scholarly journals Protein Kinase CαModulates Estrogen-Receptor-Dependent Transcription and Proliferation in Endometrial Cancer Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alicia M. Thorne ◽  
Twila A. Jackson ◽  
Van C. Willis ◽  
Andrew P. Bradford
Keyword(s):  
Estrogen Receptor ◽  
Endometrial Cancer ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Developed Countries ◽  
Critical Element ◽  
Estrogen Exposure ◽  
Cancer Cell Survival ◽  
Phosphoinositide 3 Kinase

Endometrial cancer is the most common invasive gynecologic malignancy in developed countries. The most prevalent endometrioid tumors are linked to excessive estrogen exposure and hyperplasia. However, molecular mechanisms and signaling pathways underlying their etiology and pathophysiology remain poorly understood. We have shown that protein kinase Cα(PKCα) is aberrantly expressed in endometrioid tumors and is an important mediator of endometrial cancer cell survival, proliferation, and invasion. In this study, we demonstrate that expression of active, myristoylated PKCαconferred ligand-independent activation of estrogen-receptor- (ER-) dependent promoters and enhanced responses to estrogen. Conversely, knockdown of PKCαreduced ER-dependent gene expression and inhibited estrogen-induced proliferation of endometrial cancer cells. The ability of PKCαto potentiate estrogen activation of ER-dependent transcription was attenuated by inhibitors of phosphoinositide 3-kinase (PI3K) and Akt. Evidence suggests that PKCαand estrogen signal transduction pathways functionally interact, to modulate ER-dependent growth and transcription. Thus, PKCαsignaling, via PI3K/Akt, may be a critical element of the hyperestrogenic environment and activation of ER that is thought to underlie the development of estrogen-dependent endometrial hyperplasia and malignancy. PKCα-dependent pathways may provide much needed prognostic markers of aggressive disease and novel therapeutic targets in ER positive tumors.

scholarly journals Estrogen-independent molecular actions of mutant estrogen receptor alpha in endometrial cancer

2018 ◽  
Author(s):  
Zannel Blanchard ◽  
Jeffery M. Vahrenkamp ◽  
Kristofer C. Berrett ◽  
Spencer Arnesen ◽  
Jason Gertz
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endometrial Cancer ◽  
Cancer Cells ◽  
Estrogen Receptor Alpha ◽  
Chromatin Accessibility ◽  
Large Set ◽  
Regulatory Changes ◽  
Estrogen Exposure ◽  
Independent Mutant

AbstractEstrogen receptor 1 (ESR1) mutations have been identified in hormone therapy resistant breast cancer and primary endometrial cancer. Analyses in breast cancer suggests that mutant ESR1 exhibits estrogen independent activity. In endometrial cancer, ESR1 mutations are associated with worse outcomes and less obesity, however experimental investigation of these mutations has not been performed. Using a unique CRISPR/Cas9 strategy, we introduced the D538G mutation, a common endometrial cancer mutation that alters the ligand binding domain of ESR1, while epitope tagging the endogenous locus. We discovered estrogen-independent mutant ESR1 genomic binding that is significantly altered from wildtype ESR1. The D538G mutation impacted expression, including a large set of non-estrogen regulated genes, and chromatin accessibility, with most affected loci bound by mutant ESR1. Mutant ESR1 is unique from constitutive ESR1 activity as mutant-specific changes are not recapitulated with prolonged estrogen exposure. Overall, D538G mutant ESR1 confers estrogen-independent activity while causing additional regulatory changes in endometrial cancer cells that are distinct from breast cancer cells.

Lupeol Inhibits Proliferation and Promotes Apoptosis of Ovarian Cancer Cells by Inactivating Phosphoinositide-3-Kinase/Protein Kinase B/ Mammalian Target of Rapamycin Pathway

2020 ◽  
Vol 19 (2) ◽  
pp. 206-210
Author(s):  
Feng Chen ◽  
Bei Zhang
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Protein Kinase ◽  
Cell Viability ◽  
Cancer Cells ◽  
Protein Kinase B ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Ovarian Cancer Cells ◽  
Phosphoinositide 3 Kinase

Lupeol exhibits multiple pharmacological activities including, anticancerous, anti-inflammatory, and antioxidant. The aim of this study was to explore the anticancerous activity of lupeol on ovarian cancer cells and examine its mechanism of action. To this end, increasing concentrations of lupeol on cell viability, cell cycle, and apoptosis in Caov-3 cells were evaluated. Lupeol inhibited cell viability, induced G1 phase arrest in cell cycle, increased cell apoptosis, and inhibited the ratio of phospho-Akt/protein kinase B and phospho-mammalian target of rapamycin/mammalian target of rapamycin. In conclusion, these data suggest that lupeol may play a therapeutic role in ovarian cancer.

Estrogen receptor-mediated effects of tamoxifen on human endometrial cancer cells

2002 ◽  
Vol 192 (1-2) ◽  
pp. 93-104 ◽  
Author(s):  
Takako Sakamoto ◽  
Hidetaka Eguchi ◽  
Yoko Omoto ◽  
Takuya Ayabe ◽  
Hiroyuki Mori ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Endometrial Cancer ◽  
Cancer Cells ◽  
Mediated Effects

scholarly journals Protein kinase C-independent stimulation of activator protein-1 and c-Jun N-terminal kinase activity in human endometrial cancer cells by the LHRH agonist triptorelin

2001 ◽  
pp. 651-658 ◽  
Author(s):  
C Grundker ◽  
L Schlotawa ◽  
V Viereck ◽  
G Emons
Keyword(s):  
Cell Proliferation ◽  
Endometrial Cancer ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Fold Increase ◽  
Lhrh Agonist ◽  
Activator Protein 1 ◽  
Kinase C ◽  
Lhrh Receptor

OBJECTIVE: The expression of luteinizing hormone-releasing hormone (LHRH) and its receptor as a part of an autocrine regulatory system of cell proliferation has been demonstrated in a number of human malignant tumours, including cancers of the endometrium. The signalling pathway through which LHRH acts in endometrial cancer is distinct from that in pituitary gonadotrophs. The LHRH receptor interacts with the mitogenic signal transduction of growth factor receptors via activation of a phosphotyrosine phosphatase, resulting in down-regulation of cancer cell proliferation. In addition, LHRH activates nucleus factor kappaB (NFkappaB) and protects the cancer cells from apoptosis. This study was conducted to investigate additional signalling mechanisms of the LHRH receptor cooperating with NFkappaB in endometrial cancer cells. DESIGN: The LHRH agonist triptorelin-induced activator protein-1 (AP-1) activation was analysed using a pAP-1-SEAP reporter gene assay. Expression of c-jun mRNA was quantified using quantitative reverse transcription (RT)-PCR. c-Jun N-terminal kinase (JNK) activity was measured by quantification of phosphorylated c-Jun protein. RESULTS: Treatment of Ishikawa and Hec-1A human endometrial cancer cells with 100 nM triptorelin resulted in a 3.1-fold and 3.5-fold activation of AP-1 respectively (P<0.05). If the cells had been made quiescent, treatment with triptorelin (100 nM) resulted in a 41.7-fold and 48.6-fold increase of AP-1 activation respectively (P<0.001). This effect was completely blocked by simultaneous treatment with pertussis toxin (PTX). A 17.6-fold and 17.3-fold increase of c-jun mRNA expression respectively (P<0.001) was obtained after 20 min of stimulation with triptorelin (100 nM). Treatment with 1 nM triptorelin resulted in a 12.5-fold or an 11.9-fold increase, and treatment with 10 pM triptorelin resulted in a 6.5-fold or a 5.2-fold increase of maximal c-jun mRNA expression respectively (P<0.001). Maximal c-Jun phosphorylation (68.5-fold and 60.2-fold, respectively, P<0.001) was obtained after 90 min incubation with triptorelin (100 nM). CONCLUSIONS: These results suggest that the LHRH agonist triptorelin stimulates the activity of AP-1 in human endometrial cancer cells mediated through PTX-sensitive G-protein alphai. In addition, triptorelin activates JNK, known to activate AP-1. In earlier investigations we have shown that triptorelin does not activate phospholipase and protein kinase C (PKC) in endometrial cancer cells. In addition, it has been demonstrated that triptorelin inhibits growth factor-induced mitogen activated protein kinase (MAPK, ERK) activity. Thus triptorelin-induced activation of the JNK/AP-1 pathway in endometrial cancer cells is independent of the known AP-1 activators, PKC or MAPK (ERK).

scholarly journals Cancer Endometrium: An Update

2012 ◽  
Vol 4 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Piyush Kumar ◽  
Jai Kishan Goel
Keyword(s):  
Endometrial Cancer ◽  
Gynecological Cancer ◽  
Preoperative Staging ◽  
Abnormal Uterine Bleeding ◽  
Developed Countries ◽  
Endometrial Biopsy ◽  
External Beam Radiation ◽  
Beam Radiation ◽  
Estrogen Exposure ◽  
Cardinal Symptom

ABSTRACT Endometrial cancer is the most common gynecological cancer in developed countries and second most common in developing countries. Its incidence is increasing in postmenopausal women. Factors related to chronic estrogen exposure are associated with a higher incidence. Abnormal uterine bleeding is the cardinal symptom. All women with suspected endometrial cancer require transvaginal ultrasonography and most will undergo endometrial biopsy; more sophisticated radiological examinations are required for preoperative staging. The general approach for treatment of endometrial cancer is hysterectomy, bilateral salpingo-oophorectomy, abdominopelvic washings, lymph node evaluation and maximal surgical cytoreduction for those with advanced disease. Postoperative adjuvant therapy [vaginal brachytherapy, external beam radiation therapy (RT), chemotherapy] may be recommended depending on the estimated risk of recurrence. Individual patient characteristics and surgical as well as pathologic staging are the main factors that are used for postsurgical risk stratification, which in turn, directs the selection of adjuvant treatment. How to cite this article Goel JK, Kumar P. Cancer Endometrium: An Update. J South Asian Feder Obst Gynae 2012;4(2):75-84.

scholarly journals Nuclear upregulation of PI3K p110β correlates with increased rRNA transcription in endometrial cancer cells

2019 ◽  
Author(s):  
Fatemeh Mazloumi Gavgani ◽  
Thomas Karlsson ◽  
Ingvild L Tangen ◽  
Andrea Papdiné Morovicz ◽  
Victoria Smith Arnesen ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Pi3k Pathway ◽  
Clinical Samples ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Cytoplasmic Staining ◽  
Ec Cells

AbstractGenes encoding for components of the phosphoinositide 3-kinase (PI3K) pathway are frequently mutated in cancer, including inactivating mutations of PTEN and activating mutations of PIK3CA, encoding the PI3K catalytic subunit p110α. PIK3CB, encoding p110β, is rarely mutated, but can contribute to tumourigenesis in some PTEN-deficient tumours. The underlying molecular mechanisms are however poorly understood. By analysing cell lines and annotated clinical samples, we have previously found that p110β is highly expressed in endometrial cancer (EC) cell lines and that PIK3CB mRNA levels increase early in primary tumours correlating with lower survival. Selective inhibition of p110α and p110β led to different effects on cell signalling and cell function, p110α activity being correlated to cell survival in PIK3CA mutant cells and p110β with cell proliferation in PTEN-deficient cells. To understand the mechanisms governing the differential roles of these isoforms, we assessed their sub-cellular localisation. p110α was cytoplasmic whereas p110β was both cytoplasmic and nuclear with increased levels in both compartments in cancer cells. Immunohistochemistry of p110β in clinically annotated patient tumour sections revealed high nuclear/cytoplasmic staining ratio, which correlated significantly with higher grades. Consistently, the presence of high levels of p110β in the nuclei of EC cells, correlated with high levels of its product phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) in the nucleus. Using immunofluorescence labelling, we observed both p110β and PtdIns(3,4,5)P3 in the nucleoli of EC cell lines. The production of nucleolar PtdIns(3,4,5)P3 was dependent upon p110β activity. EC cells with high levels of nuclear PtdIns(3,4,5)P3 and p110β showed elevated nucleolar activity as assessed by the increase in 47S pre-rRNA transcriptional levels in a p110β-dependent manner. Altogether, these results present a nucleolar role for the PI3K pathway that may contribute to tumour progression in endometrial cancer.

Calcineurin regulates the stability and activity of estrogen receptor α

2021 ◽  
Vol 118 (44) ◽  
pp. e2114258118
Author(s):  
Takahiro Masaki ◽  
Makoto Habara ◽  
Yuki Sato ◽  
Takahiro Goshima ◽  
Keisuke Maeda ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
The Stability ◽  
Positive Breast Cancer

Estrogen receptor α (ER-α) mediates estrogen-dependent cancer progression and is expressed in most breast cancer cells. However, the molecular mechanisms underlying the regulation of the cellular abundance and activity of ER-α remain unclear. We here show that the protein phosphatase calcineurin regulates both ER-α stability and activity in human breast cancer cells. Calcineurin depletion or inhibition down-regulated the abundance of ER-α by promoting its polyubiquitination and degradation. Calcineurin inhibition also promoted the binding of ER-α to the E3 ubiquitin ligase E6AP, and calcineurin mediated the dephosphorylation of ER-α at Ser294 in vitro. Moreover, the ER-α (S294A) mutant was more stable and activated the expression of ER-α target genes to a greater extent compared with the wild-type protein, whereas the extents of its interaction with E6AP and polyubiquitination were attenuated. These results suggest that the phosphorylation of ER-α at Ser294 promotes its binding to E6AP and consequent degradation. Calcineurin was also found to be required for the phosphorylation of ER-α at Ser118 by mechanistic target of rapamycin complex 1 and the consequent activation of ER-α in response to β-estradiol treatment. Our study thus indicates that calcineurin controls both the stability and activity of ER-α by regulating its phosphorylation at Ser294 and Ser118. Finally, the expression of the calcineurin A–α gene (PPP3CA) was associated with poor prognosis in ER-α–positive breast cancer patients treated with tamoxifen or other endocrine therapeutic agents. Calcineurin is thus a promising target for the development of therapies for ER-α–positive breast cancer.

Cisplatin increases B-cell-lymphoma-2 expression via activation of protein kinase C and Akt2 in endometrial cancer cells

2011 ◽  
Vol 130 (8) ◽  
pp. 1755-1767 ◽  
Author(s):  
Alexandre Rouette ◽  
Sophie Parent ◽  
Julie Girouard ◽  
Valérie Leblanc ◽  
Eric Asselin
Keyword(s):  
Endometrial Cancer ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
B Cell ◽  
Cancer Cells ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Kinase C

scholarly journals GH-Releasing Hormone Induces Cardioprotection in Isolated Male Rat Heart via Activation of RISK and SAFE Pathways

Endocrinology ◽  
2013 ◽  
Vol 154 (4) ◽  
pp. 1624-1635 ◽  
Author(s):  
Claudia Penna ◽  
Fabio Settanni ◽  
Francesca Tullio ◽  
Letizia Trovato ◽  
Pasquale Pagliaro ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Reperfusion Injury ◽  
Molecular Mechanisms ◽  
Male Rat ◽  
Signal Transducer ◽  
Rat Hearts ◽  
Phosphoinositide 3 Kinase ◽  
Amp Activated Protein Kinase ◽  
Transcription 3 ◽  
Isolated Rat

Abstract GHRH stimulates GH synthesis and release from the pituitary and exerts direct effects in extrapituitary tissues. We have previously shown that pretreatment with GHRH reduces cardiomyocyte apoptosis and improves heart function in isolated rat hearts subjected to ischemia/reperfusion (I/R). Here, we determined whether GHRH given at reperfusion reduces myocardial reperfusion injury and investigated the molecular mechanisms involved in GHRH effects. Isolated rat hearts subjected to I/R were treated at the onset of reperfusion with: 1) GHRH; 2) GHRH+GHRH antagonist JV-1-36; 3) GHRH+mitochondrial ATP-dependent potassium channel inhibitor 5-hydroxydecanoate; 4) GHRH+mitochondrial permeability transition pore opener atractyloside; 5) GHRH+ phosphoinositide 3-kinase/Akt inhibitor Wortmannin (WM); and 6) GHRH+signal transducer and activator of transcription-3 inhibitor tyrphostin-AG490 (AG490). GHRH reduced infarct size at the end of reperfusion and reverted contractility dysfunction in I/R hearts. These effects were inhibited by either JV-1-36, 5-hydroxydecanoate, atractylosid, WM, or AG490. Western blot analysis on left ventricles showed GHRH-induced phosphorylation of either the reperfusion injury salvage kinases (RISK), phosphoinositide 3-kinase/Akt, ERK1/2, and glycogen synthase kinase-3β or signal transducer and activator of transcription-3, as part of the survivor activating factor enhancement (SAFE) pathway. GHRH-induced activation of RISK and SAFE pathways was blocked by JV-1-36, WM, and AG490. Furthermore, GHRH increased the phosphorylation of endothelial nitric oxide synthase and AMP-activated protein kinase and preserved postischemic nicotinamide adenine dinucleotide (NAD+) levels. These results suggest that GHRH protects the heart from I/R injury through receptor-mediated mechanisms, leading to activation of RISK and SAFE pathways, which converge on mitochondria and possibly on AMP-activated protein kinase.

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