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Hjortebjerg R, Høgdall C, Hansen KH, Høgdall E, Frystyk J. The IGF-PAPP-A-Stanniocalcin Axis in Serum and Ascites Associates with Prognosis in Patients with Ovarian Cancer. Int J Mol Sci 2024; 25:2014. [PMID: 38396692 PMCID: PMC10888379 DOI: 10.3390/ijms25042014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/25/2024] Open
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) and PAPP-A2 modulate insulin-like growth factor (IGF) action and are inhibited by the stanniocalcins (STC1 and STC2). We previously demonstrated increased PAPP-A and IGF activity in ascites from women with ovarian carcinomas. In this prospective, longitudinal study of 107 women with ovarian cancer and ascites accumulation, we determined corresponding serum and ascites levels of IGF-1, IGF-2, PAPP-A, PAPP-A2, STC1, and STC2 and assessed their relationship with mortality. As compared to serum, we found highly increased ascites levels of PAPP-A (51-fold) and PAPP-A2 (4-fold). Elevated levels were also observed for IGF-1 (12%), STC1 (90%) and STC2 (68%). In contrast, IGF-2 was reduced by 29% in ascites. Patients were followed for a median of 38.4 months (range: 45 days to 8.9 years), during which 73 patients (68.2%) died. Overall survival was longer for patients with high serum IGF-1 (hazard ratio (HR) per doubling in protein concentration: 0.60, 95% CI: 0.40-0.90). However, patients with high ascites levels of IGF-1 showed a poorer prognosis (HR: 2.00 (1.26-3.27)). High serum and ascites IGF-2 levels were associated with increased risk of mortality (HR: 2.01 (1.22-3.30) and HR: 1.78 (1.24-2.54), respectively). Similarly, serum PAPP-A2 was associated with mortality (HR: 1.26 (1.08-1.48)). Our findings demonstrate the presence and activity of the IGF system in the local tumor ecosystem, which is likely a characteristic feature of malignant disease and plays a role in its peritoneal dissemination. The potential clinical implications are supported by our finding that serum levels of the proteins are associated with patient prognosis.
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Affiliation(s)
- Rikke Hjortebjerg
- Steno Diabetes Center Odense, Odense University Hospital, 5000 Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, 5230 Odense, Denmark;
| | - Claus Høgdall
- Department of Gynecology, Juliane Marie Center, Rigshospitalet, 2100 Copenhagen, Denmark;
| | - Kristian Horsman Hansen
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital, 5000 Odense, Denmark;
- OPEN Lab, Odense University Hospital, 5000 Odense, Denmark
| | - Estrid Høgdall
- Department of Pathology, Herlev University Hospital, 2730 Herlev, Denmark;
| | - Jan Frystyk
- Department of Clinical Research, University of Southern Denmark, 5230 Odense, Denmark;
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital, 5000 Odense, Denmark;
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Conover CA, Oxvig C. The Pregnancy-Associated Plasma Protein-A (PAPP-A) Story. Endocr Rev 2023; 44:1012-1028. [PMID: 37267421 DOI: 10.1210/endrev/bnad017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/01/2023] [Accepted: 05/31/2023] [Indexed: 06/04/2023]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the circulation of pregnant women. In the mid-to-late 1990s, PAPP-A was discovered to be a metzincin metalloproteinase, expressed by many nonplacental cells, that regulates local insulin-like growth factor (IGF) activity through cleavage of high-affinity IGF binding proteins (IGFBPs), in particular IGFBP-4. With PAPP-A as a cell surface-associated enzyme, the reduced affinity of the cleavage fragments results in increased IGF available to bind and activate IGF receptors in the pericellular environment. This proteolytic regulation of IGF activity is important, since the IGFs promote proliferation, differentiation, migration, and survival in various normal and cancer cells. Thus, there has been a steady growth in investigation of PAPP-A structure and function outside of pregnancy. This review provides historical perspective on the discovery of PAPP-A and its structure and cellular function, highlights key studies of the first 50 years in PAPP-A research, and introduces new findings from recent years.
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Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
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Hjortebjerg R, Pedersen DA, Mengel-From J, Jørgensen LH, Christensen K, Frystyk J. Heritability and circulating concentrations of pregnancy-associated plasma protein-A and stanniocalcin-2 in elderly monozygotic and dizygotic twins. Front Endocrinol (Lausanne) 2023; 14:1193742. [PMID: 37334305 PMCID: PMC10272750 DOI: 10.3389/fendo.2023.1193742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Pregnancy-associated plasma protein-A (PAPP-A) is an IGF-activating enzyme suggested to influence aging-related diseases. However, knowledge on serum PAPP-A concentration and regulation in elderly subjects is limited. Therefore, we measured serum PAPP-A in elderly same-sex monozygotic (MZ) and dizygotic (DZ) twins, as this allowed us to describe the age-relationship of PAPP-A, and to test the hypothesis that serum PAPP-A concentrations are genetically determined. As PAPP-A is functionally related to stanniocalcin-2 (STC2), an endogenous PAPP-A inhibitor, we included measurements on STC2 as well as IGF-I and IGF-II. Methods The twin cohort contained 596 subjects (250 MZ twins, 346 DZ twins), whereof 33% were males. The age ranged from 73.2 to 94.3 (mean 78.8) years. Serum was analyzed for PAPP-A, STC2, IGF-I, and IGF-II by commercial immunoassays. Results In the twin cohort, PAPP-A increased with age (r=0.19; P<0.05), whereas IGF-I decreased (r=-0.12; P<0.05). Neither STC2 nor IGF-II showed any age relationship. When analyzed according to sex, PAPP-A correlated positively with age in males (r=0.18; P<0.05) and females (r=0.25; P<0.01), whereas IGF-I correlated inversely in females only (r=-0.15; P<0.01). Males had higher levels of PAPP-A (29%), STC2 (18%) and IGF-I (19%), whereas serum IGF-II was 28% higher in females (all P<0.001). For all four proteins, within-pair correlations were significantly higher for MZ twins than for DZ twins, and they demonstrated substantial and significant heritability, which after adjustment for age and sex averaged 59% for PAPP-A, 66% for STC2, 58% for IGF-I, and 52% for IGF-II. Discussion This twin study confirms our hypothesis that the heritability of PAPP-A serum concentrations is substantial, and the same is true for STC2. As regards the age relationship, PAPP-A increases with age, whereas STC2 remains unchanged, thereby supporting the idea that the ability of STC2 to inhibit PAPP-A enzymatic activity decreases with increasing age.
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Affiliation(s)
- Rikke Hjortebjerg
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
| | - Dorthe Almind Pedersen
- The Danish Twin Registry and Danish Aging Research Center, University of Southern Denmark, Odense, Denmark
| | - Jonas Mengel-From
- The Danish Twin Registry and Danish Aging Research Center, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | | | - Kaare Christensen
- The Danish Twin Registry and Danish Aging Research Center, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Jan Frystyk
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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4
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The Proteolytic Landscape of Ovarian Cancer: Applications in Nanomedicine. Int J Mol Sci 2022; 23:ijms23179981. [PMID: 36077371 PMCID: PMC9456334 DOI: 10.3390/ijms23179981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Ovarian cancer (OvCa) is one of the leading causes of mortality globally with an overall 5-year survival of 47%. The predominant subtype of OvCa is epithelial carcinoma, which can be highly aggressive. This review launches with a summary of the clinical features of OvCa, including staging and current techniques for diagnosis and therapy. Further, the important role of proteases in OvCa progression and dissemination is described. Proteases contribute to tumor angiogenesis, remodeling of extracellular matrix, migration and invasion, major processes in OvCa pathology. Multiple proteases, such as metalloproteinases, trypsin, cathepsin and others, are overexpressed in the tumor tissue. Presence of these catabolic enzymes in OvCa tissue can be exploited for improving early diagnosis and therapeutic options in advanced cases. Nanomedicine, being on the interface of molecular and cellular scales, can be designed to be activated by proteases in the OvCa microenvironment. Various types of protease-enabled nanomedicines are described and the studies that focus on their diagnostic, therapeutic and theranostic potential are reviewed.
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Birzniece V, Lam T, McLean M, Reddy N, Shahidipour H, Hayden A, Gurney H, Stone G, Hjortebjerg R, Frystyk J. Insulin-like growth factor role in determining the anti-cancer effect of metformin: RCT in prostate cancer patients. Endocr Connect 2022; 11:EC-21-0375. [PMID: 35324467 PMCID: PMC9066575 DOI: 10.1530/ec-21-0375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 03/23/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Androgen deprivation therapy (ADT), a principal therapy in patients with prostate cancer, is associated with the development of obesity, insulin resistance, and hyperinsulinemia. Recent evidence indicates that metformin may slow cancer progression and improves survival in prostate cancer patients, but the mechanism is not well understood. Circulating insulin-like growth factors (IGFs) are bound to high-affinity binding proteins, which not only modulate the bioavailability and signalling of IGFs but also have independent actions on cell growth and survival. The aim of this study was to investigate whether metformin modulates IGFs, IGF-binding proteins (IGFBPs), and the pregnancy-associated plasma protein A (PAPP-A) - stanniocalcin 2 (STC2) axis. DESIGN AND METHODS In a blinded, randomised, cross-over design, 15 patients with prostate cancer on stable ADT received metformin and placebo treatment for 6 weeks each. Glucose metabolism along with circulating IGFs and IGFBPs was assessed. RESULTS Metformin significantly reduced the homeostasis model assessment as an index of insulin resistance (HOMA IR) and hepatic insulin resistance. Metformin also reduced circulating IGF-2 (P < 0.05) and IGFBP-3 (P < 0.01) but increased IGF bioactivity (P < 0.05). At baseline, IGF-2 correlated significantly with the hepatic insulin resistance (r2= 0.28, P < 0.05). PAPP-A remained unchanged but STC2 declined significantly (P < 0.05) following metformin administration. During metformin treatment, change in HOMA IR correlated with the change in STC2 (r2= 0.35, P < 0.05). CONCLUSION Metformin administration alters many components of the circulating IGF system, either directly or indirectly via improved insulin sensitivity. Reduction in IGF-2 and STC2 may provide a novel mechanism for a potential metformin-induced antineoplastic effect.
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Affiliation(s)
- Vita Birzniece
- School of Medicine, Western Sydney University, New South Wales, Australia
- Department of Diabetes and Endocrinology, Blacktown Hospital, New South Wales, Australia
- Garvan Institute of Medical Research, New South Wales, Australia
- School of Medical Sciences, University of New South Wales, New South Wales, Australia
- Correspondence should be addressed to V Birzniece:
| | - Teresa Lam
- School of Medicine, Western Sydney University, New South Wales, Australia
- Department of Diabetes and Endocrinology, Blacktown Hospital, New South Wales, Australia
- Department of Diabetes and Endocrinology, Westmead Hospital, New South Wales, Australia
| | - Mark McLean
- School of Medicine, Western Sydney University, New South Wales, Australia
- Department of Diabetes and Endocrinology, Blacktown Hospital, New South Wales, Australia
| | - Navneeta Reddy
- Department of Diabetes and Endocrinology, Blacktown Hospital, New South Wales, Australia
| | - Haleh Shahidipour
- School of Medicine, Western Sydney University, New South Wales, Australia
- Department of Diabetes and Endocrinology, Blacktown Hospital, New South Wales, Australia
| | - Amy Hayden
- School of Medicine, Western Sydney University, New South Wales, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia
- Crown Princess Mary Cancer Centre, Westmead Hospital, New South Wales, Australia
| | - Howard Gurney
- Crown Princess Mary Cancer Centre, Westmead Hospital, New South Wales, Australia
| | - Glenn Stone
- School of Computing, Engineering and Mathematics, Western Sydney University, New South Wales, Australia
| | - Rikke Hjortebjerg
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital & Department of Clinical Research, Faculty of Health, University of Southern Denmark, Odense, Denmark
- Steno Diabetes Center Odense, Odense University Hospital & Department of Clinical Research, Faculty of Health, University of Southern Denmark, Odense, Denmark
| | - Jan Frystyk
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital & Department of Clinical Research, Faculty of Health, University of Southern Denmark, Odense, Denmark
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Development of a Sensitive Bioassay for the Analysis of IGF-Related Activation of AKT/mTOR Signaling in Biological Matrices. Cells 2021; 10:cells10030482. [PMID: 33668197 PMCID: PMC7995968 DOI: 10.3390/cells10030482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/15/2021] [Accepted: 02/21/2021] [Indexed: 12/11/2022] Open
Abstract
The bioactivity of the IGF system is not a function of isolated hormone concentrations in a given biological matrix. Instead, the biological activities of IGFs are regulated by IGFBPs, IGFBP proteases, and inhibitors of IGFBP proteases. Therefore, assays based on IGF-related bioactivity may describe functions of the complete IGF system in a given biological matrix. Of particular interest are the IGF system effects on the AKT/mTOR pathway, as a dominant system for controlling growth, metabolism, and aging. In order to improve the sensitivity of IGF-dependent bioactivity, we made use of the known short-term and enhancing effects of IGFBP2 on the intracellular PI3K pathway. As a specific readout of this pathway, and further as a marker of the mTOR pathway, we assessed the phosphorylation of AKT-Ser473. Preincubation using IGFBP2 enhanced IGF1-dependent AKT-Ser473 phosphorylation in our experimental system. The assay's specificity was demonstrated by inhibition of IGF1 receptors outside or inside the cell, using antiserum or small molecule inhibitors, which reduced AKT phosphorylation in response to exogenous IGF1 (p < 0.05). The maximal response of AKT phosphorylation was recorded 15 to 60 min after the addition of IGF1 to cell monolayers (p < 0.001). In our cellular system, insulin induced AKT phosphorylation only at supra-physiological concentrations (µM). Using this novel assay, we identified the differential biological activity of the IGF system in AKT-Ser473 phosphorylation in serum (mouse, naked mole rat, and human), in cerebrospinal fluid (human), and in colostrum or mature milk samples (dairy cow). We have developed a sensitive and robust bioassay to assess the IGF-related activation of the AKT/mTOR pathway. The assay works efficiently and does not require expensive cell culture systems. By using capillary immuno-electrophoresis, the readout of IGF-related bioactivity is substantially accelerated, requiring a minimum of hands-on time. Importantly, the assay system is useful for studying IGF-related activity in the AKT/mTOR pathway in a broad range of biological matrices.
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7
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Hjortebjerg R, Rasmussen LM, Gude MF, Irmukhamedov A, Riber LP, Frystyk J, De Mey JGR. Local IGF Bioactivity Associates with High PAPP-A Activity in the Pericardial Cavity of Cardiovascular Disease Patients. J Clin Endocrinol Metab 2020; 105:5900391. [PMID: 32875328 DOI: 10.1210/clinem/dgaa617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/28/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Pregnancy-associated plasma protein-A (PAPP-A) has been suggested as a proatherogenic enzyme by its ability to locally increase insulin-like growth factor (IGF) activity through proteolytic cleavage of IGF binding protein-4 (IGFBP-4). Recently, stanniocalcin-2 (STC2) was discovered as an inhibitor of PAPP-A. This study aimed to investigate IGFBP-4, PAPP-A, and STC2 as local regulators of IGF bioactivity in the cardiac microenvironment by comparing levels in the pericardial fluid with those in the circulation of patients with cardiovascular disease. METHODS Plasma and pericardial fluid were obtained from 39 patients undergoing elective cardiothoracic surgery, hereof 15 patients with type 2 diabetes. Concentrations of IGF-I, intact and fragmented IGFBP-4, PAPP-A, and STC2 were determined by immunoassays and IGF bioactivity by a cell-based assay. RESULTS In pericardial fluid, the concentrations of total IGF-I, intact IGFBP-4, and STC2 were 72 ± 10%, 91 ± 5%, and 40 ± 24% lower than in plasma, while PAPP-A was 15 times more concentrated. The levels of the 2 IGFBP-4 fragments generated by PAPP-A and reflecting PAPP-A activity were elevated by more than 25%. IGF bioactivity was 62 ± 81% higher in the pericardial fluid than plasma. Moreover, pericardial fluid levels of both IGFBP-4 fragments correlated with the concentration of PAPP-A and with the bioactivity of IGF. All protein levels were similar in pericardial fluid from nondiabetic and diabetic subjects. CONCLUSIONS PAPP-A increases IGF bioactivity by cleavage of IGFBP-4 in the pericardial cavity of cardiovascular disease patients. This study provides evidence for a distinct local activity of the IGF system, which may promote cardiac dysfunction and coronary atherosclerosis.
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Affiliation(s)
- Rikke Hjortebjerg
- Department of Molecular Endocrinology (KMEB), University of Southern Denmark, Odense, Denmark
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Denmark
| | - Lars Melholt Rasmussen
- Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark
- Centre for Individualized Medicine in Arterial Diseases (CIMA), Odense University Hospital, Odense, Denmark
| | - Mette Faurholdt Gude
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Denmark
| | - Akhmadjon Irmukhamedov
- Department of Cardiac, Thoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark
| | - Lars P Riber
- Department of Cardiac, Thoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark
| | - Jan Frystyk
- Department of Molecular Endocrinology (KMEB), University of Southern Denmark, Odense, Denmark
- Department of Endocrinology, Odense University Hospital, Denmark
| | - Jo G R De Mey
- Centre for Individualized Medicine in Arterial Diseases (CIMA), Odense University Hospital, Odense, Denmark
- Department of Cardiac, Thoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
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8
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Prithviraj P, Anaka M, Thompson EW, Sharma R, Walkiewicz M, Tutuka CSA, Behren A, Kannourakis G, Jayachandran A. Aberrant pregnancy-associated plasma protein-A expression in breast cancers prognosticates clinical outcomes. Sci Rep 2020; 10:13779. [PMID: 32792532 PMCID: PMC7426935 DOI: 10.1038/s41598-020-70774-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/03/2020] [Indexed: 01/15/2023] Open
Abstract
Elevated levels of pregnancy-associated plasma protein-A (PAPP-A) have been implicated in the pathogenesis of various malignancies, including breast cancers. Breast cancer is one of the most frequent carcinomas and is the second most common cancer type detected in women of child-bearing age. Throughout pregnancy PAPP-A is produced and secreted by the placental syncytiotrophoblast cells; co-incidentally pregnancy-associated breast cancers often have an aggressive clinical course. The components of the PAPP-A/IGF axis was assessed in a panel of breast cancer cell lines. Using neutralising antibodies the impact of PAPP-A/IGF axis on cell motility was evaluated. PAPP-A was expressed in four of the twelve breast cancer cell lines tested. Blocking PAPP-A and IGFBP4 with neutralising antibodies significantly decreased motiliy of MDA-MB-231 cells. Upregulation of PAPP-A expression in breast tumours resulted in a trend towards worse overall survival. Notably, PAPP-A expression also positively correlated with epithelial-to-mesenchymal transition markers. In conclusion, these results indicate that PAPP-A plays an important role in breast cancer progression and it may be a promising therapeutic target in breast cancer.
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Affiliation(s)
- Prashanth Prithviraj
- Cancer Immunobiology Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,Department of Medicine, University of Melbourne, Victoria, Australia.,Fiona Elsey Cancer Research Institute, Ballarat Technology Park- Central Suite 23, 106-110 Lydiard St Sth, Ballarat, VIC, 3350, Australia.,Federation University Australia, Ballarat, VIC, Australia
| | - Matthew Anaka
- Department of Medicine, University of Alberta, Alberta, Canada
| | - Erik W Thompson
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.,Translational Research Institute, Woolloongabba, Australia
| | - Revati Sharma
- Fiona Elsey Cancer Research Institute, Ballarat Technology Park- Central Suite 23, 106-110 Lydiard St Sth, Ballarat, VIC, 3350, Australia.,Federation University Australia, Ballarat, VIC, Australia
| | - Marzena Walkiewicz
- Cancer Immunobiology Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
| | - Candani S A Tutuka
- Cancer Immunobiology Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,School of Cancer Medicine, La Trobe University, Victoria, Australia
| | - Andreas Behren
- Cancer Immunobiology Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,Department of Medicine, University of Melbourne, Victoria, Australia.,School of Cancer Medicine, La Trobe University, Victoria, Australia
| | - George Kannourakis
- Fiona Elsey Cancer Research Institute, Ballarat Technology Park- Central Suite 23, 106-110 Lydiard St Sth, Ballarat, VIC, 3350, Australia.,Federation University Australia, Ballarat, VIC, Australia
| | - Aparna Jayachandran
- Fiona Elsey Cancer Research Institute, Ballarat Technology Park- Central Suite 23, 106-110 Lydiard St Sth, Ballarat, VIC, 3350, Australia. .,Gallipoli Medical Research Institute and The University of Queensland, Brisbane, Australia.
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9
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Frystyk J, Teran E, Gude MF, Bjerre M, Hjortebjerg R. Pregnancy-associated plasma proteins and Stanniocalcin-2 - Novel players controlling IGF-I physiology. Growth Horm IGF Res 2020; 53-54:101330. [PMID: 32693362 DOI: 10.1016/j.ghir.2020.101330] [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: 04/25/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 10/23/2022]
Abstract
IGF-I was originally discovered as a GH-dependent growth factor stimulating longitudinal growth. Currently, however, it has become evident that the biological activities of IGF-I extend well beyond those of a simple growth factor and impact such processes as insulin sensitivity, aging, cancer and cardiovascular disease. The vast majority of IGF-I is tightly bound to IGF-binding proteins (IGFBPs), which renders IGF-I unable to stimulate the IGF-I receptor (IGF-IR) in vivo. This binding means that liberation of IGF-I from the IGFBPs is an important step controlling IGF-I action. In this context, IGFBP-cleaving enzymes appear to play a key role. Enzymatic cleavage of the IGFBPs markedly lowers their ligand affinity, and as a consequence, IGF-I becomes liberated and hence available for stimulation of the IGF-IR. Two of the best-characterized IGFBP-cleaving enzymes are pregnancy-associated plasma protein-A (PAPP-A) and its paralog PAPP-A2. The two enzymes (often referred to as pappalysins) regulate the liberation of IGF-I in a highly controlled manner. PAPP-A is believed to act predominantly in tissues, serving to liberate IGF-I at the cell surface in close proximity to the IGF-IR. In keeping with this notion, mice lacking PAPP-A exhibit reduced body size, despite having normal circulating IGF-I concentrations. In contrast, human findings indicate that altered PAPP-A2 activity changes circulating IGF-I concentrations, although PAPP-A2 is also present in high concentrations in tissues. Thus, PAPP-A2 appears to impact circulating, as well as tissue, IGF-I activity. The enzymatic activity of PAPP-A and PAPP-A2 was recently discovered to be regulated by the protein Stanniocalcin-2 (STC2). By binding to the enzymatic sites of PAPP-A and PAPP-A2, STC2 inhibits their activity. To date, the majority of findings demonstrating the ability of pappalysins and STC2 to regulate IGF-I action are from preclinical studies. However, clinical studies are now beginning to emerge. In this review, we will summarize our data on STC2, PAPP-A and PAPP-A2 in humans. These results indicate that pappalysins and STC2 constitute an important IGF-I activity-regulating system that warrants further investigation.
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Affiliation(s)
- Jan Frystyk
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital & Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark.
| | - Enrique Teran
- Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito, Ecuador
| | - Mette Faurholdt Gude
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus, Denmark
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus, Denmark
| | - Rikke Hjortebjerg
- Endocrine Research Unit, Department of Endocrinology, Odense University Hospital & Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark; Steno Diabetes Center Odense (SDCO), Odense University Hospital, Odense, Denmark
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10
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Agerholm J, Hjortebjerg R, Espelund U, Rasmussen TR, Folkersen B, Bjerre M, Frystyk J. Development of a novel assay for IGFBP-2 complexed with IGF-I and-II in human serum. Growth Horm IGF Res 2020; 51:38-45. [PMID: 32035328 DOI: 10.1016/j.ghir.2020.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Insulin-like growth factor binding-protein 2 (IGFBP-2) was originally identified as an IGF-carrier, governing IGF half-life, tissue accessibility and biological effects. Later, IGFBP-2 was discovered to possess IGF-independent effects. IGFBP-2 circulates in several forms, as free protein, complexed with IGF-I or IGF-II, or as IGFBP-2 fragments. The various IGFBP-2 forms are all included when measuring serum IGFBP-2 concentrations by immunoassay (i.e., immunoreactive (ir-)IGFBP-2). In this study, we describe a novel method to measure the amount of IGF that circulates bound to IGFBP-2. METHOD IGFBP-2 was immunoprecipitated from human serum using magnetic beads, which were subsequently eluted by acidification. After neutralization, eluates were assayed for ir-IGFBP-2, IGF-I and IGF-II and compared to serum concentrations. This allowed measurement of IGFBP-2-compexed IGF-I and IGF-II, respectively. To test the method clinically, serum from 146 patients with lung cancer, 151 patients with non-cancer pulmonary diseases and 28 healthy controls were analyzed. RESULTS We immuno-precipitated 97 ± 3.3% of serum IGFBP-2 and recovered > 75% of IGFBP-2-complexed IGFs, with intra- and inter-assay coefficient of variations (CVs) averaging < 5% and < 13%, respectively. No co-precipitation with IGFBP-1, -3 or - 4 was detected. Serum levels of ir-IGFBP-2 (median [25;75%]) differed between groups (cancer patients vs. non-cancer patients vs. healthy controls): 342 [260;480] vs. 262 [189;388] vs. 190 [141;269] μg/l (p < .0001). In parallel with this, concentrations of IGF-II carried by IGFBP-2 averaged: 45.0 [33.3;52.5] vs. 34.2 [25.4;46.1] vs. 19.8 [14.1;26.0] μg/l (p < .0001), and concentrations of IGF-I 8.0 [5.2;11.8] vs. 5.4 [3.6;7.3] vs. 7.0 [3.8;13.0] μg/l (p < .0001). Thus, IGFBP-2 carried more IGF-II than IGF-I in all groups (p < .0001). When expressed relative to IGF-concentrations, IGFBP-2 carried 9.0 [5.3;15.5] % of the IGF-I and 4.8 [2.9;5.8] % of the IGF-II in serum from healthy subjects. Notably, in patients, IGFBP-2 carried relatively less IGF-I, but more IGF-II (p < .0001). CONCLUSION Using our novel assay, we demonstrate: that IGFBP-2 carries ≈10% of circulating IGF-I and ≈5% of circulating IGF-II in healthy subjects; that IGF-II is the primary ligand for IGFBP-2; and that IGFBP-2 carries even more IGF-II in patients than in healthy subjects. Thus, our assay may provide information on IGFBP-2 beyond what is achievable by simply measuring ir-IGFBP-2.
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Affiliation(s)
- Jonas Agerholm
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus DK-8200, Denmark
| | - Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus DK-8200, Denmark
| | - Ulrick Espelund
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus DK-8200, Denmark
| | - Torben Riis Rasmussen
- Department of Pulmonary Medicine, Aarhus University Hospital, Aarhus DK-8000, Denmark
| | - Birgitte Folkersen
- Department of Pulmonary Medicine, Aarhus University Hospital, Aarhus DK-8000, Denmark
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus DK-8200, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus DK-8200, Denmark; The Research Unit for Endocrinology, Department of Endocrinology, Odense University Hospital, Odense, Denmark; Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense DK-5000, Denmark.
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11
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Hjortebjerg R, Espelund U, Rasmussen TR, Folkersen B, Steiniche T, Georgsen JB, Oxvig C, Frystyk J. Pregnancy-Associated Plasma Protein-A2 Is Associated With Mortality in Patients With Lung Cancer. Front Endocrinol (Lausanne) 2020; 11:614. [PMID: 32982990 PMCID: PMC7492290 DOI: 10.3389/fendo.2020.00614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/28/2020] [Indexed: 12/13/2022] Open
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) and its homolog PAPP-A2 are enzymes that modulate the availability and mitogenic activity of insulin-like growth factor-I (IGF-I). PAPP-A has been implicated in numerous cancers but reports on PAPP-A2 in malignancy are non-existent. In a prospective observational study of 689 patients under suspicion of lung cancer, we examined levels of PAPP-A and PAPP-A2 and their relationship with mortality. Serum PAPP-A and PAPP-A2 concentrations were determined in pre-diagnostic blood samples using ELISA, and immunohistochemical staining of PAPP-A and PAPP-A2 was performed in malignant tissue from five operable patients. A total of 144 patients were diagnosed with lung cancer, whereas the diagnosis was rejected in 545 subjects, who served as a control group. PAPP-A2 concentrations were higher in patients with lung cancer [median (IQR): 0.33 (0.21-0.56) ng/mL] than in controls [0.27 (0.17-0.39) ng/mL], p < 0.001, whereas PAPP-A levels did not differ. Presence of PAPP-A and PAPP-A2 were confirmed in tumor specimens, and staining occurred in a heterogeneous pattern. Patients were observed for a median (range) of 7 (6; 8) years, during which 114 patients (79.2%) died. Patient mortality differed according to PAPP-A2 tertile (p < 0.001). PAPP-A2 was associated with mortality with an unadjusted hazard ratio (95% CI) per doubling in protein concentration of 1.30 (1.12; 1.53), p = 0.001. In a multivariable model adjusted for age, sex, and BMI, PAPP-A2 remained predictive of the endpoint with a hazard ratio per doubling in protein concentration of 1.25 (1.05; 1.48), p = 0.013. Collectively, PAPP-A2, but not PAPP-A, is elevated in patients with lung cancer and associated with mortality. This novel role of PAPP-A2 in cancer warrants further functional studies as well as validation in external cohorts.
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Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Molecular Endocrinology (KMEB), University of Southern Denmark, Odense, Denmark
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- *Correspondence: Rikke Hjortebjerg
| | - Ulrick Espelund
- Medical Research Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Birgitte Folkersen
- Department of Pulmonary Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Torben Steiniche
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan Frystyk
- Department of Molecular Endocrinology (KMEB), University of Southern Denmark, Odense, Denmark
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
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12
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Janssen JAMJL, Varewijck AJ, Brugts MP. The insulin-like growth factor-I receptor stimulating activity (IRSA) in health and disease. Growth Horm IGF Res 2019; 48-49:16-28. [PMID: 31493625 DOI: 10.1016/j.ghir.2019.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 07/26/2019] [Accepted: 08/19/2019] [Indexed: 10/26/2022]
Abstract
Determination of true IGF-I bioactivity in serum and other biological fluids is still a substantial challenge. The IGF-IR Kinase Receptor Activation assay (IGF-IR KIRA assay) is a novel tool to asses IGF-IR stimulating activity (IRSA) and has opened a new era in studying the IGF system. In this paper we discuss many studies showing that measuring IRSA by the IGF-IR KIRA assay often provides fundamentally different information about the IGF system than the commonly used total IGF-I immunoassays. With the IGF-IR KIRA assay phosphorylation of tyrosine residues of the IGF-IR is used as read out to quantify IRSA in unknown (serum) samples. The IGF-IR KIRA assay gives information about net overall effects of circulating IGF-I, IGF-II, IGFBPs and IGFBP-proteases on IGF-IR activation and seems especially superior to immunoreactive total IGF-I in monitoring therapeutic interventions. Although the IRSA as measured by the IGF-IR KIRA assay probably more closely reflects true bioactive IGF-I than measurements of total IGF-I in serum, the IGF-IR KIRA assay in its current form does not give information about all the post-receptor intracellular events mediated by the IGF-IR. Interestingly, in several conditions in health and disease IRSA measured by the IGF-IR KIRA assay is considerably higher in interstitial fluid and ascites than in serum. This suggests that both the paracrine (local) and endocrine (circulating) IRSA should be measured to get a complete picture about the role of the IGF system in health and disease.
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Affiliation(s)
- Joseph A M J L Janssen
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, Rotterdam, the Netherlands.
| | - Aimee J Varewijck
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, Rotterdam, the Netherlands
| | - Michael P Brugts
- Department of Internal Medicine, Ikazia Hospital, Rotterdam, the Netherlands
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13
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Hjortebjerg R, Thomsen KL, Agnholt J, Frystyk J. The IGF system in patients with inflammatory bowel disease treated with prednisolone or infliximab: potential role of the stanniocalcin-2 / PAPP-A / IGFBP-4 axis. BMC Gastroenterol 2019; 19:83. [PMID: 31159802 PMCID: PMC6547608 DOI: 10.1186/s12876-019-1000-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 05/23/2019] [Indexed: 01/09/2023] Open
Abstract
Background Patients with inflammatory bowel disease (IBD) present with reduced serum insulin-like growth factor I (IGF-I). Anti-inflammatory treatment with prednisolone or infliximab ameliorates symptoms and increases circulating IGF-I, but prednisolone induces catabolism, whereas infliximab may promote protein synthesis. Recently, stanniocalcin-2 (STC2) was discovered as a novel inhibitor of the enzyme pregnancy-associated plasma protein-A (PAPP-A), which modulates IGF-I activity. PAPP-A can cleave IGF binding protein-4 (IGFBP-4), upon which IGF-I is liberated. We hypothesized that prednisolone and infliximab exert different effects on levels of STC2, PAPP-A, and IGFBP-4, thereby explaining the distinct metabolic effects of prednisolone and infliximab. Methods Thirty-eight patients with active IBD treated with either prednisolone (n = 17) or infliximab (n = 21) were examined before and after 7 days of treatment. Circulating levels of IGF-I, IGF-II, IGFBP-3, PAPP-A, and STC2 were measured by immunoassays. Intact IGFBP-4 and two IGFBP-4 fragments were determined by a novel immunoassay. Bioactive IGF was assessed by cell-based IGF receptor activation assay. Concentrations of IGFBP-4, PAPP-A, and STC2 on day 0 and 7 were compared to healthy control subjects. Results Following seven days of prednisolone treatment, total and bioactive IGF-I were increased (p < 0.001 and p < 0.05, respectively). Upon infliximab treatment, total IGF-I levels were augmented (p < 0.05), yet IGF bioactivity remained unaltered. Intact IGFBP-4 and the two IGFBP-4 fragments generated upon cleavage by PAPP-A were all decreased following treatment with either prednisolone or infliximab (all p < 0.05). PAPP-A levels were only increased by infliximab (p = 0.005), whereas the inhibitor STC2 did not respond to any of the treatments. Conclusion IGF-I and IGFBP-4 concentrations were markedly altered in patients with IBD and near-normalized with disease remission following treatment with prednisolone or infliximab. Thus, IGFBP-4 may modulate IGF bioavailability in IBD. The effect of immunosuppression did not appear to extend beyond the regulation of IGF and IGFBP-4, as neither PAPP-A nor STC2 were discernibly affected. Trial registration ClinicalTrials.gov: NCT00955123. Date of registration: August 7, 2009 (retrospectively registered).
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Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark. .,The Danish Diabetes Academy, Odense, Denmark.
| | - Karen L Thomsen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Jørgen Agnholt
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark.,Department of Clinical Research, Faculty of Health, University of Southern Denmark, Odense, Denmark.,Department of Endocrinology, Odense University Hospital, Odense, Denmark
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14
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Smith YE, Toomey S, Napoletano S, Kirwan G, Schadow C, Chubb AJ, Mikkelsen JH, Oxvig C, Harmey JH. Recombinant PAPP-A resistant insulin-like growth factor binding protein 4 (dBP4) inhibits angiogenesis and metastasis in a murine model of breast cancer. BMC Cancer 2018; 18:1016. [PMID: 30348128 PMCID: PMC6196427 DOI: 10.1186/s12885-018-4950-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/15/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The Insulin-like growth factor (IGF) pathway plays a role in tumour development and progression. In vivo, IGF1 activity is regulated by the IGF binding proteins (IGFBPs). IGFBP4 inhibits the activity of IGF1 but proteolytic cleavage by pregnancy-associated plasma protein-A (PAPP-A) releases active IGF1. A modified IGFBP4, dBP4, which was resistant to PAPP-A cleavage but retained IGF1 binding capacity, was engineered, expressed in Human Embryonic Kidney (HEK) 293 cells and purified. This study examined the effects of dBP4 on IGF1-induced cell migration, invasion and angiogenesis in vitro. The effect of intra-tumour injections of dBP4 on tumour angiogenesis and metastasis was examined using the 4T1.2luc orthotopic model of breast cancer. METHODS PAPP-A resistance and IGF binding capacity of dBP4 were characterized by Western blot and surface plasmon resonance, respectively. 4T1.2luc are mouse mammary adenocarcinoma cells transfected with luciferase to allow in vivo imaging. The effect of dBP4 on IGF1-induced Akt activation in 4T1.2luc cells was assessed by Western blot. Cell migration and invasion assays were performed using 4T1.2luc cells. Angiokit™ assays and Matrigel® implants were used to assess the effects of dBP4 on angiogenesis in vitro and in vivo, respectively. An orthotopic breast cancer model - 4T1.2luc cells implanted in the mammary fat pad of BALB/c mice - was used to assess the effect of intra tumour injection of purified dBP4 on tumour angiogenesis and metastasis. Tumour growth and lung metastasis were examined by in vivo imaging and tumour angiogenesis was evaluated by CD31 immunohistochemistry. RESULTS Our engineered, PAPP-A resistant IGFBP4 (dBP4) retained IGF1 binding capacity and inhibited IGF1 activation of Akt as well as IGF1-induced migration and invasion by 4T1.2 mammary adenocarcinoma cells. dBP4 inhibited IGF1-induced angiogenesis in vitro and in Matrigel implants in vivo. Direct intra-tumour injection of soluble dBP4 reduced angiogenesis in 4T1.2 luc mammary tumours tumour and reduced lung metastasis. CONCLUSION A PAPP-A resistant IGFBP4, dBP4, inhibits angiogenesis and metastasis in 4T1.2 mammary fat pad tumours. This study highlights the therapeutic potential of dBP4 as an approach to block the tumour-promoting actions of IGF1.
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Affiliation(s)
- Y E Smith
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - S Toomey
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - S Napoletano
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - G Kirwan
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - C Schadow
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - A J Chubb
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - J H Mikkelsen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - C Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - J H Harmey
- Angiogenesis and Metastasis Research, Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
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15
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Hjortebjerg R. IGFBP-4 and PAPP-A in normal physiology and disease. Growth Horm IGF Res 2018; 41:7-22. [PMID: 29864720 DOI: 10.1016/j.ghir.2018.05.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 05/15/2018] [Accepted: 05/29/2018] [Indexed: 02/07/2023]
Abstract
Insulin-like growth factor (IGF) binding protein-4 (IGFBP-4) is a modulator of the IGF system, exerting both inhibitory and stimulatory effects on IGF-induced cellular growth. IGFBP-4 is the principal substrate for the enzyme pregnancy-associated plasma protein-A (PAPP-A). Through IGF-dependent cleavage of IGFBP-4 in the vicinity of the IGF receptor, PAPP-A is able to increase IGF bioavailability and stimulate IGF-mediated growth. Recently, the stanniocalcins (STCs) were identified as novel inhibitors of PAPP-A proteolytic activity, hereby adding additional members to the seemingly endless list of proteins belonging to the IGF family. Our understanding of these proteins has advanced throughout recent years, and there is evidence to suggest that the role of IGFBP-4 and PAPP-A in defining the relationship between total IGF and IGF bioactivity can be linked to a number of pathological conditions. This review provides an overview of the experimental and clinical findings on the IGFBP-4/PAPP-A/STC axis as a regulator of IGF activity and examines the conundrum surrounding extrapolation of circulating concentrations to tissue action of these proteins. The primary focus will be on the biological significance of IGFBP-4 and PAPP-A in normal physiology and in pathophysiology with emphasis on metabolic disorders, cardiovascular diseases, and cancer. Finally, the review assesses current new trajectories of IGFBP-4 and PAPP-A research.
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Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; The Danish Diabetes Academy, Odense, Denmark.
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16
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Kim M, Baek M, Kim DJ. Protein Tyrosine Signaling and its Potential Therapeutic Implications in Carcinogenesis. Curr Pharm Des 2018. [PMID: 28625132 DOI: 10.2174/1381612823666170616082125] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein tyrosine phosphorylation is a crucial signaling mechanism that plays a role in epithelial carcinogenesis. Protein tyrosine kinases (PTKs) control various cellular processes including growth, differentiation, metabolism, and motility by activating major signaling pathways including STAT3, AKT, and MAPK. Genetic mutation of PTKs and/or prolonged activation of PTKs and their downstream pathways can lead to the development of epithelial cancer. Therefore, PTKs became an attractive target for cancer prevention. PTK inhibitors are continuously being developed, and they are currently used for the treatment of cancers that show a high expression of PTKs. Protein tyrosine phosphatases (PTPs), the homeostatic counterpart of PTKs, negatively regulate the rate and duration of phosphotyrosine signaling. PTPs initially were considered to be only housekeeping enzymes with low specificity. However, recent studies have demonstrated that PTPs can function as either tumor suppressors or tumor promoters, depending on their target substrates. Together, both PTK and PTP signal transduction pathways are potential therapeutic targets for cancer prevention and treatment.
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Affiliation(s)
- Mihwa Kim
- Department of Biomedical Sciences, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Minwoo Baek
- Department of Biomedical Sciences, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Dae Joon Kim
- Department of Biomedical Sciences, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
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17
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Abstract
The zinc metalloproteinase, PAPP-A, enhances local insulin-like growth factor (IGF) action through cleavage of inhibitory IGF-binding proteins, thereby increasing IGF available for IGF receptor-mediated cell proliferation, migration and survival. In many tumors, enhanced IGF receptor signaling is associated with tumor growth, invasion and metastasis. We will first discuss PAPP-A structure and function, and post-translational inhibitors of PAPP-A expression or proteolytic activity. We will then review the evidence supporting an important role for PAPP-A in many cancers, including breast, ovarian and lung cancer, and Ewing sarcoma.
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Affiliation(s)
- Cheryl A Conover
- From the Division of Endocrinology Mayo ClinicRochester, Minnesota, USA
| | - Claus Oxvig
- Department of Molecular Biology and GeneticsAarhus University, Aarhus, Denmark
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18
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Guo Y, Bao Y, Guo D, Yang W. Pregnancy-associated plasma protein a in cancer: expression, oncogenic functions and regulation. Am J Cancer Res 2018; 8:955-963. [PMID: 30034934 PMCID: PMC6048405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023] Open
Abstract
Pregnancy-associated plasma protein A (PAPPA) is a protease that plays important roles in pregnancy, but interestingly acts as an oncogene outside of pregnancy. This review summarizes the oncogenic roles of PAPPA, including its expression levels in multiple malignancies, regulatory and signaling interactions, and pro-tumor functions, which include promoting tumor cell proliferation, invasion, migration and metastasis. These PAPPA activities are linked to IGFBP-4 proteolysis, increased IFG bioavailability, and activation of the NF-κB, PI3K/AKT and ERK signaling pathways. Therefore, PAPPA could be used as a biomarker for monitoring cancer development and progression as well as a potential therapeutic target.
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Affiliation(s)
- Yongchen Guo
- Institute of Precision Medicine, Jining Medical UniversityJining, China
| | - Yonghua Bao
- Institute of Precision Medicine, Jining Medical UniversityJining, China
| | - Dongli Guo
- Department of Surgery, Affiliated Hospital of Jining Medical UniversityJining, China
| | - Wancai Yang
- Institute of Precision Medicine, Jining Medical UniversityJining, China
- Department of Pathology, University of Illinois at ChicagoChicago, IL, USA
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19
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Espelund U, Renehan AG, Cold S, Oxvig C, Lancashire L, Su Z, Flyvbjerg A, Frystyk J. Prognostic relevance and performance characteristics of serum IGFBP-2 and PAPP-A in women with breast cancer: a long-term Danish cohort study. Cancer Med 2018; 7:2391-2404. [PMID: 29722920 PMCID: PMC6010701 DOI: 10.1002/cam4.1504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 03/06/2018] [Accepted: 03/09/2018] [Indexed: 02/03/2023] Open
Abstract
Measurement of circulating insulin‐like growth factors (IGFs), in particular IGF‐binding protein (IGFBP)‐2, at the time of diagnosis, is independently prognostic in many cancers, but its clinical performance against other routinely determined prognosticators has not been examined. We measured IGF‐I, IGF‐II, pro‐IGF‐II, IGF bioactivity, IGFBP‐2, ‐3, and pregnancy‐associated plasma protein A (PAPP‐A), an IGFBP regulator, in baseline samples of 301 women with breast cancer treated on four protocols (Odense, Denmark: 1993–1998). We evaluated performance characteristics (expressed as area under the curve, AUC) using Cox regression models to derive hazard ratios (HR) with 95% confidence intervals (CIs) for 10‐year recurrence‐free survival (RFS) and overall survival (OS), and compared those against the clinically used Nottingham Prognostic Index (NPI). We measured the same biomarkers in 531 noncancer individuals to assess multidimensional relationships (MDR), and evaluated additional prognostic models using survival artificial neural network (SANN) and survival support vector machines (SSVM), as these enhance capture of MDRs. For RFS, increasing concentrations of circulating IGFBP‐2 and PAPP‐A were independently prognostic [HRbiomarker doubling: 1.474 (95% CIs: 1.160, 1.875, P = 0.002) and 1.952 (95% CIs: 1.364, 2.792, P < 0.001), respectively]. The AUCRFS for NPI was 0.626 (Cox model), improving to 0.694 (P = 0.012) with the addition of IGFBP‐2 plus PAPP‐A. Derived AUCRFS using SANN and SSVM did not perform superiorly. Similar patterns were observed for OS. These findings illustrate an important principle in biomarker qualification—measured circulating biomarkers may demonstrate independent prognostication, but this does not necessarily translate into substantial improvement in clinical performance.
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Affiliation(s)
- Ulrick Espelund
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus, Denmark
| | - Andrew G Renehan
- The Christie NHS Foundation Trust, Division of Molecular and Clinical Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Søren Cold
- Department of Oncology, Odense University Hospital, Odense, Denmark
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Science and Technology, Aarhus University, Aarhus, Denmark
| | | | | | - Allan Flyvbjerg
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center Copenhagen (SDCC), The Capital Region of Denmark and University of Copenhagen, Copenhagen, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Health, Aarhus University, Aarhus, Denmark.,Department of Endocrinology, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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20
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Hjortebjerg R, Berryman DE, Comisford R, List EO, Oxvig C, Bjerre M, Frystyk J, Kopchick JJ. Depot-specific and GH-dependent regulation of IGF binding protein-4, pregnancy-associated plasma protein-A, and stanniocalcin-2 in murine adipose tissue. Growth Horm IGF Res 2018; 39:54-61. [PMID: 29398370 DOI: 10.1016/j.ghir.2018.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 12/21/2017] [Accepted: 01/15/2018] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Pregnancy-associated plasma protein-A (PAPP-A) stimulates insulin-like growth factor (IGF)-I action through proteolytic cleavage of IGF binding protein-4 (IGFBP-4). Recently, stanniocalcin-2 (STC2) was discovered as an inhibitor of PAPP-A. Most members of the IGF system are expressed in adipose tissue (AT), but there is a relative paucity of information on the distribution of IGFBP-4, PAPP-A, and STC2 in different AT depots. Since IGF-I expression in AT is highly GH-dependent, we used bovine GH transgenic (bGH) and GH receptor knockout (GHR-/-) mice to investigate AT depot-specific expression patterns of IGFBP-4, PAPP-A, and STC2, and whether the regulation is GH-dependent. METHODS Seven-month-old male bGH, GHR-/- and wild type (WT) control mice were used. Body composition was determined, and subcutaneous, epididymal, retroperitoneal, mesenteric and brown adipose tissue (BAT) depots were collected. RNA expression of Igfbp4, Pappa, and Stc2 was assessed by reverse transcription quantitative PCR and IGFBP-4 protein by Western blotting. RESULTS Igfbp4, Pappa, and Stc2 RNA levels were differentially expressed in an AT depot-dependent manner in WT mice. Igfbp4 RNA levels were significantly higher in all white AT depots than in BAT. Pappa was most highly expressed in the mesenteric depot: levels were 7.5-fold higher in mesenteric than in subcutaneous AT (p < .001). Although intraabdominal in origin, epididymal and retroperitoneal Pappa expression levels were 69% and 68% lower, respectively, as compared to mesenteric levels (p < .001). Stc2 RNA expression was significantly higher in all intraabdominal white AT as compared to subcutaneous AT and BAT; levels in epididymal, retroperitoneal, and mesenteric were all more than three-fold higher than in subcutaneous AT (p < .001) and 12-fold higher than in BAT (p < .001). Gene expression patterns in bGH and GHR-/- mice mimicked those in WT mice, suggesting that GH does not affect the transcription of the STC2-PAPP-A-IGFBP-4-axis in AT. However, proteins levels of intact IGFBP-4 were significantly increased in bGH mice and decreased in GHR-/- mice, whereas the PAPP-A-generated IGFBP-4 fragment level was unaltered. CONCLUSION Expression of Igfbp4, Pappa, and Stc2 differ between AT depots and is generally higher in white AT than in BAT. The transcription appears to occur in a GH-independent manner, whereas IGFBP-4 protein levels are highly influenced by altered GH activity.
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Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; Danish Diabetes Academy, Odense, Denmark; Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA.
| | - Darlene E Berryman
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Ross Comisford
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Edward O List
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark.
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark.
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | - John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; The Diabetes Institute, Ohio University, Athens, OH 45701, USA.
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Ramshanker N, Aagaard M, Hjortebjerg R, Voss TS, Møller N, Jørgensen JOL, Jessen N, Bjerring P, Magnusson NE, Bjerre M, Oxvig C, Frystyk J. Effects of Prednisolone on Serum and Tissue Fluid IGF-I Receptor Activation and Post-Receptor Signaling in Humans. J Clin Endocrinol Metab 2017; 102:4031-4040. [PMID: 28945869 DOI: 10.1210/jc.2017-00696] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 09/08/2017] [Indexed: 02/13/2023]
Abstract
CONTEXT Short-term glucocorticoid exposure increases serum insulinlike growth factor I (IGF-I) concentrations but antagonizes IGF-I tissue signaling. The underlying mechanisms remain unknown. OBJECTIVE To identify at which levels glucocorticoid inhibits IGF-I signaling. DESIGN AND METHODS Nineteen healthy males received prednisolone (37.5 mg/d) and placebo for 5 days in a randomized, double-blinded, placebo-controlled crossover study. Serum was collected on days 1, 3, and 5, and abdominal skin suction blister fluid (SBF; ~interstitial fluid) was taken on day 5 (n = 9) together with muscle biopsy specimens (n = 19). The ability of serum and SBF to activate the IGF-I receptor (IGF-IR) (bioactive IGF) and its downstream signaling proteins was assessed using IGF-IR-transfected cells. RESULTS Prednisolone increased IGF-I concentrations and bioactive IGF in serum (P ≤ 0.001) but not in SBF, which, compared with serum, contained less bioactive IGF (~28%) after prednisolone (P < 0.05). This observation was unexplained by SBF concentrations of IGFs and IGF-binding proteins (IGFBPs) 1 to 4. However, following prednisolone treatment, SBF contained less IGFBP-4 fragments (P < 0.05) generated by pregnancy-associated plasma protein A (PAPP-A). Concomitantly, prednisolone increased SBF levels of stanniocalcin 2 (STC2) (P = 0.02) compared with serum. STC2 blocks PAPP-A from cleaving IGFBP-4. Finally, prednisolone suppressed post-IGF-IR signaling pathways at the level of insulin receptor substrate 1 (P < 0.05) but did not change skeletal muscle IGF-IR, IGF-I, or STC2 messenger RNA. CONCLUSION Prednisolone increased IGF-I concentrations and IGF bioactivity in serum but not in tissue fluid. The latter may relate to a STC2-mediated inhibition of PAPP-A in tissue fluids. Furthermore, prednisolone induced post-IGF-IR resistance. Thus, glucocorticoid may exert distinct, compartment-specific effects on IGF action.
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Affiliation(s)
- Nilani Ramshanker
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Maiken Aagaard
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
- Danish Diabetes Academy, DK-5000 Odense, Denmark
| | - Thomas Schmidt Voss
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Niels Møller
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
| | - Jens Otto Lunde Jørgensen
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Peter Bjerring
- Mølholm Research, Mølholm Private Hospital A/S, DK-7100 Vejle, Denmark
| | - Nils Erik Magnusson
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Faculty of Science & Technology, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
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22
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Espelund US, Bjerre M, Hjortebjerg R, Rasmussen TR, Lundby A, Hoeflich A, Folkersen BH, Oxvig C, Frystyk J. Insulin-Like Growth Factor Bioactivity, Stanniocalcin-2, Pregnancy-Associated Plasma Protein-A, and IGF-Binding Protein-4 in Pleural Fluid and Serum From Patients With Pulmonary Disease. J Clin Endocrinol Metab 2017; 102:3526-3534. [PMID: 28911149 DOI: 10.1210/jc.2017-00033] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 07/11/2017] [Indexed: 01/02/2023]
Abstract
CONTEXT Members of the insulin-like growth factor (IGF) system are primarily produced in the liver and secreted into the circulation, but they are also produced, recruited, and activated locally in tissues. OBJECTIVE To compare activity and concentrations of IGF system components in pleural fluid and blood. DESIGN Pathological pleural fluid, secondary to lung cancer or nonmalignant disease, and matching blood samples were collected from 24 patients ages 66.7 to 81.9 years. METHODS IGF-related proteins and cytokine levels were measured by immunoassays or immunoblotting. Bioactive IGF was measured by an IGF-1 receptor phosphorylation assay. RESULTS Total IGF-1 concentration did not differ between the compartments, but concentrations of free IGF-1 and bioactive IGF were more than threefold higher in pleural fluid than in corresponding serum samples (P = 0.0004), regardless of etiology. Median pregnancy-associated plasma protein-A (PAPP-A) and interleukin (IL)-6 levels were increased 47-fold and 143-fold, respectively, in pleural fluid compared with plasma (P < 0.0001). PAPP-A and IL-6 concentrations correlated positively (r = 0.46; P = 0.02). In pleural fluid, levels of PAPP-A-generated IGF binding protein-4 fragments correlated inversely with that of stanniocalcin-2 (r ≤ -0.42; P ≤ 0.05), a PAPP-A inhibitor; such correlations were absent in plasma. CONCLUSION Pathological pleural fluid is characterized by increased in vitro IGF bioactivity and elevated concentrations of PAPP-A, an IGF-activating proteinase. Thus, the tissue activity of the IGF system may differ substantially from that of the circulating IGF system. The correlation between IL-6 and PAPP-A indicates that inflammation plays a role in promoting local tissue IGF activity.
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Affiliation(s)
- Ulrick Skipper Espelund
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
- Danish Diabetes Academy, DK-5000 Odense C, Denmark
| | - Torben Riis Rasmussen
- Department of Pulmonary Medicine, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
| | - Anders Lundby
- Safety and GI Biology, Novo Nordisk A/S, Novo Nordisk Park, G9.S.17, DK-2760 Måløv, Denmark
| | - Andreas Hoeflich
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology, D-18196 Dummerstorf, Germany
| | | | - Claus Oxvig
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
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23
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Conover CA, Oxvig C. PAPP-A: a promising therapeutic target for healthy longevity. Aging Cell 2017; 16:205-209. [PMID: 28035757 PMCID: PMC5334524 DOI: 10.1111/acel.12564] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2016] [Indexed: 12/16/2022] Open
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) is a proteolytic enzyme that was discovered to increase local insulin-like growth factor (IGF) availability for receptor activation through cleavage of inhibitory IGF binding proteins (IGFBPs). Reduced IGF signaling has been associated with increased lifespan and healthspan. Therefore, inhibition of PAPP-A represents a novel approach to indirectly decrease the availability of bioactive IGF. Here, we will review data in support of PAPP-A as a therapeutic target to promote healthy longevity.
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Affiliation(s)
| | - Claus Oxvig
- Department of Molecular Biology and Genetics; Aarhus Universitet; Aarhus Denmark
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24
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Yunusova NV, Villert AB, Spirina LV, Frolova AE, Kolomiets LA, Kondakova IV. Insulin-Like Growth Factors and Their Binding Proteins in Tumors and Ascites of Ovarian Cancer Patients: Association With Response To Neoadjuvant Chemotherapy. Asian Pac J Cancer Prev 2016; 17:5315-5320. [PMID: 28125879 PMCID: PMC5454676 DOI: 10.22034/apjcp.2016.17.12.5315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Purpose: Tumor cell growth and sensitivity to chemotherapy depend on many factors, among which insulin-like growth factors (IGFs) may play important roles. The aim of the present study was to evaluate the levels of insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in primary tumors and ascites as predictors of response to neoadjuvant chemotherapy in ovarian cancer (OC) patients. Materials and Methods: Tumor tissue samples and ascitic fluid were obtained from 59 patients with advanced OC. The levels of IGF-I, IGF-II, IGFBP-3, IGFBP-4 and PAPP-A were determined using ELISA kits. Taking into account the data on expression of these IGF-related proteins and outcome, logistic regression was performed to identify predictors of response to neoajuvant chemotherapy. Results: Human ovarian tumors expressed IGFs, IGFBP-3, IGFBP-4 and PAPP-A and these proteins were also present in ascites fluid and associated with its volume. IGFs and IGFBPs in ascites and soluble PAPP-A might play a key role in ovarian cancer progression . However, levels of proteins of the IGF system in tumors were not significant predictors of objective clinical response (oCR). Univariate analysis showed that the level of IGF-I in ascites was the only independent predictor for oCR. Conclusion: The level of IGF-I in ascites was shown to be an independent predictor of objective clinical response to chemotherapy for OC patients treated with neoadjuvant chemotherapy and debulking surgery.
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Affiliation(s)
- Natalia V Yunusova
- Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia.
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