UMLS:C0476089 (endometrial cancer)
11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gonadotropin-releasing hormone type II (GnRH-II) has an antiproliferative effect on human endometrial cancer cells. Apoptosis in cancer cells may play a critical role in regulating cell proliferation. However, more studies are necessary to elucidate the underlying molecular mechanisms and develop potential applications of GnRH-II. Therefore, we explored the mechanisms of GnRH-II-induced apoptosis and the effects of GnRH-II on GADD45alpha activation in human endometrial cancer cell lines. GnRH-II decreased cell viability in a dose- and time-dependent manner. Apoptosis was induced with increased terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling apoptotic cells after GnRH-II treatment. Knockdown of the endogenous GnRH-I receptor with small interfering RNA (siRNA) rescued the cells from GnRH-II-mediated cell growth inhibition and abolished the induction of apoptosis. GnRH-II activated extracellular signal-regulated kinase (ERK)-1/2 and p38 mitogen-activated protein kinase (MAPK) in a time-dependent manner, and the activation was abolished by GnRH-I receptor siRNA and MAPK inhibitors. Cells pretreated with MAPK inhibitors were rescued from GnRH-II-mediated cell growth inhibition. Moreover, both inhibitors abolished GnRH-II-induced apoptosis. GnRH-II induced GADD45alpha expression, which was abolished by knockdown of endogenous GnRH-I receptors and MAPK inhibitors. GnRH-II-stimulated cell growth inhibition was rescued by knockdown of endogenous GADD45alpha with siRNA. Cells treated with GADD45alpha siRNA were refractory to GnRH-II-induced apoptosis. Thus, GnRH-II inhibits cell growth by inducing apoptosis through binding of the GnRH-I receptor, activation of the ERK1/2 and p38 MAPK pathways, and induction of GADD45alpha signaling. This finding may provide a new concept relating to the mechanism of GnRH-II-induced antiproliferation and apoptosis in endometrial cancer cells, indicating the possibility of GnRH-II as a promising therapeutic intervention for human endometrial cancer.
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PMID:Gonadotropin-releasing hormone type II induces apoptosis of human endometrial cancer cells by activating GADD45alpha. 1936 94

In the oncogenic process, cell growth control plays a crucial role, and growth factor receptors and their signaling pathways are known to be altered in endometrial cancer, mostly in type I carcinomas. Two main pathways are involved in transmitting the proliferative signal from the membrane receptors to the nucleus: phosphatydil-inositol-3-kinase-protein kinase B-mammalian target of rapamycin and RAS-RAF-ERK pathways. A final effector of these signaling cascades is the cap-dependent mRNA translation initiation complex, which is negatively regulated by 4E-BP1. The aim of our work was to study the relative importance of the factors involved in these pathways and to see their correlation with the clinicopathologic features of the tumors and their prognosis. We studied 120 endometrial carcinomas, including 93 type I and 27 type II carcinomas, and 18 control cases. Tissue microarrays were constructed and immunohistochemistry was performed for HER2, p53, and the phosphorylated forms of protein kinase B, extracellular signal-regulated kinase, and 4E-BP1. HER2 was overexpressed in 11% of carcinomas but not in control cases, and 30% of carcinomas showed activation of protein kinase B and extracellular signal-regulated kinase, mostly in type II carcinomas. The phosphorylated form of 4E-BP1 was found to be cytoplasmic in 31% of cases, and in 63% of cases it showed nuclear expression; the latter was only found in carcinomas. p53 positivity was found in type II and in grade 3 type I carcinomas. This nuclear expression of phospho-4E-BP1 and HER2 overexpression were the only characteristics with prognostic significance. The activation of the signaling pathways that control cell growth is a common event in endometrial carcinomas. 4E-BP1 is a downstream effector of these pathways whose activation status correlates with aggressive phenotypes and prognosis. This factor can reflect the activity of these pathways, regardless of the upstream molecular alterations, and, therefore, it can be a hallmark of the transmission of the oncogenic signal to the nucleus.
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PMID:Cell signaling in endometrial carcinoma: phosphorylated 4E-binding protein-1 expression in endometrial cancer correlates with aggressive tumors and prognosis. 1942 47

The regulatory mechanism of endometrial carcinoma and the signal transduction pathways involved in hormone action are poorly defined. It has become apparent that the G protein-coupled receptor (GPR) 30 mediates the non-genomic signaling of 17beta-estradiol (E2). Here we show that GPR30 is highly expressed in endometrial cancer tissues and cancer cell lines and positively regulates cell proliferation and invasion. GPR30 expression was detected in 50 human endometrial carcinomas. The transcription level of GPR30 was significantly higher in the tissue of endometrial carcinoma than in normal endometrium (P < 0.05). Immunohistochemical assays revealed that the positive expression rate of GPR30 protein in endometrial carcinoma tissue (35/50, 70%) was statistically higher than in normal endometrium tissue (8/30, 26.67%) (chi2 = 14.16, P = 0.0002). GPR30 overexpression was correlated with high-grade endometrial carcinoma. GPR30 expression was also found in two human endometrial cancer cell lines: RL95-2 (estrogen receptor positive) and KLE (estrogen receptor negative). The roles of GPR30 in proliferative and invasive responses to E2 and G1, a non-steroidal GPR30-specific agonist, in RL95-2 and KLE cell lines were then explored. We showed that E2 and G1 could initiate the MAPK/ERK mitogen-activated protein kinase pathway in both cell lines. What's more, E2 and G1 promoted KLE and RL95-2 proliferation and stimulated matrix metalloproteinase production and activity via the GPR30-mediated MEK/ERK mitogen-activated protein kinase pathway, as well as increased interleukin-6 secretion. These findings suggest that GPR30-mediated non-genomic signaling could play an important role in endometrial cancer.
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PMID:Estrogenic G protein-coupled receptor 30 signaling is involved in regulation of endometrial carcinoma by promoting proliferation, invasion potential, and interleukin-6 secretion via the MEK/ERK mitogen-activated protein kinase pathway. 1943 2

There is increasing evidence that prolactin (PRL), a hormone/cytokine, plays a role in breast, prostate, and colorectal cancers via local production or accumulation. Elevated levels of serum PRL in ovarian and endometrial cancers have been reported, indicating a potential role for PRL in endometrial and ovarian carcinogenesis. In this study, we show that serum PRL levels are significantly elevated in women with a strong family history of ovarian cancer. We show dramatically increased expression of PRL receptor in ovarian and endometrial tumors as well as in endometrial hyperplasia, signifying the importance of PRL signaling in malignant and premalignant conditions. PRL mRNA was expressed in ovarian and endometrial tumors, indicating the presence of an autocrine loop. PRL potently induced proliferation in several ovarian and endometrial cancer cell lines. Binding of PRL to its receptor was followed by rapid phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, mitogen-activated protein kinase/ERK kinase 1, signal transducer and activator of transcription 3, CREB, ATF-2, and p53 and activation of 37 transcription factors in ovarian and endometrial carcinoma cells. PRL also activated Ras oncogene in these cells. When human immortalized normal ovarian epithelial cells were chronically exposed to PRL, a malignant transformation occurred manifested by the acquired ability of transformed cells to form clones, grow in soft agar, and form tumors in severe combined immunodeficient-beige mice. Transformation efficiency was diminished by a Ras inhibitor, providing proof that PRL-induced transformation uses the Ras pathway. In summary, we present findings that indicate an important role for PRL in ovarian and endometrial tumorigenesis. PRL may represent a risk factor for ovarian and endometrial cancers.
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PMID:Biological significance of prolactin in gynecologic cancers. 1949 Dec 63

Estrogens and selective estrogen receptor (ER) modulators such as tamoxifen are known to increase uterine cell proliferation. Mounting evidence suggests that estrogen signaling is mediated not only by ERalpha and ERbeta nuclear receptors, but also by GPR30 (GPER), a seven transmembrane (7TM) receptor. Here, we report that primary human endometriotic H-38 cells express high levels of GPR30 with no detectable ERalpha or ERbeta. Using a novel tamoxifen analogue, STX, which activates GPR30 but not ERs, significant stimulation of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways was observed in H-38 cells and in Ishikawa endometrial cancer cells expressing GPR30; a similar effect was observed in JEG3 choriocarcinoma cells. STX treatment also increased cellular pools of phosphatidylinositol (3,4,5) triphosphate, a proposed ligand for the nuclear hormone receptor SF-1 (NR5A1). Consistent with these findings, STX, tamoxifen, and the phytoestrogen genistein were able to increase SF-1 transcription, promote Ishikawa cell proliferation, and induce the SF-1 target gene aromatase in a GPR30-dependent manner. Our findings suggest a novel signaling paradigm that is initiated by estrogen activation of the 7TM receptor GPR30, with signal transduction cascades (PI3K and MAPK) converging on nuclear hormone receptors (SF-1/LRH-1) to modulate their transcriptional output. We propose that this novel GPR30/SF-1 pathway increases local concentrations of estrogen, and together with classic ER signaling, mediate the proliferative effects of synthetic estrogens such as tamoxifen, in promoting endometriosis and endometrial cancers.
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PMID:Stimulating the GPR30 estrogen receptor with a novel tamoxifen analogue activates SF-1 and promotes endometrial cell proliferation. 1954 22

The link between estrogen and metabolic developmental factors of endometrial carcinoma is well established. PPAR- gamma, (an important modulator of metabolism) and estrogen receptor belong to a family of nuclear hormone receptors that were shown to interact with each other. The interaction may affect transcriptional activity of these transcription factors. The anti-diabetic troglitazone (TGZ) is well known PPAR- gamma ligand. The effect of troglitazone-induced PPAR- gamma activation on estrogen-dependent stimulation of collagen biosynthesis was studied in the Ishikawa endometrial adenocarcinoma cell line. We have found that the presence of estrogen activity in growth medium (1nM) augmented collagen biosynthesis in the cells. An addition of PPAR- gamma agonists, as troglitazone or clofibrat to the growth medium induced inhibition of collagen biosynthesis. The inhibition was effective only when estrogen receptor was stimulated, since removal of estrogen receptor by ICI 182- 780-dependent degradation did not affect collagen biosynthesis. The mechanism of the inhibition was found at the level of NF-kB (known inhibitor of collagen gene expression) and MAPK signaling. PPAR- gamma ligands stimulated expression of NF-kB, while they inhibited expression of p-38 but not ERK1/ERK2. The data document for the first time that inhibitory effect of PPAR- gamma ligands on collagen biosynthesis in endometrial adenocarcinoma cells requires functional estrogen receptor.
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PMID:Estrogen-dependent regulation of PPAR-gamma signaling on collagen biosynthesis in adenocarcinoma endometrial cells. 1958 Mar 48

Reduced E-cadherin expression is associated with tumour progression of many carcinomas, including endometrial cancers. The transcription factor Snail is known as one of the most prominent transcriptional E-cadherin repressors; its regulation in cancer tissues, however, still remains unclear. Here, we report that activation of epidermal growth factor receptor (EGFR) resulted in overexpression of Snail and also identified critical downstream signalling molecules. Stimulation of two endometrial carcinoma cell lines with epidermal growth factor (EGF) lead to an increase of Snail protein expression. In primary human endometrioid endometrial carcinomas Snail protein expression correlated with the activated, phosphorylated form of EGFR (Tyr1086) as revealed by profiling 24 different signalling proteins using protein lysate microarrays. In addition, we observed an inverse correlation between Snail and E-cadherin protein levels in these tumours. Most likely, p38 MAPK, PAK1, AKT, ERK1/2 and GSK-3beta are involved in the up-regulation of Snail downstream of EGFR. Snail mRNA expression did not show a correlation with activated EGFR in these tumours. Taken together, profiling of signalling proteins in primary human tissues provided strong evidence that EGFR signalling is involved in Snail protein overexpression.
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PMID:Activation of epidermal growth factor receptor results in snail protein but not mRNA overexpression in endometrial cancer. 1960 15

Endometrial carcinoma is the most common neoplasm of the female genital tract, accounting for nearly one half of all gynecologic cancers in the Western world. Although intensive research on pathological phenomena of endometrial cancer is currently going on, but exact cause and biological aspects of this disease are not well described yet. In addition to well-documented roles of gonadotropin-releasing hormone (GnRH) in hypopituitary ovarian (HPO) axis, the agonistic or antagonistic analogs (or both) of GnRH have been shown to inhibit the proliferation of a variety of human gynecologic cancers. Thus, in the present study, we further examined the possibility that GnRH induces integrin beta3 and activation of focal adhesion kinase (FAK) through mitogen-activated protein kinases (MAPKs), ERK1/2 and p38, to inhibit the growth of HEC1A endometrial cancer cell line. As a result, both GnRH-I and GnRH-II resulted in a significant increase in integrin beta3 expression and evoked the activation of FAK in a time-dependent manner in these cells. In addition, these analogs induced an activation of ERK1/2 and p38 MAPK in a time-dependent manner as downstream pathways of FAK. It appears that GnRH-II has much greater effect on the activation of FAK, ERK1/2 and p38 compared to GnRH-I in these cells. Further, we demonstrated that the growth inhibition of HEC1A cells by GnRH-I or GnRH-II is involved in the activation of integrin-FAK and ERK1/2 and p38 MAPK pathways. Taken together, these results suggest that GnRH may be involved in the inhibition of endometrial cancer cell growth via activation of integrin beta3 and FAK as a direct effect. This knowledge could contribute to a better understanding of the mechanisms implicated in the therapeutic action of GnRH and its biomedical application for the treatment against endometrial cancer.
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PMID:Gonadotropin-releasing hormone (GnRH)-I and GnRH-II induce cell growth inhibition in human endometrial cancer cells: involvement of integrin beta3 and focal adhesion kinase. 1965 90

Expression of Migration inducting gene-7 (Mig-7) is limited to tumor cells and to date not found in normal tissues. Multiple tumor microenvironment factors, such as epidermal and hepatocyte growth factors, in concert with alphavbeta5 integrin ligation, induce Mig-7 mRNA expression. Gain or loss of Mig-7 protein studies shows that Mig-7 promotes invasion of colon and endometrial carcinoma cells. These data led us to hypothesize that targeting Mig-7 through various methods could decrease invasion, enhance monocyte cell killing of tumor cells, and inhibit disease progression. To begin testing this hypothesis, an in vitro chemoinvasion assay of endometrial carcinoma cells treated with Mig-7-specific or control antibodies was used. Mig-7 antibody significantly reduced invasion by >60% compared with controls. In another approach to test this hypothesis, an in vitro analysis of peptide-stimulated human peripheral blood monocyte cells and their killing of MCF-7 breast carcinoma cells was used. Mig-7 peptide treatment increased monocyte cell tumor necrosis factor expression and killing of MCF-7 cells 30-fold over no peptide stimulation and 3-fold over MUC-1 or control peptide treatments. Furthermore, stably expressing Mig-7-specific short hairpin RNA resulted in significantly reduced Mig-7 protein levels and early primary tumor growth in a xenograft nude mouse model. Reduced phosphorylation of ERK1/2, Akt, and S6 kinase as well as decreased membrane-type 1 matrix metalloproteinase activity were mechanisms through which Mig-7 protein caused these effects. Based on these collective data, Mig-7 expression could be a potential candidate for future targeted cancer therapies.
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PMID:Targeting migration inducting gene-7 inhibits carcinoma cell invasion, early primary tumor growth, and stimulates monocyte oncolytic activity. 1967 48

Insulin receptor (IR) and type 1 insulin-like growth factor receptor (IGF-IR) can assemble heteromerically as a hybrid insulin/IGF-I receptor (hybrid-R) in tissues that express both molecules. There is little information about hybrid-R in endometrial carcinoma, in which both IR and IGF-IR are frequently overexpressed. We used immunoprecipitation to detect hybrid-R expression in two endometrial carcinoma cell lines: HEC-1a, which has low estrogen receptor (ER) expression, and Ishikawa, which is positive for ER expression. To explore the role of hybrid-R in endometrial carcinoma cells, we examined phosphorylation of extracellular signal-regulated kinase (ERK1/2), which is a key molecule in the mitogen-activated protein kinase (MAPK) pathway. The effect of inhibiting IGF-I, IGF-II, and insulin on cell cycle progression and apoptosis was assessed by flow cytometry. Both cell lines expressed hybrid-R, and HEC-1a cells had higher expression levels than did Ishikawa cells. IGF-I induced ERK1/2 phosphorylation in HEC-1a cells mainly through hybrid-R; in Ishikawa cells, this effect was mediated only in part by hybrid-R. Insulin stimulated ERK1/2 phosphorylation partly through hybrid-R in HEC-1a cells, but not in Ishikawa cells. Both IGFs and insulin increased cellular DNA content in the S phase of the cell cycle in HEC-1a through hybrid-R. In contrast, in Ishikawa cells, only insulin enhanced DNA content in S phase through hybrid-R. Both IGFs and insulin significantly decreased apoptosis in HEC-1a cells through hybrid-R, and a similar but moderate effect was observed in Ishikawa cells. Hybrid-R, which is present in endometrial carcinoma cells, may have an important role in mediating IGF- and insulin-induced cell growth and in preventing apoptosis.
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PMID:The expression and role of hybrid insulin/insulin-like growth factor receptor type 1 in endometrial carcinoma cells. 2062 May 97


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