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Qi Y, Li L, Wei Y, Ma F. PP2A as a potential therapeutic target for breast cancer: Current insights and future perspectives. Biomed Pharmacother 2024; 173:116398. [PMID: 38458011 DOI: 10.1016/j.biopha.2024.116398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 03/10/2024] Open
Abstract
Breast cancer has become the most prevalent malignancy worldwide; however, therapeutic efficacy is far from satisfactory. To alleviate the burden of this disease, it is imperative to discover novel mechanisms and treatment strategies. Protein phosphatase 2 A (PP2A) comprises a family of mammalian serine/threonine phosphatases that regulate many cellular processes. PP2A is dysregulated in several human diseases, including oncological pathologies, and plays a pivotal role in the initiation and progression of tumours. The role of PP2A as a tumour suppressor has been extensively studied, and its regulation can serve as a target for anticancer therapy. Recent studies have shown that PP2A is a tumour promotor. PP2A-mediated anticancer therapy may involve two opposing mechanisms: activation and inhibition. In general, the contradictory roles of PP2A should not be overlooked, and more work is needed to determine the molecular mechanism by which PP2A affects in tumours. In this review, the literature on the role of PP2A in tumours, especially in breast cancer, was analysed. This review describes relevant targets of breast cancer, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may lead to effective therapeutic strategies or influence drug development in breast cancer.
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Affiliation(s)
- Yalong Qi
- Department of Medical Oncology, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Chaoyang District, Pan jia yuan nan Road 17, Beijing 100021, China
| | - Lixi Li
- Department of Medical Oncology, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Chaoyang District, Pan jia yuan nan Road 17, Beijing 100021, China
| | - Yuhan Wei
- Department of Medical Oncology, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Chaoyang District, Pan jia yuan nan Road 17, Beijing 100021, China
| | - Fei Ma
- Department of Medical Oncology, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Chaoyang District, Pan jia yuan nan Road 17, Beijing 100021, China.
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Chakraborty A, Roy S, Chakraborty MP, Roy SS, Purkait K, Koley TS, Das R, Acharya M, Mukherjee A. Cytotoxic Ruthenium(II) Complexes of Pyrazolylbenzimidazole Ligands That Inhibit VEGFR2 Phosphorylation. Inorg Chem 2021; 60:18379-18394. [PMID: 34780170 DOI: 10.1021/acs.inorgchem.1c02979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Eight new ruthenium(II) complexes of N,N-chelating pyrazolylbenzimidazole ligands of the general formula [RuII(p-cym)(L)X]+ [where the ligand L is 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole (L1) substituted at the 4 position of the pyrazole ring by Cl (L2), Br (L3), or I (L4) and X = Cl- and I-] were synthesized and characterized using various analytical techniques. Complexes 1 and 3 were also characterized by single-crystal X-ray crystallography, and they crystallized as a monoclinic crystal system in space groups P21/n and P21/c, respectively. The complexes display good solution stability at physiological pH 7.4. The iodido-coordinated pyrazolylbenzimidazole ruthenium(II) p-cymene complexes (2, 4, 6, and 8) are more resistant toward hydrolysis and have less tendency to form monoaquated complexes in comparison to their chlorido analogues (1, 3, 5, and 7). The halido-substituted 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole ligands, designed as organic-directing molecules, inhibit vascular endothelial growth factor receptor 2 (VEGFR2) phosphorylation. In addition, the ruthenium(II) complexes display a potential to bind to DNA bases. The cytotoxicity profile of the complexes (IC50 ca. 9-12 μM for 4-8) against the triple-negative breast cancer cells (MDA-MB-231) show that most of the complexes are efficient. The lipophilicity and cellular accumulation data of the complexes show a good correlation with the cytotoxicity profile of 1-8. The representative complexes 3 and 7 demonstrate the capability of arresting the cell cycle in the G2/M phase and induce apoptosis. The inhibition of VEGFR2 phosphorylation with the representative ligands L2 and L4 and the corresponding metal complexes 3 and 7 in vitro shows that the organic-directing ligands and their complexes inhibit VEGFR2 phosphorylation. Besides, L2, L4, 3, and 7 inhibit the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and proto-oncogene tyrosine-protein kinase (Src), capable of acting downstream of VEGFR2 as well as independently. Compounds L2, L4, 3, and 7 have a lesser effect on ERK1/2 and more prominently affect Src phosphorylation. We extended the study for L2 and 3 in the Tg(fli1:gfp) zebrafish model and found that L2 is more effective in vivo compared to 3 in inhibiting angiogenesis.
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Cristóbal I, Torrejón B, Martínez-Useros J, Madoz-Gurpide J, Rojo F, García-Foncillas J. PP2A regulates signaling through hormonal receptors in breast cancer with important therapeutic implications. Biochim Biophys Acta Rev Cancer 2017; 1868:435-438. [PMID: 28916342 DOI: 10.1016/j.bbcan.2017.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/10/2017] [Accepted: 08/31/2017] [Indexed: 11/27/2022]
Abstract
The functional inhibition of protein phosphatase 2A (PP2A) has emerged in the last years as a common alteration in breast cancer that determines poor outcome and contributes to disease progression and aggressiveness. Furthermore, expression of estrogen receptor (ER) is a high relevant molecular event with key therapeutic implications in breast cancer, and androgen receptor (AR) signaling is involved in the pathogenesis of breast cancer and represents a novel target with crescent importance in this disease. In this review, we summarize the role of the tumor suppressor PP2A in modulating ER and AR signaling in breast cancer, the molecular mechanisms involved, and its biological and therapeutic impact.
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Affiliation(s)
- Ion Cristóbal
- Translational Oncology Division, Oncohealth Institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz", Madrid, Spain.
| | - Blanca Torrejón
- Translational Oncology Division, Oncohealth Institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz", Madrid, Spain
| | - Javier Martínez-Useros
- Translational Oncology Division, Oncohealth Institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz", Madrid, Spain
| | | | - Federico Rojo
- Pathology Department, IIS "Fundación Jiménez Diaz", Madrid, Spain.
| | - Jesús García-Foncillas
- Translational Oncology Division, Oncohealth Institute, IIS-Fundacion Jimenez Diaz, UAM, University Hospital "Fundacion Jimenez Diaz", Madrid, Spain.
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Lee YH, Morrison BL, Bottaro DP. Synergistic signaling of tumor cell invasiveness by hepatocyte growth factor and hypoxia. J Biol Chem 2015; 289:20448-61. [PMID: 24914205 DOI: 10.1074/jbc.m114.580597] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatocyte growth factor (HGF) signaling promotes tumor invasiveness in renal cell carcinoma (RCC) and other cancers. In clear cell RCC, VHL loss generates pseudohypoxia that exacerbates HGF-driven invasion through β-catenin deregulation. Hypoxia also enhances HGF-driven invasiveness by papillary RCC cells, but in the absence of VHL, loss signaling integration involves three parallel routes: 1) hypoxia-induced reactive oxygen species production and decreased DUSP2 expression, leading to enhanced mitogen-activated protein kinase (MAPK) cascade activation; 2) reactive oxygen species-induced diacylglycerol production by phospholipase Cγ, leading to protein kinase C activation and increased protein phosphatase- 2A activity, thereby suppressing HGF-induced Akt activation; and 3) a profound shift from HGF-enhanced, proliferation- oriented metabolism to autophagy-dependent invasion and suppression of proliferation. This tripartite signaling integration was not unique to RCC or HGF; in RCC cells, invasive synergy induced by the combination of hypoxia and epidermal growth factor occurred through the same mechanism, and in estrogen receptor-positive breast cancer cells, this mechanism was suppressed in the absence of estrogen. These results define the molecular basis of growth factor and hypoxia invasive synergy in VHL-competent papillary RCC cells, illustrate the plasticity of invasive and proliferative tumor cell states, and provide signaling profiles by which they may be predicted.
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Zhang H, Liu J, Zhao X, Liang B, Wen Z, Li M. Loss of PP2A and PTEN immunoexpression coexists with survivin overexpression in adenomyosis. Reprod Biol 2014; 14:200-5. [DOI: 10.1016/j.repbio.2014.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 04/22/2014] [Accepted: 04/24/2014] [Indexed: 10/25/2022]
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Choi YA, Koo JS, Park JS, Park MY, Jeong AL, Oh KS, Yang Y. Estradiol enhances CIP2A expression by the activation of p70 S6 kinase. Endocr Relat Cancer 2014; 21:189-202. [PMID: 24280132 DOI: 10.1530/erc-13-0453] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cancerous inhibitor of PP2A (CIP2A) stimulates the proliferation of various cancer cells, and 17β-estradiol (E₂) enhances the proliferation of breast cancer cells. E₂ activates epidermal growth factor receptor (EGFR), stimulating the MEK1/2 and PI3K pathways, and CIP2A expression is increased by the MEK1/2-induced transcription factor ETS1. It is possible for E₂ to increase CIP2A expression. This study examined whether E₂ could increase CIP2A expression and whether CIP2A is highly expressed in estrogen receptor (ER)-positive breast cancer tissues. E₂ increased CIP2A expression at the translational level in a c-MYC-independent manner in MCF-7 cells. E₂-enhanced proliferation was impaired without CIP2A expression. E₂-stimulated EGFR activated the MAPK and PI3K pathways, which converged to activate p70 S6 kinase (S6K). Phosphorylation at all the three phosphorylation sites (S424/T421, T229, and T389) on S6K was required for the phosphorylation of eukaryotic initiation factor 4B (eIF4B), which was responsible for the increase in CIP2A translation. Furthermore, CIP2A expression was higher in ER-positive tissues than in ER-negative tissues. This is the first study, to our knowledge, to demonstrate that CIP2A is a key factor in E₂-enhanced proliferation and that estrogen regulates CIP2A expression by non-genomic action through EGFR.
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Affiliation(s)
- Yeon A Choi
- Department of Life Science, Research Center for Women's Disease, Sookmyung Women's University, Seoul 140-742, Republic of Korea Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea
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The exposure of breast cancer cells to fulvestrant and tamoxifen modulates cell migration differently. BIOMED RESEARCH INTERNATIONAL 2013; 2013:147514. [PMID: 23936773 PMCID: PMC3713599 DOI: 10.1155/2013/147514] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/10/2013] [Indexed: 12/28/2022]
Abstract
There is no doubt that there are increased benefits of hormonal therapy to breast cancer patients; however, current evidence suggests that estrogen receptor (ER) blockage using antiestrogens is associated with a small induction of invasiveness in vitro. The mechanism by which epithelial tumor cells escape from the primary tumor and colonize to a distant site is not entirely understood. This study investigates the effect of two selective antagonists of the ER, Fulvestrant (Fulv) and Tamoxifen (Tam), on the invasive ability of breast cancer cells. We found that 17β-estradiol (E2) demonstrated a protective role regarding cell migration and invasion. Fulv did not alter this effect while Tam stimulated active cell migration according to an increase in Snail and a decrease in E-cadherin protein expression. Furthermore, both tested agents increased expression of matrix metalloproteinases (MMPs) and enhanced invasive potential of breast cancer cells. These changes were in line with focal adhesion kinase (FAK) rearrangement. Our data indicate that the anti-estrogens counteracted the protective role of E2 concerning migration and invasion since their effect was not limited to antiproliferative events. Although Fulv caused a less aggressive result compared to Tam, the benefits of hormonal therapy concerning invasion and metastasis yet remain to be investigated.
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Jamshidi M, Schmidt MK, Dörk T, Garcia-Closas M, Heikkinen T, Cornelissen S, van den Broek AJ, Schürmann P, Meyer A, Park-Simon TW, Figueroa J, Sherman M, Lissowska J, Keong GTH, Irwanto A, Laakso M, Hautaniemi S, Aittomäki K, Blomqvist C, Liu J, Nevalinna H. Germline variation in TP53 regulatory network genes associates with breast cancer survival and treatment outcome. Int J Cancer 2013; 132:2044-55. [PMID: 23034890 PMCID: PMC4159753 DOI: 10.1002/ijc.27884] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/31/2012] [Indexed: 12/12/2022]
Abstract
Germline variation in the TP53 network genes PRKAG2, PPP2R2B, CCNG1, PIAS1 and YWHAQ was previously suggested to have an impact on drug response in vitro. Here, we investigated the effect on breast cancer survival of germline variation in these genes in 925 Finnish breast cancer patients and further analyzed five single nucleotide polymorphisms (SNPs) in PRKAG2 (rs1029946, rs4726050, rs6464153, rs7789699) and PPP2R2B (rs10477313) for 10-year survival in breast cancer patients, interaction with TP53 R72P and MDM2-SNP309, outcome after specific adjuvant therapy and correlation to tumor characteristics in 4,701 invasive cases from four data sets. We found evidence for carriers of PRKAG2-rs1029946 and PRKAG2-rs4726050 having improved survival in the pooled data (HR 0.53, 95% CI 0.3-0.9; p = 0.023 for homozygous carriers of the rare G-allele and HR 0.85, 95% CI 0.7-0.9; p = 0.049 for carriers of the rare G allele, respectively). PRKAG2-rs4726050 showed a significant interaction with MDM2-SNP309, with PRKAG2-rs4726050 rare G-allele having a dose-dependent effect for better breast cancer survival confined only to MDM2 SNP309 rare G-allele carriers (HR 0.45, 95% CI 0.2-0.7; p = 0.001). This interaction also emerged as an independent predictor of better survival (p = 0.047). PPP2R2B-rs10477313 rare A-allele was found to predict better survival (HR 0.82, 95% CI 0.6-0.9; p = 0.018), especially after hormonal therapy (HR 0.66, 95% CI 0.5-0.9; p = 0.048). These findings warrant further studies and suggest that genetic markers in TP53 network genes such as PRKAG2 and PPP2R2B might affect prognosis and treatment outcome in breast cancer patients.
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MESH Headings
- AMP-Activated Protein Kinases/genetics
- Adult
- Antineoplastic Agents, Hormonal/therapeutic use
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Carcinoma, Ductal, Breast/drug therapy
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Lobular/drug therapy
- Carcinoma, Lobular/genetics
- Carcinoma, Lobular/mortality
- Female
- Gene Regulatory Networks/genetics
- Genotype
- Germ-Line Mutation/genetics
- Humans
- Middle Aged
- Neoplasm Grading
- Neoplasm Invasiveness
- Neoplasm Metastasis
- Nerve Tissue Proteins/genetics
- Polymorphism, Single Nucleotide/genetics
- Prognosis
- Protein Phosphatase 2/genetics
- Proto-Oncogene Proteins c-mdm2/genetics
- RNA, Messenger/genetics
- RNA, Neoplasm/genetics
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Survival Rate
- Tumor Suppressor Protein p53/genetics
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Affiliation(s)
- Maral Jamshidi
- Department of Obstetrics and Gynecology, Biomedicum Helsinki, University of Helsinki and Helsinki University Central Hospital, P.O. Box 700, 00029 Helsinki, Finland
| | - Marjanka K Schmidt
- Department of Molecular Pathology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- Department of Psychosocial Research and Epidemiology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Thilo Dörk
- Clinics of Gynecology and Obstetrics, Hannover Medical School, Hannover, Germany
| | - Montserrat Garcia-Closas
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Department of Health and Human Services, Bethesda, Maryland
- Division of Genetics and Epidemiology, Institute of Cancer Research and Breakthrough Breast Cancer Research Centre, London, UK
| | - Tuomas Heikkinen
- Department of Obstetrics and Gynecology, Biomedicum Helsinki, University of Helsinki and Helsinki University Central Hospital, P.O. Box 700, 00029 Helsinki, Finland
| | - Sten Cornelissen
- Department of Molecular Pathology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Alexandra J van den Broek
- Department of Psychosocial Research and Epidemiology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Peter Schürmann
- Clinics of Gynecology and Obstetrics, Hannover Medical School, Hannover, Germany
| | - Andreas Meyer
- Clinics of Radiation Oncology, Hannover Medical School, Hannover, Germany
| | | | - Jonine Figueroa
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892
| | - Mark Sherman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Jolanta Lissowska
- Department of Cancer Epidemiology and Prevention, M. Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland
| | | | - Astrid Irwanto
- Human Genetics Division, Genome Institute of Singapore, Singapore
| | - Marko Laakso
- Computational Systems Biology Laboratory, Genome-Scale Biology Research Program, Institute of Biomedicine, University of Helsinki, Finland
| | - Sampsa Hautaniemi
- Computational Systems Biology Laboratory, Genome-Scale Biology Research Program, Institute of Biomedicine, University of Helsinki, Finland
| | - Kristiina Aittomäki
- Department of Clinical Genetics, Helsinki University Central Hospital, Helsinki, Finland
| | - Carl Blomqvist
- Department of Oncology, Helsinki University Central Hospital, Helsinki, Finland
| | - Jianjun Liu
- Human Genetics Division, Genome Institute of Singapore, Singapore
| | - Heli Nevalinna
- Department of Obstetrics and Gynecology, Biomedicum Helsinki, University of Helsinki and Helsinki University Central Hospital, P.O. Box 700, 00029 Helsinki, Finland
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Casein Kinase I epsilon positively regulates the Akt pathway in breast cancer cell lines. Biochem Biophys Res Commun 2008; 368:801-7. [PMID: 18262492 DOI: 10.1016/j.bbrc.2008.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Accepted: 02/01/2008] [Indexed: 12/11/2022]
Abstract
The Akt pathway is very important in both development and cancer. Here we show that, expression of Casein Kinase I epsilon (CKIepsilon) causes up-regulation of the Akt pathway despite normal protein expression of the pathway inhibitor phosphate and tensin homologue deleted on chromosome ten (PTEN). Conversely, we show that a CKIepsilon/delta-specific inhibitor can inhibit Akt phosphorylation at both Thr308 and Ser473 and drastically reduce phosphorylation of the Akt target Glycogen Synthase Kinase 3beta (GSK3beta). These conclusions were confirmed between MCF7 cells transiently transfected with CKIepsilon and Hs578T cells which already express endogenous CKIepsilon. The results suggest that CKIepsilon is a new positive regulator of the Akt pathway. Here we propose that, rather than inhibiting PTEN function, CKIepsilon positively regulates Akt possibly by inhibiting Protein Phosphatase 2A (PP2A).
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Liu J, Sidell N. Anti-estrogenic effects of conjugated linoleic acid through modulation of estrogen receptor phosphorylation. Breast Cancer Res Treat 2007; 94:161-9. [PMID: 16261415 DOI: 10.1007/s10549-005-6942-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We previously showed that conjugated linoleic acids (CLA) can inhibit transcriptional activation mediated by estrogen response elements (EREs) and that this activity can, at least in part, account for the reported anti-tumor effects of these compounds on breast cancer cells. Using estrogen receptor positive (ER+) MCF-7 cells, we now demonstrate that CLA inhibited both the transactivation of artificial reporter constructs driven by canonical EREs, and the expression of endogenous progesterone receptors, a gene which is transcriptionally regulated by estrogen through novel ER-binding sites. This inhibition was accompanied by downregulation of ER alpha expression and decreased ER alpha-ERE binding activity. These effects on ER alpha were not causally linked since transfection of an ER alpha expression plasmid in MCF-7 cells failed to antagonize CLA downregulation of ER alpha-ERE binding. Immunoprecipitation/Western blot studies revealed that CLA dose-dependently suppressed the degree of phosphorylation of ER alpha, a modification known to inhibit receptor-ERE interactions. As a mechanism that may account for this induced dephosphorylation of ER alpha in MCF-7, we found that CLA specifically stimulated protein phosphatase 2A (PP2A) activity. Experiments using the PP2A inhibitor okadaic acid (OA) showed that OA antagonized both the dephosphorylation effects of CLA on ER alpha and its inhibition of ER alpha-ERE binding. These results provide evidence that the anti-estrogenic activity of CLA is caused by inducing the dephosphorylation of ER alpha through stimulation of PP2A activity.
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Affiliation(s)
- Jingbo Liu
- Department of Gynecology and Obstetrics, Division of Research, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Secreto FJ, Monroe DG, Dutta S, Ingle JN, Spelsberg TC. Estrogen receptor α/β isoforms, but not βcx, modulate unique patterns of gene expression and cell proliferation in Hs578T cells. J Cell Biochem 2007; 101:1125-47. [PMID: 17520659 DOI: 10.1002/jcb.21205] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The actions of 17beta-estradiol (E2) and selective estrogen receptor modulators (SERMs) have been extensively investigated regarding their ability to act through estrogen receptor-alpha (ERalpha) to perturb estrogen receptor positive (ER+) breast cancer (BC) growth. However, many BCs also express ERbeta, along with multiple estrogen receptor (ER) splice variants such as ERbetacx, an ERbeta splice variant incapable of binding ligand. To gain a more comprehensive understanding of ER action in BC cells, we stably expressed ERalpha, ERbeta, or ERbetacx under doxycycline (Dox) control in Hs578T cells. Microarrays performed on E2 or 4OH-tamoxifen (4HT) treated Hs578T ERalpha and ERbeta cells revealed distinct ligand and receptor-dependent patterns of gene regulation, while the induction of ERbetacx did not alter gene expression patterns. E2 stimulation of Hs578T ERbeta cells resulted in a 27% decrease in cellular proliferation, however, no significant change in proliferation was observed following the exposure of Hs578T ERalpha or ERbeta cells to 4HT. Expression of ERbetacx in Hs578T cells did not effect cellular proliferation. Flow cytometry assays revealed a 50% decrease in E2-stimulated Hs578T ERbeta cells entering S-phase, along with a 17% increase in G0/G1 cell-cycle arrest. We demonstrate here that ERalpha and ERbeta regulate unique gene expression patterns in Hs578T cells, and such regulation likely is responsible for the observed isoform-specific changes in cell proliferation. Hs578T ER expressing cell-lines provide a unique BC model system, permitting the comparison of ERalpha, ERbeta, and ERbetacx actions in the same cell-line.
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Affiliation(s)
- Frank J Secreto
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA.
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12
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Vani G, Devi CSS. Effect of histone H1 on estrogen receptor status of human breast cancer MCF 7 cells. Mol Cell Biochem 2005; 272:151-5. [PMID: 16010982 DOI: 10.1007/s11010-005-6983-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The effects of exogenous histone H1 on estrogen receptor status of human breast cancer MCF 7 cells were investigated in presence and absence of estrogen. Exogenous histone H1 was significantly cytotoxic in a dose- and time-dependent manner. Cell cycle analysis revealed a significant increase in the percentage of cell accumulation in G0/G1 phase. In histone H1-treated cells, a significant decrease in the estrogen receptor content and an increase in the dissociation constant (KD) of ER was observed compared to control.
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Affiliation(s)
- G Vani
- Department of Biochemistry, University of Madras, Guindy Campus, Chennai, India.
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13
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Renò F, Baj G, Surico N, Cannas M. Exogenous prostaglandin E2 inhibits TPA induced matrix metalloproteinase-9 production in MCF-7 cells. Prostaglandins Other Lipid Mediat 2005; 73:237-47. [PMID: 15287155 DOI: 10.1016/j.prostaglandins.2004.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Elevated levels of prostaglandin E2 (PGE2) have been reported in many high metastatic human breast cancers, but no relationship between exogenous PGE2 activity, expression of matrix metalloproteinases (MMPs) and metastasis in human tumor cells has been reported. The poorly invasive human breast cancer cell line MCF-7 was cultured for 24h in the presence of both phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA, 50 nM) and PGE2 (1 microM) and the activity of MMP-9, one of the MMPs involved in metastasis, was measured, in growth medium by gelatin substrate zymography. TPA induced a strong production of MMP-9 while exogenous PGE2 had no effect on the basal MMP-9 level, but inhibited the TPA induced enzyme expression and matrigel invasiveness. We showed that MCF-7 cells expressed EP2, EP3 and EP4 receptors for PGE2 and that its action was probably mediated by EP4 receptor and adenylyl cyclase activation while cAMP dependent PKA was not involved in the process of inhibition of MMP-9 production. These findings suggest a possible inhibitory role for exogenous PGE2 in the metastatic process development.
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Affiliation(s)
- F Renò
- Human Anatomy Laboratory, Medical Sciences Department, University of Eastern Piedmont A. Avogadro, Via Solaroli 17, 28100 Novara, Italy
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Keen JC, Zhou Q, Park BH, Pettit C, Mack KM, Blair B, Brenner K, Davidson NE. Protein phosphatase 2A regulates estrogen receptor alpha (ER) expression through modulation of ER mRNA stability. J Biol Chem 2005; 280:29519-24. [PMID: 15965230 DOI: 10.1074/jbc.m505317200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein phosphatase 2A (PP2A) is a ubiquitously expressed member of the serine-threonine phosphatase family that is involved in regulation of many cellular processes including transcription, translation, cellular metabolism, and apoptosis. Because of a correlation between PP2A and estrogen receptor alpha (ER) expression in several human breast cancer cell lines, the effect of PP2A on regulation of ER expression in the human breast cancer cell line MCF-7 was studied. Inhibition of PP2A using the pharmacologic inhibitor okadaic acid at 250 nm for 16 h resulted in a 60% reduction in PP2A activity in MCF-7 cells concurrent with a 75% reduction in ER mRNA and protein expression. Similar results were obtained with a small interfering RNA probe that specifically inhibited PP2A expression. ER promoter studies showed that regulation of ER through the PP2A pathway did not occur through transcriptional activation. Rather, PP2A mediated ER expression through modulation of ER mRNA stability through degradation of ER mRNA, reversible with concomitant treatment with the proteasomal inhibitor MG 132. These data suggest a novel pathway controlling ER expression resulting from the activation of PP2A, potentially providing a novel therapeutic target.
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Affiliation(s)
- Judith C Keen
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland 21231, USA
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Levy-Nissenbaum O, Sagi-Assif O, Kapon D, Hantisteanu S, Burg T, Raanani P, Avigdor A, Ben-Bassat I, Witz IP. Dual-specificity phosphatase Pyst2-L is constitutively highly expressed in myeloid leukemia and other malignant cells. Oncogene 2003; 22:7649-60. [PMID: 14576828 DOI: 10.1038/sj.onc.1206971] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Northern blotting confirmed previous results indicating that the mitogen-activated protein kinase (MAPK) phosphatase Pyst2-L was highly expressed in leukocytes obtained from acute myeloid leukemia (AML) patients. High levels of Pyst2-L mRNA were expressed in bone marrow (BM) and peripheral leukocytes from nine AML and acute lymphoblastic leukemia (ALL) patients. BM from healthy individuals expressed very low levels of Pyst2-L. Whereas high levels of Pyst2-L mRNA and protein were detected in several leukemia cell lines, Pyst2-L mRNA was detected neither in 33/34 samples of normal peripheral blood mononuclear cells (PBMC) nor in leukocyte fractions enriched with CD34+ cells. Certain solid tumor and lymphoblastoid cell lines expressed high levels of Pyst2-L mRNA. In view of the association of Pyst2-L to MAPK signaling cascades, we tested if cell activation, a process involving MAPK signaling, influences Pyst2-L expression. Indeed, activation of T cells and endothelial cells increased Pyst2-L in these cells. Furthermore, TPA, a known MAPK activator, induces the expression of both Pyst2-L mRNA as well as the Pyst2-L protein in leukemia cells. This induction was partially inhibited by PD098059, an Mek1/2-specific inhibitor. Based on the results of this and previous studies, we hypothesize that the high levels of Pyst2-L detected in the active state of AML and ALL diseases and in other types of cancer reflect an altered MAPK signaling pathway in such malignant processes. This alteration may be the result of a failed attempt to counter the constitutive activation of MAPK in transformed cells or alternatively, may represent the activated state of such cells.
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Affiliation(s)
- Orlev Levy-Nissenbaum
- Department of Cell Research and Immunology, George S Wise Faculty of Life Sciences, Tel-Aviv, Israel
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Rabenoelina F, Semlali A, Duchesne MJ, Freiss G, Pons M, Badia E. Effect of prolonged hydroxytamoxifen treatment of MCF-7 cells on mitogen activated kinase cascade. Int J Cancer 2002; 98:698-706. [PMID: 11920638 DOI: 10.1002/ijc.10252] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Resistance to the antiestrogen tamoxifen is the main stumbling block for the success of breast cancer therapy. We focused our study on cellular alterations induced by a prolonged treatment with the active tamoxifen metabolite hydroxytamoxifen (OHT). We show that a prolonged OHT treatment (for up to 7 days) led to a progressive increase in the level of phosphorylated p44/42 mitogen activated kinase (MAP kinase) induced by 10(-7) M TPA stimulation, without any significant change in the protein level. This effect was also observed in MCF-7 cells grown first in medium containing dextran-coated charcoal-treated FCS (DCC medium) for 20 days prior to OHT treatment, indicating a specific effect of the antiestrogen and not an effect of estrogen deprivation. It was prevented by cotreatment with estradiol and not observed in the estrogen receptor negative HeLa cell line, suggesting that it was mediated by the estrogen receptor. TPA induced phosphorylation of MEK1/2 was also raised by OHT treatment, without any change in their protein level or Raf-1 and H-Ras levels. When the MCF-7R OHT resistant cell line was grown in antiestrogen containing medium, the level of phosphorylated p44/42 MAP kinase was also high but reversed when the antiestrogen was removed. The 2 other MAP kinase, JNK and P38 pathways were not affected in the same way by OHT treatment. In conclusion, our data reveal that a prolonged OHT treatment, by increasing p44/42 MAPK activity, affects a key step in the growth control of MCF-7 cells, although not sufficiently to overcome the growth inhibitory effect of the drug.
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Krueger JS, Keshamouni VG, Atanaskova N, Reddy KB. Temporal and quantitative regulation of mitogen-activated protein kinase (MAPK) modulates cell motility and invasion. Oncogene 2001; 20:4209-18. [PMID: 11464287 DOI: 10.1038/sj.onc.1204541] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2001] [Revised: 04/09/2001] [Accepted: 04/12/2001] [Indexed: 11/08/2022]
Abstract
We have shown that ER-negative and invasive human breast cancer cell lines MDA-MB-468 and MDA-MB-231 have constitutively higher mitogen activated protein kinase (ERK1&2/MAPK) when compared to the ER-positive and non-invasive MCF-7 human breast cancer cells. In MCF-7 cells, TGFalpha stimulation induced only transient MAPK activation, leading to a transient increase in cell migration. However, MDA 231 and MDA 468 cells, TGFalpha stimulation induced sustained MAPK activation, which correlated with enhanced cell motility and in vitro invasion. Serum stimulation activates ERK/MAPK activity persistently in both ER-positive and ER-negative breast cancer cells, leading to enhanced and sustained cell migration. Inhibition of MAPK activation by anti-sense MEK expression in MDA-MB-468 cells significantly inhibits cell migration and in vitro invasion. In contrast, MCF-7 cells expressing constitutively activated MEK show a significant increase in MAPK activity and cell migration, but this failed to enhance in vitro invasion. The kinetic profiles of MAPK activation and inhibition show a relationship between the duration and magnitude of MAPK activation and cell migration in both ER-positive and ER-negative human breast cancer cells. These studies show that cell motility is modulated by the magnitude and the duration of MAPK activation; but increased activation of MAPK may not be sufficient to allow in vitro invasion in non-invasive MCF-7 breast cancer cells.
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Affiliation(s)
- J S Krueger
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan, MI 48201, USA
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