1
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Damjanovic J, Miao J, Huang H, Lin YS. Elucidating Solution Structures of Cyclic Peptides Using Molecular Dynamics Simulations. Chem Rev 2021; 121:2292-2324. [PMID: 33426882 DOI: 10.1021/acs.chemrev.0c01087] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein-protein interactions are vital to biological processes, but the shape and size of their interfaces make them hard to target using small molecules. Cyclic peptides have shown promise as protein-protein interaction modulators, as they can bind protein surfaces with high affinity and specificity. Dozens of cyclic peptides are already FDA approved, and many more are in various stages of development as immunosuppressants, antibiotics, antivirals, or anticancer drugs. However, most cyclic peptide drugs so far have been natural products or derivatives thereof, with de novo design having proven challenging. A key obstacle is structural characterization: cyclic peptides frequently adopt multiple conformations in solution, which are difficult to resolve using techniques like NMR spectroscopy. The lack of solution structural information prevents a thorough understanding of cyclic peptides' sequence-structure-function relationship. Here we review recent development and application of molecular dynamics simulations with enhanced sampling to studying the solution structures of cyclic peptides. We describe novel computational methods capable of sampling cyclic peptides' conformational space and provide examples of computational studies that relate peptides' sequence and structure to biological activity. We demonstrate that molecular dynamics simulations have grown from an explanatory technique to a full-fledged tool for systematic studies at the forefront of cyclic peptide therapeutic design.
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Affiliation(s)
- Jovan Damjanovic
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Jiayuan Miao
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - He Huang
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Yu-Shan Lin
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
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2
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Orafaie A, Bahrami AR, Matin MM. Use of anticancer peptides as an alternative approach for targeted therapy in breast cancer: a review. Nanomedicine (Lond) 2021; 16:415-433. [PMID: 33615876 DOI: 10.2217/nnm-2020-0352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Breast cancer is the most common cancer in women worldwide. Traditional therapies are expensive and cause severe side effects. Targeted therapy is a powerful method to circumvent the problems of other therapies. It also allows drugs to localize at predefined targets in a selective manner. Currently, there are several monoclonal antibodies which target breast cancer cell surface markers. However, using antibodies has some limitations. In the last two decades, many investigators have discovered peptides that may be useful to target breast cancer cells. In this article, we provide an overview on anti-breast cancer peptides, their sources and biological activities. We further discuss the pros and cons of using anticancer peptides with further emphasis on how to improve their effectiveness in cancer therapy.
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Affiliation(s)
- Ala Orafaie
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ahmad Reza Bahrami
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.,Industrial Biotechnology Research Group, Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Maryam M Matin
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.,Novel Diagnostics & Therapeutics Research Group, Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran
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3
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Bennett JA, Mansouri W, Lin Q, Feustel P, Andersen TT. Pharmacodynamic and Pharmacokinetic Properties of AFPep, a Novel Peptide for the Treatment of Breast Cancer. Int J Pept Res Ther 2017. [DOI: 10.1007/s10989-017-9628-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Nielsen DS, Shepherd NE, Xu W, Lucke AJ, Stoermer MJ, Fairlie DP. Orally Absorbed Cyclic Peptides. Chem Rev 2017; 117:8094-8128. [PMID: 28541045 DOI: 10.1021/acs.chemrev.6b00838] [Citation(s) in RCA: 266] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Peptides and proteins are not orally bioavailable in mammals, although a few peptides are intestinally absorbed in small amounts. Polypeptides are generally too large and polar to passively diffuse through lipid membranes, while most known active transport mechanisms facilitate cell uptake of only very small peptides. Systematic evaluations of peptides with molecular weights above 500 Da are needed to identify parameters that influence oral bioavailability. Here we describe 125 cyclic peptides containing four to thirty-seven amino acids that are orally absorbed by mammals. Cyclization minimizes degradation in the gut, blood, and tissues by removing cleavable N- and C-termini and by shielding components from metabolic enzymes. Cyclization also folds peptides into bioactive conformations that determine exposure of polar atoms to solvation by water and lipids and therefore can influence oral bioavailability. Key chemical properties thought to influence oral absorption and bioavailability are analyzed, including molecular weight, octanol-water partitioning, hydrogen bond donors/acceptors, rotatable bonds, and polar surface area. The cyclic peptides violated to different degrees all of the limits traditionally considered to be important for oral bioavailability of drug-like small molecules, although fewer hydrogen bond donors and reduced flexibility generally favored oral absorption.
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Affiliation(s)
- Daniel S Nielsen
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Nicholas E Shepherd
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Weijun Xu
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Andrew J Lucke
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Martin J Stoermer
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
| | - David P Fairlie
- Division of Chemistry and Structural Biology, and ‡Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland , Brisbane, QLD 4072, Australia
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5
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Temelso B, Alser KA, Gauthier A, Palmer AK, Shields GC. Structural Analysis of α-Fetoprotein (AFP)-like Peptides with Anti-Breast-Cancer Properties. J Phys Chem B 2014; 118:4514-26. [DOI: 10.1021/jp500017b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Berhane Temelso
- Dean’s
Office, College of Arts and Sciences, and Department of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837, United States
- Dean’s Office, College of Science and Technology, and Department of Chemistry & Physics, Armstrong Atlantic State University, 11935 Abercorn Street, Savannah, Georgia 31419, United States
| | - Katherine A. Alser
- Dean’s
Office, College of Arts and Sciences, and Department of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837, United States
| | - Arianne Gauthier
- Dean’s Office, College of Science and Technology, and Department of Chemistry & Physics, Armstrong Atlantic State University, 11935 Abercorn Street, Savannah, Georgia 31419, United States
| | - Amber Kay Palmer
- Dean’s Office, College of Science and Technology, and Department of Chemistry & Physics, Armstrong Atlantic State University, 11935 Abercorn Street, Savannah, Georgia 31419, United States
| | - George C. Shields
- Dean’s
Office, College of Arts and Sciences, and Department of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837, United States
- Dean’s Office, College of Science and Technology, and Department of Chemistry & Physics, Armstrong Atlantic State University, 11935 Abercorn Street, Savannah, Georgia 31419, United States
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6
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Development of an Active Site Peptide Analog of α-Fetoprotein That Prevents Breast Cancer. Cancer Prev Res (Phila) 2014; 7:565-73. [DOI: 10.1158/1940-6207.capr-13-0405] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Abstract
Alpha-fetoprotein (AFP) is a major mammalian embryo-specific and tumor-associated protein that is also present in small quantities in adults at normal conditions. Discovery of the phenomenon of AFP biosynthesis in carcinogenesis by G. Abelev and Yu. Tatarinov 50 years ago, in 1963, provoked intensive studies of this protein. AFPs of some mammalian species were isolated, purified and physico-chemically and immunochemically characterized. Despite the significant success in study of AFP, its three-dimensional structure, mechanisms of receptor binding along with a structure of the receptor itself and, what is the most important, its biological role in embryo- and carcinogenesis remain still obscure. Due to difficulties linked with methodological limitations, research of AFP was to some extent extinguished by the 1990 s. However, over the last decade a growing number of investigations of AFP and its usage as a tumor-specific biomarker have been observed. This was caused by the use of new technologies, primarily, computer-based and genetic engineering approaches in studying of this very important oncodevelopmental protein. Our review summarizes efforts of different scientific groups throughout the world in studying AFP for 50 years with emphasis on detailed description of recent achievements in this field.
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Bryan A, Joseph L, Bennett JA, Jacobson HI, Andersen TT. Design and synthesis of biologically active peptides: a 'tail' of amino acids can modulate activity of synthetic cyclic peptides. Peptides 2011; 32:2504-10. [PMID: 22015269 PMCID: PMC3230782 DOI: 10.1016/j.peptides.2011.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/05/2011] [Accepted: 10/05/2011] [Indexed: 10/16/2022]
Abstract
In earlier work, we synthesized a cyclic 9-amino acid peptide (AFPep, cyclo[EKTOVNOGN]) and showed it to be useful for prevention and therapy of breast cancer. In an effort to explore the structure-function relationships of AFPep, we have designed analogs that bear a short 'tail' (one or two amino acids) attached to the cyclic peptide distal to its pharmacophore. Analogs that bore a tail of either one or two amino acids, either of which had a hydrophilic moiety in the side chain (e.g., cyclo[EKTOVNOGN]FS) exhibited greatly diminished biological activity (inhibition of estrogen-stimulated uterine growth) relative to AFPep. Analogs that bore a tail of either one or two amino acids which had hydrophobic (aliphatic or aromatic) side chains (e.g., cyclo[EKTOVNOGN]FI) retained (or had enhanced) growth inhibition activity. Combining in the same biological assay a hydrophilic-tailed analog with either AFPep or a hydrophobic-tailed analog resulted in decreased activity relative to that for AFPep or for the hydrophobic-tailed analog alone, suggesting that hydrophilic-tailed analogs are binding to a biologically active receptor. An analog with a disrupted pharmacophore (cyclo[EKTOVGOGN]) exhibited little or no growth inhibition activity. An analog with a hydrophilic tail and a disrupted pharmacophore (cyclo[EKTOVGOGN]FS) exhibited no growth inhibition activity of its own and did not affect the activity of a hydrophobic-tailed analog, but enhanced the growth inhibition activity of AFPep. These results are discussed in the context of a two-receptor model for binding of AFPep and ring-and-tail analogs. We suggest that tails on cyclic peptides may comprise a useful method to enhance diversity of peptide design and specificity of ligand-receptor interactions.
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Affiliation(s)
- Alberto Bryan
- Center for Cardiovascular Science Albany Medical College 47 New Scotland Avenue Albany, NY 12208
| | - Leroy Joseph
- Center for Cardiovascular Science Albany Medical College 47 New Scotland Avenue Albany, NY 12208
| | - James A. Bennett
- Center for Immunology and Microbial Diseases Albany Medical College 47 New Scotland Avenue Albany, NY 12208
| | - Herbert I. Jacobson
- Center for Immunology and Microbial Diseases Albany Medical College 47 New Scotland Avenue Albany, NY 12208
| | - Thomas T. Andersen
- Center for Cardiovascular Science Albany Medical College 47 New Scotland Avenue Albany, NY 12208
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9
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Mizejewski GJ. Mechanism of Cancer Growth Suppression of Alpha-Fetoprotein Derived Growth Inhibitory Peptides (GIP): Comparison of GIP-34 versus GIP-8 (AFPep). Updates and Prospects. Cancers (Basel) 2011; 3:2709-33. [PMID: 24212829 PMCID: PMC3757439 DOI: 10.3390/cancers3022709] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/02/2011] [Accepted: 06/14/2011] [Indexed: 12/31/2022] Open
Abstract
The Alpha-fetoprotein (AFP) derived Growth Inhibitory Peptide (GIP) is a 34-amino acid segment of the full-length human AFP molecule that inhibits tumor growth and metastasis. The GIP-34 and its carboxy-terminal 8-mer segment, termed GIP-8, were found to be effective as anti-cancer therapeutic peptides against nine different human cancer types. Following the uptake of GIP-34 and GIP-8 into the cell cytoplasm, each follows slightly different signal transduction cascades en route to inhibitory pathways of tumor cell growth and proliferation. The parallel mechanisms of action of GIP-34 versus GIP-8 are demonstrated to involve interference of signaling transduction cascades that ultimately result in: (1) cell cycle S-phase/G2-phase arrest; (2) prevention of cyclin inhibitor degradation; (3) protection of p53 from inactivation by phosphorylation; and (4) blockage of K+ ion channels opened by estradiol and epidermal growth factor (EGF). The overall mechanisms of action of both peptides are discussed in light of their differing modes of cell attachment and uptake fortified by RNA microarray analysis and electrophysiologic measurements of cell membrane conductance and resistance. As a chemotherapeutic adjunct, the GIPs could potentially aid in alleviating the negative side effects of: (1) tamoxifen resistance, uterine hyperplasia/cancer, and blood clotting; (2) Herceptin antibody resistance and cardiac (arrest) arrhythmias; and (3) doxorubicin's bystander cell toxicity.
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Affiliation(s)
- Gerald J. Mizejewski
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201, USA; E-Mail: ; Tel.: +1-518-486-5900; Fax: +1-518-402-5002
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10
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Mizejewski GJ, Mirowski M, Garnuszek P, Maurin M, Cohen BD, Poiesz BJ, Posypanova GA, Makarov VA, Severin ES, Severin SE. Targeted delivery of anti-cancer growth inhibitory peptides derived from human alpha-fetoprotein: review of an International Multi-Center Collaborative Study. J Drug Target 2010; 18:575-88. [PMID: 20151941 DOI: 10.3109/10611861003587243] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The alpha-fetoprotein derived growth inhibitory peptide (GIP) is a 34-amino acid peptide composed of three biologically active subfragments. GIP-34 and its three constituent segments have been synthesized, purified, and studied for biological activity. The GIP-34 and GIP-8 have been characterized as anticancer therapeutic peptides. An multicenter study was initiated to elucidate the means by which these peptide drugs could be targeted to tumor cells. The study first established which cancer types were specifically targeted by the GIP peptides in both in vitro and in vivo investigations. It was next demonstrated that radiolabeled peptide ((125)I GIP-34) is specifically localized to rodent breast tumors at 24 h post-injection. The radionuclide studies also provided evidence for a proposed cell surface receptor; this was confirmed in a further study using fluorescent-labeled GIP-nanobeads which localized at the plasma membrane of MCF-7 breast cancer cells. Finally, it was readily demonstrated that GIP conjugated to either fluorescein or doxorubicin (DOX) underwent tumor cell uptake; subsequently, DOX-GIP conjugates induced cytotoxic cell destruction indicating the utility of GIP segments as cancer therapeutic agents. Following a discussion of the preceding results, a candidate cell surface receptor family was proposed which correlated with previous published reports for a putative AFP/GIP receptor.
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Affiliation(s)
- G J Mizejewski
- Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, New York 12201, USA.
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11
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Jacobson HI, Lemanski N, Agarwal A, Narendran A, Turner KE, Bennett JA, Andersen TT. A proposed unified mechanism for the reduction of human breast cancer risk by the hormones of pregnancy. Cancer Prev Res (Phila) 2009; 3:212-20. [PMID: 19934340 DOI: 10.1158/1940-6207.capr-09-0050] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Parity in women is associated with reduced lifetime risk of breast cancer, and hormones of pregnancy [estrogen (E), progesterone (P), human chorionic gonadotropin (hCG)] are implicated. Parity also reduces mammary cancer risk in carcinogen-exposed rats, and administering pregnancy hormones to these animals is similarly effective. Because pregnancy hormones are also able to stimulate cancer growth, we proposed to resolve this dichotomy by determining whether administered pregnancy hormones elicit the cancer-inhibiting agent alpha-fetoprotein (AFP) from the liver, which would implicate AFP as a proximal effector of hormonal anticancer activity. Accordingly, we treated groups of nitrosomethylurea-exposed rats with saline, E(3), E(2) + P, E(3) + P, hCG, or allowed them to experience pregnancy, and then monitored mammary cancer incidence and serum levels of AFP over time. Each hormone treatment reduced mammary cancer incidence and elevated serum AFP levels. To challenge human tissues, human HepG2 liver cells in culture were treated with the same hormonal agents. Each hormone regimen increased the levels of AFP in the culture medium. Medium containing AFP elicited by hCG inhibited the E(2)-stimulated proliferation of cultured human MCF7 breast cancer cells, whereas hCG alone did not inhibit their growth. Furthermore, antibodies to AFP neutralized the growth-inhibiting effect of AFP-containing HepG2 medium. We conclude that in the treatment of carcinogen-exposed rats with the hormones of pregnancy, and by inference in women who have experienced pregnancy, that AFP is a proximal agent that inhibits mammary gland cancer.
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Affiliation(s)
- Herbert I Jacobson
- Center for Immunology and Microbial Diseases, Albany Medical College, NY 12208, USA.
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12
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Jensen EV, Jacobson HI, Walf AA, Frye CA. Estrogen action: a historic perspective on the implications of considering alternative approaches. Physiol Behav 2009; 99:151-62. [PMID: 19737574 DOI: 10.1016/j.physbeh.2009.08.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/29/2009] [Accepted: 08/31/2009] [Indexed: 10/20/2022]
Abstract
In the 50 years since the initial reports of a cognate estrogen receptor (ER), much has been learned about the diverse effects and mechanisms of estrogens, such as 17beta-estradiol (E(2)). This expert narrative review briefly summarizes perspectives and/or recent work of the authors, who have been addressing different aspects of estrogen action, but take a common approach of using alternative considerations to gain insight into mechanisms with clinical relevance, and inform future studies, regarding estrogen action. Their "Top Ten" favorite alternatives that are discussed herein are as follows. 1 - E(2) has actions by binding to a receptor that do not require its enzymatic conversion. 2 - Using a different strategy for antibody binding could make the estrogen receptor (ER) more discernible. 3 - Blocking ERs, rather than E(2) production, may be a useful strategy for breast cancer therapy. 4 - Secretion of alpha-fetoprotein (AFP), rather than only levels of E(2) and/or progesterone, may influence breast cancer risk. 5 - A peptide derived from the active site of AFP can produce the same benefits of the entire endogenous protein in endocrine cancers. 6 - Differential distribution of ER subtypes in the body and brain may underlie specific effects of estrogens. 7 - ERbeta may be sufficient for the trophic effects of estrogen in the brain, and ERalpha may be the primary target of trophic effects in the body. 8 - ERbeta may play a role in the trophic effects of androgens, and may also be relevant in the periphery. 9 - Downstream of E(2)'s effects at ERbeta, there may be consequences for biosynthesis of progestogens and/or androgens. 10 - Changes in histones and/or other factors, which may be downstream of ERbeta, potentially underlie the divergent effects of E(2) in the brain and peripheral tissues.
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Affiliation(s)
- Elwood V Jensen
- Department of Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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13
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Computational approaches for the design of peptides with anti-breast cancer properties. Future Med Chem 2009; 1:201-12. [DOI: 10.4155/fmc.09.13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background: Breast cancer is the most common cancer among women. Tamoxifen is the preferred drug for estrogen receptor-positive breast cancer treatment, yet many of these cancers are intrinsically resistant to tamoxifen or acquire resistance during treatment. Therefore, scientists are searching for breast cancer drugs that have different molecular targets. Methodology: Recently, a computational approach was used to successfully design peptides that are new lead compounds against breast cancer. We used replica exchange molecular dynamics to predict the structure and dynamics of active peptides, leading to the discovery of smaller bioactive peptides. Conclusions: These analogs inhibit estrogen-dependent cell growth in a mouse uterine growth assay, a test showing reliable correlation with human breast cancer inhibition. We outline the computational methods that were tried and used along with the experimental information that led to the successful completion of this research.
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Joseph LC, Bennett JA, Kirschner KN, Shields GC, Hughes J, Lostritto N, Jacobson HI, Andersen TT. Antiestrogenic and anticancer activities of peptides derived from the active site of alpha-fetoprotein. J Pept Sci 2009; 15:319-25. [DOI: 10.1002/psc.1119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Studies on 99mTc-labeling of the modified fragment of human alfa-fetoprotein (P149-QY). J Radioanal Nucl Chem 2007. [DOI: 10.1007/s10967-007-6980-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Mizejewski GJ. The alpha-fetoprotein-derived growth inhibitory peptide 8-mer fragment: review of a novel anticancer agent. Cancer Biother Radiopharm 2007; 22:73-98. [PMID: 17627416 DOI: 10.1089/cbr.2006.343] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This review describes the antigrowth and anticancer activities of the alpha-fetoprotein (AFP)-derived growth inhibitory peptide (GIP) 8-mer fragment. The 8-amino acid peptide (GIP-8) comprises the carboxy-terminal portion of a 34-amino acid peptide (GIP-34) previously identified as an occult epitopic segment of the full-length human AFP molecule. The GIP-8 segment has been chemically synthesized, purified, characterized, and bioassayed. The purified 8-mer segment was characterized as a random coil (disordered) structure extending from a C-terminal beta-hairpin that forms a horseshoe-shaped partially cyclic octapeptide; this structure can be formulated into a fully cyclic form by the addition of asparagine or glutamine residues. The pharmacophore of the octo- and nanopeptide forms is largely composed of a PXXP motif known to interact with Src-3 (SH3) domains of serine/theronine kinases. The GIP-8 has been shown to be growth-suppressive largely in estradiol (E2)-dependent neonatal and tumor-cell proliferation models and to inhibit tumor-cell adhesion to extracellular matrices. The 8-mer GIP displays antigrowth properties in immature mouse uterine cells and anticancer cell proliferation traits in estrogen receptor positive (ER(+)), but not (ER()) negative breast tumor cells. Even though its mechanism of action has not been fully elucidated, GIP-8 has been shown by computer modeling to dock with the extracellular loops of G-coupled seven transmembrane helical-like receptors, which could possibly interfere with signal transduction through MAP kinase pathways. It was apparent that the GIP-8 derived from the 34-mer GIP fragment of HAFP represented an E2-sensitive growth inhibitory motif, which allows the participation in cellular events, such as receptor binding, contact inhibition, extracellular matrix adhesion, angiogenesis, and T-cell activation. Thus, it was proposed that the 8-mer fragment derived from GIP could potentially serve as a lead compound for targeted cancer therapeutic agents of the biologic-response modifier type.
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Affiliation(s)
- Gerald J Mizejewski
- Diagnostic Oncology Section, Division of Molecular Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA.
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17
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Andersen TT, Georgekutty J, Defreest LA, Amaratunga G, Narendran A, Lemanski N, Jacobson HI, Bennett JA. An alpha-fetoprotein-derived peptide reduces the uterine hyperplasia and increases the antitumour effect of tamoxifen. Br J Cancer 2007; 97:327-33. [PMID: 17637684 PMCID: PMC2360332 DOI: 10.1038/sj.bjc.6603882] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/01/2007] [Accepted: 06/19/2007] [Indexed: 11/09/2022] Open
Abstract
Tamoxifen (Tam) is effective for the treatment and prevention of breast cancer. However, it has toxic drawbacks and has limited-duration utility because, over time, human tumours become refractory to Tam. Recently, a new nontoxic peptide, alpha-fetoprotein-derived peptide (AFPep) has been proposed for the treatment and prevention of breast cancer. The purpose of this paper is to determine whether combining AFPep with Tam would increase efficacy and reduce toxicity in experimental models of breast cancer. Low doses of AFPep and Tam were more effective in combination than either agent alone against breast cancer growth in cell culture, in tumour-xenografted mice, and in carcinogen-exposed rats. alpha-Fetoprotein-derived peptide interfered with Tam-induced uterine hyperplasia in immature mice, and showed no toxic effects. Unlike Tam, AFPep did not inhibit binding of oestradiol (E(2)) to oestrogen receptor (ER). Thus, these two agents utilise different mechanisms to interfere with ER functionality, yet work cooperatively to reduce breast cancer growth and alleviate Tam's troubling toxicity of uterine hyperplasia and appear to be a rational combination for the treatment of ER-positive breast cancer.
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Affiliation(s)
- T T Andersen
- Center for Cardiovascular Sciences, Albany Medical College, Albany, NY 12208, USA.
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18
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Kirschner KN, Lexa KW, Salisburg AM, Alser KA, Joseph L, Andersen TT, Bennett JA, Jacobson HI, Shields GC. Computational design and experimental discovery of an antiestrogenic peptide derived from alpha-fetoprotein. J Am Chem Soc 2007; 129:6263-8. [PMID: 17441722 PMCID: PMC4272344 DOI: 10.1021/ja070202w] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Breast cancer is the most common cancer among women, and tamoxifen is the preferred drug for estrogen receptor-positive breast cancer treatment. Many of these cancers are intrinsically resistant to tamoxifen or acquire resistance during treatment. Consequently, there is an ongoing need for breast cancer drugs that have different molecular targets. Previous work has shown that 8-mer and cyclic 9-mer peptides inhibit breast cancer in mouse and rat models, interacting with an unsolved receptor, while peptides smaller than eight amino acids did not. We show that the use of replica exchange molecular dynamics predicts the structure and dynamics of active peptides, leading to the discovery of smaller peptides with full biological activity. Simulations identified smaller peptide analogues with the same conserved reverse turn demonstrated in the larger peptides. These analogues were synthesized and shown to inhibit estrogen-dependent cell growth in a mouse uterine growth assay, a test showing reliable correlation with human breast cancer inhibition.
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19
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Terentiev AA, Moldogazieva NT. Structural and functional mapping of alpha-fetoprotein. BIOCHEMISTRY (MOSCOW) 2006; 71:120-32. [PMID: 16489915 DOI: 10.1134/s0006297906020027] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alpha-fetoprotein (AFP) is a major mammalian oncofetal protein, which is also present in small quantities in adults. It is a member of the albuminoid gene superfamily, which consists of AFP, serum albumin, vitamin D binding protein, and alpha-albumin (afamin). Although physicochemical and immunological properties of AFP have been well-studied, its biological role in embryo- and carcinogenesis and in adult organisms as well as mechanisms underlying its functioning remain unclear. During the recent decades, the biological role of AFP has been evaluated by identification of its functionally important sites. Comparison of primary structure of AFP and some physiologically active proteins revealed similarity of some polypeptide regions. This has been used for prediction of AFP functions (i.e., its multifunctionality). Localization of functionally important sites followed by determination of their amino acid composition and type of biological activity has provided valuable information for structural-functional mapping of AFP. Some peptide fragments of AFP have been synthesized and tested for biological activity. This review summarizes data on structural-functional interrelationships. We also describe functionally important AFP sites found by various groups during the last decade of structural-functional mapping of AFP with experimentally confirmed and putative biologically active sites.
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Affiliation(s)
- A A Terentiev
- Russian State Medical University, 117997 Moscow, Russia.
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20
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Parikh RR, Gildener-Leapman N, Narendran A, Lin HY, Lemanski N, Bennett JA, Jacobson HI, Andersen TT. Prevention of N-methyl-N-nitrosourea-induced breast cancer by alpha-fetoprotein (AFP)-derived peptide, a peptide derived from the active site of AFP. Clin Cancer Res 2006; 11:8512-20. [PMID: 16322315 DOI: 10.1158/1078-0432.ccr-05-1651] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE alpha-Fetoprotein (AFP) is a protein of pregnancy associated with a decrease in lifetime risk of breast cancer in parous women. A synthetic, cyclic nonapeptide has been developed that mimics the antioncogenic active site of AFP. To test the hypothesis that the AFP-derived peptide (AFPep) can prevent breast cancer, the N-methyl-N-nitrosourea-induced breast cancer model was used in rats. EXPERIMENTAL DESIGN AFPep was given daily by injection beginning 10 days after N-methyl-N-nitrosourea treatment and continued for 23 days (a time designed to mimic pregnancy) or for other times to assess efficacy as a function of drug duration. Tumor incidence, multiplicity, and latency were noted as end points. At necropsy, pathology analysis of tumors and major organs were obtained. RESULTS AFPep prevented cancer in a dose-dependent fashion. Significantly longer mean tumor-free days (P < 0.02), lower tumor incidence (P = 0.004), and lower tumor multiplicity were observed for AFPep-treated groups. No evidence of host toxicity as measured by body weight, cage activity, fur texture, and organ weights (liver, uterus, heart, kidney, and spleen) were found in animals treated with AFPep. Mechanistic studies using transplantable human breast cancer xenografts showed that the peptide interfered with estrogen-dependent breast cancer growth inhibited the phosphorylation of the estrogen receptor and activated phosphorylation of p53. CONCLUSIONS AFPep is a well-tolerated, mechanistically novel, chemopreventive agent in models of breast cancer and warrants further development for the prevention and treatment of this disease in humans.
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Affiliation(s)
- Rahul R Parikh
- Center for Cardiovascular Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, Albany Medical College, Albany, New York 12208, USA
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21
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Bakker J, De Mees C, Douhard Q, Balthazart J, Gabant P, Szpirer J, Szpirer C. Alpha-fetoprotein protects the developing female mouse brain from masculinization and defeminization by estrogens. Nat Neurosci 2006; 9:220-6. [PMID: 16388309 DOI: 10.1038/nn1624] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 12/06/2005] [Indexed: 11/08/2022]
Abstract
Two clearly opposing views exist on the function of alpha-fetoprotein (AFP), a fetal plasma protein that binds estrogens with high affinity, in the sexual differentiation of the rodent brain. AFP has been proposed to either prevent the entry of estrogens or to actively transport estrogens into the developing female brain. The availability of Afp mutant mice (Afp(-/-)) now finally allows us to resolve this longstanding controversy concerning the role of AFP in brain sexual differentiation, and thus to determine whether prenatal estrogens contribute to the development of the female brain. Here we show that the brain and behavior of female Afp(-/-) mice were masculinized and defeminized. However, when estrogen production was blocked by embryonic treatment with the aromatase inhibitor 1,4,6-androstatriene-3,17-dione, the feminine phenotype of these mice was rescued. These results clearly demonstrate that prenatal estrogens masculinize and defeminize the brain and that AFP protects the female brain from these effects of estrogens.
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Affiliation(s)
- Julie Bakker
- Center for Cellular & Molecular Neurobiology, University of Liège, Avenue de l'Hôpital 1, B36, 4000 Liège, Belgium.
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22
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Strohsnitter WC, Noller KL, Titus-Ernstoff L, Troisi R, Hatch EE, Poole C, Glynn RJ, Hsieh CC. Breast cancer incidence in women prenatally exposed to maternal cigarette smoke. Epidemiology 2005; 16:342-5. [PMID: 15824550 DOI: 10.1097/01.ede.0000158741.07645.9b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Clinical studies show that maternal cigarette smoking reduces pregnancy estrogen levels. Women prenatally exposed to maternal cigarette smoke may, therefore, have a lower breast cancer risk because the fetal mammary gland's exposure to maternal estrogen is decreased. Associations between prenatal maternal cigarette smoke exposure and breast cancer, however, have not been observed in previous case-control studies that relied on exposure assessment after the onset of cancer. At the start of this study, cigarette smoking history was obtained directly from the mother. METHODS The National Cooperative DES Adenosis project was a follow-up study of health outcomes in women prenatally exposed to diethylstilbestrol (DES). At the start of the study, women's mothers provided information about cigarette smoking habits during the time they were pregnant with the study participant. In the current study, the breast cancer rates are compared among 4031 women who were or were not prenatally exposed to maternal cigarette smoke. The resultant relative rate (RR) is adjusted for potential confounding by other breast cancer risk factors using Poisson regression modeling. RESULTS Fetal exposure to maternal cigarette smoke appeared to be inversely associated with breast cancer incidence (RR = 0.49; 95% confidence interval [CI] = 0.24-1.03). The inverse association was more apparent among women whose mothers smoked 15 cigarettes or fewer per day than among daughters of heavier smokers. There were, however, too few cases to precisely estimate a possible dose-response relationship. CONCLUSION These results support the hypothesis that in utero exposure to maternal cigarette smoke reduces breast cancer incidence.
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Affiliation(s)
- William C Strohsnitter
- Department of Obstetrics and Gynecology, Tufts-New England Medical Center, 750 Washington Street, Boston, MA 02111, USA.
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Abstract
Alpha-fetoprotein (AFP) is the main fetus serum glycoprotein with a very low concentration in the adult. AFP deficiency is a rare phenomenon. We studied two families with congenital AFP deficiency and searched for mutations in the AFP gene. We identified one mutation of 2 base deletion in exon 8, in both families, that leads to the congenital deficiency of AFP. The mutation nt930-931delCT (T294fs25X) creates a frameshift after codon 294 that leads to a stop codon after 24 amino acids, thus truncating the normal length of AFP of 609 amino acids. All the affected children were found to be homozygous for the mutation as was one of the fathers. The affected individuals were asymptomatic and presented normal development. This first identification of a mutation in the AFP gene demonstrates for the first time that deficiency of AFP is compatible with human normal fetal development and further reproduction in males.
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Affiliation(s)
- Reuven Sharony
- The Genetic Institute, Sapir Medical Center - Meir Hospital, Kfar Saba 44281, Israel
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DeFreest LA, Mesfin FB, Joseph L, McLeod DJ, Stallmer A, Reddy S, Balulad SS, Jacobson HI, Andersen TT, Bennett JA. Synthetic peptide derived from alpha-fetoprotein inhibits growth of human breast cancer: investigation of the pharmacophore and synthesis optimization. ACTA ACUST UNITED AC 2004; 63:409-19. [PMID: 15140158 DOI: 10.1111/j.1399-3011.2004.00139.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Asynthetic peptide that inhibits the growth of estrogen receptor positive (ER+) human breast cancers, growing as xenografts in mice, has been reported. The cyclic 9-mer peptide, cyclo[EMTOVNOGQ], is derived from alpha-fetoprotein (AFP), a safe, naturally occurring human protein produced during pregnancy, which itself has anti-estrogenic and anti-breast cancer activity. To determine the pharmacophore of the peptide, a series of analogs was prepared using solid-phase peptide synthesis. Analogs were screened in a 1-day bioassay, which assessed their ability to inhibit the estrogen-stimulated growth of uterus in immature mice. Deletion of glutamic acid, Glu1, abolished activity of the peptide, but glutamine (Gln) or asparagine (Asn) could be substituted for Glu1 without loss of activity. Methionine (Met2) was replaced with lysine (Lys) or tyrosine (Tyr) with retention of activity. Substitution of Lys for Met2 in the cyclic molecule resulted in a compound with activity comparable with the Met2-containing cyclic molecule, but with a greater than twofold increase in purity and corresponding increase in yield. This Lys analog demonstrated anti-breast cancer activity equivalent to that of the original Met-containing peptide. Therefore, Met2 is not essential for biologic activity and substitution of Lys is synthetically advantageous. Threonine (Thr3) is a nonessential site, and can be substituted with serine (Ser), valine (Val), or alanine (Ala) without significant loss of activity. Hydroxyproline (Hyp), substituted in place of the naturally occurring prolines (Pro4, Pro7), allowed retention of activity and increased stability of the peptide during storage. Replacement of the first Pro (Pro4) with Ser maintains the activity of the peptide, but substitution of Ser for the second Pro (Pro7) abolishes the activity of the peptide. This suggests that the imino acid at residue 7 is important for conformation of the peptide, and the backbone atoms are part of the pharmacophore, but Pro4 is not essential. Valine (Val5) can be substituted only with branched-chain amino acids (isoleucine, leucine or Thr); replacement by d-valine or Ala resulted in loss of biologic activity. Thus, for this site, the bulky branched side chain is essential. Asparagine (Asn6) is essential for activity. Substitution with Gln or aspartic acid (Asp), resulted in reduction of biologic activity. Removal of glycine (Gly8) resulted in a loss of activity but nonconservative substitutions can be made at this site without a loss of activity indicating that it is not part of the pharmacophore. Cyclization of the peptide is facilitated by addition of Gln9, but this residue does not occur in AFP nor is it necessary for activity. Gln9 can be replaced with Asn, resulting in a molecule with similar activity. These data indicate that the pharmacophore of the peptide includes side chains of Val5 and Asn6 and backbone atoms contributed by Thr3, Val5, Asn6, Hyp7 and Gly8. Met2 and Gln9 can be modified or replaced. Glu1 can be replaced with charged amino acids, and is not likely to be part of the binding site of the peptide. The results of this study provide information that will be helpful in the rational modification of cyclo[EMTOVNOGQ] to yield peptide analogs and peptidomimetics with advantages in synthesis, pharmacologic properties, and biologic activity.
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Affiliation(s)
- L A DeFreest
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
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25
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Semenkova L, Dudich E, Dudich I, Tokhtamisheva N, Tatulov E, Okruzhnov Y, Garcia-Foncillas J, Palop-Cubillo JA, Korpela T. Alpha-fetoprotein positively regulates cytochrome c-mediated caspase activation and apoptosome complex formation. ACTA ACUST UNITED AC 2003; 270:4388-99. [PMID: 14622304 DOI: 10.1046/j.1432-1033.2003.03836.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Previous results have shown that the oncoembryonic marker alpha-fetoprotein (AFP) is able to induce apoptosis in tumor cells through activation of caspase 3, bypassing Fas-dependent and tumor necrosis factor receptor-dependent signaling. In this study we further investigate the molecular interactions involved in the AFP-mediated signaling of apoptosis. We show that AFP treatment of tumor cells is accompanied by cytosolic translocation of mitochondrial cytochrome c. In a cell-free system, AFP mediates processing and activation of caspases 3 and 9 by synergistic enhancement of the low-dose cytochrome c-mediated signals. AFP was unable to regulate activity of caspase 3 in cell extracts depleted of cytochrome c or caspase 9. Using high-resolution chromatography, we show that AFP positively regulates cytochrome c/dATP-mediated apoptosome complex formation, enhances recruitment of caspases and Apaf-1 into the complex, and stimulates release of the active caspases 3 and 9 from the apoptosome. By using a direct protein-protein interaction assay, we show that pure human AFP almost completely disrupts the association between processed caspases 3 and 9 and the cellular inhibitor of apoptosis protein (cIAP-2), demonstrating its release from the complex. Our data suggest that AFP may regulate cell death by displacing cIAP-2 from the apoptosome, resulting in promotion of caspase 3 activation and its release from the complex.
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26
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Hamza A, Sarma MH, Sarma RH. Plausible interaction of an alpha-fetoprotein cyclopeptide with the G-protein-coupled receptor model GPR30: docking study by molecular dynamics simulated annealing. J Biomol Struct Dyn 2003; 20:751-8. [PMID: 12744705 DOI: 10.1080/07391102.2003.10506892] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In this manuscript, the procedure of molecular dynamics simulated annealing is applied to locate a probable receptor and binding site of a cyclicpeptide that inhibits estrogen-stimulated proliferation of breast cancer. The hydrophilic cyclopeptide EMTOVNOGQ (O = 4-hydroxyproline), derived from alpha-fetoprotein, is an inhibitor of estrogen-stimulated proliferation of human breast cancer. This peptide has been shown to act through a mechanism different from that of estrogen; however, its receptor is unknown. We report computer experiments that suggest that this peptide may execute its actions by interacting with GPR30, a G-protein-coupled receptor. The subject of this work is the simulation, by molecular dynamics simulated annealing, of the interaction of cyclopeptide EMTOVNOGQ with receptor GPR30 protein. A conformational analysis of the cyclopeptide was undertaken and the final structure was docked on several sites of the GPR30 3D model. Our results show that the cyclopeptide interacts on the pocket located between TM6 and TM7 transmembrane helices of the G-protein, triggering a slight conformational change in the secondary structure of the receptor in the complex. Based on differences in accessible surface areas between GPR30 and its ligand, the residues in the interaction zone were identified. The cyclopeptide is stabilized in the active site by forming a network of hydrogen bonds between Glu, Thr, (1)Pro(OH) and GLn residues of the ligand and Arg-259, Cys-271, Asn-316, Asn-320 and Tyr-324 of the G-protein. Moreover, the study of the electrostatic surface potential on the GPR30 receptor shows that the active site is more positively charged than the other sites. Our modeling indicates a plausible interaction of the cyclopeptide with the seven transmembrane GPR30 protein. This may have profound implications for the treatment of breast cancer.
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Affiliation(s)
- A Hamza
- Unité de Modélisation Moleculaire, Institut Pasteur de Tunis, 13 place Pasteur, BP 74, 1002 Tunis-Belvedere, Tunisia.
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Butterstein G, MacColl R, Mizejewski GJ, Eisele LE, Meservey M. Biophysical studies and anti-growth activities of a peptide, a certain analog and a fragment peptide derived from alpha-fetoprotein. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2003; 61:213-8. [PMID: 12605606 DOI: 10.1034/j.1399-3011.2003.00049.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A chemically synthesized 34-amino acid peptide, an analog, and a fragment of the peptide have been purified and studied. Biophysical studies were carried out to determine some of the metal ion binding properties of the original peptide and an analog of this parent peptide, in which the two histidine residues were replaced by alanines. As shown by visible absorption spectroscopy, Co (II) forms a complex with the parent peptide, but not with the analog peptide, and one or two histidines in the parent peptide are ligands for Co (II) ion binding. The effects on disulfide bond formation in the peptide by Zn (II) and Co (II) ions were also examined for this analog. Anti-growth assays were performed using the original cysteine-containing peptide with Zn (II) ion complexed to the peptide through the two cysteine residues. These rat uterine growth assays showed that the complexing of Zn (II) ion to the peptide maintained the anti-growth activity of the peptide, while gel-filtration experiments showed the zinc ions maintained the peptide in its anti-growth form indefinitely in solution. A saliently important part of this research was the discovery that a fragment of the peptide consisting of a middle sequence of 14 amino acids was found to have significant anti-growth activity in the rat uterine assay. Its activity suggested that this fragment might be considered a viable candidate for testing in anti-cancer protocols.
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Affiliation(s)
- G Butterstein
- Department of Biological Sciences, Union College, Schenectady, NY 12308-2311, USA
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Hasenbein ME, Andersen TT, Bizios R. Micropatterned surfaces modified with select peptides promote exclusive interactions with osteoblasts. Biomaterials 2002; 23:3937-42. [PMID: 12162326 DOI: 10.1016/s0142-9612(02)00129-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microcontact printing techniques were used to pattern circles (diameters 10. 50, 100, and 200 microm) of N1[3-(trimethoxysilyl)-propyl]diethylenetriamine (DETA) surrounded by octadecyltrichlorosilane (OTS) borders on borosilicate glass, a model substrate. The DETA regions were further modified by immobilization of either the cell-adhesive peptides Arginine-Glycine-Aspartic Acid-Serine (RGDS) and Lysine-Arginine-Serine-Arginine (KRSR) or the non-adhesive peptides Arginine-Aspartic Acid-Glycine-Serine (RDGS) and Lysine-Serine-Serine-Arginine (KSSR). After four hours under standard cell culture conditions but in the absence of serum, adhesion of either osteoblasts or fibroblasts on surfaces patterned with the non-adhesive peptides RDGS and KSSR was random and low. In contrast, both osteoblasts and fibroblasts adhered and formed clusters onto circles modified with the adhesive peptide RGDS, whereas only osteoblasts adhered and formed clusters onto the circles modified with KRSR, a peptide that selectively promotes adhesion of osteoblasts. These results provide evidence that patterning of select peptides can direct adhesion of specific cell lines exclusively to predetermined regions on material surfaces.
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Affiliation(s)
- M E Hasenbein
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA
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29
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Bennett JA, Mesfin FB, Andersen TT, Gierthy JF, Jacobson HI. A peptide derived from alpha-fetoprotein prevents the growth of estrogen-dependent human breast cancers sensitive and resistant to tamoxifen. Proc Natl Acad Sci U S A 2002; 99:2211-5. [PMID: 11830647 PMCID: PMC122344 DOI: 10.1073/pnas.251667098] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An 8-mer peptide (EMTOVNOG) derived from alpha-fetoprotein was compared with tamoxifen for activity against growth of human breast cancer xenografts implanted in immune-deficient mice. Both peptide and tamoxifen prevented growth of estrogen-receptor-positive MCF-7 and T47D human breast cancer xenografts. A subline of MCF-7, made resistant to tamoxifen by a 6-month exposure to this drug in culture, was found to be resistant to tamoxifen in vivo. Peptide completely prevented the xenograft growth of this tamoxifen-resistant subline of MCF-7. Neither peptide nor tamoxifen was effective in slowing the xenograft growth of the estrogen-receptor-negative MDA-MB-231 human breast cancer. A worrisome side effect of tamoxifen is its hypertrophic effect on the uterus. In this study, tamoxifen was shown to stimulate the growth of the immature mouse uterus in vivo, and the peptide significantly inhibited tamoxifen's uterotrophic effect. The mechanism of action of peptide is different from that of tamoxifen in that the peptide does not interfere with the binding of [(3)H]estradiol to the estrogen receptor. In conclusion, alpha-fetoprotein-derived peptide appears to be a novel agent that interferes with the growth of tamoxifen-sensitive as well as tamoxifen-resistant estrogen-receptor-positive human breast cancers; it inhibits the uterotrophic side effect of tamoxifen and, thus, it may be useful in combination with or in place of tamoxifen for treatment of estrogen-receptor-positive human breast cancers.
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30
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MacColl R, Eisele LE, Stack RF, Hauer C, Vakharia DD, Benno A, Kelly WC, Mizejewski GJ. Interrelationships among biological activity, disulfide bonds, secondary structure, and metal ion binding for a chemically synthesized 34-amino-acid peptide derived from alpha-fetoprotein. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1528:127-34. [PMID: 11687299 DOI: 10.1016/s0304-4165(01)00182-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A 34-amino-acid peptide has been chemically synthesized based on a sequence from human alpha-fetoprotein. The purified peptide is active in anti-growth assays when freshly prepared in pH 7.4 buffer at 0.20 g/l, but this peptide slowly becomes inactive. This functional change is proven by mass spectrometry to be triggered by the formation of an intrapeptide disulfide bond between the two cysteine residues on the peptide. Interpeptide cross-linking does not occur. The active and inactive forms of the peptide have almost identical secondary structures as shown by circular dichroism (CD). Zinc ions bind to the active peptide and completely prevents formation of the inactive form. Cobalt(II) ions also bind to the peptide, and the UV-Vis absorption spectrum of the cobalt-peptide complex shows that: (1) a near-UV sulfur-to-metal-ion charge-transfer band had a molar extinction coefficient consistent with two thiolate bonds to Co(II); (2) the lowest-energy visible d-d transition maximum at 659 nm, also, demonstrated that the two cysteine residues are ligands for the metal ion; (3) the d-d molar extinction coefficient showed that the metal ion-ligand complex was in a distorted tetrahedral symmetry. The peptide has two cysteines, and it is speculated that the other two metal ion ligands might be the two histidines. The Zn(II)- and Co(II)-peptide complexes had similar peptide conformations as indicated by their ultraviolet CD spectra, which differed very slightly from that of the free peptide. Surprisingly, the cobalt ions acted in the reverse of the zinc ions in that, instead of stabilizing anti-growth form of the peptide, they catalyzed its loss. Metal ion control of peptide function is a saliently interesting concept. Calcium ions, in the conditions studied, apparently do not bind to the peptide. Trifluoroethanol and temperature (60 degrees C) affected the secondary structure of the peptide, and the peptide was found capable of assuming various conformations in solution. This conformational flexibility may possibly be related to the biological activity of the peptide.
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Affiliation(s)
- R MacColl
- Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509, USA.
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31
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Mesfin FB, Andersen TT, Jacobson HI, Zhu S, Bennett JA. Development of a synthetic cyclized peptide derived from alpha-fetoprotein that prevents the growth of human breast cancer. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2001; 58:246-56. [PMID: 11576331 DOI: 10.1034/j.1399-3011.2001.00922.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The peptide, EMTPVNPG, derived from alpha-fetoprotein, inhibits estrogen-stimulated growth of immature mouse uterus and estrogen-dependent proliferation of human breast cancer cells. However, the biological activities of the peptide diminish over time in storage, even when in the lyophilized state, probably because of peptide aggregation through hydrophobic interaction among monomers. Two analogs of EMTPVNPG were designed with the intent of minimizing aggregation and retaining biological activity during prolonged storage. EMTOVNOG, where O is 4-hydroxyproline, is a linear peptide generated by substituting 4-hydroxyproline for the two prolines, thereby increasing peptide hydrophilicity. This analog exhibited a dose-dependent inhibition of estrogen-stimulated growth of immature mouse uterus similar to that of EMTPVNPG (maximal activity at 1 microg/mouse). A second analog, cyclo-(EMTOVNOGQ), a hydrophilic, cyclic analog with increased conformational constraint, was as potent as the other peptides in its inhibition of estrogen-dependent growth of immature mouse uterus, and had an expanded effective dose range. Both linear and cyclized hydroxyproline-substituted analogs exhibited indefinite shelf-life. Furthermore, both analogs inhibited the estrogen-dependent growth of MCF-7 human breast cancer growing as a xenograft in SCID mice. These analogs may become significant, novel agents for the treatment of breast cancer.
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Affiliation(s)
- F B Mesfin
- Center for Immunology and Microbial Diseases, Albany Medical College, Albany 12208, USA
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32
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Eisele LE, Mesfin FB, Bennett JA, Andersen TT, Jacobson HI, Vakharia DD, MacColl R, Mizejewski GJ. Studies on analogs of a peptide derived from alpha-fetoprotein having antigrowth properties. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2001; 57:539-46. [PMID: 11437957 DOI: 10.1034/j.1399-3011.2001.00903.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A 34-amino acid portion of the third domain of alpha-fetoprotein possesses antigrowth and anticancer activities. Three analogs of this sequence were chemically synthesized, in which the two cysteines of the original sequence were replaced by alanines, glycines or serines. The original cysteine and alanine peptides formed trimers at 0.20 g/L in pH 7.4 phosphate buffer, and the glycine and serine peptides formed dimers. Trimer preparations were more potent in inhibiting estrogen-induced growth in the mouse uterine assays than the two dimeric oligomers. Of salient importance is that the alanine peptide retained its trimeric form in solution much longer than the cysteine peptide. Antigrowth assays were performed starting with stock solutions at a peptide concentration of 0.20 g/L, because at very high peptide concentration (8.0 g/L) the peptides aggregated extensively. All the peptides, although differing in biological activity, had almost identical secondary structures. Unlike alpha-fetoprotein, the three peptides have low amounts of alpha-helix. Trifluoroethanol has the ability to convert peptides into a helical conformation when they have a propensity for that structure. At trifluoroethanol concentrations of 20% and higher, the alanine and glycine peptides were changed into highly helical structures.
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Affiliation(s)
- L E Eisele
- Wadsworth Center, New York State Department of Health, Albany, NY 12201-0500, USA
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33
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Mizejewski GJ. Peptides as receptor ligand drugs and their relationship to G-coupled signal transduction. Expert Opin Investig Drugs 2001; 10:1063-73. [PMID: 11772235 DOI: 10.1517/13543784.10.6.1063] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Peptides act as effector agents that regulate and/or mediate physiological processes, serving as hormones, neurotransmitters and signal transducing factors. The low molecular weight peptides affect receptor-mediated events, which influence cardiovascular, gastrointestinal and neurocranial systems. While some peptides have been marketed as drugs, many have served as leads or templates for the development of non-peptide drugs that mimic peptide actions. This review presents the advantages and disadvantages of using peptides as drugs that bind as ligands to cell-surface receptors and considers their applications in such events. The value of both the peptides and their mimics is based on their participation in the biomodulation of physiological processes, which frequently employ scaffolding proteins acting in a cascading sequence of protein-to-protein interactions. The peptides bind to G-coupled surface receptors to initiate a signal that is transduced to the interior of the cell through multiple layers of phosphorylating enzymes and binding proteins. Peptides have been further employed to identify the molecular targets of signal transduction, the uncoupling of which might provide a means for various disease therapies. The exploitation of such peptide-mediated signal pathways, which are of primary importance to tumour cells, may provide an attractive strategy for anticancer therapy in the future.
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Affiliation(s)
- G J Mizejewski
- Wadsworth Center, New York State Dept. of Health, Empire State Plaza, Albany, NY 12201, USA.
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