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Zeng Z, Peng Q, Yang F, Wu J, Guo H, Deng H, Zhao L, Long K, Wang X. Transcriptome analysis of pigeon pituitary gland: expression changes of genes encoding protein and peptide hormones at different breeding stages. Poult Sci 2024; 103:103742. [PMID: 38670056 PMCID: PMC11068619 DOI: 10.1016/j.psj.2024.103742] [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: 01/31/2024] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Unlike other poultry, parent pigeons produce "pigeon milk" in their crops to nurture their squabs, which is mainly controlled by prolactin (PRL). Exception for PRL, the pituitary gland may also release various other peptide and protein hormones. However, whether these hormones change during pigeon crop lactation and their potential physiological functions remain unclear. Here, to identify potential peptide or protein hormone genes that regulate crop lactation, we conducted transcriptome analysis of pigeon pituitary glands at 3 different breeding stages (the ceased stage-nonincubation and non-nurturing stage, the 11th d of the incubation, and the 1st d of the nurturing stage) using RNA sequencing (RNA-Seq). Our analysis identified a total of 15,191 mRNAs and screened out 297 differentially expressed genes (DEG), including PRL, VIP, etc. The expression abundance of PRL mRNA on the 1st d of the nurturing stage was respectively 4.93 and 3.62 folds higher when compared to the ceased stage and the 11th d of the incubation stage. Additionally, the expression abundance of VIP is higher in the 1st d of the nurturing stage than in the ceased stage. Protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) analysis identified several vital DEGs (e.g., GHRHR, VIP, etc.), being closely linked with hormone and enriched in neuropeptide signaling pathway and response to the hormone. Expression pattern analysis revealed that these DEGs exhibited 4 distinct expression patterns (profile 10, 16, 18, 19). Genes in profile 10 and 19 presented a trend with the highest expression level on 1st d of the nurturing stage, and functional enrichment analysis indicated that these genes are involved in neuropeptide hormone activity, receptor-ligand activity, and the extracellular matrix, etc. Taken together, being consistent with PRL, some genes encoding peptide and protein hormones (e.g., VIP) presented differentially expressed in different breeding stages. It suggests that these hormones may be involved in regulation of the crop lactation process or corresponding behavior in domestic pigeons. The results of this study help to gain new insights into the role of pituitary gland in regulating pigeon lactation.
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Affiliation(s)
- Zhanggui Zeng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Qiyi Peng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Fuxing Yang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Jie Wu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Hongrui Guo
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, P. R. of China
| | - Huidan Deng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, P. R. of China
| | - Ling Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, P. R. of China
| | - Keren Long
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Xun Wang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China; Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China.
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Singina GN, Shedova EN, Lopukhov AV, Mityashova OS, Lebedeva IY. Delaying Effects of Prolactin and Growth Hormone on Aging Processes in Bovine Oocytes Matured In Vitro. Pharmaceuticals (Basel) 2021; 14:684. [PMID: 34358110 PMCID: PMC8308928 DOI: 10.3390/ph14070684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/05/2021] [Accepted: 07/13/2021] [Indexed: 11/16/2022] Open
Abstract
Aging processes accelerate dramatically in oocytes that have reached the metaphase-II (M-II) stage. The present work aimed to study the patterns and intracellular pathways of actions of prolactin (PRL) and growth hormone (GH) on age-associated changes in bovine M-II oocytes aging in vitro. To this end, we analyzed spontaneous parthenogenetic activation (cytogenetic assay), apoptosis (TUNEL assay), and the developmental capacity (IVF/IVC) of in vitro-matured oocytes after prolonged culturing. Both PRL and GH reduced the activation rate of aging cumulus-enclosed oocytes (CEOs) and denuded oocytes (DOs), and their respective hormone receptors were revealed in the ova. The inhibitor of Src-family tyrosine kinases PP2 eliminated the effects of PRL and GH on meiotic arrest in DOs, whereas the MEK inhibitor U0126 only abolished the PRL effect. Furthermore, PRL was able to maintain the apoptosis resistance and developmental competence of aging CEOs. The protein kinase C inhibitor calphostin C suppressed both the actions of PRL. Thus, PRL and GH can directly support meiotic arrest in aging M-II oocytes by activating MAP kinases and/or Src-family kinases. The effect of PRL in maintaining the developmental capacity of aging oocytes is cumulus-dependent and related to the pro-survival action of the protein kinase C-mediated signal pathway.
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Affiliation(s)
| | | | | | | | - Irina Y. Lebedeva
- Department of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Federal Research Center for Animal Husbandry, 142132 Podolsk, Russia; (G.N.S.); (E.N.S.); (A.V.L.); (O.S.M.)
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Canzoneri R, Naipauer J, Stedile M, Rodriguez Peña A, Lacunza E, Gandini NA, Curino AC, Facchinetti MM, Coso OA, Kordon E, Abba MC. Identification of an AP1-ZFP36 Regulatory Network Associated with Breast Cancer Prognosis. J Mammary Gland Biol Neoplasia 2020; 25:163-172. [PMID: 32248342 DOI: 10.1007/s10911-020-09448-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/24/2020] [Indexed: 01/05/2023] Open
Abstract
It has been established that ZFP36 (also known as Tristetraprolin or TTP) promotes mRNA degradation of proteins involved in inflammation, proliferation and tumor invasiveness. In mammary epithelial cells ZFP36 expression is induced by STAT5 activation during lactogenesis, while in breast cancer ZFP36 expression is associated with lower grade and better prognosis. Here, we show that the AP-1 transcription factor components, i.e. JUN, JUNB, FOS, FOSB, in addition to DUSP1, EGR1, NR4A1, IER2 and BTG2, behave as a conserved co-regulated group of genes whose expression is associated to ZFP36 in cancer cells. In fact, a significant down-modulation of this gene network is observed in breast, liver, lung, kidney, and thyroid carcinomas compared to their normal counterparts. In breast cancer, the normal-like and Luminal A, show the highest expression of the ZFP36 gene network among the other intrinsic subtypes and patients with low expression of these genes display poor prognosis. It is also proposed that AP-1 regulates ZFP36 expression through responsive elements detected in the promoter region of this gene. Culture assays show that AP-1 activity induces ZFP36 expression in mammary cells in response to prolactin (PRL) treatment thorough ERK1/2 activation. These results suggest that JUN, JUNB, FOS and FOSB are not only co-expressed, but would also play a relevant role in regulating ZFP36 expression in mammary epithelial cells.
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Affiliation(s)
- R Canzoneri
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, CINIBA, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - J Naipauer
- Laboratorio de Expresión Génica en Mama y Apoptosis, LEGMA, IFIBYNE-CONICET, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M Stedile
- Laboratorio de Expresión Génica en Mama y Apoptosis, LEGMA, IFIBYNE-CONICET, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - A Rodriguez Peña
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, CINIBA, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - E Lacunza
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, CINIBA, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - N A Gandini
- Laboratorio de Biología del Cáncer, INIBIBB, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - A C Curino
- Laboratorio de Biología del Cáncer, INIBIBB, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - M M Facchinetti
- Laboratorio de Biología del Cáncer, INIBIBB, Universidad Nacional del Sur - CONICET, Bahía Blanca, Argentina
| | - O A Coso
- Laboratorio de Expresión Génica en Mama y Apoptosis, LEGMA, IFIBYNE-CONICET, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - E Kordon
- Laboratorio de Expresión Génica en Mama y Apoptosis, LEGMA, IFIBYNE-CONICET, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - M C Abba
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, CINIBA, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
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Prolactin/androgen-inducible carboxypeptidase-D increases with nitrotyrosine and Ki67 for breast cancer progression in vivo, and upregulates progression markers VEGF-C and Runx2 in vitro. Breast Cancer Res Treat 2017; 164:27-40. [PMID: 28364216 DOI: 10.1007/s10549-017-4223-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/24/2017] [Indexed: 12/19/2022]
Abstract
PURPOSE Carboxypeptidase-D (CPD) cleaves C-terminal arginine (Arg) to produce nitric oxide (NO). Upregulation of CPD and NO by 17β-estradiol, prolactin (PRL), and androgen increases survival of human breast cancer (BCa) cells in vitro. To demonstrate similar events in vivo, CPD, nitrotyrosine (NT, hallmark of NO action), androgen receptor (AR), prolactin receptor (PRLR), and phospho-Stat5a (for activated PRLR) levels were evaluated in benign and malignant human breast tissues, and correlated with cell proliferation (Ki67) and BCa progression (Cullin-3) biomarkers. METHODS Paraffin-embedded breast tissues were analyzed by immunohistochemistry (IHC). BCa progression markers in human MCF-7 and T47D BCa cell lines treated with NO donor SIN-1 or PRL, ±CPD inhibitors were analyzed by RT-qPCR and immunoblotting. RESULTS IHC showed progressive increases in CPD, NT, Ki67, and Cullin-3 from low levels in benign tissues to high levels in ductal carcinoma in situ, low-grade, high-grade, and triple-negative BCa. CPD and NT staining were closely associated, implicating CPD in NO production. Phospho-Stat5a increased significantly from benign to high-grade BCa and was mostly nuclear. AR and PRLR were abundant in benign breast and BCa, including triple-negative tumors. SIN-1 and PRL increased VEGF-C and Runx2, but not Cullin-3, in BCa cell lines. PRL induction of VEGF-C and Runx2 was inhibited partly by CPD inhibitors, implicating NO, produced by PRL-regulated CPD, in BCa progression. CONCLUSIONS The CPD-Arg-NO pathway contributes to BCa progression in vitro and in vivo. PRL/androgen activation of the pathway support combined AR and PRLR blockade as an additional therapy for BCa.
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Espada J, Martín-Pérez J. An Update on Src Family of Nonreceptor Tyrosine Kinases Biology. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 331:83-122. [DOI: 10.1016/bs.ircmb.2016.09.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Harrington KM, Clevenger CV. Identification of NEK3 Kinase Threonine 165 as a Novel Regulatory Phosphorylation Site That Modulates Focal Adhesion Remodeling Necessary for Breast Cancer Cell Migration. J Biol Chem 2016; 291:21388-21406. [PMID: 27489110 PMCID: PMC5076809 DOI: 10.1074/jbc.m116.726190] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 07/27/2016] [Indexed: 01/09/2023] Open
Abstract
Accumulating evidence supports a role for prolactin (PRL) in the development and progression of human breast cancer. Although PRL is an established chemoattractant for breast cancer cells, the precise molecular mechanisms of how PRL regulates breast cancer cell motility and invasion are not fully understood. PRL activates the serine/threonine kinase NEK3, which was reported to enhance breast cancer cell migration, invasion, and the actin cytoskeletal reorganization necessary for these processes. However, the specific mechanisms of NEK3 activation in response to PRL signaling have not been defined. In this report, a novel PRL-inducible regulatory phosphorylation site within the activation segment of NEK3, threonine 165 (Thr-165), was identified. Phosphorylation at NEK3 Thr-165 was found to be dependent on activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway using both pharmacological inhibition and siRNA-mediated knockdown approaches. Strikingly, inhibition of phosphorylation at NEK3 Thr-165 by expression of a phospho-deficient mutant (NEK3-T165V) resulted in increased focal adhesion size, formation of zyxin-positive focal adhesions, and reorganization of the actin cytoskeleton into stress fibers. Concordantly, NEK3-T165V cells exhibited migratory defects. Together, these data support a modulatory role for phosphorylation at NEK3 Thr-165 in focal adhesion maturation and/or turnover to promote breast cancer cell migration.
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Affiliation(s)
- Katherine M Harrington
- From the Department of Pathology, Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 and
| | - Charles V Clevenger
- the Department of Pathology, Virginia Commonwealth University, Richmond, Virginia 23298
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Lebedeva IY, Singina GN, Lopukhov AV, Shedova EN, Zinovieva NA. Prolactin and growth hormone affect metaphase-II chromosomes in aging oocytes via cumulus cells using similar signaling pathways. Front Genet 2015; 6:274. [PMID: 26379702 PMCID: PMC4550791 DOI: 10.3389/fgene.2015.00274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/10/2015] [Indexed: 01/09/2023] Open
Abstract
General senescence of the adult organism is closely connected with reproductive one. Meanwhile, the age-related reduction in the female fertility is primarily associated with a decline in the gamete quality. Molecular and cellular changes in oocytes of old mammalian females are very similar to those occurring during aging of matured ova of their young counterparts, suggesting similarities in underlying mechanisms. The aim of the present work was to study actions of two related pituitary hormones, prolactin (PRL) and growth hormone (GH), on age-associated modifications of metaphase-II (M-II) chromosomes in bovine oocytes using a model of the prolonged culture. We analyzed: (1) effects of PRL and GH on abnormal changes in the chromosome morphology in aging matured oocytes and the role of cumulus cells in these effects and (2) signaling pathways involved in the hormone actions. During the prolonged culture of oocytes, a gradual rise in the frequency of destructive modifications of M-II chromosomes was revealed. In the case of cumulus-enclosed oocytes (CEOs), PRL and GH exerted dose-dependent biphasic effects on the frequency of these modifications. Both PRL (50 ng/ml) and GH (10 ng/ml) decelerated the abnormal chromosome changes in CEOs, but did not affect the chromosome configuration in denuded oocytes. Concurrently, the presence of PRL and GH receptors in cumulus cells surrounding matured oocytes was demonstrated. Attenuating effects of both hormones on the chromosome modifications in aging CEOs were abolished by PP2 (an inhibitor of Src-family tyrosine kinases), triciribine (an inhibitor of Akt kinase), and calphostin C (a protein kinase C inhibitor). Our findings indicate that PRL and GH can exert the similar decelerating action on age-associated alterations in the M-II chromosome morphology in bovine ova, which is mediated by cumulus cells and may be related to activation of Src-family tyrosine kinases as well as Akt- and protein kinase C-dependent signal pathways.
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Affiliation(s)
- Irina Y Lebedeva
- Center of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Institute of Animal Husbandry , Podolsk, Moscow Region, Russia
| | - Galina N Singina
- Center of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Institute of Animal Husbandry , Podolsk, Moscow Region, Russia
| | - Alexander V Lopukhov
- Center of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Institute of Animal Husbandry , Podolsk, Moscow Region, Russia
| | - Ekaterina N Shedova
- Center of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Institute of Animal Husbandry , Podolsk, Moscow Region, Russia
| | - Natalia A Zinovieva
- Center of Animal Biotechnology and Molecular Diagnostics, L.K. Ernst Institute of Animal Husbandry , Podolsk, Moscow Region, Russia
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Liu TT, Qu ZW, Ren C, Gan X, Qiu CY, Hu WP. Prolactin potentiates the activity of acid-sensing ion channels in female rat primary sensory neurons. Neuropharmacology 2015; 103:174-82. [PMID: 26188144 DOI: 10.1016/j.neuropharm.2015.07.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 07/13/2015] [Accepted: 07/14/2015] [Indexed: 02/06/2023]
Abstract
Prolactin (PRL) is a polypeptide hormone produced and released from the pituitary and extrapituitary tissues. It regulates activity of nociceptors and causes hyperalgesia in pain conditions, but little is known the molecular mechanism. We report here that PRL can exert a potentiating effect on the functional activity of acid-sensing ion channels (ASICs), key sensors for extracellular protons. First, PRL dose-dependently increased the amplitude of ASIC currents with an EC50 of (5.89 ± 0.28) × 10(-8) M. PRL potentiation of ASIC currents was also pH dependent. Second, PRL potentiation of ASIC currents was blocked by Δ1-9-G129R-hPRL, a PRL receptor antagonist, and removed by intracellular dialysis of either protein kinase C inhibitor GF109203X, protein interacting with C-kinase 1(PICK1) inhibitor FSC-231, or PI3K inhibitor AS605240. Third, PRL altered acidosis-evoked membrane excitability of DRG neurons and caused a significant increase in the amplitude of the depolarization and the number of spikes induced by acid stimuli. Four, PRL exacerbated nociceptive responses to injection of acetic acid in female rats. Finally, PRL displayed a stronger effect on ASIC mediated-currents and nociceptive behavior in intact female rats than OVX female and male rats and thus modulation of PRL may be gender-dependent. These results suggest that PRL up-regulates the activity of ASICs and enhances ASIC mediated nociceptive responses in female rats, which reveal a novel peripheral mechanism underlying PRL involvement in hyperalgesia.
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Affiliation(s)
- Ting-Ting Liu
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Zu-Wei Qu
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Cuixia Ren
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Xiong Gan
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China
| | - Chun-Yu Qiu
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China.
| | - Wang-Ping Hu
- Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China.
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O'Leary KA, Shea MP, Schuler LA. Modeling prolactin actions in breast cancer in vivo: insights from the NRL-PRL mouse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 846:201-20. [PMID: 25472540 DOI: 10.1007/978-3-319-12114-7_9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Elevated exposure to prolactin (PRL) is epidemiologically associated with an increased risk of aggressive ER+ breast cancer. To understand the underlying mechanisms and crosstalk with other oncogenic factors, we developed the NRL-PRL mouse. In this model, mammary expression of a rat prolactin transgene raises local exposure to PRL without altering estrous cycling. Nulliparous females develop metastatic, histotypically diverse mammary carcinomas independent from ovarian steroids, and most are ER+. These characteristics resemble the human clinical disease, facilitating study of tumorigenesis, and identification of novel preventive and therapeutic approaches.
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Affiliation(s)
- Kathleen A O'Leary
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA,
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Prolactin (PRL) in Adipose Tissue: Regulation and Functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 846:1-35. [DOI: 10.1007/978-3-319-12114-7_1] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Belugin S, Diogenes AR, Patil MJ, Ginsburg E, Henry MA, Akopian AN. Mechanisms of transient signaling via short and long prolactin receptor isoforms in female and male sensory neurons. J Biol Chem 2013; 288:34943-55. [PMID: 24142695 PMCID: PMC3843105 DOI: 10.1074/jbc.m113.486571] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 10/09/2013] [Indexed: 01/01/2023] Open
Abstract
Prolactin (PRL) regulates activity of nociceptors and causes hyperalgesia in pain conditions. PRL enhances nociceptive responses by rapidly modulating channels in nociceptors. The molecular mechanisms underlying PRL-induced transient signaling in neurons are not well understood. Here we use a variety of cell biology and pharmacological approaches to show that PRL transiently enhanced capsaicin-evoked responses involve protein kinase C ε (PKCε) or phosphatidylinositol 3-kinase (PI3K) pathways in female rat trigeminal (TG) neurons. We next reconstituted PRL-induced signaling in a heterologous expression system and TG neurons from PRL receptor (PRLR)-null mutant mice by expressing rat PRLR-long isoform (PRLR-L), PRLR-short isoform (PRLR-S), or a mix of both. Results show that PRLR-S, but not PRLR-L, is capable of mediating PRL-induced transient enhancement of capsaicin responses in both male and female TG neurons. However, co-expression of PRLR-L with PRLR-S (1:1 ratio) leads to the inhibition of the transient PRL actions. Co-expression of PRLR-L deletion mutants with PRLR-S indicated that the cytoplasmic site adjacent to the trans-membrane domain of PRLR-L was responsible for inhibitory effects of PRLR-L. Furthermore, in situ hybridization and immunohistochemistry data indicate that in normal conditions, PRLR-L is expressed mainly in glia with little expression in rat sensory neurons (3-5%) and human nerves. The predominant PRLR form in TG neurons/nerves from rats and humans is PRLR-S. Altogether, PRL-induced transient signaling in sensory neurons is governed by PI3K or PKCε, mediated via the PRLR-S isoform, and transient effects mediated by PRLR-S are inhibited by presence of PRLR-L in these cells.
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Affiliation(s)
| | | | - Mayur J. Patil
- Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229 and
| | - Erika Ginsburg
- the NCI, National Institutes of Health, Bethesda, Maryland 20892
| | | | - Armen N. Akopian
- From the Departments of Endodontics and
- Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229 and
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O'Leary KA, Rugowski DE, Sullivan R, Schuler LA. Prolactin cooperates with loss of p53 to promote claudin-low mammary carcinomas. Oncogene 2013; 33:3075-82. [PMID: 23873024 DOI: 10.1038/onc.2013.278] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 04/13/2013] [Accepted: 05/16/2013] [Indexed: 01/05/2023]
Abstract
TP53 is one of the most commonly mutated genes in cancer. In breast cancer, it is mutated in about 40% of primary clinical tumors and is associated with poor survival. The mammotrophic hormone, prolactin (PRL), and/or its receptor are also expressed in many breast cancers, and accumulating epidemiologic data link PRL to breast cancer development and progression. Like TP53 mutations, evidence for PRL activity is evident across several molecular cancer subtypes, and elevated PRL expression and loss of p53 have been observed in some of the same clinical tumors. In order to examine the interaction of these factors, we used genetically modified mouse models of mammary-specific p53 loss and local overexpression of PRL. We demonstrated that mammary PRL decreased the latency of tumors in the absence of p53, and increased the proportion of triple-negative claudin-low carcinomas, which display similarities to human clinical metaplastic carcinomas. Moreover, PRL/p53(-/-) carcinomas displayed higher rates of proliferation and more aggressive behavior. Transcripts associated with cell cycle progression, invasion and stromal reactivity were differentially expressed in carcinomas that developed in the presence of elevated PRL. PRL/p53(-/-) carcinomas also exhibited selectively altered expression of activating protein-1 components, including higher levels of c-Jun and FosL1, which can drive transcription of many of these genes and the epithelial-mesenchymal transition. The ability of PRL to promote claudin-low carcinomas demonstrates that PRL can influence this subset of triple-negative breast cancers, which may have been obscured by the relative infrequency of this cancer subtype. Our findings suggest novel therapeutic approaches, and provide a preclinical model to develop possible agents.
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Affiliation(s)
- K A O'Leary
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - D E Rugowski
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - R Sullivan
- University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
| | - L A Schuler
- 1] Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA [2] University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin-Madison, Madison, WI, USA
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Rider L, Oladimeji P, Diakonova M. PAK1 regulates breast cancer cell invasion through secretion of matrix metalloproteinases in response to prolactin and three-dimensional collagen IV. Mol Endocrinol 2013; 27:1048-64. [PMID: 23744893 DOI: 10.1210/me.2012-1322] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
p21-Activated serine-threonine kinase (PAK1) is implicated in breast cancer. We have shown previously that PAK1 is tyrosyl phosphorylated by prolactin (PRL)-activated Janus tyrosine kinase (JAK2). Although a role for both PRL and PAK1 in breast cancer is widely acknowledged, the mechanism remains poorly understood. In the present study, PRL-activated PAK1 stimulates the invasion of TMX2-28 human breast cancer cells through Matrigel. Three-dimensional (3D) collagen IV stimulates the secretion of the matrix proteases, metalloproteinase (MMP)-1 and -3 that is further enhanced by the PRL-dependent tyrosyl phosphorylation of PAK1. 3D collagen IV also stimulates the expression and secretion of MMP-2, but in contrast to MMP-1 and -3, PRL/PAK1 signaling down-regulates MMP-2 expression and secretion. In contrast, MMP-9 expression and secretion are stimulated by 3D collagen I, not collagen IV, and are not affected by PRL but are down-regulated by PAK1. MMP-1 and -3 are required and MMP-2 contributes to PRL-dependent invasion. ERK1/2 signaling appears to be required for the enhanced expression and secretion of MMP-1 and -3 and enhanced PRL-dependent invasion. p38 MAPK and c-Jun N-terminal kinase 1/2 pathways participate in production of MMP-1 and -3 as well as in PRL/PAK1-dependent cell invasion. Together, these data illustrate the complex interaction between the substratum and PRL/PAK1 signaling in human breast cancer cells and suggest a pivotal role for PRL-dependent PAK1 tyrosyl phosphorylation in MMP secretion.
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Affiliation(s)
- Leah Rider
- Department of Biological Sciences, University of Toledo, 2801 West Bancroft Street, Toledo, Ohio 43606-3390, USA
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Barcus CE, Keely PJ, Eliceiri KW, Schuler LA. Stiff collagen matrices increase tumorigenic prolactin signaling in breast cancer cells. J Biol Chem 2013; 288:12722-32. [PMID: 23530035 DOI: 10.1074/jbc.m112.447631] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clinically, circulating prolactin levels and density of the extracellular matrix (ECM) are individual risk factors for breast cancer. As tumors develop, the surrounding stroma responds with increased deposition and cross-linking of the collagen matrix (desmoplasia). In mouse models, prolactin promotes mammary carcinomas that resemble luminal breast cancers in women, and increased collagen density promotes tumor metastasis and progression. Although the contributions of the ECM to the physiologic actions of prolactin are increasingly understood, little is known about the functional relationship between the ECM and prolactin signaling in breast cancer. Here, we examined consequences of increased ECM stiffness on prolactin signals to luminal breast cancer cells in three-dimensional collagen I matrices in vitro. We showed that matrix stiffness potently regulates a switch in prolactin signals from physiologic to protumorigenic outcomes. Compliant matrices promoted physiological prolactin actions and activation of STAT5, whereas stiff matrices promoted protumorigenic outcomes, including increased matrix metalloproteinase-dependent invasion and collagen scaffold realignment. In stiff matrices, prolactin increased SRC family kinase-dependent phosphorylation of focal adhesion kinase (FAK) at tyrosine 925, FAK association with the mitogen-activated protein kinase mediator GRB2, and pERK1/2. Stiff matrices also increased co-localization of prolactin receptors and integrin-activated FAK, implicating altered spatial relationships. Together, these results demonstrate that ECM stiffness is a powerful regulator of the spectrum of prolactin signals and that stiff matrices and prolactin interact in a feed-forward loop in breast cancer progression. Our study is the first reported evidence of altered ECM-prolactin interactions in breast cancer, suggesting the potential for new therapeutic approaches.
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Affiliation(s)
- Craig E Barcus
- Department of Comparative Biosciences, University of Wisconsin, Madison, Wisconsin 53706, USA
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Prolactin and epidermal growth factor stimulate adipophilin synthesis in HC11 mouse mammary epithelial cells via the PI3-kinase/Akt/mTOR pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:987-96. [DOI: 10.1016/j.bbamcr.2012.02.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 02/08/2012] [Accepted: 02/27/2012] [Indexed: 11/19/2022]
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Tao J, Oladimeji P, Rider L, Diakonova M. PAK1-Nck regulates cyclin D1 promoter activity in response to prolactin. Mol Endocrinol 2011; 25:1565-78. [PMID: 21719533 DOI: 10.1210/me.2011-0062] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Prolactin (PRL) is critical for alveolar proliferation and differentiation in normal mammary development and is also implicated in breast cancer. PRL influences cell proliferation and growth by altering the expression of cyclin D1. Cyclin D1 expression is directly regulated by PRL through the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5-mediated transcriptional activation of the cyclin D1 promoter. A p21-activated serine-threonine kinase (PAK)1 has also been implicated in the regulation of cyclin D1 gene expression. We have previously demonstrated that JAK2 directly phosphorylates PAK1 and extend these data here to demonstrate that PAK1 activates the cyclin D1 promoter in response to PRL. We show that mutation of PAK1 Tyr 153, 201, and 285 (sites of JAK2 phosphorylation; PAK1 Y3F) decreases both PAK1 nuclear translocation in response to PRL and PRL-induced cyclin D1 promoter activity by 55%. Mutation of the PAK1 nuclear localization signals decreases PRL-induced cyclin D1 promoter activity by 46%. A PAK1 Y3F mutant lacking functional nuclear localization signals decreases PRL-induced cyclin D1 activity by 68%, suggesting that there is another PAK1-dependent mechanism to activate the cyclin D1 promoter. We have found that adapter protein Nck sequesters PAK1 in the cytoplasm and that coexpression of both PAK1 and Nck inhibits the amplifying effect of PRL-induced PAK1 on cyclin D1 promoter activity (95% inhibition). This inhibition is partially abolished by disruption of PAK1-Nck binding. We propose two PAK1-dependent mechanisms to activate cyclin D1 promoter activity in response to PRL: via nuclear translocation of tyrosyl-phosphorylated PAK1 and via formation of a Nck-PAK1 complex that sequesters PAK1 in the cytoplasm.
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Affiliation(s)
- Jing Tao
- Department of Biological Sciences, University of Toledo, Toledo, Ohio 43606-3390, USA
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Arendt LM, Rugowski DE, Grafwallner-Huseth TA, Garcia-Barchino MJ, Rui H, Schuler LA. Prolactin-induced mouse mammary carcinomas model estrogen resistant luminal breast cancer. Breast Cancer Res 2011; 13:R11. [PMID: 21276249 PMCID: PMC3109579 DOI: 10.1186/bcr2819] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Revised: 11/30/2010] [Accepted: 01/28/2011] [Indexed: 02/07/2023] Open
Abstract
Introduction Tumors that express estrogen receptor alpha (ERα+) comprise 75% of breast cancers in women. While treatments directed against this receptor have successfully lowered mortality rates, many primary tumors initially or later exhibit resistance. The paucity of murine models of this "luminal" tumor subtype has hindered studies of factors that promote their pathogenesis and modulate responsiveness to estrogen-directed therapeutics. Since epidemiologic studies closely link prolactin and the development of ERα+ tumors in women, we examined characteristics of the aggressive ERα+ and ERα- carcinomas which develop in response to mammary prolactin in a murine transgenic model (neu-related lipocalin- prolactin (NRL-PRL)). To evaluate their relationship to clinical tumors, we determined phenotypic relationships among these carcinomas, other murine models of breast cancer, and features of luminal tumors in women. Methods We examined a panel of prolactin-induced tumors for characteristics relevant to clinical tumors: histotype, ERα/progesterone receptor (PR) expression and estrogen responsiveness, Activating Protein 1 (AP-1) components, and phosphorylation of signal transducer and activator of transcription 5 (Stat5), extracellular signal regulated kinase (ERK) 1/2 and AKT. We compared levels of transcripts in the ERα-associated "luminal" signature that defines this subtype of tumors in women and transcripts enriched in various mammary epithelial lineages to other well-studied genetically modified murine models of breast cancer. Finally, we used microarray analyses to compare prolactin-induced ERα+ and ERα- tumors, and examined responsiveness to estrogen and the anti-estrogen, Faslodex, in vivo. Results Prolactin-induced carcinomas were markedly diverse with respect to histotype, ERα/PR expression, and activated signaling cascades. They constituted a heterogeneous, but distinct group of murine mammary tumors, with molecular features of the luminal subtype of human breast cancer. In contrast to morphologically normal and hyperplastic structures in NRL-PRL females, carcinomas were insensitive to ERα-mediated signals. These tumors were distinct from mouse mammary tumor virus (MMTV)-neu tumors, and contained elevated transcripts for factors associated with luminal/alveolar expansion and differentiation, suggesting that they arose from physiologic targets of prolactin. These features were shared by ERα+ and ERα- tumors, suggesting a common origin, although the former exhibited transcript profiles reflecting greater differentiation. Conclusions Our studies demonstrate that prolactin can promote diverse carcinomas in mice, many of which resemble luminal breast cancers, providing a novel experimental model to examine the pathogenesis, progression and treatment responsiveness of this tumor subtype.
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Affiliation(s)
- Lisa M Arendt
- Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Dr., Madison, WI 53706, USA
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Eilon T, Barash I. Forced activation of Stat5 subjects mammary epithelial cells to DNA damage and preferential induction of the cellular response mechanism during proliferation. J Cell Physiol 2010; 226:616-26. [DOI: 10.1002/jcp.22381] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Arendt LM, Evans LC, Rugowski DE, Garcia-Barchino MJ, Rui H, Schuler LA. Ovarian hormones are not required for PRL-induced mammary tumorigenesis, but estrogen enhances neoplastic processes. J Endocrinol 2009; 203:99-110. [PMID: 19635758 PMCID: PMC2841967 DOI: 10.1677/joe-09-0221] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Epidemiologic studies have demonstrated that increased prolactin (PRL) exposure raises the risk of invasive estrogen receptor alpha (ERalpha)-positive breast cancer in women. However, the mechanism(s) whereby this occurs and the interactions with estrogen itself in this disease remain poorly understood. In order to investigate the role of ovarian hormones in the disease process, we employed a transgenic model neu-related lipocalin (NRL)-PRL in which transgenic PRL is directed to mammary epithelial cells by the PRL- and estrogen-insensitive NRL promoter, mimicking the endogenous PRL expression within the breast observed in women. This high local exposure leads to mammary lesion development and eventually carcinomas. Ovariectomy (ovx), shortly after puberty, did not alter the incidence or latency of PRL-induced mammary carcinomas, consistent with the independence of PRL from circulating estrogens as a risk factor for invasive breast cancer in women. However, chronic estrogen administration to ovx NRL-PRL females decreased the latency of both ERalpha-positive and -negative tumors. We identified multiple mechanisms that may underlie this observation. Elevated estrogen exposure cooperated with PRL to increase epithelial proliferation and myoepithelial abnormalities, increasing the incidence of preneoplastic lesions. Critical components of the extracellular matrix secreted by the myoepithelium were reduced with age, and transgenic PRL raised transcripts for tenascin-C and maspin, both associated with tumor progression and poor prognosis in subclasses of clinical breast tumors. Mammary pERK1/2 and pAkt, but not phosphorylated Stat5, were markedly elevated by local PRL. Together, these findings indicate that PRL employs multiple mechanisms to promote mammary tumorigenesis.
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Affiliation(s)
- Lisa M Arendt
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Carver KC, Arendt LM, Schuler LA. Complex prolactin crosstalk in breast cancer: new therapeutic implications. Mol Cell Endocrinol 2009; 307:1-7. [PMID: 19524120 PMCID: PMC3190192 DOI: 10.1016/j.mce.2009.03.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 03/23/2009] [Indexed: 12/27/2022]
Abstract
The contributions of prolactin (PRL) to breast cancer are becoming increasingly recognized. To better understand the role for PRL in this disease, its interactions with other oncogenic growth factors and hormones must be characterized. Here, we review our current understanding of PRL crosstalk with other mammary oncogenic factors, including estrogen, epidermal growth factor (EGF) family members, and insulin-like growth factor-I (IGF-I). The ability of PRL to potentiate the actions of these targets of highly successful endocrine and molecular therapies suggests that PRL and/or its receptor (PRLR) may be an attractive therapeutic target(s). We discuss the potential benefit of PRL/PRLR-targeted therapy in combination with established therapies and implications for de novo and acquired resistance to treatment.
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Affiliation(s)
- Kristopher C. Carver
- Cellular and Molecular Biology Program, University of Wisconsin-Madison, Madison, WI 53706, United States
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI 53706, United States
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Lisa M. Arendt
- Cellular and Molecular Biology Program, University of Wisconsin-Madison, Madison, WI 53706, United States
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Linda A. Schuler
- Cellular and Molecular Biology Program, University of Wisconsin-Madison, Madison, WI 53706, United States
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI 53706, United States
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, United States
- Corresponding author at: Department of Comparative Biosciences, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, United States. Tel.: +1 608 263 9825; fax: +1 608 263 3926. (L.A. Schuler)
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Tyrosine phosphorylation of Grb2: role in prolactin/epidermal growth factor cross talk in mammary epithelial cell growth and differentiation. Mol Cell Biol 2009; 29:2505-20. [PMID: 19273609 DOI: 10.1128/mcb.00034-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Characterizing mechanisms regulating mammary cell growth and differentiation is vital, as they may contribute to breast carcinogenesis. Here, we examine a cross talk mechanism(s) downstream of prolactin (PRL), a primary differentiation hormone, and epidermal growth factor (EGF), an important proliferative factor, in mammary epithelial cell growth and differentiation. Our data indicate that EGF exerts inhibitory effects on PRL-induced cellular differentiation by interfering with Stat5a-mediated gene expression independent of the PRL-proximal signaling cascade. Additionally, our data show that PRL is a potent inhibitor of EGF-induced cell proliferation. We identify tyrosine phosphorylation of the growth factor receptor-bound protein 2 (Grb2) as a critical mechanism by which PRL antagonizes EGF-induced cell proliferation by attenuating the activation of the Ras/mitogen-activated protein kinase (MAPK) pathway. Together, our results define a novel negative cross-regulation between PRL and EGF involving the Jak2/Stat5a and Ras/MAPK pathways through tyrosine phosphorylation of Grb2.
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Arendt LM, Grafwallner-Huseth TL, Schuler LA. Prolactin-growth factor crosstalk reduces mammary estrogen responsiveness despite elevated ERalpha expression. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:1065-74. [PMID: 19179608 DOI: 10.2353/ajpath.2009.080719] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most breast cancers that occur in women express estrogen receptor alpha (ERalpha). However, a large subset of these cancers either does not initially respond to anti-estrogen therapy or develops resistance to such treatment modalities. One postulated mechanism of this failure is signaling cross talk between hormones and local growth factors. To examine these complex interactions in vivo, we assessed the effects of estrogen on transforming growth factor alpha (TGFalpha)- and prolactin (PRL)-induced mammary tumorigenesis in transgenic mice. Both PRL and estrogen reduced the latency of TGFalpha-induced oncogenesis, resulting in tumors that were variably ERalpha-positive, but were progesterone receptor-negative. However, despite elevated ERalpha levels in NRL-PRL/TGFalpha glands, tumor latency was not reduced with increasing estrogen levels, nor increased after ovariectomy. Furthermore, PRL and TGFalpha in combination blocked the mitogenic effects of estrogen, dramatically reduced progesterone receptor levels, and diminished ERalpha down-regulation in response to circulating estrogen levels, in contrast to the other genotypes. Notably, however, ductal morphology remained responsive to estrogen, indicating that TGFalpha and PRL in combination can inhibit some, but not all, estrogenic signals. Both in vitro and in vivo, PRL and TGFalpha cooperatively enhanced Akt phosphorylation, which is associated with endocrine resistance in human disease. These findings provide insight into the interactions of PRL with growth factors during mammary oncogenesis and suggest combinatorial approaches that may result in improved therapeutic efficacy.
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Affiliation(s)
- Lisa M Arendt
- Department of Comparative Biosciences, University of Wisconsin, 2015 Linden Dr., Madison, WI 53706, USA
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Abstract
Both prolactin (PRL) and estrogen (E2) are involved in the pathogenesis and progression of mammary neoplasia, but the mechanisms by which these hormones interact to exert their effects in breast cancer cells are not well understood. We show here that PRL is able to activate the unliganded estrogen receptor (ER). In breast cancer cells, PRL activates a reporter plasmid containing estrogen response elements (EREs) and induces the ER target gene pS2. These actions are blocked by the antagonist ICI 182,780, showing that ER is required for the PRL-mediated effect. Moreover, PRL leads to phosphorylation of ERalpha in serine-118 (P-ERalpha), a modification related to the potentiation of ligand-independent transcriptional activation. In addition, PRL mimics the effect of E2 on target gene expression by inducing cyclical recruitment of ERalpha and P-ERalpha to ERE-containing promoters, resulting in recruitment of co-activators and acetylation of histone H3. Finally, PRL induces expression of c-Myc and Cyclin D1 and leads to increased cell proliferation, which is specifically antagonized by ICI 182,780 or ERalpha depletion. These results show that ligand-independent ERalpha activation appears to be an important component of the proliferative and transcriptional actions of PRL in breast cancer cells.
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Howell SJ, Anderson E, Hunter T, Farnie G, Clarke RB. Prolactin receptor antagonism reduces the clonogenic capacity of breast cancer cells and potentiates doxorubicin and paclitaxel cytotoxicity. Breast Cancer Res 2008; 10:R68. [PMID: 18681966 PMCID: PMC2575541 DOI: 10.1186/bcr2129] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 07/14/2008] [Accepted: 08/05/2008] [Indexed: 11/26/2022] Open
Abstract
Introduction Exogenous prolactin is mitogenic and antiapoptotic in breast cancer cells, and overexpression of autocrine prolactin cDNA in breast cancer cell lines has been shown to stimulate their growth and to protect against chemotherapy-induced apoptosis. We examined the effects of the 'pure' prolactin receptor antagonist Δ1–9-G129R-hPrl (Δ1–9) on the breast cancer cell number and clonogenicity, alone and in combination with chemotherapy. Methods The effects of doxorubicin, paclitaxel and Δ1–9 on the growth of breast cancer cell lines (MCF-7, T47D, MDA-MB-453, MDA-MB-468 and SK-BR-3) in monolayer culture were assessed by the sulphorhodamine B assay. Effects on clonogenicity were assessed by soft agar assay for the cell lines and by the mammosphere assay for disaggregated primary ductal carcinoma in situ samples. Dual-fluorescence immunocytochemistry was used to identify subpopulations of cells expressing the prolactin receptor and autocrine prolactin. Results Δ1–9 as a single agent had no effect on the cell number in monolayer culture, but potentiated the cytotoxic effects of doxorubicin and paclitaxel. Doxorubicin accordingly induced expression of prolactin mRNA and protein in all five breast cancer cell lines tested. Δ1–9 alone inhibited the clonogenicity in soft agar of cell lines by ~90% and the mammosphere forming efficiency of six disaggregated primary ductal carcinoma in situ samples by a median of 56% (range 32% to 88%). Subpopulations of cells could be identified in the cell lines based on the prolactin receptor and prolactin expression. Conclusion Autocrine prolactin appears to act as an inducible survival factor in a clonogenic subpopulation of breast cancer cells. The rational combination of cytotoxics and Δ1–9 may therefore improve outcomes in breast cancer therapy by targeting this cell population.
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Affiliation(s)
- Sacha J Howell
- Breast Biology Group, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK.
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Harvey PW, Everett DJ, Springall CJ. Adverse effects of prolactin in rodents and humans: breast and prostate cancer. J Psychopharmacol 2008; 22:20-7. [PMID: 18709700 DOI: 10.1177/0269881107082624] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Drugs and chemicals shown to induce mammary carcinogenesis in the rat/rodent via prolactin excess have traditionally been argued to pose little or no risk to humans in a regulatory toxicology context. The basis for this assumption is reviewed and placed into context with new evidence in humans that prolactin may be a tumour promoter in the breast and prostate. This evidence includes epidemiology, patient studies involving endocrine evaluation and molecular biology in human cells. It is concluded that hyperprolactinaemia is associated with an increase in breast cancer risk in both post and premenopausal women, that rat carcinogenicity studies are predictive of the human response, and that in a regulatory toxicology context prolactin-induced mammary tumours from nongenotoxic drugs and chemicals are an adverse effect that should not be ignored. More evidence is required concerning prostate cancer risk but molecular biology indicates that prolactin also induces prostate cell proliferation and inhibits apoptosis, which are similar to the responses observed in breast cancer cells.
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Affiliation(s)
- Philip W Harvey
- Department of Toxicology, Covance Laboratories Ltd., Otley Road, Harrogate, North Yorkshire, UK.
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Sultan AS, Brim H, Sherif ZA. Co-overexpression of Janus kinase 2 and signal transducer and activator of transcription 5a promotes differentiation of mammary cancer cells through reversal of epithelial-mesenchymal transition. Cancer Sci 2008; 99:272-9. [PMID: 18271926 PMCID: PMC11159878 DOI: 10.1111/j.1349-7006.2007.00685.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Signal transducer and activator of transcription (Stat) 5 appears to play a vital role in prolactin (PRL)-induced cell differentiation and normal mammary gland development. We previously showed that PRL-activated Stat5a induced expression of E-cadherin-beta-catenin complex in vitro and in xenotransplant tumors in vivo led to inhibition of breast cancer invasion. In the present study, we show that human breast cancer cells co-overexpressing Stat5a and its tyrosine kinase (Jak) 2 cultured in three-dimensional (3D) Matrigel culture demonstrate changes consistent with induction of mesenchymal-epithelial redifferentiation. Jak2 and Stat5a-co-overexpressing cells treated with cocktail (PRL, dexamethasone, and insulin), effectively reverse epithelial-mesenchymal transition by stimulating 3D organoids more reminiscent of the acinar growth of normal mammary epithelial cells, compared with cells overexpressing only Stat5a or Jak2. In contrast, dominant-negative dominant-negative-Stat5 blocks 3D organoid formation, causing cells to grow in layers instead. Hyperactivation of Jak2 and Stat5a in T-47D cells induces alveolar-like structures, mamospheres, with marked lumen formation through central apoptosis and restores a polarized epithelial phenotype. However, Jak2 and Stat5a overexpression in BT-20 cells induces partially differentiated 3D organoids with no central lumen, but effectively re-expresses estrogen receptor alpha. Jak2 and Stat5a-induced 3D differentiated organoids are accompanied by increased expression of E-cadherin, zonula occludens-1, and cytokeratins 8 and 18, and decreased levels of vimentin and Snail, indicating a shift from a mesenchymal phenotype toward an epithelial phenotype. Collectively, Jak2 and Stat5a co-overexpression cooperatively reverses epithelial-mesenchymal transition and promotes differentiation in human breast cancer cells, which may provide a mechanism to explain the invasive suppressor role of PRL-activated Stat5a in mammary cancer cells.
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Affiliation(s)
- Ahmed S Sultan
- Department of Oncology, Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
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Sultan AS, Brim H, Sherif ZA. Co-overexpression of Janus kinase 2 and signal transducer and activator of transcription 5a promotes differentiation of mammary cancer cells through reversal of epithelial-mesenchymal transition. Cancer Sci 2008; 99:272-279. [PMID: 18271926 DOI: 10.1111/j.1349-7006.2007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/28/2024] Open
Abstract
Signal transducer and activator of transcription (Stat) 5 appears to play a vital role in prolactin (PRL)-induced cell differentiation and normal mammary gland development. We previously showed that PRL-activated Stat5a induced expression of E-cadherin-beta-catenin complex in vitro and in xenotransplant tumors in vivo led to inhibition of breast cancer invasion. In the present study, we show that human breast cancer cells co-overexpressing Stat5a and its tyrosine kinase (Jak) 2 cultured in three-dimensional (3D) Matrigel culture demonstrate changes consistent with induction of mesenchymal-epithelial redifferentiation. Jak2 and Stat5a-co-overexpressing cells treated with cocktail (PRL, dexamethasone, and insulin), effectively reverse epithelial-mesenchymal transition by stimulating 3D organoids more reminiscent of the acinar growth of normal mammary epithelial cells, compared with cells overexpressing only Stat5a or Jak2. In contrast, dominant-negative dominant-negative-Stat5 blocks 3D organoid formation, causing cells to grow in layers instead. Hyperactivation of Jak2 and Stat5a in T-47D cells induces alveolar-like structures, mamospheres, with marked lumen formation through central apoptosis and restores a polarized epithelial phenotype. However, Jak2 and Stat5a overexpression in BT-20 cells induces partially differentiated 3D organoids with no central lumen, but effectively re-expresses estrogen receptor alpha. Jak2 and Stat5a-induced 3D differentiated organoids are accompanied by increased expression of E-cadherin, zonula occludens-1, and cytokeratins 8 and 18, and decreased levels of vimentin and Snail, indicating a shift from a mesenchymal phenotype toward an epithelial phenotype. Collectively, Jak2 and Stat5a co-overexpression cooperatively reverses epithelial-mesenchymal transition and promotes differentiation in human breast cancer cells, which may provide a mechanism to explain the invasive suppressor role of PRL-activated Stat5a in mammary cancer cells.
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Affiliation(s)
- Ahmed S Sultan
- Department of Oncology, Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
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Prolactin, TNF alpha and nitric oxide expression in nitroso-N-methylurea-induced-mammary tumours. J Carcinog 2007; 6:18. [PMID: 18045456 PMCID: PMC2219956 DOI: 10.1186/1477-3163-6-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 11/28/2007] [Indexed: 01/28/2023] Open
Abstract
Background The N-Nitrosomethylurea breast cancer model induced in rats is used for the study of carcinogenesis in mammary cancer, prostate, pancreas, etc. This model is very similar to human neoplastic disease. Methods The present experimental study was designed to assess whether metoclopramide administration has any effect on development of MNU-induced tumours, and evaluate the treatment of goserelin acetate on PRL, TNF alpha and NO expression. NMU was administered to female Wistar rats on 2 occasions (5 mg/100 g body w/rat). PRL and TNF alpha were performed by immune-assay. Nitric Oxide by semi automated-assay and ploidy analyses by flow cytometry. Results The administration of metoclopramide made the induction time shorter and increased the incidence and average of tumours per rat. Tumours development was inhibited by a goserelin chronic administration. The ploidy of adenocarcinoma was polyploid-aneuploid type (average S = 60%). It was higher basal PRL plasma levels in rats with NMU induced tumours than in basal controls without tumour (p < 0.001). The goserelin "in bolus" administration showed maximal inhibition of plasma PRL at 90 min. Plasmatic TNF alpha expression was inhibited at 60 min and also remained inhibited in tissue homogenate post chronic treatment (P < 0.0125). Plasmatic NO expression is higher in rats with induced tumours than healthy controls (P < 0.001). In tissue homogenate NO values were inhibited at 90 min (P < 0.01), as well during chronically goserelin treatment (P < 0.005). Conclusion The increase of blood PRL levels in NMU-induced rats may be an indicator of a poor prognosis of mammary cancer evolution. The metoclopramide administration accelerates tumour growth. However goserelin administration achieves regression in tumour development associated to inhibition PRL, TNF alpha and NO expression.
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Harvey PW, Everett DJ, Springall CJ. Hyperprolactinaemia as an adverse effect in regulatory and clinical toxicology: role in breast and prostate cancer. Hum Exp Toxicol 2007; 25:395-404. [PMID: 16898168 DOI: 10.1191/0960327106ht643oa] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Historically, hyperprolactinaemia has been considered of low toxicological relevance when detected in toxicity studies, and even mammary carcinogenesis induced in the rat by prolactin excess has been considered of no relevance to humans. However, recent findings from human epidemiology and molecular biology suggests that prolactin is a risk factor for human breast cancer, and probably prostate cancer. Therefore, this new evidence should be considered in the various decisions to develop and license a new drug or chemical if the compound causes hyperprolactinaemia. This emerging evidence suggests that prolactin can also be produced locally from human breast cancer cells, and that, regardless of source (ie, pituitary or autocrine/paracrine production from cancer cells), prolactin is mitogenic, stimulates proliferation and suppresses apoptosis in breast and prostate cancer cells. This review outlines the evidence that hyperprolactinaemia should be considered a toxicological adverse effect and concludes that prolactin-induced rodent mammary carcinogenesis is relevant to humans and is not species-specific. The effects of prolactin on the prostate gland are also discussed; hyperprolactinaemia may be an additional risk factor for prostate cancer and this also requires consideration in toxicological risk assessments. The implications of increased prolactin secretion as an adverse effect for regulatory toxicology of drugs and chemicals, and in high risk patients receiving therapeutic drugs with hyperprolactinaemic side effects, is discussed. Alteration of prolactin level is also a novel mechanism that requires consideration in endocrine disruption research, since both endogenous oestrogens and also xenoestrogens stimulate prolactin secretion or affect prolactin receptors.
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Affiliation(s)
- P W Harvey
- Department of Toxicology, Covance Laboratories Ltd., Harrogate, North Yorkshire, UK.
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30
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Abstract
Pituitary-derived prolactin (PRL) is a well-known regulator of the lactating mammary gland. However, the recent discovery that human adipose tissue produces PRL as well as expresses the PRL receptor (PRLR) highlights a previously unappreciated action of PRL as a cytokine involved in adipose tissue function. Biologically active PRL is secreted by all adipose tissue depots examined: breast, visceral and subcutaneous. The expression of adipose PRL is regulated by a non-pituitary, alternative superdistal promoter. PRL expression and release increases during early pre-adipocyte differentiation and is stimulated by cyclic AMP activators, including beta adrenergic receptor agonists. PRL release from subcutaneous adipose explants is attenuated during obesity, suggesting that adipose PRL production is altered by the metabolic state. Several lines of evidence indicate that PRL suppresses lipid storage as well as the release of adipokines such as adiponectin, interleukin-6 and possibly leptin. PRL has also been implicated in the regulation of adipogenesis. A newly developed PRL-secreting human adipocyte cell line, LS14, should allow comprehensive examination of the regulation and function of adipocyte-derived PRL. Collectively, these studies raise the prospect that PRL affects energy homeostasis through its action as an adipokine and is involved in the manifestation of insulin resistance.
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Affiliation(s)
- T Brandebourg
- Department of Cell Biology, University of Cincinnati School of Medicine, Cincinnati, OH, USA
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31
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Neilson LM, Zhu J, Xie J, Malabarba MG, Sakamoto K, Wagner KU, Kirken RA, Rui H. Coactivation of janus tyrosine kinase (Jak)1 positively modulates prolactin-Jak2 signaling in breast cancer: recruitment of ERK and signal transducer and activator of transcription (Stat)3 and enhancement of Akt and Stat5a/b pathways. Mol Endocrinol 2007; 21:2218-32. [PMID: 17550976 DOI: 10.1210/me.2007-0173] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Prolactin (PRL) receptors (PRLRs) have been considered selective activators of Janus tyrosine kinase (Jak)2 but not Jak1, Jak3, or Tyk2. We now report marked PRL-induced tyrosine phosphorylation of Jak1, in addition to Jak2, in a series of human breast cancer cell lines, including T47D, MCF7, and SKBR3. In contrast, PRL did not activate Jak1 in immortalized, noncancerous breast epithelial lines HC11, MCF10A, ME16C, and HBL-100, or in CWR22Rv1 prostate cancer cells or MDA-MB-231 breast cancer cells. However, introduction of exogenous PRLR into MCF10A, ME16C, or MDA-MB-231 cells reconstituted both PRL-Jak1 and PRL-Jak2 signals. In vitro kinase assays verified that PRL stimulated enzymatic activity of Jak1 in T47D cells, and PRL activated Jak1 and Jak2 with indistinguishable time and dose kinetics. Relative Jak2 deficiency did not cause PRLR activation of Jak1, because overexpression of Jak2 did not interfere with PRL activation of Jak1. Instead, PRL activated Jak1 through a Jak2-dependent mechanism, based on disruption of PRL activation of Jak1 after Jak2 suppression by 1) lentiviral delivery of Jak2 short hairpin RNA, 2) adenoviral delivery of dominant-negative Jak2, and 3) AG490 pharmacological inhibition. Finally, suppression of Jak1 by lentiviral delivery of Jak1 short hairpin RNA blocked PRL activation of ERK and signal transducer and activator of transcription (Stat)3 and suppressed PRL activation of Jak2, Stat5a, Stat5b, and Akt, as well as tyrosine phosphorylation of PRLR. The data suggest that PRL activation of Jak1 represents a novel, Jak2-dependent mechanism that may serve as a regulatory switch leading to PRL activation of ERK and Stat3 pathways, while also serving to enhance PRL-induced Stat5a/b and Akt signaling.
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Affiliation(s)
- Lynn M Neilson
- Kimmel Cancer Center, Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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32
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Gutzman JH, Rugowski DE, Nikolai SE, Schuler LA. Stat5 activation inhibits prolactin-induced AP-1 activity: distinct prolactin-initiated signals in tumorigenesis dependent on cell context. Oncogene 2007; 26:6341-8. [PMID: 17438530 PMCID: PMC3190200 DOI: 10.1038/sj.onc.1210454] [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: 01/18/2023]
Abstract
The essential role of prolactin (PRL) in normal mammary gland growth and differentiation has implicated this hormone in the development and progression of breast cancer. Although Stat5 is the best-characterized mediator of PRL signals, PRL also activates multiple other signals, whose roles in normal and pathologic processes are not well understood. We have shown that PRL stimulates activating protein-1 (AP-1) activity in breast cancer cells, and can cooperate with estradiol in this pathway. AP-1 modulates many processes critical for carcinogenesis, including cell proliferation, survival, transformation, invasion and angiogenesis, and is elevated in many neoplasms, including breast tumors. Here, we investigated the relationship between PRL signals to AP-1 and Stat5. We found that PRL activation of Stat5a and Stat5b, but not Stat1 or Stat3, reduced PRL signals to AP-1, without altering estradiol-induced AP-1 activity. The truncation mutant, Stat5/Delta53C, but not Stat5Y699F, was an effective inhibitor, consistent with a requirement for Stat5 dimerization and nuclear accumulation, but not its C-terminal transactivation activity. The association of Stat5 with AP-1 proteins suggests that this underlies the inhibition. Predictably, the ability of PRL to activate Stat5 and AP-1 was inversely related in mammary cell lines. Further, reduction of Stat5 protein with siRNA in T47D cells, which contain elevated Stat5, increased PRL-induced AP-1 signals, transcripts for the AP-1 target, matrix metalloproteinase-2 and associated invasive behavior. This study points to the importance of cell context in determining the spectrum of PRL-induced actions, which is critical for understanding the contributions of PRL to breast cancer.
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Affiliation(s)
- JH Gutzman
- Molecular and Environmental Toxicology Program, University of Wisconsin-Madison, Madison, WI, USA
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - DE Rugowski
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - SE Nikolai
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - LA Schuler
- Molecular and Environmental Toxicology Program, University of Wisconsin-Madison, Madison, WI, USA
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
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33
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Huang Y, Li X, Jiang J, Frank SJ. Prolactin modulates phosphorylation, signaling and trafficking of epidermal growth factor receptor in human T47D breast cancer cells. Oncogene 2006; 25:7565-76. [PMID: 16785991 DOI: 10.1038/sj.onc.1209740] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Prolactin (PRL) is a polypeptide hormone produced by the anterior pituitary gland and other sites that acts both systemically and locally to cause lactation and other biological effects by interacting with the PRL receptor, a Janus kinase (JAK)2-coupled cytokine receptor family member, and activating downstream signal pathways. Recent evidence suggests PRL is a player in the pathogenesis and progression of breast cancer. Epidermal growth factor (EGF) also has effects on breast tissue, working through its receptors, epidermal growth factor receptor (EGFR) and ErbB-2 (c-neu, HER2), both intrinsic tyrosine kinase growth factor receptors. EGFR promotes pubertal breast ductal morphogenesis in mice, and both EGFR and ErbB-2 are relevant in pathogenesis and behavior of breast and other human cancers. Previous studies showed that PRL and EGF synergize to enhance motility in the human breast cancer cell line, T47D. In this study, we explored crosstalk between the PRL and EGF signaling pathways in T47D cells, with an ultimate aim of understanding how these two important factors might work together in vivo to affect breast cancer behavior. Both PRL and EGF caused robust signaling in T47D cells; PRL acutely activated JAK2, signal transducer and activator of transcription-5 (STAT5), and extracellular signal-regulated kinase-1 and -2 (ERK1 and ERK2), whereas EGF caused EGFR activation and consequent src homology collagen (SHC) activation and ERK activation. Notably, PRL also caused phosphorylation of the EGFR and ErbB-2 at sites detected by PTP101, an antibody that recognizes threonine phosphorylation at consensus motifs for ERK-induced phosphorylation. PRL-induced PTP101-reactive phosphorylation was prevented by pretreatment with PD98059, an ERK pathway inhibitor. Furthermore, PRL synergized with EGF in activating SHC and ERK and transactivating a luciferase reporter driven by c-fos gene enhancer elements, suggesting that PRL allowed markedly enhanced EGF signaling. This was accompanied by substantial inhibition of EGF-induced EGFR downregulation when PRL and EGF cotreatment was compared to EGF treatment alone. This effect of PRL was abrogated by ERK pathway inhibitor pretreatment. Our data suggest that PRL synergistically augments EGF signaling in T47D breast cancer cells at least in part by lessening EGF-induced EGFR downregulation and that this effect requires PRL-induced ERK activity and threonine phosphorylation of EGFR.
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Affiliation(s)
- Y Huang
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
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34
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Nouhi Z, Chughtai N, Hartley S, Cocolakis E, Lebrun JJ, Ali S. Defining the role of prolactin as an invasion suppressor hormone in breast cancer cells. Cancer Res 2006; 66:1824-32. [PMID: 16452244 DOI: 10.1158/0008-5472.can-05-2292] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Prolactin hormone (PRL) is well characterized as a terminal differentiation factor for mammary epithelial cells and as an autocrine growth/survival factor in breast cancer cells. However, this function of PRL may not fully signify its role in breast tumorigenesis. Cancer is a complex multistep progressive disease resulting not only from defects in cell growth but also in cell differentiation. Indeed, dedifferentiation of tumor cells is now recognized as a crucial event in invasion and metastasis. PRL plays a critical role in inducing/maintaining differentiation of mammary epithelial cells, suggesting that PRL signaling could serve to inhibit tumor progression. We show here that in breast cancer cells, PRL and Janus-activated kinase 2, a major kinase involved in PRL signaling, play a critical role in regulating epithelial-mesenchymal transformation (EMT), an essential process associated with tumor metastasis. Activation of the PRL receptor (PRLR), achieved by restoring PRL/JAK2 signaling in mesenchymal-like breast cancer cells, MDA-MB-231, suppressed their mesenchymal properties and reduced their invasive behavior. While blocking PRL autocrine function in epithelial-like breast cancer cells, T47D, using pharmacologic and genetic approaches induced mesenchymal-like phenotypic changes and enhanced their invasive propensity. Moreover, our results indicate that blocking PRL signaling led to activation of mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2) and transforming growth factor-beta/Smad signaling pathways, two major prometastatic pathways. Furthermore, our results indicate that following PRL/JAK2 inhibition, ERK1/2 activation precedes and is required for Smad2 activation and EMT induction in breast cancer cells. Together, these results highlight PRL as a critical regulator of epithelial plasticity and implicate PRL as an invasion suppressor hormone in breast cancer.
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Affiliation(s)
- Zaynab Nouhi
- Hormones and Cancer Research Unit, Department of Medicine, McGill University, Montreal, Quebec, Canada
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35
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Harvey PW, Everett DJ. Regulation of endocrine-disrupting chemicals: critical overview and deficiencies in toxicology and risk assessment for human health. Best Pract Res Clin Endocrinol Metab 2006; 20:145-65. [PMID: 16522525 DOI: 10.1016/j.beem.2005.09.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Regulation of endocrine-disrupting chemicals is reviewed in terms of hazard assessment (regulatory toxicology) and risk assessment. The current range of regulatory general toxicology protocols can detect endocrine toxicity, but specific endocrine toxicology tests are required to confirm mechanisms (e.g. oestrogenic, anti-androgenic). Strategies for validating new endocrine toxicology protocols and approaches to data assessment are discussed, and deficiencies in regulatory toxicology testing (e.g. lack of adrenocortical function assessment) identified. Recent evidence of a role of prolactin in human breast cancer also highlights deficiencies in regulatory evaluation. Actual human exposure to chemicals and the high-exposure example of chemicals in body-care cosmetics is reviewed with reference to evidence that common ingredients (e.g. parabens, cyclosiloxanes) are oestrogenic. The hypothesis and epidemiology concerning chemical exposure from body-care cosmetics (moisturizers, lotions, sun screens, deodorants) and breast cancer in women is reviewed, applying Bradford-Hill criteria for association and causality, and research requirements are identified.
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Affiliation(s)
- Philip W Harvey
- Toxicology Department, Covance Laboratories Ltd, Otley Road, Harrogate, North Yorkshire HG3 1PY, UK.
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36
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Bolander FF. The compartmentalization of prolactin signaling in the mouse mammary gland. Mol Cell Endocrinol 2005; 245:105-10. [PMID: 16337084 DOI: 10.1016/j.mce.2005.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 09/21/2005] [Accepted: 11/02/2005] [Indexed: 10/25/2022]
Abstract
In mammary epithelial cells, prolactin (PRL) activates at least two signaling pathways: Jak/Stat and nitric oxide (NO). The former induces differentiation as measured by alpha-lactalbumin accumulation, while experiments with sodium nitroprusside (SNP) show that NO inhibits differentiation. In order to resolve this apparent contradiction, the kinetics, inducibility, and cellular localization of NO production and sensitivity in mammary cells were examined. First, mammary cells remained responsive to PRL throughout the incubation with respect to NO production. Second, although desensitization occurred with continuous PRL exposure, recovery began as quickly as 30 min after PRL withdrawal. Since PRL is secreted in pulses in vivo, complete desensitization was not a likely explanation for the cells' escape from NO inhibition. Finally, the cellular site of transduction was examined using the caveolar disrupting agent, methyl-beta-cyclodextrin (MBCD). MBCD inhibited the accumulation of PRL-induced NO but not alpha-lactalbumin. This finding was confirmed by membrane fractionation studies where the PRL-induced NO production occurred primarily in caveolae and PRL-stimulated tyrosine phosphorylation of Stat5, which transcribes the alpha-lactalbumin gene, occurred predominantly in noncaveolar membranes. Finally, endogenous elevations of NO by arginine did not inhibit differentiation. As such, the inhibition seen with SNP appeared to be an artifact of the ubiquitous generation of NO from SNP. Physiologically, PRL induces NO only in caveolae and this restricted distribution does not interfere with differentiation.
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Affiliation(s)
- Franklyn F Bolander
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, USA.
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37
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Abstract
The mitogen-activated protein kinase (MAPK) ERK5 plays an important role in mammary epithelial proliferation, endothelial cell survival and normal embryonic development. In nonhaematopoietic cells, mitogenic and stress signals activate the ERK5 cascade. Here, we investigated the role of the ERK5 pathway in T-cell activation and show that primary and leukaemic T cells express ERK5, whose activating phosphorylation is induced by antibodies against CD3 but not by phorbol myristate acetate treatment. ERK5 localized in the cytosol and nucleus in quiescent and activated T cells. In the latter, ERK5 phosphorylation was mainly observed in the nucleus. Selective activation of the ERK5 cascade by transfecting constitutively active MEK5 and wildtype ERK5 induced a reporter gene driven by the IL-2 promoter while barely affecting CD69 expression. These results suggest a new role for the ERK5 cascade in intracellular signalling in T cells.
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Affiliation(s)
- J Garaude
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR5535, IFR 122, 34293 Montpellier cedex 5, France
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38
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Harvey PW. Human relevance of rodent prolactin-induced non-genotoxic mammary carcinogenesis: prolactin involvement in human breast cancer and significance for toxicology risk assessments. J Appl Toxicol 2005; 25:179-83. [PMID: 15856525 DOI: 10.1002/jat.1063] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Prolactin-induced mammary carcinogenesis in rodents, particularly rats, is often stated to be of low toxicological relevance to humans. This opinion appears to have developed from a number of lines of cited evidence. Firstly, there had been long experience of use of dopamine antagonists (that increase prolactin) in human medicine and no evidence of an increase in breast cancer incidence or risk had been reported. Secondly, dopamine agonists (that lower prolactin) had been shown to have no effect in human breast cancer treatment. Thirdly, the actions of prolactin were considered different between rodents and humans. However, recent evidence now suggests that prolactin has a major role in human breast cancer, and the similarity of mechanism with the rodent suggests that prolactin-mediated mammary carcinogenesis in rodents could be of much higher toxicological relevance to humans than previously thought. Large epidemiology studies have upgraded a limited database and shown that dopamine antagonists (both antipsychotics and anti-emetics) increase breast cancer risk, that hyperprolactinaemia is consistently associated with human breast cancer growth, development and poor prognosis, and that prolactin is indeed a mitogen in human breast cancer cells that suppresses apoptosis and upregulates BRCA1. It is now clear that initial studies giving dopamine agonists to breast cancer patients had no effect because breast cancer cells also produced prolactin independently of the pituitary, which remained uncontrolled and unrecognized in early clinical studies. The evidence for the role of prolactin in human breast cancer is now strong and consistent, and is discussed and related to the risk assessment of drugs and chemicals. The conclusion is that it is invalid to suggest that prolactin-induced mammary carcinogenesis in rodents is of low relevance to humans because prolactin can induce an adverse response in the mammary tissue of both rodents and humans alike. Drugs and chemicals causing rodent prolactin-induced mammary carcinogenesis may therefore pose a risk to humans via the same mechanism if exposures also increase prolactin secretion in humans.
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Affiliation(s)
- Philip W Harvey
- Department of Toxicology, Covance Laboratories, Otley Road, Harrogate, North Yorkshire HG3 1PY, UK.
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Gutzman JH, Nikolai SE, Rugowski DE, Watters JJ, Schuler LA. Prolactin and estrogen enhance the activity of activating protein 1 in breast cancer cells: role of extracellularly regulated kinase 1/2-mediated signals to c-fos. Mol Endocrinol 2005; 19:1765-78. [PMID: 15746191 PMCID: PMC1630766 DOI: 10.1210/me.2004-0339] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Despite the important roles of both prolactin (PRL) and 17beta-estradiol (E2) in normal mammary development as well as in breast cancer, and coexpression of the estrogen receptor (ER) and PRL receptor in many mammary tumors, the interactions between PRL and E2 in breast cancer have not been well studied. The activating protein 1 (AP-1) transcription factor, a known regulator of processes essential for normal growth and development as well as carcinogenesis, is a potential site for cross-talk between these hormones in breast cancer cells. Here we demonstrate that PRL and E2 cooperatively enhance the activity of AP-1 in MCF-7-derived cells. In addition to the acute PRL-induced ERK1/2 activation, PRL and E2 also individually elicited delayed, sustained rises in levels of phosphorylated p38 and especially ERK1/2. Together, these hormones increased the dynamic phosphorylation of ERK1/2 and c-Fos, and induced c-fos promoter activity. Synergistic activation of the transcription factor, Elk-1, reflected the PRL-E2 interaction at ERK1/2 and is a likely mechanism for activation of the c-fos promoter via the serum response element. The enhanced AP-1 activity resulting from the interaction of these hormones may increase expression of many target genes that are critical for oncogenesis and may contribute to neoplastic progression.
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Affiliation(s)
| | | | | | | | - Linda A. Schuler
- Address all correspondence and requests for reprints to: L.A. Schuler, Department of Comparative Biosciences, University of Wisconsin, 2015 Linden Drive, Madison, Wisconsin 53706. E-mail:
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