1
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Association of epidermal growth factor receptor and mitogen-activated protein kinase with cystic neoplasms of the pancreas. Mod Pathol 2010; 23:1127-35. [PMID: 20495538 DOI: 10.1038/modpathol.2010.97] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The molecular pathobiology of pancreatic cystic neoplasms is poorly understood. The aim of this study was to know the involvement of epidermal growth factor receptor (EGFR) and its downstream targets in the serous cystic neoplasms and the mucinous cystic neoplasms of the pancreas. In a total of 72 pancreatic cystic neoplasms, including 39 serous cystic neoplasms and 33 mucinous cystic neoplasms, we examined the expression of native and phosphorylated EGFR, mitogen-activated protein kinase (MAPK), and AKT by immunohistochemistry and somatic mutations in EGFR, KRAS, BRAF, and PIK3CA, by direct sequencing. We also assessed the copy numbers of EGFR transcripts and the amplification of the EGFR gene in some of the samples. We found that EGFR, phosphorylated EGFR, MAPK, and phosphorylated MAPK were evidently expressed in 100, 54, 100, and 69% of the serous cystic neoplasms, and in 12%, none, 33, and 27% of the mucinous cystic neoplasms, respectively; the expression was significantly higher and more prevalent in the serous cystic neoplasms than in the mucinous cystic neoplasms. The expression of AKT and phosphorylated AKT was low in both the types of neoplasms. On average, EGFR transcripts in the serous cystic neoplasms and the mucinous cystic neoplasms increased 53.5- and 2.5-fold, respectively, as compared with that in normal tissues, with the increase in the former being significantly greater than that in the latter. Amplification of the EGFR gene was not detected in any of the examined serous cystic neoplasms. None of the tumors had mutations in any of the examined portions of the genes, except two mucinous cystic neoplasms with mutations in codon-12 of KRAS. These results indicate that EGFR and MAPK are actively involved in the pathobiology of serous cystic neoplasms and may therefore be potential diagnostic markers and therapeutic targets in patients with the above mentioned types of neoplasms.
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2
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Gong R, Huang L, Shi J, Luo K, Qiu G, Feng H, Tien P, Xiao G. Syncytin-A mediates the formation of syncytiotrophoblast involved in mouse placental development. Cell Physiol Biochem 2007; 20:517-26. [PMID: 17762178 DOI: 10.1159/000107535] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2007] [Indexed: 01/08/2023] Open
Abstract
Syncytin-A, a new mouse endogenous retroviral envelope protein expressed in placenta, can mediate cell fusion in vitro. But its physiological function was still unknown. We proposed a role for syncytin-A in syncytiotrophoblast (SynT) formation derived from the differentiation of trophoblast stem (TS) cells during placental development. To evaluate this hypothesis, we analyzed the involvement of syncytin-A in the differentiation of mouse TS cells. After withdrawing fibroblast growth factor 4 (FGF4), TS cells can fuse to form SynT cells. We found syncytin-A mRNA and protein expression are colinear with fusion index increase during TS cell differentiation. Expression of syncytin-A is localized in SynT cells through in situ immunofluorescent staining. By using specific antibody and antisense oligonucleotides, we demonstrated that inhibition of syncytin-A lead to obvious decrease of SynT cell formation. These results present evidence in support of the direct role for syncytin-A in mouse TS cell fusion and differentiation involved in placental development.
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Affiliation(s)
- Rui Gong
- State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan, China
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3
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Maioli E, Fortino V, Pacini A. Parathyroid Hormone-Related Protein in Preeclampsia: A Linkage Between Maternal and Fetal Failures. Biol Reprod 2004; 71:1779-84. [PMID: 15286039 DOI: 10.1095/biolreprod.104.030932] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Preeclampsia is a disorder associated with pregnancy that affects both the mother and the fetus. Typical features of the disease are maternal hypertension, proteinuria, and edema as well as fetal growth retardation. Although the etiological details are still being debated, a consensus exists that the starting point is deficient placentation in the first half of pregnancy. The crucial early steps are reduced trophoblast invasiveness and enhanced apoptotic death. In the present review, we demonstrate that parathyroid hormone-related protein is involved not only in the maternal and fetal failures but also in the etiological aspects of the disease. We hypothesize that reduced local production of the peptide is a major causative event.
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Affiliation(s)
- Emanuela Maioli
- Department of Physiology, Section of Immunoendocrinology and Reproductive Physiology, University of Siena, 8-53100 Siena, Italy.
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4
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Abstract
BACKGROUND Information is presented on prostatic neuroendocrine cells and neuroendocrine differentiation in prostatic carcinoma. The prognostic and therapeutic implications of neuroendocrine differentiation in prostatic carcinoma are reviewed. METHODS Data are presented that support the intriguing link between neuroendocrine differentiation, tumor progression, and androgen-independent prostate cancer. The hormones, and the receptors, expressed by prostatic neuroendocrine cells are investigated in order to elucidate their significance for prognosis and therapy. RESULTS The prognostic significance of neuroendocrine differentiation in prostatic malignancy has been controversial, but recent studies employing markers such as chromogranin A and neuron-specific enolase suggest that neuroendocrine differentiation, as reflected by increased tissue expression and/or blood levels of these neuroendocrine secretory products, correlates with poor prognosis, tumor progression, and androgen-independence. Since all malignant neuroendocrine cells are devoid of androgen receptors and since neuroendocrine phenotypic expression is not suppressed by androgen ablation, clonal propagation of androgen receptor-negative neuroendocrine cells may play an important role in the pathway towards the androgen-independent state of prostatic carcinoma. This would have significant implications for the treatment of prostate cancer, as several of the hormones known to be expressed by neuroendocrine-differentiated, malignant prostatic cells are potential candidates for drug therapy. A limited number of hormones have been tested in this context, in particular somatostatin, bombesin, and serotonin. CONCLUSIONS Neuroendocrine differentiation in carcinoma of the prostate appears to be associated with poor prognosis, tumor progression, and the androgen-independent state, for which there is currently no successful therapy. Therefore, new therapeutic protocols and trials need to be developed to test drugs based on neuroendocrine hormones and/or their antagonists. An evaluation of this new therapeutic approach against prostatic carcinoma with neuroendocrine differentiation, including hormone-refractory cancer, is easily justified, since these tumors are unresponsive to current modes of therapy.
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Affiliation(s)
- P A Abrahamsson
- Department of Urology, University Hospitals of Malmö and Lund, University of Lund, Sweden.
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5
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Weidler M, Marx UC, Seidel G, Schäfer W, Hoffmann E, Esswein A, Rösch P. The structure of human parathyroid hormone-related protein(1-34) in near-physiological solution. FEBS Lett 1999; 444:239-44. [PMID: 10050767 DOI: 10.1016/s0014-5793(98)01658-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Parathyroid hormone-related protein plays a major role in the pathogenesis of humoral hypercalcemia of malignancy. Under normal physiological conditions, parathyroid hormone-related protein is produced in a wide variety of tissues and acts in an autocrine or paracrine fashion. Parathyroid hormone-related protein and parathyroid hormone bind to and activate the same G-protein-coupled receptor. Here we present the structure of the biologically active NH2-terminal domain of human parathyroid hormone-related protein(1-34) in near-physiological solution in the absence of crowding reagents as determined by two-dimensional proton magnetic resonance spectroscopy. An improved strategy for structure calculation revealed the presence of two helices, His-5-Leu-8 and Gln-16-Leu-27, connected by a flexible linker. The parathyroid hormone-related protein(1-34) structure and the structure of human parathyroid hormone(1-37) as well as human parathyroid hormone(1-34) are highly similar, except for the well defined turn, His-14-Ser-17, present in parathyroid hormone. Thus, the similarity of the binding affinities of parathyroid hormone and parathyroid hormone-related protein to their common receptor may be based on their structural similarity.
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Affiliation(s)
- M Weidler
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany
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6
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Ferguson JE, Seaner RM, Bruns DE, Iezzoni JC, Bruns ME. Expression and specific immunolocalization of the human parathyroid hormone/parathyroid hormone-related protein receptor in the uteroplacental unit. Am J Obstet Gynecol 1998; 179:321-9. [PMID: 9731833 DOI: 10.1016/s0002-9378(98)70359-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Our purpose in these studies was to determine the expression and cellular localization of the parathyroid hormone/parathyroid hormone-related protein receptor in the human uteroplacental unit. STUDY DESIGN Human uteroplacental tissues were obtained and ribonucleic acid was extracted. Reverse transcriptase-polymerase chain reaction was performed with use of primers for both the parathyroid hormone/parathyroid hormone-related protein receptor and human phosphoglyceraldehyde dehydrogenase. Ethidium bromide-stained gels and Southern blots were evaluated, and polymerase chain reaction fragments were sequenced. For immunohistochemistry, slides were incubated with a newly developed antibody (3D1.1) specific for the parathyroid hormone/parathyroid hormone-related protein receptor, and bound monoclonal antibody was detected by use of the avidin-biotin technique. RESULTS Reverse transcriptase polymerase chain reaction gels and blots showed that receptor messenger ribonucleic acid was present in choriodecidua, placenta, and myometrium. Sequence analysis revealed complete identity of the receptor product and the known nucleotide sequence in the receptor. There was intense receptor staining of the myometrial smooth muscle as well as staining of the endothelium and smooth muscle of the associated vasculature. In umbilical cord immunoreactive receptor was found in the vascular endothelium and vascular smooth muscle cells and in stromal cells. In choriodecidua receptor was found in chorionic trophoblasts and decidualized endometrial stromal cells. In all tissues immunostaining was specific, as evidenced by the blocking of staining after addition of receptor peptide to the antibody (absorbed controls). CONCLUSION The parathyroid hormone/parathyroid hormone-related protein receptor is widely expressed in the human uteroplacental unit. The cellular localizations of the receptor in smooth muscle reflect the ability of parathyroid hormone-related protein to relax both uterine and vascular smooth muscle. The presence of novel autocrine and paracrine systems in the human uteroplacental unit is suggested by the finding that the same cells or adjacent cells produce both parathyroid hormone-related protein and its receptor.
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Affiliation(s)
- J E Ferguson
- Department of Obstetrics and Gynecology, University of Virginia School of Medicine, Charlottesville, USA
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7
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Abstract
During pregnancy, the trophoblast, supporting the main functions of the placenta, develops from the fusion of cytotrophoblastic cells into a syncytiotrophoblast. Gap junction channels consisting of connexins link the cytosols of cells in contact. Gap junctional communication has been involved in the control of cell and tissue differentiation. Recently, a gap junctional communication was demonstrated in trophoblast cell culture by means of the fluorescence recovery after photobleaching (gap-FRAP) technique. This gap junctional communication appeared to be stimulated by human chorionic gonadotropin (hCG). Therefore, the specificity of hCG action and the signalling mechanisms implicated in gap junctional communication were investigated by means of gap-FRAP. In culture, cytotrophoblastic cells develop into cellular aggregates, then into a syncytium, within 1-2 days after plating. During this in vitro differentiation, gap junctional communication was measured, and the maximum percentage of coupling between adjacent cells occurred on the fourth day. In the presence of 500 mIU/ml hCG, the percentage of coupled cells was increased at all stages of culture, and the highest proportion of coupled cells was observed after 2 days instead of 4 days in control conditions. The hCG action was specific, since the addition of heat-inactivated hCG of oFSH or of bTSH did not affect gap junctional communication in trophoblastic cells. The addition of a polyclonal hCG antibody decreased basal gap junctional communication as well as the response to exogenous hCG. Moreover, the presence of 8Br-cAMP (0.5 or 1 mM) mimicked the stimulation by hCG. Interestingly, H89 (2 microM), a specific protein kinase-A inhibitor, dramatically decreased the responses to hCG (500 mIU/ml) and the 8Br-cAMP (0.5 mM) stimulation of trophoblastic gap junctional communication. Calphostin (1 or 2 microM), a specific protein kinase-C inhibitor, strongly stimulated gap junctional communication. In conclusion, the demonstration by means of the gap-FRAP method of a gap junctional communication preceding cellular fusion could be considered as an objective and physiological criterion to mark the beginning of trophoblast differentiation. hCG, a hormone produced by the trophoblast, and two signalling mechanisms are implicated in this phenomenon.
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Affiliation(s)
- L Cronier
- Laboratoire de Physiologie Cellulaire, CNRS URA 1869, Université de Poitiers, France
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8
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Karl PI, Chusid J, Tagoe C, Fisher SE. Ca2+ flux in human placental trophoblasts. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:C1776-80. [PMID: 9227404 DOI: 10.1152/ajpcell.1997.272.6.c1776] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Intracellular Ca2+ is an important second messenger. In the placenta, regulation of intracellular Ca2+ concentration ([Ca2+]i) by extracellular factors has received relatively little attention. Cultured human placental trophoblasts were treated with a series of potential Ca(2+)-mobilizing ligands. After 3 days in culture, there was an increase in [Ca2+]i in response to angiotensin, endothelin, transforming growth factor-alpha, and ATP in approximately 8, 54, 17, and 100% of the cells, respectively. The response to ATP was dose dependent. At low ATP concentrations (1-10 microM), the response to repeat ATP application remained unchanged, whereas at 100 microM, response to repeat stimulation resulted in lower peak value. The order of potency for the ATP derivatives was ATP = UTP > benzoylbenzoic-ATP > ATP gamma S > ADP beta S > ADP > alpha,beta-MeATP > AMP. This suggests action via the P2u purinergic receptor. Removal of extracellular Ca2+ decreased the ATP-induced Ca2+ response by 45%; this indicates that a substantial portion of the increase in [Ca2+]i was due to influx from extracellular space. Finally, ATP rapidly induced inositol 1,4,5-trisphosphate formation in cultured trophoblasts. Therefore, ATP-induced changes in Ca2+ flux may be due in part to activation of phosphoinositide-specific phospholipase C. In summary, ATP is a potent calciotropic ligand in human placental trophoblasts, acting through the P2u receptor. The effect of ATP on [Ca2+]i may prove to be involved in the modulation of various trophoblast functions, including hormone secretion and active transport of nutrients.
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Affiliation(s)
- P I Karl
- Department of Pediatrics, North Shore University Hospital, New York University School of Medicine, Manhasset 11030, USA
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9
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Abstract
The extensive role played by protein kinase C (PKC) in signal transduction prompted this study of the expression and localization of PKC isoforms in human placental syncytiotrophoblast. Membranes prepared from these cells and samples of villous tissue were analysed by immunoblotting and immunocytochemistry using isoform-specific antibodies. PKC beta 2, gamma, epsilon and zeta were found to be present in both microvillous and basal membranes from term placenta. The alpha isoform was observed only on the basal membrane while the beta 1 isoform was confined to the microvillous membrane. The basal microvillous ratios for beta 2, gamma, epsilon and zeta ranged between 0.3 and 0.5, demonstrating a substantial asymmetry in plasma membrane localization. Immunocytochemistry supported the isoform identification and localization observed in the immunoblotting experiments. Moreover the cellular distribution showed that the majority of syncytical PKC was bound to the plasma membranes, in contrast to the other villous cell types. Immunoblotting experiments demonstrated significant increases in PKC beta 2 and epsilon on the microvillous membrane and PKC gamma and epsilon on the basal membrane between 16 and 40 of weeks gestation. This is the first detailed mapping of PKC isoform distribution in an epithelial cell type and demonstrates the potential for selectivity in signal transduction through phosphorylation of isoform specific and spatially-separated substrates.
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Affiliation(s)
- A L Ruzycky
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, USA
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10
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Iwamura M, Hellman J, Cockett AT, Lilja H, Gershagen S. Alteration of the hormonal bioactivity of parathyroid hormone-related protein (PTHrP) as a result of limited proteolysis by prostate-specific antigen. Urology 1996; 48:317-25. [PMID: 8753751 DOI: 10.1016/s0090-4295(96)00182-3] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To discover whether the proteolytic activity of prostate-specific antigen (PSA) affects the structure and function of parathyroid hormone-related protein (PTHrP), as both are abundant components of human seminal plasma. METHODS The ability of PTHrP to act as a substrate was studied by incubating a synthetic polypeptide, consisting of 34 amino acid residues of the amino-terminal domain of PTHrP, with purified PSA. The incubate was then analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-pressure liquid chromatography separation, amino-terminal peptide sequencing, and mass spectrometry. The physiologic effect of the proteolytic activity of PSA on PTHrP was studied by measuring any alteration in PTHrP (1-34)-induced elevation of cyclic adenosine monophosphate (cAMP) production by UMR-106 rat osteosarcoma cells in culture. All cell culture experiments were performed with PSA and PTHrP (1-34) at physiologic concentrations. RESULTS. Our data show that PSA proteolytically cleaves PTHrP (1-34) after either residue 22 or 23, generating three peptide fragments. Both cleavages occur carboxy terminally of a phenylalanine residue. The cAMP production in rat osteosarcoma cells, induced by the amino-terminal portion of PTHrP (1-34), as a result of its structural similarity with parathyroid hormone (PTH), was abated by PSA in a dose- and time-dependent fashion. In contrast, heat-inactivated PSA had no effect on cAMP production. CONCLUSIONS Our study demonstrates that PTHrP is a substrate for PSA. The cleavage of the amino-terminal portion of PTHrP completely disrupts its ability to interact with the PTH/PTHrP receptor and thus inhibits its PTH-like activity. The proteolytic processing of PTHrP by PSA may play an important role in the post-translational/post-secretional regulation of prostatic PTHrP activities, which are believed to include regulation of prostate growth and differentiation.
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Affiliation(s)
- M Iwamura
- Department of Urology, University of Rochester Medical Center, New York, USA
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11
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Roulier S, Rochette-Egly C, Alsat E, Dufour S, Porquet D, Evain-Brion D. EGF increases retinoid X receptor-alpha expression in human trophoblastic cells in culture: relationship with retinoic acid induced human chorionic gonadotropin secretion. Mol Cell Endocrinol 1996; 118:125-35. [PMID: 8735598 DOI: 10.1016/0303-7207(96)03773-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the present study, the effect of retinoic acid (RA) and epidermal growth factor (EGF) on the functions of human trophoblastic cells in culture were analysed. In these cells, RA potentiated the hCG secretion increase induced by EGF. To gain a better understanding of such a synergistic effect, the expression of retinoic acid receptors (RAR alpha and beta) and retinoid X receptor (RXR alpha) was studied by immunoblotting in RA- and EGF-treated cells. EGF treatment specifically increased the level of RXR alpha protein and RXR alpha transcripts. In parallel, we demonstrated that the choriocarcinoma cells JEG 3, which respond to RA by an increase in hCG secretion, express constitutively high levels of RXR alpha protein. Furthermore, RXR alpha-transfected trophoblastic cells also become RA responsive for hCG secretion. All these data suggest that RXR alpha expression is modulated by EGF, and may be involved in the effect of RA on hCG secretion.
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Affiliation(s)
- S Roulier
- INSERM U427, Faculté des Sciences Pharmaceutiques et Biologiques de Paris, Université René Descartes-Paris V, France
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12
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Ingleton PM, Danks JA. Distribution and functions of parathyroid hormone-related protein in vertebrate cells. INTERNATIONAL REVIEW OF CYTOLOGY 1996; 166:231-80. [PMID: 8881777 DOI: 10.1016/s0074-7696(08)62510-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Parathyroid hormone-related protein (PTHrP) was isolated from tumors and identified as the agent of humoral hypercalcemia of malignancy (HHM) in 1987. Since then its gene structure in several mammalian and an avian species has been analyzed and its gene expression demonstrated in many adult and embryonic tissues derived from all three germ layers. The composition and structure of PTHrP peptide depends on both differential gene splicing and posttranslational processing, which result in a range of peptides of potentially diverse functions. This chapter describes the distribution of PTHrP in both normal and neoplastic adult and embryonic tissues. PTHrP is of fundamental importance to cell survival because the absence of the gene is fatal; this aspect of PTHrP function in cell physiology becomes overwhelmingly important in neoplasia. Intracrine or paracrine actions for PTHrP seem to be most likely in mammalian and avian physiology, but in fishes high circulating levels suggest classic endocrine functions as well. Much remains to be learned of the biology of this fascinating protein.
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Affiliation(s)
- P M Ingleton
- Institute of Endocrinology, Sheffield University Medical School, United Kingdom
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13
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Bruns ME, Ferguson JE, Bruns DE, Burton DW, Brandt DW, Jüppner H, Segre GV, Deftos LJ. Expression of parathyroid hormone-related peptide and its receptor messenger ribonucleic acid in human amnion and chorion-decidua: implications for secretion and function. Am J Obstet Gynecol 1995; 173:739-46. [PMID: 7573236 DOI: 10.1016/0002-9378(95)90333-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE Our purpose was to define the location and packaging of parathyroid hormone-related peptide in amnion-chorion and the potential target tissues for its action in fetal membranes. STUDY DESIGN We studied fetal membranes by use of light microscopic immunocytochemistry with three monoclonal antibodies against distinct regions of the parathyroid hormone-related peptide molecule. For electron microscopy immunogold analysis with a monoclonal antibody specific to the 109-141 fragment was used to observe parathyroid hormone-related peptide intracellularly in amnion membrane and in the chorion layers. Multiplex reverse transcriptase-polymerase chain reaction with Southern blotting was used to identify parathyroid hormone/parathyroid hormone-related peptide receptor and control messenger ribonucleic acids in amnion and chorion-decidua. RESULTS All monoclonal antibodies revealed immunoreactive parathyroid hormone-related peptide in the amniotic epithelial cells and in some fibroblast-like cells embedded in the extracellular matrix of the amnion. Parathyroid hormone-related peptide was also found in the chorion in fibroblast and trophoblast layers and in decidua. Ultrastructurally immunogold particles were evenly distributed throughout the amniotic epithelial cells and were present in apical microvilli and near the basal membranes. Electron microscopy studies of the chorion cytotrophoblast also showed freely dispersed immunogold particles of parathyroid hormone-related peptide with no packaging in secretory granules. Low to undetectable levels of parathyroid hormone/parathyroid hormone-related peptide receptor messenger ribonucleic acid were found in amnion tissue, whereas abundant receptor messenger ribonucleic acid was found in chorion-decidua. CONCLUSIONS These results suggest the presence of a parathyroid hormone-related peptide paracrine system within the human fetal membranes.
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Affiliation(s)
- M E Bruns
- Department of Pathology, University of Virginia, Charlottesville, USA
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14
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15
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Roulier S, Rochette-Egly C, Rebut-Bonneton C, Porquet D, Evain-Brion D. Nuclear retinoic acid receptor characterization in cultured human trophoblast cells: effect of retinoic acid on epidermal growth factor receptor expression. Mol Cell Endocrinol 1994; 105:165-73. [PMID: 7859922 DOI: 10.1016/0303-7207(94)90166-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Vitamin A is an important factor during gestation and its metabolite, retinoic acid (RA), is a potent teratogen. However, RA action on the placenta is still poorly understood. In this study we analysed the presence of RARs and RXRs in human trophoblastic cells. We determined that RAR alpha was the more expressed form in term placenta, and that RAR beta was induced by RA treatment. Then we analysed RA effects on endocrine activities and on epidermal growth factor (EGF) receptor expression. We found that RA decreased 125I-labeled EGF binding and EGF-dependent phosphorylation. Furthermore, RA treatment led to a concentration-dependent decrease in the amount of EGFR protein expression. This treatment also decreased EGF receptor mRNA levels, suggesting transcriptional regulation of the EGF receptor. Thus we demonstrated that RA could interact with feto-placental development by modulating trophoblast EGF receptors expression, probably via its nuclear receptors.
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MESH Headings
- Blotting, Northern
- Cell Differentiation/drug effects
- Cell Nucleus/chemistry
- Cell Nucleus/ultrastructure
- Cells, Cultured
- Dose-Response Relationship, Drug
- Epidermal Growth Factor/metabolism
- ErbB Receptors/analysis
- ErbB Receptors/drug effects
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Female
- Gene Expression Regulation, Developmental/drug effects
- Humans
- Iodine Radioisotopes
- Nuclear Proteins/analysis
- Nuclear Proteins/drug effects
- Nuclear Proteins/genetics
- Placenta/chemistry
- Placenta/cytology
- Placenta/ultrastructure
- Pregnancy
- Protein-Tyrosine Kinases/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Receptors, Retinoic Acid/analysis
- Receptors, Retinoic Acid/drug effects
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism
- Retinoid X Receptors
- Transcription Factors/analysis
- Transcription Factors/drug effects
- Transcription Factors/genetics
- Transcription, Genetic
- Tretinoin/toxicity
- Trophoblasts/chemistry
- Trophoblasts/cytology
- Trophoblasts/drug effects
- Trophoblasts/ultrastructure
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Affiliation(s)
- S Roulier
- Laboratoire de Physiopathologie du Développement, CNRS URA 1337, ENS, Paris, France
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16
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Abstract
Alteration of placental development directly interferes with fetal growth. Epidermal growth factor (EGF) plays a major role in placental implantation, growth and differentiation. EGF acts on its placental target cells, i.e. the trophoblasts, via a specific receptor (EGFR) which belongs to the tyrosine kinase receptor family. Abundant placental EGF receptors are located in the brush border at the fetomaternal interface. EGFR expression is modulated by trophoblast differentiation and by hormones or toxic substances such as smoke. Interestingly, in microvilli purified from placentae of infants with intrauterine growth retardation (IUGR) a decrease or absence of tyrosine kinase activity is observed. This suggests that an alteration of EGFR biological activity might interfere with the fetoplacental unit development.
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Affiliation(s)
- D Evain-Brion
- Laboratoire de Physiopathologie du Développement, CNRS URA 1337, Ecole Normale Supérieure, Paris, France
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17
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Iwamura M, di Sant'agnese PA, Wu G, Benning CM, Cockett AT, Gershagen S. Overexpression of human epidermal growth factor receptor and c-erbB-2 by neuroendocrine cells in normal prostatic tissue. Urology 1994; 43:838-43. [PMID: 7910990 DOI: 10.1016/0090-4295(94)90146-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE It has been suggested that prostatic neuroendocrine (NE) cells play an important role in the growth and differentiation of the prostate by secreting various neuropeptides and serotonin. However, the mechanism by which NE cells themselves are regulated is virtually unknown. In the present study we evaluated the expression of the human epidermal growth factor receptor (EGFR) family (HER) in prostatic NE cells. METHODS Formalin-fixed, paraffin-embedded tissue sections from twenty radical prostatectomy specimens were immunostained with validated rabbit polyclonal antibodies raised against human EGFR and c-erbB-2, using the streptavidin-peroxidase enzyme conjugate method. RESULTS A strong immunoreactivity was observed with both antibodies in the cytosol of a few epithelial cells. These cells frequently had a dendritic appearance and were located in the acini and ducts. The EGFR-positive cells were predominant in most cases. Double immunostaining revealed the colocalization of both antigens with chromogranin A, a polypeptide that is expressed by most NE cells. Moreover, EGFR and c-erbB-2 appeared to be colocalized as well as independently expressed by different subpopulations of NE cells. CONCLUSIONS The results suggest that prostatic NE cells might be regulated by the HER protein family, probably, in a ligand-specific fashion. This is the first report identifying a potential pathway regulating prostatic NE cells.
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Affiliation(s)
- M Iwamura
- Department of Urology, University of Rochester Medical Center, New York
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Alteration of epidermal growth factor receptor in placental membranes of smokers: Relationship with intrauterine growth retardation. Am J Obstet Gynecol 1994. [DOI: 10.1016/s0002-9378(13)90441-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gabriel R, Alsat E, Evain-Brion D. Alteration of epidermal growth factor receptor in placental membranes of smokers: relationship with intrauterine growth retardation. Am J Obstet Gynecol 1994; 170:1238-43. [PMID: 8178844 DOI: 10.1016/s0002-9378(94)70133-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE The study of a possible alteration of epidermal growth factor receptor in placental membranes of smokers was performed. STUDY DESIGN We investigated the binding capacity and the autophosphorylation of epidermal growth factor receptor in membranes of 33 term placentas from smokers and nonsmokers with appropriate-for-gestational-age or small-for-gestational-age babies. RESULTS The binding capacity of epidermal growth factor receptor was similar in the four subgroups of placental membranes. In contrast, epidermal growth factor receptor autophosphorylation was impaired in the membranes from smokers relative to those from nonsmokers. This decrease was significant (p < 0.001) in the membranes from smokers with small-for-gestational-age babies. Insulin receptor phosphorylation was similar in the four groups. CONCLUSION Intrauterine growth retardation in women who smoke is associated with an alteration of placental epidermal growth factor receptor bioactivity and suggests that the regulatory role of epidermal growth factor in placental growth and differentiation is defective in this setting.
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Affiliation(s)
- R Gabriel
- Hôpital Maison-Blanche, Maternité, Reims, France
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Affiliation(s)
- G Desoye
- Department of Obstetrics and Gynecology, University of Graz, Austria
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Saxe A. Invited commentary. World J Surg 1994. [DOI: 10.1007/bf00353785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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