1
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Kelly JJ, Ankrom ET, Newkirk SE, Thévenin D, Pires MM. Targeted acidosis mediated delivery of antigenic MHC-binding peptides. Front Immunol 2024; 15:1337973. [PMID: 38665920 PMCID: PMC11043575 DOI: 10.3389/fimmu.2024.1337973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Cytotoxic T lymphocytes are the primary effector immune cells responsible for protection against cancer, as they target peptide neoantigens presented through the major histocompatibility complex (MHC) on cancer cells, leading to cell death. Targeting peptide-MHC (pMHC) complex offers a promising strategy for immunotherapy due to their specificity and effectiveness against cancer. In this work, we exploit the acidic tumor micro-environment to selectively deliver antigenic peptides to cancer using pH(low) insertion peptides (pHLIP). We demonstrated the delivery of MHC binding peptides directly to the cytoplasm of melanoma cells resulted in the presentation of antigenic peptides on MHC, and activation of T cells. This work highlights the potential of pHLIP as a vehicle for the targeted delivery of antigenic peptides and its presentation via MHC-bound complexes on cancer cell surface for activation of T cells with implications for enhancing anti-cancer immunotherapy.
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Affiliation(s)
- Joey J. Kelly
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Emily T. Ankrom
- Department of Chemistry, Lehigh University, Bethlehem, PA, United States
| | - Sarah E. Newkirk
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University, Bethlehem, PA, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
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2
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Kelly JJ, Ankrom E, Thévenin D, Pires MM. Targeted Acidosis Mediated Delivery of Antigenic MHC-Binding Peptides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.18.562409. [PMID: 37904977 PMCID: PMC10614887 DOI: 10.1101/2023.10.18.562409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Cytotoxic T lymphocytes are the primary effector immune cells responsible for protection against cancer, as they target peptide neoantigens presented through the major histocompatibility complex (MHC) on cancer cells, leading to cell death. Targeting peptide-MHC (pMHC) complexes offers a promising strategy for immunotherapy due to its specificity and effectiveness against cancer. In this work, we exploit the acidic tumor micro-environment to selectively deliver antigenic peptides to cancer cells using pH(low) insertion peptides (pHLIP). We demonstrated that the delivery of MHC binding peptides directly to the cytoplasm of melanoma cells resulted in the presentation of antigenic peptides on MHC, and subsequent activation of T cells. This work highlights the potential of pHLIP as a vehicle for targeted delivery of antigenic peptides and their presentation via MHC-bound complexes on cancer cell surfaces for activation of T cells with implications for enhancing anti-cancer immunotherapy.
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3
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Rizzo S, Sikorski E, Park S, Im W, Vasquez‐Montes V, Ladokhin AS, Thévenin D. Promoting the activity of a receptor tyrosine phosphatase with a novel pH-responsive transmembrane agonist inhibits cancer-associated phenotypes. Protein Sci 2023; 32:e4742. [PMID: 37515426 PMCID: PMC10461461 DOI: 10.1002/pro.4742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/18/2023] [Accepted: 07/27/2023] [Indexed: 07/30/2023]
Abstract
Cell signaling by receptor protein tyrosine kinases (RTKs) is tightly controlled by the counterbalancing actions of receptor protein tyrosine phosphatases (RPTPs). Due to their role in attenuating the signal-initiating potency of RTKs, RPTPs have long been viewed as therapeutic targets. However, the development of activators of RPTPs has remained limited. We previously reported that the homodimerization of a representative member of the RPTP family (protein tyrosine phosphatase receptor J or PTPRJ) is regulated by specific transmembrane (TM) residues. Disrupting this interaction by single point mutations promotes PTPRJ access to its RTK substrates (e.g., EGFR and FLT3), reduces RTK's phosphorylation and downstream signaling, and ultimately antagonizes RTK-driven cell phenotypes. Here, we designed and tested a series of first-in-class pH-responsive TM peptide agonists of PTPRJ that are soluble in aqueous solution but insert as a helical TM domain in lipid membranes when the pH is lowered to match that of the acidic microenvironment of tumors. The most promising peptide reduced EGFR's phosphorylation and inhibited cancer cell EGFR-driven migration and proliferation, similar to the PTPRJ's TM point mutations. Developing tumor-selective and TM-targeting peptide binders of critical RPTPs could afford a potentially transformative approach to studying RPTP's selectivity mechanism without requiring less specific inhibitors and represent a novel class of therapeutics against RTK-driven cancers.
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Affiliation(s)
- Sophie Rizzo
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - Eden Sikorski
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - Soohyung Park
- Department of Biological SciencesLehigh UniversityBethlehemPennsylvaniaUSA
| | - Wonpil Im
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
- Department of Biological SciencesLehigh UniversityBethlehemPennsylvaniaUSA
| | - Victor Vasquez‐Montes
- Department of Biochemistry and Molecular BiologyThe University of Kansas Medical CenterKansas CityKansasUSA
| | - Alexey S. Ladokhin
- Department of Biochemistry and Molecular BiologyThe University of Kansas Medical CenterKansas CityKansasUSA
| | - Damien Thévenin
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
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4
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Bauer D, Visca H, Weerakkody A, Carter LM, Samuels Z, Kaminsky S, Andreev OA, Reshetnyak YK, Lewis JS. PET Imaging of Acidic Tumor Environment With 89Zr-labeled pHLIP Probes. Front Oncol 2022; 12:882541. [PMID: 35664740 PMCID: PMC9160799 DOI: 10.3389/fonc.2022.882541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Acidosis of the tumor microenvironment is a hallmark of tumor progression and has emerged as an essential biomarker for cancer diagnosis, prognosis, and evaluation of treatment response. A tool for quantitatively visualizing the acidic tumor environment could significantly advance our understanding of the behavior of aggressive tumors, improving patient management and outcomes. 89Zr-labeled pH-low insertion peptides (pHLIP) are a class of radiopharmaceutical imaging probes for the in vivo analysis of acidic tumor microenvironments via positron emission tomography (PET). Their unique structure allows them to sense and target acidic cancer cells. In contrast to traditional molecular imaging agents, pHLIP’s mechanism of action is pH-dependent and does not rely on the presence of tumor-specific molecular markers. In this study, one promising acidity-imaging PET probe ([89Zr]Zr-DFO-Cys-Var3) was identified as a candidate for clinical translation.
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Affiliation(s)
- David Bauer
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Hannah Visca
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Anuradha Weerakkody
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Lukas M. Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Zachary Samuels
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Spencer Kaminsky
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Oleg A. Andreev
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Yana K. Reshetnyak
- Department of Physics, University of Rhode Island, Kingston, RI, United States
| | - Jason S. Lewis
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
- Department of Pharmacology Program, Weill Cornell Medical College, New York, NY, United States
- *Correspondence: Jason S. Lewis,
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5
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Sikorski EL, Wehr J, Ferraro NJ, Rizzo SM, Pires MM, Thévenin D. Selective Display of a Chemoattractant Agonist on Cancer Cells Activates the Formyl Peptide Receptor 1 on Immune Cells. Chembiochem 2022; 23:e202100521. [PMID: 35199442 PMCID: PMC9035110 DOI: 10.1002/cbic.202100521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/26/2022] [Indexed: 11/11/2022]
Abstract
Current immunotherapeutics often work by directing components of the immune system to recognize biomarkers on the surface of cancer cells to generate an immune response. However, variable changes in biomarker distribution and expression can result in inconsistent patient response. The development of a more universal tumor-homing strategy has the potential to improve selectivity and extend therapy to cancers with decreased expression or absence of specific biomarkers. Here, we designed a bifunctional agent that exploits the inherent acidic microenvironment of most solid tumors to selectively graft the surface of cancer cells with a formyl peptide receptor ligand (FPRL). Our approach is based on the pH(Low) insertion peptide (pHLIP), a unique peptide that selectively targets tumors in vivo by anchoring to cancer cells in a pH-dependent manner. We establish that selectively remodeling cancer cells with a pHLIP-based FPRL activates formyl peptide receptors on recruited immune cells, potentially initiating an immune response towards tumors.
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Affiliation(s)
- Eden L. Sikorski
- Department of Chemistry, Lehigh University. Bethlehem, Pennsylvania 18015, United States
| | - Janessa Wehr
- Department of Chemistry, Lehigh University. Bethlehem, Pennsylvania 18015, United States
| | - Noel J. Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Sophia M. Rizzo
- Department of Chemistry, Lehigh University. Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University. Bethlehem, Pennsylvania 18015, United States
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Chen YH, Yu MM, Wang ZG. Inhibition of MDA-MB-231 cell proliferation by pHLIP(Var7)-P1AP and SPECT imaging of MDA-MB-231 breast cancer-bearing nude mice using 125I-pHLIP(Var7)-P1AP. Nuklearmedizin 2021; 60:240-248. [PMID: 33759146 DOI: 10.1055/a-1307-1923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIM To observe the effect of pHLIP(Var7)-P1AP on the proliferation of MDA-MB-231 triple-negative breast cancer cells and the small-animal single-photon-emission computed tomography (SPECT) imaging of breast cancer-bearing mice carrying MDA-MB-231 cells. METHODS Peptide pHLIP(Var7)-P1AP was synthesized by solid-phase peptide synthesis. The binding of fluorescently labeled pHLIP(Var7)-P1AP to MDA-MB-231 cells under various pH conditions and its effect on MDA-MB-231 cell proliferation were analyzed. pHLIP(Var7)-P1AP was labeled with 125I, and the biological distribution of 125I-pHLIP(Var7)-P1AP in the breast cancer mouse model carrying MDA-MB-231 cells as well as the outcome of small-animal SPECT imaging were evaluated. RESULTS pHLIP(Var7)-P1AP was successfully synthesized. Under pH 6.0, fluorescently labeled pHLIP(Var7)-P1AP had a higher binding ability to MDA-MB-231 cells and significantly inhibited the proliferation of MDA-MB-231 cells. The labeling efficiency of pHLIP(Var7)-P1AP with 125I was 33.1 ± 2.7 %, and the radiochemical purity was 98.5 ± 1.8 %. 125I-pHLIP(Var7)-P1AP showed a high concentration in tumors. Small-animal SPECT imaging showed clearly visible tumors at 4 h after injection. CONCLUSIONS In the acidic environment, pHLIP(Var7)-P1AP can efficiently target MDA-MB-231 cells and inhibit their growth. Small-animal SPECT of 125I-pHLIP(Var7)-P1AP can clearly image tumors.
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Affiliation(s)
- Yue Hua Chen
- Intensive Care Unit, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ming Ming Yu
- Nuclear Medicine Department, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Zhen Guang Wang
- Nuclear Medicine Department, The Affiliated Hospital of Qingdao University, Qingdao, China
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7
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An Experimental Study on [ 125I]I-pHLIP (Var7) for SPECT/CT Imaging of an MDA-MB-231 Triple-Negative Breast Cancer Mouse Model by Targeting the Tumor Microenvironment. Mol Imaging 2021; 2021:5565932. [PMID: 33746628 PMCID: PMC7953584 DOI: 10.1155/2021/5565932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/15/2021] [Indexed: 12/19/2022] Open
Abstract
Objective To evaluate the diagnostic efficacy of MDA-MB-231 triple-negative breast cancer with 125I-labeled pHLIP (Var7) by single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. Methods The binding fraction of [125I]I-pHLIP (Var7) and MDA-MB-231 cells was measured at pH 7.4 and pH 6.0, and tumor-bearing mice were subjected to small-animal SPECT/CT imaging studies. Results At pH = 6.0, the binding fractions of [125I]I-pHLIP (Var7) and MDA-MB-231 cells at 10 min, 40 min, 1 h, and 2 h were 1.9 ± 0.1%, 3.5 ± 0.1%, 6.3 ± 0.8%, and 6.6 ± 0.3%, respectively. At pH = 7.4, there was no measured binding between [125I]I-pHLIP (Var7) and MDA-MB-231 cells. Small-animal SPECT/CT imaging showed clearly visible tumors at 1 and 2 h after injection. Conclusions [125I]I-pHLIP (Var7) could bind to MDA-MB-231 cells in an acidic environment, and small-animal SPECT/CT imaging showed clear tumors at 1 and 2 h after probe injection.
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8
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Wehr J, Sikorski EL, Bloch E, Feigman MS, Ferraro NJ, Baybutt TR, Snook AE, Pires MM, Thévenin D. pH-Dependent Grafting of Cancer Cells with Antigenic Epitopes Promotes Selective Antibody-Mediated Cytotoxicity. J Med Chem 2020; 63:3713-3722. [PMID: 32196345 DOI: 10.1021/acs.jmedchem.0c00016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A growing class of immunotherapeutics work by redirecting components of the immune system to recognize markers on the surface of cancer cells. However, such modalities will remain confined to a relatively small subgroup of patients because of the lack of universal targetable tumor biomarkers among all patients. Here, we designed a unique class of agents that exploit the inherent acidity of solid tumors to selectively graft cancer cells with immuno-engager epitopes. Our targeting approach is based on pHLIP, a unique peptide that selectively targets tumors in vivo by anchoring to cancer cell surfaces in a pH-dependent manner. We established that pHLIP-antigen conjugates trigger the recruitment of antibodies to the surface of cancer cells and induce cytotoxicity by peripheral blood mononuclear and engineered NK cells. These results indicate that these agents have the potential to be applicable to treating a wide range of solid tumors and to circumvent problems associated with narrow windows of selectivity.
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Affiliation(s)
- Janessa Wehr
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Eden L Sikorski
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Elizabeth Bloch
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Mary S Feigman
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Noel J Ferraro
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Trevor R Baybutt
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - Adam E Snook
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - Marcos M Pires
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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9
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Yu M, Chen Y, Wang Z, Ding X. pHLIP(Var7)-P1AP suppresses tumor cell proliferation in MDA-MB-231 triple-negative breast cancer by targeting protease activated receptor 1. Breast Cancer Res Treat 2020; 180:379-384. [PMID: 32034579 PMCID: PMC7066270 DOI: 10.1007/s10549-020-05560-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/31/2020] [Indexed: 01/17/2023]
Abstract
PURPOSE Protease-activated receptor 1 (PAR1) is a signaling protein ubiquitously present on the surface of tumor cells, and its homologous protein fragment, PAR1-activating peptide (P1AP), can inhibit protein signal transduction of PAR1/G in tumor cells. pH (Low) insertion peptide (pHLIP) can target the acidic tumor microenvironment (TME) and can be used as an excellent carrier to deliver P1AP to tumor cells for therapeutic purposes. METHODS PAR1 expression on the surface of MDA-MB-231 cells and human MCF10A mammary epithelial cells was observed. The binding between fluorescent-labeled pHLIP(Var7)-P1AP and MDA-MB-231 cells under different pH values was analyzed. The effect of pHLIP(Var7)-P1AP on the proliferation of MDA-MB-231 cells was analyzed under the conditions of pH 7.4 and 6.0. RESULTS PAR1 was highly expressed on the surface of MDA-MB-231 cells. In an acidic environment (pH 6.0 and 5.0), fluorescent-labeled pHLIP(Var7)-P1AP and MDA-MB-231 cells had a high binding ability, and the binding ability increased with the decrease in pH. In an acidic environment (pH 6.0), pHLIP(Var7)-P1AP significantly inhibited MDA-MB-231 cell proliferation. With 0.5 μg, 1 μg, 2 μg, 4 μg, and 8 μg of pHLIP(Var7)-P1AP, the cell proliferation inhibition rates were 3.39%, 5.27%, 14.29%, 22.14%, and 35.69%, respectively. CONCLUSION PAR1 was highly expressed on the surface of MDA-MB-231 cells. pHLIP(Var7)-P1AP can effectively target MDA-MB-231 cells in an acidic environment and inhibit the growth of MDA-MB-231 cells by inhibiting the signal transduction of PAR1/G protein.
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Affiliation(s)
- MingMing Yu
- Department of Nuclear Medicine, The Affiliated Hospital of Qingdao University, No. 59, Haier Rd., Qingdao, 266100, China
| | - YueHua Chen
- Intensive Care Unit, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - ZhenGuang Wang
- Department of Nuclear Medicine, The Affiliated Hospital of Qingdao University, No. 59, Haier Rd., Qingdao, 266100, China.
| | - XiaoDong Ding
- Department of Neurosurgery, The Affiliated Hospital of Qingdao University, Qingdao, China
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Abstract
As basic research into GPCR signaling and its association with disease has come into fruition, greater clarity has emerged with regards to how these receptors may be amenable to therapeutic intervention. As a diverse group of receptor proteins, which regulate a variety of intracellular signaling pathways, research in this area has been slow to yield tangible therapeutic agents for the treatment of a number of diseases including cancer. However, recently such research has gained momentum based on a series of studies that have sought to define GPCR proteins dynamics through the elucidation of their crystal structures. In this chapter, we define the approaches that have been adopted in developing better therapeutics directed against the specific parts of the receptor proteins, such as the extracellular and the intracellular domains, including the ligands and auxiliary proteins that bind them. Finally, we also briefly outline how GPCR-derived signaling transduction pathways hold great potential as additional targets.
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Affiliation(s)
- Surinder M Soond
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russian Federation.
| | - Andrey A Zamyatnin
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russian Federation; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation.
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11
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Gerhart J, Thévenin AF, Bloch E, King KE, Thévenin D. Inhibiting Epidermal Growth Factor Receptor Dimerization and Signaling Through Targeted Delivery of a Juxtamembrane Domain Peptide Mimic. ACS Chem Biol 2018; 13:2623-2632. [PMID: 30133245 DOI: 10.1021/acschembio.8b00555] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Overexpression and deregulation of the epidermal growth factor receptor (EGFR) are implicated in multiple human cancers and therefore are a focus for the development of therapeutics. Current strategies aimed at inhibiting EGFR activity include monoclonal antibodies and tyrosine kinase inhibitors. However, activating mutations severely limit the efficacy of these therapeutics. There is thus a growing need for novel methods to inhibit EGFR. One promising approach involves blocking the association of the cytoplasmic juxtamembrane (JM) domain of EGFR, which has been shown to be essential for receptor dimerization and kinase function. Here, we aim to improve the selectivity and efficacy of an EGFR JM peptide mimic by utilizing the pH(low) insertion peptide (pHLIP), a unique molecule that can selectively target cancer cells solely based on their extracellular acidity. This delivery strategy potentially allows for more selective targeting to tumors than current methods and for anchoring the peptide mimic to the cytoplasmic leaflet of the plasma membrane, increasing its local concentration and thus efficacy. We show that the conjugated construct is capable of inhibiting EGFR phosphorylation and downstream signaling and of inducing concentration- and pH-dependent toxicity in cervical cancer cells. We envision that this approach could be expanded to the modulation of other single-span membrane receptors whose activity is mediated by JM domains.
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Affiliation(s)
- Janessa Gerhart
- Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Anastasia F. Thévenin
- Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Elizabeth Bloch
- Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Kelly E. King
- Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
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12
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Burns KE, Delehanty JB. Cellular delivery of doxorubicin mediated by disulfide reduction of a peptide-dendrimer bioconjugate. Int J Pharm 2018; 545:64-73. [PMID: 29709616 DOI: 10.1016/j.ijpharm.2018.04.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/08/2018] [Accepted: 04/13/2018] [Indexed: 02/07/2023]
Abstract
In this study, we developed a peptide-dendrimer-drug conjugate system for the pH-triggered direct cytosolic delivery of the cancer chemotherapeutic doxorubicin (DOX) using the pH Low Insertion Peptide (pHLIP). We synthesized a pHLIP-dendrimer-DOX conjugate in which a single copy of pHLIP displayed a generation three dendrimer bearing multiple copies of DOX via disulfide linkages. Biophysical analysis showed that both the dendrimer and a single DOX conjugate inserted into membrane bilayers in a pH-dependent manner. Time-resolved confocal microscopy indicate the single DOX conjugate may undergo a faster rate of membrane translocation, due to greater nuclear localization of DOX at 24 h and 48 h post delivery. At 72 h, however, the levels of DOX nuclear accumulation for both constructs were identical. Cytotoxicity assays revealed that both constructs mediated ∼80% inhibition of cellular proliferation at 10 µM, the dendrimer complex exhibited a 17% greater cytotoxic effect at lower concentrations and greater than three-fold improvement in IC50 over free DOX. Our findings show proof of concept that the dendrimeric display of DOX on the pHLIP carrier (1) facilitates the pH-dependent and temporally-controlled release of DOX to the cytosol, (2) eliminates the endosomal sequestration of the drug cargo, and (3) augments DOX cytotoxicity relative to the free drug.
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Affiliation(s)
- Kelly E Burns
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, Code 6900, Washington DC 20375, United States; National Research Council, Washington DC 20001, United States
| | - James B Delehanty
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, Code 6900, Washington DC 20375, United States.
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13
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Wyatt LC, Moshnikova A, Crawford T, Engelman DM, Andreev OA, Reshetnyak YK. Peptides of pHLIP family for targeted intracellular and extracellular delivery of cargo molecules to tumors. Proc Natl Acad Sci U S A 2018; 115:E2811-E2818. [PMID: 29507241 PMCID: PMC5866553 DOI: 10.1073/pnas.1715350115] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The pH (low) insertion peptides (pHLIPs) target acidity at the surfaces of cancer cells and show utility in a wide range of applications, including tumor imaging and intracellular delivery of therapeutic agents. Here we report pHLIP constructs that significantly improve the targeted delivery of agents into tumor cells. The investigated constructs include pHLIP bundles (conjugates consisting of two or four pHLIP peptides linked by polyethylene glycol) and Var3 pHLIPs containing either the nonstandard amino acid, γ-carboxyglutamic acid, or a glycine-leucine-leucine motif. The performance of the constructs in vitro and in vivo was compared with previous pHLIP variants. A wide range of experiments was performed on nine constructs including (i) biophysical measurements using steady-state and kinetic fluorescence, circular dichroism, and oriented circular dichroism to study the pH-dependent insertion of pHLIP variants across the membrane lipid bilayer; (ii) cell viability assays to gauge the pH-dependent potency of peptide-toxin constructs by assessing the intracellular delivery of the polar, cell-impermeable cargo molecule amanitin at physiological and low pH (pH 7.4 and 6.0, respectively); and (iii) tumor targeting and biodistribution measurements using fluorophore-peptide conjugates in a breast cancer mouse model. The main principles of the design of pHLIP variants for a range of medical applications are discussed.
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Affiliation(s)
- Linden C Wyatt
- Physics Department, University of Rhode Island, Kingston, RI 02881
| | - Anna Moshnikova
- Physics Department, University of Rhode Island, Kingston, RI 02881
| | - Troy Crawford
- Physics Department, University of Rhode Island, Kingston, RI 02881
| | - Donald M Engelman
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511
| | - Oleg A Andreev
- Physics Department, University of Rhode Island, Kingston, RI 02881;
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14
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Khan M, Huang T, Lin CY, Wu J, Fan BM, Bian ZX. Exploiting cancer's phenotypic guise against itself: targeting ectopically expressed peptide G-protein coupled receptors for lung cancer therapy. Oncotarget 2017; 8:104615-104637. [PMID: 29262666 PMCID: PMC5732832 DOI: 10.18632/oncotarget.18403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/23/2017] [Indexed: 02/07/2023] Open
Abstract
Lung cancer, claiming millions of lives annually, has the highest mortality rate worldwide. This advocates the development of novel cancer therapies that are highly toxic for cancer cells but negligibly toxic for healthy cells. One of the effective treatments is targeting overexpressed surface receptors of cancer cells with receptor-specific drugs. The receptors-in-focus in the current review are the G-protein coupled receptors (GPCRs), which are often overexpressed in various types of tumors. The peptide subfamily of GPCRs is the pivot of the current article owing to the high affinity and specificity to and of their cognate peptide ligands, and the proven efficacy of peptide-based therapeutics. The article summarizes various ectopically expressed peptide GPCRs in lung cancer, namely, Cholecystokinin-B/Gastrin receptor, the Bombesin receptor family, Bradykinin B1 and B2 receptors, Arginine vasopressin receptors 1a, 1b and 2, and the Somatostatin receptor type 2. The autocrine growth and pro-proliferative pathways they mediate, and the distinct tumor-inhibitory effects of somatostatin receptors are then discussed. The next section covers how these pathways may be influenced or 'corrected' through therapeutics (involving agonists and antagonists) targeting the overexpressed peptide GPCRs. The review proceeds on to Nano-scaled delivery platforms, which enclose chemotherapeutic agents and are decorated with peptide ligands on their external surface, as an effective means of targeting cancer cells. We conclude that targeting these overexpressed peptide GPCRs is potentially evolving as a highly promising form of lung cancer therapy.
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Affiliation(s)
- Mahjabin Khan
- Laboratory of Brain-Gut Research, School of Chinese Medicine, Hong Kong Baptist University, HKSAR, Kowloon Tong, P.R. China
| | - Tao Huang
- Laboratory of Brain-Gut Research, School of Chinese Medicine, Hong Kong Baptist University, HKSAR, Kowloon Tong, P.R. China
| | - Cheng-Yuan Lin
- Laboratory of Brain-Gut Research, School of Chinese Medicine, Hong Kong Baptist University, HKSAR, Kowloon Tong, P.R. China
- YMU-HKBU Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Kunming, P.R. China
| | - Jiang Wu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China
| | - Bao-Min Fan
- YMU-HKBU Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Kunming, P.R. China
| | - Zhao-Xiang Bian
- Laboratory of Brain-Gut Research, School of Chinese Medicine, Hong Kong Baptist University, HKSAR, Kowloon Tong, P.R. China
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15
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Vasquez-Montes V, Gerhart J, King KE, Thévenin D, Ladokhin AS. Comparison of lipid-dependent bilayer insertion of pHLIP and its P20G variant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:534-543. [PMID: 29138065 DOI: 10.1016/j.bbamem.2017.11.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 10/18/2017] [Accepted: 11/10/2017] [Indexed: 02/07/2023]
Abstract
The ability of the pH-Low Insertion Peptide (pHLIP) to insert into lipid membranes in a transbilayer conformation makes it an important tool for targeting acidic diseased tissues. pHLIP can also serve as a model template for thermodynamic studies of membrane insertion. We use intrinsic fluorescence and circular dichroism spectroscopy to examine the effect of replacing pHLIP's central proline on the pH-triggered lipid-dependent conformational switching of the peptide. We find that the P20G variant (pHLIP-P20G) has a higher helical propensity than the native pHLIP (pHLIP-WT), in both water:organic solvent mixtures and in the presence of lipid bilayers. Spectral shifts of tryptophan fluorescence reveal that with both pHLIP-WT and pHLIP-P20G, the deeply penetrating interfacial form (traditionally called State II) is populated only in pure phosphocholine bilayers. The presence of either anionic lipids or phosphatidylethanolamine leads to a much shallower penetration of the peptide (referred to here as State IIS, for "shallow"). This novel state can be differentiated from soluble state by a reduction in accessibility of tryptophans to acrylamide and by FRET to vesicles doped with Dansyl-PE, but not by a spectral shift in fluorescence emission. FRET experiments indicate free energies for interfacial partitioning range from 6.2 to 6.8kcal/mol and are marginally more favorable for pHLIP-P20G. The effective pKa for the insertion of both peptides depends on the lipid composition, but is always higher for pHLIP-P20G than for pHLIP-WT by approximately one pH unit, which corresponds to a difference of 1.3kcal/mol in free energy of protonation favoring insertion of pHLIP-P20G.
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Affiliation(s)
- Victor Vasquez-Montes
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, United States
| | - Janessa Gerhart
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, United States
| | - Kelly E King
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, United States
| | - Alexey S Ladokhin
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, United States.
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16
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Flaumenhaft R, De Ceunynck K. Targeting PAR1: Now What? Trends Pharmacol Sci 2017; 38:701-716. [PMID: 28558960 PMCID: PMC5580498 DOI: 10.1016/j.tips.2017.05.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 05/01/2017] [Accepted: 05/04/2017] [Indexed: 12/30/2022]
Abstract
Protease-activated receptors (PARs) are a ubiquitously expressed class of G-protein-coupled receptors (GPCRs) that enable cells to respond to proteases in the extracellular environment in a nuanced and dynamic manner. PAR1 is the archetypal family member and has been the object of large-scale drug development programs since the 1990s. Vorapaxar and drotrecogin-alfa are approved PAR1-targeted therapeutics, but safety concerns have limited the clinical use of vorapaxar and questions regarding the efficacy of drotrecogin-alfa led to its withdrawal from the market. New understanding of mechanisms of PAR1 function, discovery of improved strategies for modifying PAR1 function, and identification of novel indications for PAR1 modulators have provided new opportunities for therapies targeting PAR1. In this review, we critically evaluate prospects for the next generation of PAR1-targeted therapeutics.
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Affiliation(s)
- Robert Flaumenhaft
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
| | - Karen De Ceunynck
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
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17
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Applications of pHLIP Technology for Cancer Imaging and Therapy. Trends Biotechnol 2017; 35:653-664. [PMID: 28438340 DOI: 10.1016/j.tibtech.2017.03.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/24/2017] [Accepted: 03/29/2017] [Indexed: 12/14/2022]
Abstract
Acidity is a biomarker of cancer that is not subject to the blunting clonal selection effects that reduce the efficacy of other biomarker technologies, such as antibody targeting. The pH (low) insertion peptides (pHLIP®s) provide new opportunities for targeting acidic tissues. Through the physical mechanism of membrane-associated folding, pHLIPs are triggered by the acidic microenvironment to insert and span the membranes of tumor cells. The pHLIP platform can be applied to imaging acidic tissues, delivering cell-permeable and impermeable molecules to the cytoplasm, and promoting the cellular uptake of nanoparticles. Since acidosis is a hallmark of tumor development, progression, and aggressiveness, the pHLIP technology may prove useful in targeting cancer cells and metastases for tumor diagnosis, imaging, and therapy.
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18
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Burns KE, Hensley H, Robinson MK, Thévenin D. Therapeutic Efficacy of a Family of pHLIP-MMAF Conjugates in Cancer Cells and Mouse Models. Mol Pharm 2017; 14:415-422. [PMID: 28048942 DOI: 10.1021/acs.molpharmaceut.6b00847] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The targeting of therapeutics specifically to diseased tissue is crucial for the development of successful cancer treatments. The approach here is based on the pH(low) insertion peptide (pHLIP) for the delivery of a potent mitotic inhibitor monomethyl auristatin F (MMAF). We investigated six pHLIP variants conjugated to MMAF to compare their efficacy in vitro against cultured cancer cells. While all pHLIP-MMAF conjugates exhibit potent pH- and concentration-dependent killing, their cytotoxicity profiles are remarkably different. We also show that the lead conjugate exhibits significant therapeutic efficacy in mouse models without overt toxicities. This study confirms pHLIP-monomethyl auristatin conjugates as possible new therapeutic options for cancer treatment and supports their further development.
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Affiliation(s)
- Kelly E Burns
- Department of Chemistry, Lehigh University , 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
| | - Harvey Hensley
- Molecular Therapeutics Program, Fox Chase Cancer Center , 333 Cottman Avenue, Philadelphia, Pennsylvania 19111, United States
| | - Matthew K Robinson
- Molecular Therapeutics Program, Fox Chase Cancer Center , 333 Cottman Avenue, Philadelphia, Pennsylvania 19111, United States
| | - Damien Thévenin
- Department of Chemistry, Lehigh University , 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States
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19
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Narayanan T, Weerakkody D, Karabadzhak AG, Anderson M, Andreev OA, Reshetnyak YK. pHLIP Peptide Interaction with a Membrane Monitored by SAXS. J Phys Chem B 2016; 120:11484-11491. [PMID: 27726396 PMCID: PMC5209755 DOI: 10.1021/acs.jpcb.6b06643] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
pH (Low) Insertion Peptides (pHLIP peptides) find application in studies of membrane-associated folding because spontaneous insertion of these peptides is conveniently triggered by varying pH. Here, we employed small-angle X-ray scattering (SAXS) to investigate a wild-type (WT) pHLIP peptide oligomeric state in solution at high concentrations and monitor changes in the liposome structure upon peptide insertion into the bilayer. We established that even at high concentrations (up to 300 μM) the WT pHLIP peptide at pH 8.0 does not form oligomers larger than tetramers (which exhibit concentration-dependent transfer to the monomeric state, as was shown previously). This finding has significance for medical applications when high concentration of the peptide is injected into blood and diluted in blood circulation. The interaction of WT pHLIP peptide with liposomes does not alter the unilamellar vesicle structure upon peptide adsorption by the lipid bilayer at high pH or upon insertion across the bilayer at low pH. At the same time, SAXS data clearly demonstrate the insertion of the peptide into the membrane at low pH, which opens the possibility of investigating the kinetic process of polypeptide insertion and exit from the membrane in real time by time-resolved SAXS.
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Affiliation(s)
| | - Dhammika Weerakkody
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | | | - Michael Anderson
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Oleg A. Andreev
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Yana K. Reshetnyak
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
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20
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pH-Selective Cytotoxicity of pHLIP-Antimicrobial Peptide Conjugates. Sci Rep 2016; 6:28465. [PMID: 27334357 PMCID: PMC4917822 DOI: 10.1038/srep28465] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/02/2016] [Indexed: 01/10/2023] Open
Abstract
Positively charged antimicrobial peptides have become promising agents for the treatment of cancer by inducing apoptosis though their preferential binding and disruption of negatively charged membranes, such as the mitochondrial membrane. (KLAKLAK)2 is such a peptide but due to its polarity, it cannot cross the cellular membrane and therefore relies on the use of a delivery agent. For targeted delivery, previous studies have relied on cell penetrating peptides, nanoparticles or specific biomarkers. Herein, we investigated the first use of pHLIP to selectively target and directly translocate (KLAKLAK)2 into the cytoplasm of breast cancer cells, based on the acidic tumor micro-environment. With the goal of identifying a lead conjugate with optimized selective cytotoxicity towards cancer cells, we analyzed a family of (KLAKLAK)2 analogs with varying size, polarity and charge. We present a highly efficacious pHLIP conjugate that selectively induces concentration- and pH-dependent toxicity in breast cancer cells.
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