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Lin WW, Lu YC, Chuang CH, Cheng TL. Ab locks for improving the selectivity and safety of antibody drugs. J Biomed Sci 2020; 27:76. [PMID: 32586313 PMCID: PMC7318374 DOI: 10.1186/s12929-020-00652-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/22/2020] [Indexed: 02/06/2023] Open
Abstract
Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.
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Affiliation(s)
- Wen-Wei Lin
- Department of Laboratory Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Yun-Chi Lu
- Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Biomedical and Environmental Biology, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan
| | - Chih-Hung Chuang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tian-Lu Cheng
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
- Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan.
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
- Department of Biomedical and Environmental Biology, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan.
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Endothelial Function in Children with Acute Lymphoblastic Leukemia (ALL) May Reflect the Clinical Outcome. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7918091. [PMID: 30534565 PMCID: PMC6252207 DOI: 10.1155/2018/7918091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/08/2018] [Indexed: 12/13/2022]
Abstract
Endothelial dysfunction is a common feature of early complications of hemato-oncologic therapy. The aim of our study was to assess the profile of endothelial function at diagnosis time, then during initial treatment phase of acute lymphoblastic leukemia (ALL), and to verify the presence of its correlation with early clinical outcome (ECO). 28 ALL children and 18 healthy age-matched control ones were recruited. Study group was examined at baseline and at 33rd and 78th day of treatment. At each protocol step the endothelial function was assessed by measurement of sP-selectin (CD62-P), PAI-1(serpinE1), sE-selectin (CD62E), sICAM-1(sCD54), sVCAM-1(sCD106), and VEGF concentrations. Higher baseline sICAM-1 and sVCAM-1 levels and lower sP-selectin and VEGF were observed in children with ALL. sICAM-1, sVCAM-1, and sE-selectin levels were decreasing following the treatment with protocol I. Higher sE-selectin and lower baseline sICAM-1 levels were observed in children treated unsuccessfully. Lower PAI-1 levels were observed in children who survived. Higher baseline sE-selectin levels and lower sICAM-1 and VEGF were observed in children treated unsuccessfully. A decrease in sE-selectin and lower PAI-1 at the 78th day of therapy were associated with better ECO. High baseline VEGF and sE-selectin levels, significant increase in PAI-1, and low initial sICAM-1 levels are prognostics for poorer prognosis in the ALL children.
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Yu T. Nonlinear variable selection with continuous outcome: A fully nonparametric incremental forward stagewise approach. Stat Anal Data Min 2018; 11:188-197. [DOI: 10.1002/sam.11381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tianwei Yu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health; Emory University; Atlanta Georgia
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Mekkawy AH, Pourgholami MH, Morris DL. Involvement of urokinase-type plasminogen activator system in cancer: an overview. Med Res Rev 2014; 34:918-56. [PMID: 24549574 DOI: 10.1002/med.21308] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.
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Affiliation(s)
- Ahmed H Mekkawy
- Department of Surgery, Cancer Research Laboratories, St. George Hospital, University of New South Wales, Sydney, NSW 2217, Australia
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Cochran BJ, Croucher DR, Lobov S, Saunders DN, Ranson M. Dependence on endocytic receptor binding via a minimal binding motif underlies the differential prognostic profiles of SerpinE1 and SerpinB2 in cancer. J Biol Chem 2011; 286:24467-75. [PMID: 21606492 DOI: 10.1074/jbc.m111.225706] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor overexpression of urokinase-type plasminogen activator (uPA) and its specific inhibitor SerpinE1 (plasminogen activator inhibitor type-1) correlates with poor prognosis and increased metastatic potential. Conversely, tumor expression of uPA and another specific inhibitor, SerpinB2 (plasminogen activator inhibitor type-2), are associated with favorable outcome and relapse-free survival. It is not known how overexpression of these uPA inhibitors results in such disparate outcomes. A possible explanation may be related to the presence of a proposed low density lipoprotein receptor (LDLR)-binding motif in SerpinE1 responsible for mitogenic signaling via ERK that is absent in SerpinB2. We now show that complementation of such a LDLR-binding motif in SerpinB2 by mutagenesis of two key residues enabled high affinity binding to very LDLR (VLDLR). Furthermore, the VLDLR-binding SerpinB2 form behaved in a manner indistinguishable from SerpinE1 in terms of enhanced uPA-SerpinB2 complex endocytosis and subsequent ERK phosphorylation and cell proliferation; that is, the introduction of the LDLR-binding motif to SerpinB2 was necessary and sufficient to allow it to acquire characteristics of SerpinE1 associated with malignancy. In conclusion, this study defines the structural elements underlying the distinct interactions of SerpinE1 versus SerpinB2 with endocytic receptors and how differential VLDLR binding impacts on downstream cellular behavior. This has clear relevance to understanding the paradoxical disease outcomes associated with overexpression of these serpins in cancer.
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Affiliation(s)
- Blake J Cochran
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
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Cochran BJ, Gunawardhana LP, Vine KL, Lee JA, Lobov S, Ranson M. The CD-loop of PAI-2 (SERPINB2) is redundant in the targeting, inhibition and clearance of cell surface uPA activity. BMC Biotechnol 2009; 9:43. [PMID: 19442270 PMCID: PMC2693429 DOI: 10.1186/1472-6750-9-43] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 05/14/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasminogen activator inhibitor type-2 (PAI-2, SERPINB2) is an irreversible, specific inhibitor of the urokinase plasminogen activator (uPA). Since overexpression of uPA at the surface of cancer cells is linked to malignancy, targeting of uPA by exogenous recombinant PAI-2 has been proposed as the basis of potential cancer therapies. To this end, reproducible yields of high purity protein that maintains this targeting ability is required. Herein we validate the use in vitro of recombinant 6 x His-tagged-PAI-2 lacking the intrahelical loop between C and D alpha-helices (PAI-2 Delta CD-loop) for these purposes. RESULTS We show that PAI-2 Delta CD-loop expressed and purified from the pQE9 vector system presents an easier purification target than the previously used pET15b system. Additionally, PAI-2 Delta CD-loop gave both higher yield and purity than wild-type PAI-2 expressed and purified under identical conditions. Importantly, absence of the CD-loop had no impact on the inhibition of both solution phase and cell surface uPA or on the clearance of receptor bound uPA from the cell surface. Furthermore, uPA:PAI-2 Delta CD-loop complexes had similar binding kinetics (KD approximately 5 nM) with the endocytosis receptor Very Low Density Lipoprotein Receptor (VLDLR) to that previously published for uPA:PAI-2 complexes. CONCLUSION We demonstrate that the CD-loop is redundant for the purposes of cellular uPA inhibition and cell surface clearance (endocytosis) and is thus suitable for the development of anti-uPA targeted cancer therapeutics.
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Affiliation(s)
- Blake J Cochran
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
| | - Lakshitha P Gunawardhana
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
- Current address: Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, John Hunter Hospital, Newcastle, NSW, 2310, Australia
| | - Kara L Vine
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
| | - Jodi A Lee
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
| | - Sergei Lobov
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
| | - Marie Ranson
- School of Biological Sciences, University of Wollongong, NSW, 2522, Australia
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Hütter G, Letsch A, Nowak D, Poland J, Sinha P, Thiel E, Hofmann WK. High correlation of the proteome patterns in bone marrow and peripheral blood blast cells in patients with acute myeloid leukemia. J Transl Med 2009; 7:7. [PMID: 19146667 PMCID: PMC2630935 DOI: 10.1186/1479-5876-7-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 01/15/2009] [Indexed: 11/13/2022] Open
Abstract
Background When comparing myelogenous blasts from bone marrow and peripheral blood, immunophenotyping usually show a strong correlation of expression of surface antigens. However, it remains to be determined, whether this correlation also exists on the level of protein expression. Method Therefore, we investigated both bone marrow and peripheral blood blast cells from six patients with newly diagnosed acute myeloid leukemia (AML) using conventional two-dimensional electrophoresis in the first dimension and linear polyacrylamide gels (12%) in the second dimension. Proteins were visualized using the silver staining method and image analysis was performed using the PDQuest system. Results For each patient over 80 proteins were evaluated in the sample from peripheral blood and bone marrow. We could demonstrate that the protein expression profile of bone marrow did not significantly differ from the expression patterns of peripheral blast cells. Conclusion The proteome-set of leukemic blast cells from marrow and blood, does not differ substantially when drawn from AML patients with over 80 percent blast cells in both compartments. This indicates that in AML, blasts from peripheral blood samples can be considered suitable for investigations of the proteome using 2D-electrophoresis.
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Affiliation(s)
- Gero Hütter
- Department of Internal Medicine III (Hematology, Onkology), Charité Berlin Campus Benjamin Franklin, Berlin, Germany.
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Dass K, Ahmad A, Azmi AS, Sarkar SH, Sarkar FH. Evolving role of uPA/uPAR system in human cancers. Cancer Treat Rev 2007; 34:122-36. [PMID: 18162327 DOI: 10.1016/j.ctrv.2007.10.005] [Citation(s) in RCA: 309] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2007] [Revised: 10/30/2007] [Accepted: 10/31/2007] [Indexed: 12/12/2022]
Abstract
Recent advancements in cancer research have led to some major breakthroughs; however, the impact on overall cancer-related death rate remains unacceptable, suggesting that further insight into tumor markers and development of targeted therapies is urgently needed. The urokinase plasminogen activator (uPA) system represents a family of serine proteases that are involved in the degradation of basement membrane and the extracellular matrix, leading to tumor cell invasion and metastasis. In this review, we have provided an overview of emerging data, from basic research as well as clinical studies, highlighting the evolving role of uPA/uPAR system in tumor progression. It is currently believed that the expression and activation of uPA plays an important role in tumorigenicity, and high endogenous levels of uPA and uPAR are associated with advanced metastatic cancers. The endogenous inhibitors of this system, PAI-1 and PAI-2, regulate uPA-uPAR activity by either direct inhibition or affecting cell surface expression and internalization. PAI-1's role in cancers is rather unusual; on one hand, it inhibits uPA-uPAR leading to inhibition of invasion and metastasis and on the other it has been reported to facilitate tumor growth and angiogenesis. Individual components of uPA/uPAR system are reported to be differentially expressed in cancer tissues compared to normal tissues and, thus, have the potential to be developed as prognostic and/or therapeutic targets. Therefore, this system represents a highly attractive target that warrants further in-depth studies. Such studies are likely to contribute towards the development of molecularly-driven targeted therapies in the near future.
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Affiliation(s)
- Kathleen Dass
- Department of Pathology, Barbara Ann Karmanos Cancer Center and Wayne State University School of Medicine, Detroit, MI 48201, USA
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Yilmaz M, Dagdas S, Aki SZ, Guler N, Akoz AG, Erdin Z, Alanoglu G, Ozet G. The relation between plasminogen activator inhibitor activity and disease activation in acute myeloblastic leukaemia patients. Int J Lab Hematol 2006; 28:313-6. [PMID: 16999721 DOI: 10.1111/j.1365-2257.2006.00820.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Coagulation and fibrinolytic abnormalities are common in patients with acute myeloblastic leukaemia (AML) like other forms of leukaemias. In this study, we investigated if total plasminogen activator inhibitor (PAI) activity, which is believed to increase in initial diagnosis and relapse in AML patients could be accepted as a relapse criterion or not. Total of 34 AML patients and 18 healthy volunteers were included in this study. The patients' diagnosis were based on clinical criteria as well as morphological, cytochemical, immunuphenotypic examinations of peripheral blood and bone marrow specimens. Total PAI activity was measured with Dade Behring Bericrom PAI reagent in BCS system. Total PAI activity was higher than 3.5 U/ml in 11 AML patients while it was normal (0.3-3.5 U/ml) in control group (P < 0.01). There was no significant difference in total PAI activity between AML subgroups (P > 0.05). We found significant difference in total PAI activity between patients who have active disease and remission. In conclusion, the total PAI activity could be accepted as a relapse and an initial diagnosis criterion of AML patients during follow up.
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Affiliation(s)
- M Yilmaz
- Ankara Numune Education and Research Hospital Clinic of Hematology, Ankara, Turkey.
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10
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Kasyapa CS, Kunapuli P, Hawthorn L, Cowell JK. Induction of the plasminogen activator inhibitor-2 in cells expressing the ZNF198/FGFR1 fusion kinase that is involved in atypical myeloproliferative disease. Blood 2006; 107:3693-9. [PMID: 16410451 PMCID: PMC1895775 DOI: 10.1182/blood-2005-04-1505] [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: 12/12/2022] Open
Abstract
The ZNF198/FGFR1 fusion kinase associated with an atypical myeloproliferative disease is constitutively activated and regulates several STAT transcription factors. We used oligonucleotide microarrays to compare the gene-expression profiles between HEK-293 cells that stably express either the ZNF198/FGFR1 chimeric protein or the wild-type ZNF198 gene. Expression of the plasminogen activator inhibitor-2 (PAI-2/SERPINB2) was highly increased in cells expressing the fusion gene. Western blot analysis demonstrated that HEK-293 cells do not express PAI-2 endogenously, but in ZNF198/FGFR1-expressing cells 2 molecular forms of PAI-2, which were 47 kDa and 32 kDa, were expressed intracellularly, and a 60-kDa form was secreted. Similarly, expression of ZNF198/FGFR1 in BaF/3 mouse hematopoietic cells also induced the expression of the PAI-2 protein. Immunoprecipitation analysis revealed that both intracellular forms of PAI-2 bind to the ZNF198/FGFR1 kinase. Treatment of HEK-293 and BaF/3 cells with TNF-alpha in the presence of cycloheximide, induced apoptosis in both cases. In contrast, HEK-293 and BaF/3 cells expressing ZNF198/FGFR1 were resistant to TNF-alpha-induced apoptosis. These observations suggest that expression of the ZNF198/FGFR1 fusion gene is associated with specific PAI-2-mediated resistance to apoptosis which may contribute to the highly malignant nature of leukemic cells carrying this fusion kinase gene.
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Affiliation(s)
- Chitta S Kasyapa
- Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
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Kopf E, Miskin R. A RUNX/AML-binding motif residing in a novel 13-bp DNA palindrome may determine the expression of the proximal promoter of the human uPA gene. J Thromb Haemost 2005; 3:2057-64. [PMID: 16102112 DOI: 10.1111/j.1538-7836.2005.01510.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Urokinase-type plasminogen activator (uPA) is a multifunctional extracellular serine protease implicated in different events including fibrinolysis, tissue remodeling, and hematopoiesis. The human uPA gene contains a major promoter region at around 2000 bp upstream from the transcription start site (+1), and a second regulatory region spanning nucleotides -90/+32 within the proximal promoter. Here, an inspection of this region revealed a novel 13-bp palindrome residing at position +8/+20. Interestingly, the palindrome contains the DNA consensus-binding hexamer for the RUNX/AML family of transcription factors that play a role in hematopoiesis, leukemia, and several developmental processes. Measuring the expression for promoter-reporter constructs after transfection revealed that deletion of the palindrome abrogated most of the proximal promoter activity in 293A cell. Additionally, electrophoretic mobility shift assays have shown that the palindrome could bind the RUNX1 component in nuclear extracts of myeloid cell lines exclusively through its RUNX motif. The palindrome was found in five additional human genes, two of which (MYH11 and MLLT1) have been linked to chromosomal rearrangements leading to leukemia. The data presented here have implicated, for the first time, RUNX/AML in the regulation of the uPA gene. The significance of the novel palindrome regarding gene regulation through the RUNX motif deserves further investigation.
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Affiliation(s)
- E Kopf
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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Jones AL, Hulett MD, Altin JG, Hogg P, Parish CR. Plasminogen Is Tethered with High Affinity to the Cell Surface by the Plasma Protein, Histidine-rich Glycoprotein. J Biol Chem 2004; 279:38267-76. [PMID: 15220341 DOI: 10.1074/jbc.m406027200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plasminogen has been implicated in extracellular matrix degradation by invading cells, but few high affinity cell surface receptors for the molecule have been identified. Previous studies have reported that the plasma protein, histidine-rich glycoprotein (HRG), interacts with plasminogen and cell surfaces, raising the possibility that HRG may immobilize plasminogen/plasmin to cell surfaces. Here we show, based on optical biosensor analyses, that immobilized HRG interacts with soluble plasminogen with high affinity and with an extremely slow dissociation rate. Furthermore, the HRG-plasminogen interaction is lysine-dissociable and involves predominately the amino-terminal domain of HRG, and the fifth kringle domain of plasminogen, but not the carboxyl-terminal lysine of HRG. HRG was also shown to tether plasminogen to cell surfaces, with this interaction being potentiated by elevated Zn(2+) levels and low pH, conditions that prevail at sites of tissue injury, tumor growth, and angiogenesis. Based on these data we propose that HRG acts as a soluble adaptor molecule that binds to cells at sites of tissue injury, tumor growth, and angiogenesis, providing a high affinity receptor for tethering plasminogen to the cell surface and thereby enhancing the migratory potential of cells.
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Affiliation(s)
- Allison L Jones
- Cancer and Vascular Biology Group, Division of Immunology and Genetics, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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de Bock CE, Wang Y. Clinical significance of urokinase-type plasminogen activator receptor (uPAR) expression in cancer. Med Res Rev 2004; 24:13-39. [PMID: 14595671 DOI: 10.1002/med.10054] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The involvement of the urokinase-type plasminogen activator (uPA) system in particular has been extensively studied in the pathogenesis of cancer. The molecular role of the uPA receptor (uPAR) is well characterized with its participation in cell migration and extracellular matrix (ECM) degradation. Over-expression of uPAR in cancer has been demonstrated in many studies and is considered an attractive target for anticancer agents. We and others have down-regulated uPAR expression in an attempt to inhibit cancer metastasis based on its molecular role. Uniquely, uPAR which is a glycosyl phosphatidylinositol anchored protein is not only bound to the cell surface but also has a soluble form, suPAR. There is now accumulated clinical and experimental evidence supporting the significant role of uPAR and its soluble counterpart in a number of solid cancers. The expression of uPAR can be associated with tumor cells or stromal cells or both. Differences observed in the expression of uPAR using immunohistochemistry (IHC) are likely explained by the use of different antibodies and techniques rather than true cellular differences and are reviewed here. This review summarizes the clinical relevance of uPAR and its soluble form in the prognosis and diagnosis of different cancers.
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Affiliation(s)
- Charles Edo de Bock
- Orthopaedic Research Institute, St. George Hospital, University of New South Wales, Kogarah, Sydney, NSW 2217, Australia
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Robbie L, Berry S, Moir E, Booth NA, Culligan D, Tighe J, Watson H, King D, Bennett B. Myeloid leukaemic cells can lyse fibrin directly. Br J Haematol 2000; 111:524-9. [PMID: 11122094 DOI: 10.1046/j.1365-2141.2000.02381.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Purified preparations of circulating leukaemic blast cells from patients with acute myeloid (M1-7) or acute lymphoblastic leukaemia, and the myeloid or lymphoid cells from patients with chronic myeloid or lymphocytic forms of leukaemia, were incorporated into clots prepared from fibrinogen and plasminogen. Patterns of lysis were followed and measured by light transmission in a microtitre plate reader. Mature polymorphonuclear and mononuclear cell fractions from normal individuals were studied concurrently for comparison. Blast cells from the myeloid forms of acute leukaemia (M2-4) and 'myeloid' cell fractions from patients with chronic myeloid leukaemia were capable of lysing plasminogen-containing clots; this activity was neutralized by addition of immunoglobulin against urokinase plasminogen activator (u-PA), but not by anti-tissue plasmogen activator (t-PA). Mature polymorphonuclear and mononuclear cells from normal individuals lacked lytic activity, as did the leukaemic cells from patients with acute lymphoblastic or chronic lymphocytic leukaemia. Lysed blast cells showed the presence of free plasminogen activator on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with overlay zymography, also neutralized by anti-u-PA, whereas normal polymorphonuclear and mononuclear cells did not. These observations suggest that mechanisms underlying some forms of severe bleeding in acute myeloid leukaemias have a critical fibrinolytic component generated by the blast cells themselves.
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Affiliation(s)
- L Robbie
- Department of Medicine and Therapeutics, University of Aberdeen, UK
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Robbie L, Berry S, Moir E, Booth NA, Culligan D, Tighe J, Watson H, King D, Bennett B. Myeloid leukaemic cells can lyse fibrin directly. Br J Haematol 2000. [DOI: 10.1111/j.1365-2141.2000.02381.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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