1
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Chen R, Rajan S, Overstreet MG, Hurt EM, Thomas SB, Muniz-Medina V, Ward C, Sadowska A, Fleming R, Karanth S, Breen S, Zheng B, Wu Y, Iverson WO, Novick S, O'Day T, Shah DP, Dimasi N, Tiberghien AC, Osbourn J, Walker J. Preclinical Characterization of an Antibody-Drug Conjugate Targeting CS-1 and the Identification of Uncharacterized Populations of CS-1-Positive Cells. Mol Cancer Ther 2020; 19:1649-1659. [PMID: 32404408 DOI: 10.1158/1535-7163.mct-19-0482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 11/21/2019] [Accepted: 05/08/2020] [Indexed: 11/16/2022]
Abstract
Multiple myeloma is a hematologic cancer that disrupts normal bone marrow function and has multiple lines of therapeutic options, but is incurable as patients ultimately relapse. We developed a novel antibody-drug conjugate (ADC) targeting CS-1, a protein that is highly expressed on multiple myeloma tumor cells. The anti-CS-1 mAb specifically bound to cells expressing CS-1 and, when conjugated to a cytotoxic pyrrolobenzodiazepine payload, reduced the viability of multiple myeloma cell lines in vitro In mouse models of multiple myeloma, a single administration of the CS-1 ADC caused durable regressions in disseminated models and complete regression in a subcutaneous model. In an exploratory study in cynomolgus monkeys, the CS-1 ADC demonstrated a half-life of 3 to 6 days; however, no highest nonseverely toxic dose was achieved, as bone marrow toxicity was dose limiting. Bone marrow from dosed monkeys showed reductions in progenitor cells as compared with normal marrow. In vitro cell killing assays demonstrated that the CS-1 ADC substantially reduced the number of progenitor cells in healthy bone marrow, leading us to identify previously unreported CS-1 expression on a small population of progenitor cells in the myeloid-erythroid lineage. This finding suggests that bone marrow toxicity is the result of both on-target and off-target killing by the ADC.
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Affiliation(s)
- Ruoyan Chen
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | - Saravanan Rajan
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | | | - Elaine M Hurt
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | | | | | | | | | - Ryan Fleming
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | | | - Shannon Breen
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | - Bo Zheng
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | - Yuling Wu
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | | | - Steven Novick
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | - Terrence O'Day
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | - Dipesha P Shah
- Research and Development, AstraZeneca, Gaithersburg, Maryland
| | | | | | - Jane Osbourn
- Research and Development, AstraZeneca, Cambridge, United Kingdom
| | - Jill Walker
- Research and Development, AstraZeneca, Gaithersburg, Maryland
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2
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Sun J, Hao W, Fillmore N, Ma H, Springer D, Yu ZX, Sadowska A, Garcia A, Chen R, Muniz-Medina V, Rosenthal K, Lin J, Kuruvilla D, Osbourn J, Karathanasis SK, Walker J, Murphy E. Human Relaxin-2 Fusion Protein Treatment Prevents and Reverses Isoproterenol-Induced Hypertrophy and Fibrosis in Mouse Heart. J Am Heart Assoc 2019; 8:e013465. [PMID: 31818212 PMCID: PMC6951077 DOI: 10.1161/jaha.119.013465] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background Heart failure is one of the leading causes of death in Western countries, and there is a need for new therapeutic approaches. Relaxin‐2 is a peptide hormone that mediates pleiotropic cardiovascular effects, including antifibrotic, angiogenic, vasodilatory, antiapoptotic, and anti‐inflammatory effects in vitro and in vivo. Methods and Results We developed RELAX10, a fusion protein composed of human relaxin‐2 hormone and the Fc of a human antibody, to test the hypothesis that extended exposure of the relaxin‐2 peptide could reduce cardiac hypertrophy and fibrosis. RELAX10 demonstrated the same specificity and similar in vitro activity as the relaxin‐2 peptide. The terminal half‐life of RELAX10 was 7 days in mouse and 3.75 days in rat after subcutaneous administration. We evaluated whether treatment with RELAX10 could prevent and reverse isoproterenol‐induced cardiac hypertrophy and fibrosis in mice. Isoproterenol administration in mice resulted in increased cardiac hypertrophy and fibrosis compared with vehicle. Coadministration with RELAX10 significantly attenuated the cardiac hypertrophy and fibrosis compared with untreated animals. Isoproterenol administration significantly increased transforming growth factor β1 (TGF‐β1)–induced fibrotic signaling, which was attenuated by RELAX10. We found that RELAX10 also significantly increased protein kinase B/endothelial NO synthase signaling and protein S‐nitrosylation. In the reversal study, RELAX10‐treated animals showed significantly reduced cardiac hypertrophy and collagen levels. Conclusions These findings support a potential role for RELAX10 in the treatment of heart failure.
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Affiliation(s)
- Junhui Sun
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | | | - Natasha Fillmore
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Hanley Ma
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Danielle Springer
- Murine Phenotyping Core National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | - Zu-Xi Yu
- Pathology Core National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
| | | | | | | | | | | | | | | | | | | | | | - Elizabeth Murphy
- Cardiac Physiology Section/Cardiovascular Branch National Heart, Lung, and Blood Institute/National Institutes of Health Bethesda MD
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3
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Li JY, Perry SR, Muniz-Medina V, Wang X, Wetzel LK, Rebelatto MC, Masson Hinrichs MJ, Bezabeh BZ, Fleming RL, Dimasi N, Feng H, Toader D, Yuan AQ, Xu L, Lin J, Gao C, Wu H, Dixit R, Osbourn JK, Coats SR. A Biparatopic HER2-Targeting Antibody-Drug Conjugate Induces Tumor Regression in Primary Models Refractory to or Ineligible for HER2-Targeted Therapy. Cancer Cell 2019; 35:948-949. [PMID: 31185215 DOI: 10.1016/j.ccell.2019.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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4
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White JB, Fleming R, Masterson L, Ruddle BT, Zhong H, Fazenbaker C, Strout P, Rosenthal K, Reed M, Muniz-Medina V, Howard P, Dixit R, Wu H, Hinrichs MJ, Gao C, Dimasi N. Design and characterization of homogenous antibody-drug conjugates with a drug-to-antibody ratio of one prepared using an engineered antibody and a dual-maleimide pyrrolobenzodiazepine dimer. MAbs 2019; 11:500-515. [PMID: 30835621 DOI: 10.1080/19420862.2019.1578611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Most strategies used to prepare homogeneous site-specific antibody-drug conjugates (ADCs) result in ADCs with a drug-to-antibody ratio (DAR) of two. Here, we report a disulfide re-bridging strategy to prepare homogeneous ADCs with DAR of one using a dual-maleimide pyrrolobenzodiazepine (PBD) dimer (SG3710) and an engineered antibody (Flexmab), which has only one intrachain disulfide bridge at the hinge. We demonstrate that SG3710 efficiently re-bridge a Flexmab targeting human epidermal growth factor receptor 2 (HER2), and the resulting ADC was highly resistant to payload loss in serum and exhibited potent anti-tumor activity in a HER2-positive gastric carcinoma xenograft model. Moreover, this ADC was tolerated in rats at twice the dose compared to a site-specific ADC with DAR of two prepared using a single-maleimide PBD dimer (SG3249). Flexmab technologies, in combination with SG3710, provide a platform for generating site-specific homogenous PBD-based ADCs with DAR of one, which have improved biophysical properties and tolerability compared to conventional site-specific PBD-based ADCs with DAR of two.
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Affiliation(s)
- Jason B White
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | - Ryan Fleming
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | | | - Ben T Ruddle
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | - Haihong Zhong
- c Oncology Research , MedImmune , Gaithersburg , MD , USA
| | | | - Patrick Strout
- c Oncology Research , MedImmune , Gaithersburg , MD , USA
| | - Kim Rosenthal
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | - Molly Reed
- d Biologics Safety Assessment , MedImmune , Gaithersburg , MD , USA
| | | | - Philip Howard
- b Spirogen Ltd , QMB Innovation Center , London , UK
| | - Rakesh Dixit
- d Biologics Safety Assessment , MedImmune , Gaithersburg , MD , USA
| | - Herren Wu
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | | | - Changshou Gao
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
| | - Nazzareno Dimasi
- a Antibody Discovery and Protein Engineering , MedImmune , Gaithersburg , MD , USA
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5
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Comer FI, Wang X, Yuan AQ, Muniz-Medina V, Sadowska A, Xu L, Perry S, Thompson P, Minter R, Woods R, Hinrichs MJ, Reed M, Affif-Rider S, Rebelatto M, Brown C, Feng H, Dixit R, Coats S, Osbourn J. Abstract LB-A20: Strategies to Improve the Safety and Efficacy of Biparatopic Antibody Drug Conjugates. Mol Cancer Ther 2018. [DOI: 10.1158/1535-7163.targ-17-lb-a20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Antibody drug conjugates (ADC’s) define an emerging class of targeted therapies for cancer, with over 60 ADC’s currently in clinical development. Although antibodies can exhibit exquisite target specificity, expression of the tumor target in normal tissue can limit the tolerated dose that one can achieve with an ADC. We designed two different affinity variant biparatopic antibodies that recognize distinct epitopes on EGFR and promote receptor clustering that leads to enhanced lysosomal trafficking. These ADC’s comprise two different strategies to target EGFR expressing tumors: a high affinity, potency driven approach and a lowered affinity, threshold driven approach. We show that both ADC’s bind to tumor cells, are rapidly internalized, and traffic to the lysosome, where the warhead is efficiently released by lysosomal hydrolases. In vitro, the high affinity ADC exhibited potent killing of cancer cell lines, with IC50’s in the double digit picomolar range in cells with relative EGFR densities as low as 25,000, while the low affinity ADC was most effective when the EGFR density was greater than 500,000. The high affinity ADC was active in patient derived xenograft (PDX) models derived from colorectal and lung cancer patients harboring clinically relevant oncogenic drivers, such as KRAS and BRAF mutations or EGFR aberrations. This ADC induced tumor stasis or regression, with minimally efficacious doses between 1 and 3 mg/kg, in multiple tumor models across a broad range of EGFR expression (IHC scores ranging from 1 to 3). In a cynomolgus monkey safety study, this ADC showed a manageable safety profile at 2 mg/kg, with skin effects as the dose limiting toxicity. The potency of the high affinity ADC may provide meaningful activity across a range of EGFR expression levels, at doses that are tolerable in the clinic. The lowered affinity ADC exhibited an improved safety profile compared to the high affinity ADC, with a highest non-severely toxic dose (HNSTD) of 6 mg/kg, presumably driven by a reduction in binding to normal tissues that express comparably lower EGFR levels relative to the tumor. This lowered affinity ADC showed a more restricted anti-tumor activity, causing regressions at a minimally efficacious dose between 3 and 5 mg/kg, in PDX models that expressed high levels of EGFR, as judged by IHC scores of 3. The lowered affinity ADC required higher EGFR expression for activity, but the improved tolerability may provide a selectivity threshold that discriminates tumor from normal tissue in patients whose tumors overexpress EGFR. Our findings support the concept that modulating antibody affinity can yield distinct ADC’s that represent different strategies for balancing safety and efficacy. The work presented here provides a conceptual framework for designing unique ADC candidates tailored to the particular expression profile and safety considerations around specific tumor associated targets.
Citation Format: Frank I. Comer, Xinzhong Wang, Andy Q. Yuan, Vanessa Muniz-Medina, Agnieszka Sadowska, Lan Xu, Samuel Perry, Pamela Thompson, Ralph Minter, Robert Woods, Mary Jane Hinrichs, Molly Reed, Shameen Affif-Rider, Marlon Rebelatto, Charles Brown, Hui Feng, Rakesh Dixit, Steven Coats, Jane Osbourn. Strategies to Improve the Safety and Efficacy of Biparatopic Antibody Drug Conjugates [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A20.
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Affiliation(s)
| | | | | | | | | | - Lan Xu
- 1Medimmune, Gaithersburg, MD
| | | | | | | | | | | | | | | | | | | | - Hui Feng
- 7Topalliance Biosciences, Rockville, MD
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6
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Li JY, Perry SR, Muniz-Medina V, Wetzel LK, Rebelatto MC, Bezabeh BZ, Fleming RL, Dimasi N, Gao C, Wu H, Jenkins DW, Osbourn JK, Coats SR. Abstract PD5-08: A biparatopic HER2-targeting antibody-drug conjugate demonstrates potent antitumor activity in primary tumor models that are refractory to or ineligible for HER2-targeted therapies. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-pd5-08] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Current HER2-targeted drugs are ineffective in killing cancer cells expressing relatively low levels of HER2. Therefore, more than 60% of breast cancer patients are ineligible for HER2-targeted therapies because of lack of HER2 overexpression and the vast majority of eligible patients who initially respond to the treatment will eventually relapse. MedImmune is developing a novel HER2-targeting antibody-drug conjugate (ADC) to address this unmet medical need. We show that a bivalent biparatopic antibody targeting two distinct non-overlapping epitopes on HER2 is able to induce receptor clustering on the tumor cell surface, which in turn facilitates internalization and promotes lysosomal trafficking and degradation. When conjugated with a tubulysin-based microtubule inhibitor, the biparatopic antibody can deliver a greater quantity of cytotoxin into the targeted cancer cells. As a result, it demonstrated superior antitumor activity over Kadcyla® (T-DM1) in HER2-overexpressing (HER2-positive) tumor models. It also induced complete tumor regression in a HER2-positive tumor model that had developed acquired resistance to T-DM1 through chronic exposure. Moreover, to explore the potential clinical applications in treating the HER2 non-overexpressing (HER2-negative) patients the biparatopic ADC was evaluated across 17 primary tumor models derived from HER2-negative breast cancer patients among which 13 were triple-negative. Other criteria were also considered in the selection of these 17 models, including the degree of heterogeneity in HER2 expression, ER/PR status and histopathologic subclass, to maximize the diversity of tumor subtypes in the study. The biparatopic ADC demonstrated potent antitumor activity regardless of the histopathologic subclass and ER/PR status of the tumor. At the dose of 1 mg/kg, 41% of the tumor models (7 out of 17) showed tumor regression and 6% (1 out of 17) showed tumor stasis. At the dose of 3 mg/kg, 71% of the models (12 out of 17) showed tumor regression and 12% (2 out of 17) showed tumor stasis. Overall, our findings underscore the potential use of this novel HER2-targeting ADC to treat a large patient population that is ineligible for or relapsed/refractory to current HER2-targeted therapies, and thus warrant investigation in the clinic.
Citation Format: Li JY, Perry SR, Muniz-Medina V, Wetzel LK, Rebelatto MC, Bezabeh BZ, Fleming RL, Dimasi N, Gao C, Wu H, Jenkins DW, Osbourn JK, Coats SR. A biparatopic HER2-targeting antibody-drug conjugate demonstrates potent antitumor activity in primary tumor models that are refractory to or ineligible for HER2-targeted therapies. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD5-08.
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Affiliation(s)
- JY Li
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - SR Perry
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - V Muniz-Medina
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - LK Wetzel
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - MC Rebelatto
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - BZ Bezabeh
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - RL Fleming
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - N Dimasi
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - C Gao
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - H Wu
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - DW Jenkins
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - JK Osbourn
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
| | - SR Coats
- MedImmune LLC, Gaithersburg, MD; MedImmune Ltd, Cambridge, United Kingdom
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7
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Li JY, Perry SR, Muniz-Medina V, Wang X, Wetzel LK, Rebelatto MC, Hinrichs MJM, Bezabeh BZ, Fleming RL, Dimasi N, Feng H, Toader D, Yuan AQ, Xu L, Lin J, Gao C, Wu H, Dixit R, Osbourn JK, Coats SR. A Biparatopic HER2-Targeting Antibody-Drug Conjugate Induces Tumor Regression in Primary Models Refractory to or Ineligible for HER2-Targeted Therapy. Cancer Cell 2016; 29:117-29. [PMID: 26766593 DOI: 10.1016/j.ccell.2015.12.008] [Citation(s) in RCA: 236] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 09/18/2015] [Accepted: 12/15/2015] [Indexed: 01/29/2023]
Abstract
Antibody-drug conjugate (ADC) which delivers cytotoxic drugs specifically into targeted cells through internalization and lysosomal trafficking has emerged as an effective cancer therapy. We show that a bivalent biparatopic antibody targeting two non-overlapping epitopes on HER2 can induce HER2 receptor clustering, which in turn promotes robust internalization, lysosomal trafficking, and degradation. When conjugated with a tubulysin-based microtubule inhibitor, the biparatopic ADC demonstrates superior anti-tumor activity over ado-trastuzumab emtansine (T-DM1) in tumor models representing various patient subpopulations, including T-DM1 eligible, T-DM1 ineligible, and T-DM1 relapsed/refractory. Our findings indicate that this biparatopic ADC has promising potential as an effective therapy for metastatic breast cancer and a broader patient population may benefit from this unique HER2-targeting ADC.
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Affiliation(s)
- John Y Li
- Biosuperiors, MedImmune LLC, Gaithersburg, MD 20878, USA.
| | - Samuel R Perry
- Biosuperiors, MedImmune LLC, Gaithersburg, MD 20878, USA
| | | | - Xinzhong Wang
- Biosuperiors, MedImmune LLC, Gaithersburg, MD 20878, USA
| | | | | | | | - Binyam Z Bezabeh
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Ryan L Fleming
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Nazzareno Dimasi
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Hui Feng
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Dorin Toader
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Andy Q Yuan
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Lan Xu
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Jia Lin
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Changshou Gao
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Herren Wu
- Antibody Discovery & Protein Engineering, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Rakesh Dixit
- Biologics Safety Assessment, MedImmune LLC, Gaithersburg, MD 20878, USA
| | - Jane K Osbourn
- Biosuperiors, MedImmune LLC, Gaithersburg, MD 20878, USA; MedImmune Ltd, Granta Park, Cambridge CB21 6GH, UK
| | - Steven R Coats
- Biosuperiors, MedImmune LLC, Gaithersburg, MD 20878, USA
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8
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Kenakin T, Watson C, Muniz-Medina V, Christopoulos A, Novick S. A simple method for quantifying functional selectivity and agonist bias. ACS Chem Neurosci 2012; 3:193-203. [PMID: 22860188 DOI: 10.1021/cn200111m] [Citation(s) in RCA: 360] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 12/20/2011] [Indexed: 11/30/2022] Open
Abstract
Activation of seven-transmembrane (7TM) receptors by agonists does not always lead to uniform activation of all signaling pathways mediated by a given receptor. Relative to other ligands, many agonists are "biased" toward producing subsets of receptor behaviors. A hallmark of such "functional selectivity" is cell type dependence; this poses a particular problem for the profiling of agonists in whole cell test systems removed from the therapeutic one(s). Such response-specific cell-based variability makes it difficult to guide medicinal chemistry efforts aimed at identifying and optimizing therapeutically meaningful agonist bias. For this reason, we present a scale, based on the Black and Leff operational model, that contains the key elements required to describe 7TM agonism, namely, affinity (K(A) (-1)) for the receptor and efficacy (τ) in activating a particular signaling pathway. Utilizing a "transduction coefficient" term, log(τ/K(A)), this scale can statistically evaluate selective agonist effects in a manner that can theoretically inform structure-activity studies and/or drug candidate selection matrices. The bias of four chemokines for CCR5-mediated inositol phosphate production versus internalization is quantified to illustrate the practical application of this method. The independence of this method with respect to receptor density and the calculation of statistical estimates of confidence of differences are specifically discussed.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel
Hill, North Carolina 27599-7365, United States
| | - Christian Watson
- Platform Technology Sciences, GlaxoSmithKline Research, Research Triangle Park, North
Carolina 27709, United States
| | - Vanessa Muniz-Medina
- Infectious Diseases Discovery
Performance Unit, GlaxoSmithKline Research, Research Triangle Park, North Carolina 27709, United States
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash
Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Melbourne, Australia
| | - Steven Novick
- Discovery Analytics, GlaxoSmithKline Research, Research Triangle Park, North
Carolina 27709, United States
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9
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Kazmierski W, Muniz-Medina V, Danehower S, Jones S, Kenakin T. Small-molecule CCR5 Ligands that may Spare the CCR5 Function: Opportunity for New Antiviral Discovery? Antiviral Res 2009. [DOI: 10.1016/j.antiviral.2009.02.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Catena R, Muniz-Medina V, Moralejo B, Javierre B, Best CJM, Emmert-Buck MR, Green JE, Baker CC, Calvo A. Increased expression of VEGF121/VEGF165-189 ratio results in a significant enhancement of human prostate tumor angiogenesis. Int J Cancer 2007; 120:2096-109. [PMID: 17278099 DOI: 10.1002/ijc.22461] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Vascular endothelial growth factor (VEGF) is a proangiogenic factor upregulated in many tumors. The alternative splicing of VEGF mRNA renders 3 major isoforms of 121, 165 and 189 amino-acids in humans (1 less amino-acid for each mouse VEGF isoform). We have designed isoform specific real time QRT-PCR assays to quantitate VEGF transcripts in mouse and human normal and malignant prostates. In the human normal prostate, VEGF(165) was the predominant isoform (62.8% +/- 5.2%), followed by VEGF(121) (22.5% +/- 6.3%) and VEGF(189) (p < 0.001) (14.6% +/- 2.1%). Prostate tumors showed a significant increase in the percentage of VEGF(121) and decreases in VEGF(165) (p < 0.01) and VEGF(189) (p < 0.05). However, the amount of total VEGF mRNA was similar between normal and malignant prostates. VEGF(164) was the transcript with the highest expression in the mouse normal prostate. Unlike human prostate cancer, tumors from TRAMP mice demonstrated a significant increase in total VEGF mRNA levels and in each of the VEGF isoforms, without changes in the relative isoform ratios. Morpholino phosphorodiamide antisense oligonucleotide technology was used to increase the relative amount of VEGF(121) while proportionally decreasing VEGF(165) and VEGF(189) levels in human prostate cell lines, through the modification of alternative splicing, without changing transcription levels and total amount of VEGF. The increase in the VEGF(121)/VEGF(165-189) ratio in PC3 cells resulted in a dramatic increase in prostate tumor angiogenesis in vivo. Our results underscore the importance of VEGF(121) in human prostate carcinoma and demonstrate that the relative expression of the different VEGF isoforms has an impact on prostate carcinogenesis.
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Affiliation(s)
- Raul Catena
- Division of Oncology, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII 55, 31008 Pamplona, Spain
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11
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Khan SG, Oh KS, Shahlavi T, Ueda T, Busch DB, Inui H, Emmert S, Imoto K, Muniz-Medina V, Baker CC, DiGiovanna JJ, Schmidt D, Khadavi A, Metin A, Gozukara E, Slor H, Sarasin A, Kraemer KH. Reduced XPC DNA repair gene mRNA levels in clinically normal parents of xeroderma pigmentosum patients. Carcinogenesis 2005; 27:84-94. [PMID: 16081512 DOI: 10.1093/carcin/bgi204] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Xeroderma pigmentosum group C (XP-C) is a rare autosomal recessive disorder. Patients with two mutant alleles of the XPC DNA repair gene have sun sensitivity and a 1000-fold increase in skin cancers. Clinically normal parents of XP-C patients have one mutant allele and one normal allele. As a step toward evaluating cancer risk in these XPC heterozygotes we characterized cells from 16 XP families. We identified 15 causative mutations (5 frameshift, 6 nonsense and 4 splicing) in the XPC gene in cells from 16 XP probands. All had premature termination codons (PTC) and absence of normal XPC protein on western blotting. The cell lines from 26 parents were heterozygous for the same mutations. We employed a real-time quantitative reverse transcriptase-PCR assay as a rapid and sensitive method to measure XPC mRNA levels. The mean XPC mRNA levels in the cell lines from the XP-C probands were 24% (P<10(-7)) of that in 10 normal controls. This reduced XPC mRNA level in cells from XP-C patients was caused by the PTC that induces nonsense-mediated mRNA decay. The mean XPC mRNA levels in cell lines from the heterozygous XP-C carriers were intermediate (59%, P=10(-4)) between the values for the XP patients and the normal controls. This study demonstrates reduced XPC mRNA levels in XP-C patients and heterozygotes. Thus, XPC mRNA levels may be evaluated as a marker of cancer susceptibility in carriers of mutations in the XPC gene.
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Affiliation(s)
- Sikandar G Khan
- Basic Research Laboratory and Laboratory of Cellular Oncology, CCR, NCI, Bethesda, MD, USA
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Khan SG, Metin A, Gozukara E, Inui H, Shahlavi T, Muniz-Medina V, Baker CC, Ueda T, Aiken JR, Schneider TD, Kraemer KH. Two essential splice lariat branchpoint sequences in one intron in a xeroderma pigmentosum DNA repair gene: mutations result in reduced XPC mRNA levels that correlate with cancer risk. Hum Mol Genet 2003; 13:343-52. [PMID: 14662655 DOI: 10.1093/hmg/ddh026] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The lariat branch point sequence (BPS) is crucial for splicing of human nuclear pre-mRNA yet BPS mutations have infrequently been reported to cause human disease. Using an inverse RT-PCR technique we mapped two BPS to the adenosine residues at positions -4 and -24 in intron 3 of the human XPC DNA repair gene. We identified homozygous mutations in each of these BPS in two newly diagnosed Turkish families with the autosomal recessive disorder xeroderma pigmentosum (XP). Cells from two severely affected children in family A harbor a homozygous point mutation in XPC intron 3 (-9 T to A), located within the downstream BPS. Using a real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) assay, these cells expressed no detectable (<0.1%) normal XPC message. Instead they expressed an XPC mRNA isoform with deletion of exon 4 that has no DNA repair activity in a host cell reactivation (HCR) assay. In contrast, in cells from three mildly affected siblings in family B, the BPS adenosine located at the -24 position in XPC intron 3 is mutated to a G. Real-time QRT-PCR revealed 3-5% of normal XPC message. These cells from family B had a higher level of HCR than cells from the severely affected siblings in family A, who had multiple skin cancers. Mutations identified in two BPS of the XPC intron 3 resulted in alternative splicing that impaired DNA repair function, thus implicating both of these BPS as essential for normal pre-mRNA splicing. However, a small amount of normal XPC mRNA can provide partial protection against skin cancers.
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Affiliation(s)
- Sikandar G Khan
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute/NIH, Building 37 Room 4002 MSC 4258, Bethesda, MD 20892-4258, USA
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Khan SG, Muniz-Medina V, Shahlavi T, Baker CC, Inui H, Ueda T, Emmert S, Schneider TD, Kraemer KH. The human XPC DNA repair gene: arrangement, splice site information content and influence of a single nucleotide polymorphism in a splice acceptor site on alternative splicing and function. Nucleic Acids Res 2002; 30:3624-31. [PMID: 12177305 PMCID: PMC134237 DOI: 10.1093/nar/gkf469] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
XPC DNA repair gene mutations result in the cancer-prone disorder xeroderma pigmentosum. The XPC gene spans 33 kb and has 16 exons (82-882 bp) and 15 introns (0.08-5.4 kb). A 1.6 kb intron was found within exon 5. Sensitive real- time quantitative reverse transcription-polymerase chain reaction methods were developed to measure full-length XPC mRNA (the predominant form) and isoforms that skipped exons 4, 7 or 12. Exon 7 was skipped in approximately 0.07% of XPC mRNAs, consistent with the high information content of the exon 7 splice acceptor and donor sites (12.3 and 10.4 bits). In contrast, exon 4 was skipped in approximately 0.7% of the XPC mRNAs, consistent with the low information content of the exon 4 splice acceptor (-0.1 bits). A new common C/A single nucleotide polymorphism in the XPC intron 11 splice acceptor site (58% C in 97 normals) decreased its information content from 7.5 to 5.1 bits. Fibroblasts homozygous for A/A had significantly higher levels (approximately 2.6-fold) of the XPC mRNA isoform that skipped exon 12 than those homozygous for C/C. This abnormally spliced XPC mRNA isoform has diminished DNA repair function and may contribute to cancer susceptibility.
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Affiliation(s)
- Sikandar G Khan
- Basic Research Laboratory, National Cancer Institute, Building 37 Room 3E24, Bethesda, MD 20892, USA
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