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Boughanem H, Yubero-Serrano EM, López-Miranda J, Tinahones FJ, Macias-Gonzalez M. Potential Role of Insulin Growth-Factor-Binding Protein 2 as Therapeutic Target for Obesity-Related Insulin Resistance. Int J Mol Sci 2021; 22:ijms22031133. [PMID: 33498859 PMCID: PMC7865532 DOI: 10.3390/ijms22031133] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/13/2021] [Accepted: 01/21/2021] [Indexed: 12/26/2022] Open
Abstract
Evidence from observational and in vitro studies suggests that insulin growth-factor-binding protein type 2 (IGFBP2) is a promising protein in non-communicable diseases, such as obesity, insulin resistance, metabolic syndrome, or type 2 diabetes. Accordingly, great efforts have been carried out to explore the role of IGFBP2 in obesity state and insulin-related diseases, which it is typically found decreased. However, the physiological pathways have not been explored yet, and the relevance of IGFBP2 as an important pathway integrator of metabolic disorders is still unknown. Here, we review and discuss the molecular structure of IGFBP2 as the first element of regulating the expression of IGFBP2. We highlight an update of the association between low serum IGFBP2 and an increased risk of obesity, type 2 diabetes, metabolic syndrome, and low insulin sensitivity. We hypothesize mechanisms of IGFBP2 on the development of obesity and insulin resistance in an insulin-independent manner, which meant that could be evaluated as a therapeutic target. Finally, we cover the most interesting lifestyle modifications that regulate IGFBP2, since lifestyle factors (diet and/or physical activity) are associated with important variations in serum IGFBP2.
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Affiliation(s)
- Hatim Boughanem
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
| | - Elena M. Yubero-Serrano
- Lipids and Atherosclerosis Unit, Maimonides Institute for Biomedical Research in Cordoba (IMIBIC), Reina Sofia University Hospital, University of Córdoba, 14004 Córdoba, Spain; (E.M.Y.-S.); (J.L.-M.)
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José López-Miranda
- Lipids and Atherosclerosis Unit, Maimonides Institute for Biomedical Research in Cordoba (IMIBIC), Reina Sofia University Hospital, University of Córdoba, 14004 Córdoba, Spain; (E.M.Y.-S.); (J.L.-M.)
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Francisco J. Tinahones
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: (F.J.T.); (M.M.-G.); Tel.: +34-951-036-2647 (F.J.T. & M.M.-G.); Fax: +34-951-924-651 (F.J.T. & M.M.-G.)
| | - Manuel Macias-Gonzalez
- Department of Endocrinology and Nutrition, Institute of Biomedical Research Institute in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain;
- CIBEROBN (CIBER in Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: (F.J.T.); (M.M.-G.); Tel.: +34-951-036-2647 (F.J.T. & M.M.-G.); Fax: +34-951-924-651 (F.J.T. & M.M.-G.)
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Ohde D, Walz M, Walz C, Noce A, Brenmoehl J, Langhammer M, Hoeflich A. Sex-Specific Control of Muscle Mass: Elevated IGFBP Proteolysis and Reductions of IGF-1 Levels Are Associated with Substantial Loss of Carcass Weight in Male DU6PxIGFBP-2 Transgenic Mice. Cells 2020; 9:cells9102174. [PMID: 32993096 PMCID: PMC7600981 DOI: 10.3390/cells9102174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/18/2020] [Accepted: 09/25/2020] [Indexed: 11/16/2022] Open
Abstract
In farmed animals, carcass weight represents an important economic trait. Since we had demonstrated that IGFBP-2 represents a potent inhibitor of muscle accretion in inbred mice, we wanted to quantify the inhibitory effects of IGFBP-2 under conditions of elevated protein mass in growth selected non-inbred mice (DU6P). Therefore, we crossed male DU6P mice with female IGFBP-2 transgenic mice. Male IGFBP-2 transgenic offspring (DU6P/IGFBP-2) were characterized by more than 20% reductions of carcass mass compared to male non-transgenic littermates. The carcass mass in males was also significantly lower (p < 0.001) than in transgenic female DU6P/IGFBP-2 mice, which showed a reduction of less than 10% (p < 0.05) compared to non-transgenic female DU6P/IGFBP-2 mice. Although transgene expression was elevated in the muscle of both sexes (p < 0.001), serum levels were normal in female, but significantly reduced in male transgenic DU6P/IGFBP-2 mice (p < 0.001). In this group, also IGFBP-3 and IGFBP-4 were significantly reduced in the circulation (p < 0.01). Particularly in male transgenic mice, we were able to identify proteolytic activity against recombinant IGFBP-2 included in diluted serum. IGFBP-proteolysis in males correlated with massive reductions of IGF-1 in serum samples and the presence of elevated levels of IGFBP-2 fragments. From our data, we conclude that elevated tissue expression of IGFBP-2 is an essential effector of muscle accretion and may block more than 20% of carcass mass. However, in the circulation, intact IGFBP-2 contained no reliable biomarker content. Notably, for the estimation of breeding values in meat-producing animal species, monitoring of IGFBP-2 expression in muscle appears to be supported by the present study in a model system.
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Affiliation(s)
- Daniela Ohde
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
| | - Michael Walz
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
| | - Christina Walz
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
| | - Antonia Noce
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
| | - Julia Brenmoehl
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
| | - Martina Langhammer
- Institute of Genetics and Biometry, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany;
| | - Andreas Hoeflich
- Institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany; (D.O.); (M.W.); (C.W.); (A.N.); (J.B.)
- Correspondence: ; Tel.: +49-38208-68744
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Carter S, Lemieux I, Li Z, Alméras N, Tremblay A, Bergeron J, Poirier P, Després JP, Picard F. Changes in IGFBP-2 levels following a one-year lifestyle modification program are independently related to improvements in plasma apo B and LDL apo B levels. Atherosclerosis 2018; 281:89-97. [PMID: 30658196 DOI: 10.1016/j.atherosclerosis.2018.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/31/2018] [Accepted: 12/13/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIMS Recent transversal studies have associated insulin-like growth factor binding protein (IGFBP)-2 levels with glucose tolerance and parameters of the lipoprotein-lipid profile. Here, we aimed at determining the longitudinal effects of a one-year lifestyle modification program on IGFBP-2 levels and to identify specific metabolic improvements impacted by the changes in IGFBP-2. METHODS 99 middle-aged Caucasian men were involved in a lifestyle modification program consisting in personalized healthy eating and physical activity counseling, combined to elicit a daily 500 kcal deficit. Anthropometric and metabolic parameters as well as circulating IGFBP-2 levels were measured before and after one year of the lifestyle modification program. RESULTS The intervention triggered positive changes in many metabolic parameters and a 43% (p < 0.0001) increase of IGFBP-2 levels. Subjects with the most substantial increases in IGFBP-2 also experienced the most important metabolic improvements. Changes in IGFBP-2 levels (both absolute and relative) were correlated with markers of body fat distribution and lipoprotein-lipid profile, and independently associated with changes in LDL apolipoprotein (apo) B but not VLDL apo B concentrations. Further analyses showed that for similar changes in BMI, waist circumference and visceral adipose tissue volume, large changes in IGFBP-2 levels were required to observe improvements in LDL apo B levels. CONCLUSIONS The 1-year lifestyle modification program was associated with increased IGFBP-2 concentrations. Increases in IGFBP-2 levels were closely associated with reduced LDL apo B concentrations and independently of the modifications in fat mass and insulin sensitivity. Further mechanistic studies are required to assess the effects of IGFBP-2 levels on LDL metabolism.
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Affiliation(s)
- Sophie Carter
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Faculty of Pharmacy, Université Laval, Québec, QC, Canada
| | - Isabelle Lemieux
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Zhuo Li
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Natalie Alméras
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Angelo Tremblay
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Jean Bergeron
- Endocrinology and Nephrology Unit, CHU de Québec-Université Laval Research Center, Québec, QC, Canada
| | - Paul Poirier
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Faculty of Pharmacy, Université Laval, Québec, QC, Canada
| | - Jean-Pierre Després
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Frédéric Picard
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval, Québec, QC, Canada; Faculty of Pharmacy, Université Laval, Québec, QC, Canada.
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Asampille G, Verma BK, Swain M, Shettar A, Rosenzweig SA, Kondaiah P, Atreya HS. An ultra-stable redox-controlled self-assembling polypeptide nanotube for targeted imaging and therapy in cancer. J Nanobiotechnology 2018; 16:101. [PMID: 30526620 PMCID: PMC6286583 DOI: 10.1186/s12951-018-0427-1] [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: 08/17/2018] [Accepted: 11/24/2018] [Indexed: 01/10/2023] Open
Abstract
We introduce a self-assembling polypeptide-based nanotube system having the ability to specifically target cancer cells. The nanotubes target the cancer cell surface through integrin engagement with the help of multiple RGD units present along their surface. While the nanotubes are non-toxic towards cells in general, they can be loaded with suitable drugs to be released in a sustained manner in cancer cells. In addition, the nanotubes can be utilized for cellular imaging using any covalently tagged fluorescent dye. They are stable over a wide range of temperature due to intermolecular disulphide bonds formed during the self-assembly process. At the same time, presence of disulphide bonds provides a redox molecular switch for their degradation. Taken together this system provides a unique avenue for multimodal formulation in cancer therapy.
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Affiliation(s)
- Gitanjali Asampille
- NMR Research Centre, Indian Institute of Science, Bangalore, 560012, India.,Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Brijesh Kumar Verma
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Monalisa Swain
- NMR Research Centre, Indian Institute of Science, Bangalore, 560012, India.,Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India.,Basic Research Laboratory, National Cancer Institute, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Abhijith Shettar
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India.,Biotechnology Engineering, Ramaiah Institute of Technology, Bangalore, Karnataka, 560054, India
| | - Steven A Rosenzweig
- Department of Cell and Molecular Pharmacology, & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Paturu Kondaiah
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India.
| | - Hanudatta S Atreya
- NMR Research Centre, Indian Institute of Science, Bangalore, 560012, India.
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Patil SS, Gokulnath P, Bashir M, Shwetha SD, Jaiswal J, Shastry AH, Arimappamagan A, Santosh V, Kondaiah P. Insulin-like growth factor binding protein-2 regulates β-catenin signaling pathway in glioma cells and contributes to poor patient prognosis. Neuro Oncol 2016; 18:1487-1497. [PMID: 27044294 DOI: 10.1093/neuonc/now053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 03/06/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Upregulation of insulin-like growth factor binding protein 2 (IGFBP-2) is often associated with aggressiveness of glioblastoma (GBM) and contributes to poor prognosis for GBM patients. In view of the regulation of β-catenin by IGFBP-2 in breast cancer and the crucial role of β-catenin pathway in glioma invasion, proliferation and maintenance of glioma stem cells, the mechanism of regulation of β-catenin by IGFBP-2, and its role in GBM prognosis was studied. METHODS Regulation of the β-catenin pathway was studied by immunocytochemistry, Western blot analysis, luciferase assays, and real-time RT-PCR. The role of IGFBP-2 was studied by subcutaneous tumor xenografts in immunocompromised mice using glioma cells engineered to express IGFBP-2 and its domains. GBM patient tumor tissues (n = 112) were analyzed for expression of IGFBP-2 and β-catenin by immunohistochemistry. Survival analysis was performed employing Cox regression and Kaplan-Meier survival analyses. RESULTS IGFBP-2 knockdown in U251, T98G, and U373 or overexpression in LN229 and U87 cells revealed a role for IGFBP-2 in stabilization of β-catenin and regulation of its nuclear functions involving integrin-mediated inactivation of GSK3β. Similar results were obtained upon overexpression of the C-terminal domain of IGFBP-2 but not the N-terminal domain. Subcutaneous xenograft tumors overexpressing either full-length or the C-terminal domain of IGFBP-2 showed larger volume as compared with controls. Coexpression of high levels of IGFBP-2 and β-catenin was associated with worse prognosis (P = .001) in GBM patients. CONCLUSION IGFBP-2 potentiates GBM tumor growth by the activation of the β-catenin pathway through its C-terminal domain, and their coexpression possibly contributes to worse patient prognosis.
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Affiliation(s)
- Shilpa S Patil
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Priyanka Gokulnath
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Mohsin Bashir
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Shivayogi D Shwetha
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Janhvi Jaiswal
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Arun H Shastry
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Arivazhagan Arimappamagan
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Vani Santosh
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
| | - Paturu Kondaiah
- Molecular Reproduction, Development and Genetics department, Indian Institute of Science, Bangalore, India (S.S.P., P.G., M.B., P.K.); Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, India (S.D.S., J.J., V.S.); Clinical Neurosciences, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.H.S.); Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, India (A.A.)
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IGFBP-2: The dark horse in metabolism and cancer. Cytokine Growth Factor Rev 2015; 26:329-46. [DOI: 10.1016/j.cytogfr.2014.12.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 12/09/2014] [Indexed: 12/29/2022]
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Brahmkhatri VP, Prasanna C, Atreya HS. Insulin-like growth factor system in cancer: novel targeted therapies. BIOMED RESEARCH INTERNATIONAL 2015; 2015:538019. [PMID: 25866791 PMCID: PMC4383470 DOI: 10.1155/2015/538019] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 10/13/2014] [Accepted: 10/20/2014] [Indexed: 12/15/2022]
Abstract
Insulin-like growth factors (IGFs) are essential for growth and survival that suppress apoptosis and promote cell cycle progression, angiogenesis, and metastatic activities in various cancers. The IGFs actions are mediated through the IGF-1 receptor that is involved in cell transformation induced by tumour. These effects depend on the bioavailability of IGFs, which is regulated by IGF binding proteins (IGFBPs). We describe here the role of the IGF system in cancer, proposing new strategies targeting this system. We have attempted to expand the general viewpoint on IGF-1R, its inhibitors, potential limitations of IGF-1R, antibodies and tyrosine kinase inhibitors, and IGFBP actions. This review discusses the emerging view that blocking IGF via IGFBP is a better option than blocking IGF receptors. This can lead to the development of novel cancer therapies.
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Affiliation(s)
| | - Chinmayi Prasanna
- NMR Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Hanudatta S. Atreya
- NMR Research Centre, Indian Institute of Science, Bangalore 560012, India
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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8
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Yau SW, Azar WJ, Sabin MA, Werther GA, Russo VC. IGFBP-2 - taking the lead in growth, metabolism and cancer. J Cell Commun Signal 2015; 9:125-42. [PMID: 25617050 DOI: 10.1007/s12079-015-0261-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/12/2015] [Indexed: 10/24/2022] Open
Abstract
The activity of the Insulin-like Growth Factors (IGFs) ligands elicited via their receptors and transduced by various intracellular signal pathways is modulated by the IGF Binding Proteins (IGFBPs). Among all the IGFBPs, IGFBP-2 has been implicated in the regulation of IGF activity in most tissue and organs. Besides binding to IGFs in the circulation these IGF-regulatory activities of IGFBP-2 involve interactions with components of the extracellular matrix, cell surface proteoglycans and integrin receptors. In addition to these local peri-cellular activities, IGFBP-2 exerts other key functions within the nucleus, where IGFBP-2 directly or indirectly promotes transcriptional activation of specific genes. All of these IGFBP-2 activities, intrinsic or dependent on IGFs, contribute to its functional roles in growth/development, metabolism and malignancy as evidenced by studies in IGFBP-2 animal models and also by many in vitro studies. Finally, preclinical studies have demonstrated that IGFBP-2 administration can be beneficial in improving metabolic responses (inhibition of adipogenesis and enhanced insulin sensitivity), while blockade of IGFBP-2 appears to be an effective approach to inhibiting tumour growth and metastasis.
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Affiliation(s)
- Steven W Yau
- Deparment of Cell Biology, Hormone Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, VIC, Australia
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9
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Pickard A, McCance DJ. IGF-Binding Protein 2 - Oncogene or Tumor Suppressor? Front Endocrinol (Lausanne) 2015; 6:25. [PMID: 25774149 PMCID: PMC4343188 DOI: 10.3389/fendo.2015.00025] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/13/2015] [Indexed: 01/08/2023] Open
Abstract
The role of insulin-like growth factor binding protein 2 (IGFBP2) in cancer is unclear. In general, IGFBP2 is considered to be oncogenic and its expression is often observed to be elevated in cancer. However, there are a number of conflicting reports in vitro and in vivo where IGFBP2 acts in a tumor suppressor manner. In this mini-review, we discuss the factors influencing the variation in IGFBP2 expression in cancer and our interpretation of these findings.
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Affiliation(s)
- Adam Pickard
- Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, UK
- *Correspondence: Adam Pickard, Centre for Cancer Research and Cell Biology, Queen’s University Belfast, 97 Lisburn Road, Belfast BT7 9BL, UK e-mail:
| | - Dennis J. McCance
- Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, UK
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10
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Sunderić M, Mihailović N, Nedić O. Protein molecular forms of insulin-like growth factor binding protein-2 change with aging. Exp Gerontol 2014; 58:154-8. [PMID: 25106097 DOI: 10.1016/j.exger.2014.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/22/2014] [Accepted: 08/04/2014] [Indexed: 12/22/2022]
Abstract
Aging is considered to be an adaptive mechanism to altered needs of an organism and/or to altered stimuli. Plasma concentrations of insulin-like growth factor binding protein-2 (IGFBP-2) increase with age and it is generally assumed that IGFBP-2 is a negative predictor of healthy aging. The aim of this study was to examine the distribution of IGFBP-2 molecular forms in different age groups and, specifically, the relationship between IGFBP-2 and alpha-2-macroglobulin (α2M). The relative amount of monomer IGFBP-2 was the highest in young persons, making up approximately 2/3 of the total circulating IGFBP-2. This gradually decreased with age down to 1/3 of total IGFBP-2 in elderly individuals. Fragmented IGFBP-2 increased with age and contributed almost 60% to the total immunoreactive IGFBP-2 in the age group 61-80 years. IGFBP-2/α2M complexes represented 10-12% of the total IGFBP-2 in the two younger groups but half this level in the oldest group. The significance of these changes and whether they affect more IGF-dependent or independent interactions are unknown. Due to drastic proteolysis of IGFBP-2, it may be postulated that either over-release of IGFBP-2-bound IGFs causes unwanted events or IGFBP-2 fragments are able to over-stimulate cellular processes.
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Affiliation(s)
- Miloš Sunderić
- Institute for the Application of Nuclear Energy (INEP), University of Belgrade, Serbia.
| | - Nevena Mihailović
- Institute for the Application of Nuclear Energy (INEP), University of Belgrade, Serbia.
| | - Olgica Nedić
- Institute for the Application of Nuclear Energy (INEP), University of Belgrade, Serbia.
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11
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Lund J, Søndergaard MT, Conover CA, Overgaard MT. Heparin-binding mechanism of the IGF2/IGF-binding protein 2 complex. J Mol Endocrinol 2014; 52:345-55. [PMID: 24604839 DOI: 10.1530/jme-13-0184] [Citation(s) in RCA: 16] [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] [Indexed: 11/08/2022]
Abstract
IGF1 and IGF2 are potent stimulators of diverse cellular activities such as differentiation and mitosis. Six IGF-binding proteins (IGFBP1-IGFBP6) are primary regulators of IGF half-life and receptor availability. Generally, the binding of IGFBPs inhibits IGF receptor activation. However, it has been shown that IGFBP2 in complex with IGF2 (IGF2/IGFBP2) stimulates osteoblast function in vitro and increases skeletal mass in vivo. IGF2 binding to IGFBP2 greatly increases the affinity for 2- or 3-carbon O-sulfated glycosaminoglycans (GAGs), e.g. heparin and heparan sulfate, which is hypothesized to preferentially and specifically target the IGF2/IGFBP2 complex to the bone matrix. In order to obtain a more detailed understanding of the interactions between the IGF2/IGFBP2 complex and GAGs, we investigated heparin-binding properties of IGFBP2 and the IGF2/IGFBP2 complex in a quantitative manner. For this study, we mutated key positively charged residues within the two heparin-binding domains (HBDs) in IGFBP2 and in one potential HBD in IGF2. Using heparin affinity chromatography, we demonstrate that the two IGFBP2 HBDs contribute differentially to GAG binding in free IGFBP2 and the IGF2/IGFBP2 protein complex. Moreover, we identify a significant contribution from the HBD in IGF2 to the increased IGF2/IGFBP2 heparin affinity. Using molecular modeling, we present a novel model for the IGF2/IGFBP2 interaction with heparin where all three proposed HBDs constitute a positively charged and surface-exposed area that would serve to promote the increased heparin affinity of the complex compared with free intact IGFBP2.
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Affiliation(s)
- Jacob Lund
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Mads T Søndergaard
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Cheryl A Conover
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Michael T Overgaard
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
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12
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Forbes BE, McCarthy P, Norton RS. Insulin-like growth factor binding proteins: a structural perspective. Front Endocrinol (Lausanne) 2012; 3:38. [PMID: 22654863 PMCID: PMC3356058 DOI: 10.3389/fendo.2012.00038] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 02/16/2012] [Indexed: 11/13/2022] Open
Abstract
Insulin-like growth factor binding proteins (IGFBP-1 to -6) bind insulin-like growth factors-I and -II (IGF-I and IGF-II) with high affinity. These binding proteins maintain IGFs in the circulation and direct them to target tissues, where they promote cell growth, proliferation, differentiation, and survival via the type 1 IGF receptor. IGFBPs also interact with many other molecules, which not only influence their modulation of IGF action but also mediate IGF-independent activities that regulate processes such as cell migration and apoptosis by modulating gene transcription. IGFBPs-1 to -6 are structurally similar proteins consisting of three distinct domains, N-terminal, linker, and C-terminal. There have been major advances in our understanding of IGFBP structure in the last decade and a half. While there is still no structure of an intact IGFBP, several structures of individual N- and C-domains have been solved. The structure of a complex of N-BP-4:IGF-I:C-BP-4 has also been solved, providing a detailed picture of the structural features of the IGF binding site and the mechanism of binding. Structural studies have also identified features important for interaction with extracellular matrix components and integrins. This review summarizes structural studies reported so far and highlights features important for binding not only IGF but also other partners. We also highlight future directions in which structural studies will add to our knowledge of the role played by the IGFBP family in normal growth and development, as well as in disease.
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Affiliation(s)
- Briony E Forbes
- The School of Molecular and Biomedical Science, The University of Adelaide Adelaide, SA, Australia
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13
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Kiepe D, Van Der Pas A, Ciarmatori S, Ständker L, Schütt B, Hoeflich A, Hügel U, Oh J, Tönshoff B. Defined carboxy-terminal fragments of insulin-like growth factor (IGF) binding protein-2 exert similar mitogenic activity on cultured rat growth plate chondrocytes as IGF-I. Endocrinology 2008; 149:4901-11. [PMID: 18556354 DOI: 10.1210/en.2007-1395] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The IGF/IGF binding protein (IGFBP) system is an important component in the hormonal regulation of longitudinal growth. Evidence from in vitro studies indicates that IGFBPs may have IGF-independent effects. We analyzed the biological activity of intact IGFBP-2 and defined carboxy-terminal IGFBP-2 fragments isolated from human hemofiltrate in two cell culture systems of the growth plate: rat growth plate chondrocytes in primary culture and the mesenchymal chondrogenic cell line RCJ3.1C5.18. The IGFBP-2 fragments IGFBP-2(167-279), IGFBP-2(167-289), and IGFBP-2(104-289) exerted a strong (2- to 3-fold) mitogenic effect on growth plate chondrocytes, which was comparable with IGF-I in equimolar concentrations (7.8 nm) but was not mediated through the type 1 IGF receptor. In a dose-response experiment, the most effective concentration of IGFBP-2(104-289) for the stimulation of cell proliferation was 10 nm. This biological activity of IGFBP-2 fragments was associated with cell membrane binding, demonstrated by Western blot analysis of fractionated cell lysates and immunohistochemistry. Whereas intact IGFBP-2 did not modulate chondrocyte proliferation, partially reduced (by dithiothreitol) full-length IGFBP-2 stimulated cell proliferation to a comparable extent (3.4-fold) as carboxy-terminal IGFBP-2 fragments. The mitogenic activity of these IGFBP-2 fragments and of partially reduced full-length IGFBP-2 was mediated through the use of the MAPK/ERK 1/2. These data imply a novel role of naturally occurring IGFBP-2 fragments for the endocrine and paracrine/autocrine regulation of longitudinal growth.
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Affiliation(s)
- Daniela Kiepe
- University Children's Hospital, Im Neuenheimer Feld 153, 69120 Heidelberg, Germany.
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14
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Berg U, Bang P, Carlsson-Skwirut C. Calpain proteolysis of insulin-like growth factor binding protein (IGFBP) -2 and -3, but not of IGFBP-1. Biol Chem 2007; 388:859-63. [PMID: 17655506 DOI: 10.1515/bc.2007.098] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Calpains are cytoplasmic Ca(2+)-regulated cysteine proteases that may regulate insulin-like growth factor (IGF)-independent actions of insulin-like growth factor binding proteins (IGFBPs) through IGFBP proteolysis. In this study, [(125)I]-labeled IGFBP-2 and -3, but not IGFBP-1, were proteolyzed by Ca(2+)-activated m-calpain in vitro. Degradation of higher concentrations of the recombinant proteins IGFBP-2 and -3 by m-calpain was dose-dependent, but was terminated within 20 min by autolysis. By subjecting proteolytic fragments to N-terminal amino acid sequence analysis, the primary cleavage sites in IGFBP-2 and -3 were localized to the non-conserved central linker regions. Using the biosensor technique, in vitro binding of m-calpain to IGFBP-3 was demonstrated to be a Ca(2+)-dependent reaction with a rapid on/off rate.
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Affiliation(s)
- Ulrika Berg
- Department of Woman and Child Health, Pediatric Endocrinology and Diabetes Unit, Karolinska Institute, Astrid Lindgren Children's Hospital, S-171 76 Stockholm, Sweden
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15
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Degraff DJ, Malik M, Chen Q, Miyako K, Rejto L, Aguiar AA, Bancroft DRE, Cohen P, Sikes RA. Hormonal regulation of IGFBP-2 proteolysis is attenuated with progression to androgen insensitivity in the LNCaP progression model. J Cell Physiol 2007; 213:261-8. [PMID: 17492783 DOI: 10.1002/jcp.21123] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The identification of molecular determinants involved in the promotion of metastasis and development of androgen insensitive prostate cancer (AI-PCa) is necessary to discriminate aggressive from indolent disease and to identify therapeutic targets for advanced disease. Overexpression of one particular member of the insulin like growth factor (IGF) axis, IGFBP-2, is implicated in the development of AI-PCa and other cancers. Using the LNCaP human PCa progression model, we show that the AI and metastatic prostate cancer cell line C4-2B4 expresses greater amounts of secreted IGFBP-2 than the androgen sensitive (AS), non-metastatic LNCaP progenitor cell line. Further, the ability of androgens to decrease extracellular IGFBP-2 levels is attenuated in the AI and metastatic C4-2 cell line. The ability of androgen to negatively regulate extracellular IGFBP-2 levels was blocked by Casodex in a dose-dependent manner. The mechanism underlying the androgen-induced downregulation of secreted IGFBP-2 appears to involve extracellular proteolysis, resulting in the production of IGFBP-2 fragments lacking the ability to bind IGF-I and IGF-II. As C4-2 cells have an attenuated ability to proteolyze IGFBP-2 in response to androgen and C4-2B4 cells express greater amounts of IGFBP-2, our data implies that the diminished regulation of IGFBP-2 and loss of associated proteolytic fragments play a role in the increased metastatic behavior of these cells in vivo. Furthermore, our results suggest that either increased levels of intact IGFBP-2 or decreased levels of IGFBP-2 proteolytic fragments could serve as a biomarker to monitor for progression to AI-PCa.
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Affiliation(s)
- David J Degraff
- Laboratory for Cancer Ontogeny and Therapeutics, Department of Biological Sciences, University of Delaware, Newark, Deleware 19716, USA
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16
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John H, Schulz S, Forssmann WG. Comparative in vitro degradation of the human hemorphin LVV-H7 in mammalian plasma analysed by capillary zone electrophoresis and mass spectrometry. Biopharm Drug Dispos 2007; 28:73-85. [PMID: 17173283 DOI: 10.1002/bdd.533] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The human hemorphin LVV-H7 (L32VVYPWTQRF41) is a hemoglobin-beta, -gamma, -delta or -epsilon chain derived cationic decapeptide of the micro-opioid receptor binding family. It exhibits potential pharmacological value relevant, for example, for blood pressure regulation, learning performance and Alzheimer's disease. The regulatory potency is strictly dependent on the length of the amino acid sequence which is sensitive towards proteinases from tissues and plasma. To analyse LVV-H7 in vitro degradation in mammalian plasma, a novel multi-component quantitative capillary zone electrophoretic (CZE) procedure was applied, combined with qualitative metabolite profiling by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In all types of plasma, LVV-H7 was N-terminally truncated generating four metabolites (M1-M4) with an intact C-terminus: M1 (V33VYPWTQRF41), M2 (V34YPWTQRF41), M3 (Y35PWTQRF41) and M4 (W37TQRF41). In EDTA plasma these degradation products were detected exclusively, whereas in citrate and heparin plasma four further metabolites appeared resulting from additional C-terminal cleavage of the dipeptide R40F41: M5 (L32VVYPWTQ39), M6 (V33VYPWTQ39), M7 (V34YPWTQ39) and M8 (Y35PWTQ39). In the presence of selective proteinase inhibitors aminopeptidase M and angiotensin-converting enzyme (for N- and C-terminal truncation, respectively) were identified as plasma enzymes responsible for hemorphin degradation. Furthermore, striking inter-mammalian species distinctions were detected revealing strongly differing degradation velocities but similar metabolite patterns.
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Affiliation(s)
- Harald John
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Str. 31, Hannover, Germany.
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17
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Kuang Z, Yao S, Keizer DW, Wang CC, Bach LA, Forbes BE, Wallace JC, Norton RS. Structure, dynamics and heparin binding of the C-terminal domain of insulin-like growth factor-binding protein-2 (IGFBP-2). J Mol Biol 2006; 364:690-704. [PMID: 17020769 DOI: 10.1016/j.jmb.2006.09.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 08/31/2006] [Accepted: 09/01/2006] [Indexed: 11/24/2022]
Abstract
Insulin-like growth factor-binding protein-2 (IGFBP-2) is the largest member of a family of six proteins (IGFBP-1 to 6) that bind insulin-like growth factors I and II (IGF-I/II) with high affinity. In addition to regulating IGF actions, IGFBPs have IGF-independent functions. The C-terminal domains of IGFBPs contribute to high-affinity IGF binding, and confer binding specificity and have overlapping but variable interactions with many other molecules. Using nuclear magnetic resonance (NMR) spectroscopy, we have determined the solution structure of the C-terminal domain of IGFBP-2 (C-BP-2) and analysed its backbone dynamics based on 15N relaxation parameters. C-BP-2 has a thyroglobulin type 1 fold consisting of an alpha-helix, a three-stranded anti-parallel beta-sheet and three flexible loops. Compared to C-BP-6 and C-BP-1, structural differences that may affect IGF binding and underlie other functional differences were found. C-BP-2 has a longer disordered loop I, and an extended C-terminal tail, which is unstructured and very mobile. The length of the helix is identical with that of C-BP-6 but shorter than that of C-BP-1. Reduced spectral density mapping analysis showed that C-BP-2 possesses significant rapid motion in the loops and termini, and may undergo slower conformational or chemical exchange in the structured core and loop II. An RGD motif is located in a solvent-exposed turn. A pH-dependent heparin-binding site on C-BP-2 has been identified. Protonation of two histidine residues, His271 and His228, seems to be important for this binding, which occurs at slightly acidic pH (6.0) and is more significant at pH 5.5, but is largely suppressed at pH 7.4. Possible preferential binding of IGFBP-2 and its C- domain fragments to glycosaminoglycans in the acidic extracellular matrix (ECM) of tumours may be related to their roles in cancer.
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Affiliation(s)
- Zhihe Kuang
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3050, Australia
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18
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Robinson SA, Rosenzweig SA. Paradoxical effects of the phage display-derived peptide antagonist IGF-F1-1 on insulin-like growth factor-1 receptor signaling. Biochem Pharmacol 2006; 72:53-61. [PMID: 16684509 DOI: 10.1016/j.bcp.2006.03.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 03/30/2006] [Accepted: 03/30/2006] [Indexed: 10/24/2022]
Abstract
The insulin-like growth factor binding proteins (IGFBPs) represent a unique class of IGF antagonists regulating the bioavailability of the IGFs extracellularly. Accordingly, they represent an important class of proteins for cancer therapeutics and chemoprevention. IGF-F1-1 is a cyclic hexadecapeptide identified by high throughput phage display that binds to the IGFBP-binding domain on IGF-1. It acts as an IGFBP-mimetic, capable of inhibiting IGF-1 binding to the IGFBPs. To further examine the utility of IGF-F1-1 as an IGF-1 antagonist we tested its ability to inhibit IGFBP-2 and IGFBP-3 binding to IGF-1, (125)I-IGF-1 binding to IGF-1Rs and to block IGF-1 induced Akt activation, cell cycle changes and [(3)H]thymidine incorporation in MCF-7 cells. These biological activities were inhibited by treatment with IGFBP-2, wortmannin or the IGF-1R tyrosine kinase inhibitor, NVP-AEW541, but not by IGF-F1-1. Our findings confirm previous studies indicating that IGF-F1-1 is a weak antagonist of IGF-1 binding to the IGFBPs and the IGF-1R and suggest that it does not effectively inhibit downstream events stimulated by IGF-1. We further demonstrated that IGF-F1-1 treatment of MCF-7 cells results in the paradoxical activation of Akt, S-phase transition and [(3)H]thymidine incorporation. These results suggest that IGF-F1-1 is a weak agonist, exhibiting mitogenic actions. IGF-F1-1 may act in conjunction with IGF-1 at the IGF-1R or independently of IGF-1 at the IGF-1R or another receptor.
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Affiliation(s)
- Stephanie A Robinson
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics and Hollings Cancer Center, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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19
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Abstract
We identified 1113 articles (103 reviews, 1010 primary research articles) published in 2005 that describe experiments performed using commercially available optical biosensors. While this number of publications is impressive, we find that the quality of the biosensor work in these articles is often pretty poor. It is a little disappointing that there appears to be only a small set of researchers who know how to properly perform, analyze, and present biosensor data. To help focus the field, we spotlight work published by 10 research groups that exemplify the quality of data one should expect to see from a biosensor experiment. Also, in an effort to raise awareness of the common problems in the biosensor field, we provide side-by-side examples of good and bad data sets from the 2005 literature.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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20
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Kibbey MM, Jameson MJ, Eaton EM, Rosenzweig SA. Insulin-like growth factor binding protein-2: contributions of the C-terminal domain to insulin-like growth factor-1 binding. Mol Pharmacol 2005; 69:833-45. [PMID: 16306230 DOI: 10.1124/mol.105.016998] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Signaling by the insulin-like growth factor (IGF)-1 receptor (IGF-1R) has been implicated in the promotion and aggressiveness of breast, prostate, colorectal, and lung cancers. The IGF binding proteins (IGFBPs) represent a class of natural IGF antagonists that bind to and sequester IGF-1/2 from the IGF-1R, making them attractive candidates as therapeutics for cancer prevention and control. Recombinant human IGFBP-2 significantly attenuated IGF-1-stimulated MCF-7 cell proliferation with coaddition of 20 or 100 nM IGFBP-2 (50 or 80% inhibition, respectively). We previously identified IGF-1 contact sites both upstream and downstream of the CWCV motif (residues 247-250) in human IGFBP-2 (J Biol Chem 276:2880-2889, 2001). To further test their contributions to IGFBP-2 function, the single tryptophan in human IGFBP-2, Trp-248, was selectively cleaved with 2-(2'nitrophenylsulfenyl)-3-methyl-3 bromoindolenine (BNPS-skatole) and the BNPS-skatole products IGFBP-2(1-248) and IGFBP-2(249-289) as well as IGFBP-2(1-190) were expressed as glutathione S-transferase-fusion proteins and purified. Based on competition binding analysis, deletion of residues 249 to 289 caused an approximately 20-fold decrease in IGF-1 binding affinity (IGFBP-2 EC50 = 0.35 nM and IGFBP-2(1-248) = 7 nM). Removal of the remainder of the C-terminal domain had no further effect on affinity (IGFBP-2(1-190) EC50 = 9.2 nM). In kinetic assays, IGFBP-2(1-248) and IGFBP-2(1-190) exhibited more rapid association and dissociation rates than full-length IGFBP-2. These results confirm that regions upstream and downstream of the CWCV motif participate in IGF-1 binding. They further support the development of full-length IGFBP-2 as a cancer therapeutic.
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Affiliation(s)
- Megan M Kibbey
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA
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21
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Sala A, Capaldi S, Campagnoli M, Faggion B, Labò S, Perduca M, Romano A, Carrizo ME, Valli M, Visai L, Minchiotti L, Galliano M, Monaco HL. Structure and properties of the C-terminal domain of insulin-like growth factor-binding protein-1 isolated from human amniotic fluid. J Biol Chem 2005; 280:29812-9. [PMID: 15972819 DOI: 10.1074/jbc.m504304200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-like growth factor (IGF)-binding protein-1 (IGFBP-1) regulates the activity of the insulin-like growth factors in early pregnancy and is, thus, thought to play a key role at the fetal-maternal interface. The C-terminal domain of IGFBP-1 and three isoforms of the intact protein were isolated from human amniotic fluid, and sequencing of the four N-terminal polypeptide chains showed them to be highly pure. The addition of both intact IGFBP-1 and its C-terminal fragment to cultured fibroblasts has a similar stimulating effect on cell migration, and therefore, the domain has a biological activity on its own. The three-dimensional structure of the C-terminal domain was determined by x-ray crystallography to 1.8 Angstroms resolution. The fragment folds as a thyroglobulin type I domain and was found to bind the Fe(2+) ion in the crystals through the only histidine residue present in the polypeptide chain. Iron (II) decreases the binding of intact IGFBP-1 and the C-terminal domain to IGF-II, suggesting that the metal binding site is close to or part of the surface of interaction of the two molecules.
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Affiliation(s)
- Alberto Sala
- Department of Biochemistry A. Castellani, University of Pavia, Italy
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22
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John H, Huynh KD, Hedtmann C, Walden M, Schulz A, Anspach FB, Forssmann WG. In vitro degradation of the antimicrobial human peptide HEM-γ 130–146 in plasma analyzed by a validated quantitative LC–MS/MS procedure. Anal Biochem 2005; 341:173-86. [PMID: 15866542 DOI: 10.1016/j.ab.2005.03.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Indexed: 11/16/2022]
Abstract
In stability studies during preclinical drug development, the human antimicrobial peptide hHEM-gamma 130-146 shows progressive N-terminal degradation in plasma. To determine this effect, we developed and validated a selective and quantitative muHPLC-MS/MS procedure for this compound. Following deproteinization by precipitation, reversed-phase separation is performed with a time-saving two-column design online coupled to an ion trap mass spectrometer for electrospray ionization MS detection. Using a linear calibration curve obtained with synthetic external standards ranging nearly two orders of magnitude, we achieved good precision (repeatability and reproducibility: 5-15%), accuracy (-3 to 15%), and ruggedness with a lower limit of quantification at 0.29 microg/ml plasma (0.15 microM). Because of good linearity (r2>0.999), the recovery (84+/-3%) and ion suppression (86+/-4% remaining intensity) were calculated from specifically prepared calibration curves. The developed procedure was applied to human and animal plasma samples. Incubations in the presence and absence of proteinase inhibitors revealed at least an aminopeptidase M activity for the initial N-terminal truncation of tryptophan (W130) and a putative glutaminyl-peptide cyclotransferase activity for the resulting intermediate starting with the bared glutamine residue (Q131). The calculated periods of half-change demonstrated exceeding interspecies variations, whereas the intraspecies variations were only between 20 and 30%. The current procedure is valuable as a generic method for pharmaceutical purposes, and data give important information for further development toward a potential natural drug candidate.
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MESH Headings
- Amino Acid Sequence
- Antimicrobial Cationic Peptides/blood
- Antimicrobial Cationic Peptides/chemistry
- Chromatography, High Pressure Liquid/instrumentation
- Chromatography, High Pressure Liquid/methods
- Chromatography, High Pressure Liquid/standards
- Humans
- Membrane Proteins/blood
- Membrane Proteins/chemistry
- Molecular Sequence Data
- Peptide Fragments/blood
- Peptide Fragments/chemistry
- Spectrometry, Mass, Electrospray Ionization/instrumentation
- Spectrometry, Mass, Electrospray Ionization/methods
- Spectrometry, Mass, Electrospray Ionization/standards
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/instrumentation
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/standards
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Affiliation(s)
- Harald John
- IPF PharmaCeuticals GmbH, D-30625 Hannover, Germany.
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