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Barile E, Marconi GD, De SK, Baggio C, Gambini L, Salem AF, Kashyap MK, Castro JE, Kipps TJ, Pellecchia M. hBfl-1/hNOXA Interaction Studies Provide New Insights on the Role of Bfl-1 in Cancer Cell Resistance and for the Design of Novel Anticancer Agents. ACS Chem Biol 2017; 12:444-455. [PMID: 28026162 PMCID: PMC5320539 DOI: 10.1021/acschembio.6b00962] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Upregulation of antiapoptotic Bcl-2 proteins in certain tumors confers cancer cell resistance to chemotherapy or radiations. Members of the antiapoptotic Bcl-2 proteins, including Bcl-2, Mcl-1, Bcl-xL, Bcl-w, and Bfl-1, inhibit apoptosis by selectively binding to conserved α-helical regions, named BH3 domains, of pro-apoptotic proteins such as Bim, tBid, Bad, or NOXA. Five antiapoptotic proteins have been identified that interact with various selectivity with BH3 containing pro-apoptotic counterparts. Cancer cells present various and variable levels of these proteins, making the design of effective apoptosis based therapeutics challenging. Recently, BH3 profiling was introduced as a method to classify cancer cells based on their ability to resist apoptosis following exposure to selected BH3 peptides. However, these studies were based on binding affinities measured with model BH3 peptides and Bcl-2-proteins taken from mouse sequences. While the majority of these interactions are conserved between mice and humans, we found surprisingly that human NOXA binds to human Bfl-1 potently and covalently via conserved Cys residues, with over 2 orders of magnitude increased affinity over hMcl-1. Our data suggest that some assumptions of the original BH3 profiling need to be revisited and that perhaps further targeting efforts should be redirected toward Bfl-1, for which no suitable specific inhibitors or pharmacological tools have been reported. In this regard, we also describe the initial design and characterizations of novel covalent BH3-based agents that potently target Bfl-1. These molecules could provide a novel platform on which to design effective Bfl-1 targeting therapeutics.
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Affiliation(s)
- Elisa Barile
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Guya D. Marconi
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Surya K. De
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Carlo Baggio
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Luca Gambini
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Ahmed F. Salem
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
| | - Manoj K. Kashyap
- Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
- CLL Research
Consortium, and Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Januario E. Castro
- Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
- CLL Research
Consortium, and Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Thomas J. Kipps
- Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
- CLL Research
Consortium, and Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Maurizio Pellecchia
- Division of Biomedical
Sciences, School of Medicine, University
of California, Riverside, 900 University Avenue, Riverside, California 92521, United States
- Phone: (951)-827-7829. E-mail:
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Lessene G. Close encounter of the covalent kind: Inhibiting MCL1's proapoptotic activity with covalent inhibitors. Cell Death Discov 2017; 3:16094. [PMID: 28179993 PMCID: PMC5253618 DOI: 10.1038/cddiscovery.2016.94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Affiliation(s)
- Guillaune Lessene
- Chemical Biology Division, The Walter and Eliza Hall Institute, Parkville, VIC, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, VIC, Australia
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Jenson JM, Ryan JA, Grant RA, Letai A, Keating AE. Epistatic mutations in PUMA BH3 drive an alternate binding mode to potently and selectively inhibit anti-apoptotic Bfl-1. eLife 2017; 6:e25541. [PMID: 28594323 PMCID: PMC5464773 DOI: 10.7554/elife.25541] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/16/2017] [Indexed: 01/07/2023] Open
Abstract
Overexpression of anti-apoptotic Bcl-2 family proteins contributes to cancer progression and confers resistance to chemotherapy. Small molecules that target Bcl-2 are used in the clinic to treat leukemia, but tight and selective inhibitors are not available for Bcl-2 paralog Bfl-1. Guided by computational analysis, we designed variants of the native BH3 motif PUMA that are > 150-fold selective for Bfl-1 binding. The designed peptides potently trigger disruption of the mitochondrial outer membrane in cells dependent on Bfl-1, but not in cells dependent on other anti-apoptotic homologs. High-resolution crystal structures show that designed peptide FS2 binds Bfl-1 in a shifted geometry, relative to PUMA and other binding partners, due to a set of epistatic mutations. FS2 modified with an electrophile reacts with a cysteine near the peptide-binding groove to augment specificity. Designed Bfl-1 binders provide reagents for cellular profiling and leads for developing enhanced and cell-permeable peptide or small-molecule inhibitors.
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Affiliation(s)
- Justin M Jenson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Jeremy A Ryan
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Robert A Grant
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Anthony Letai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States
| | - Amy E Keating
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States,Department of Biology, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States,
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Ludwig LM, Nassin ML, Hadji A, LaBelle JL. Killing Two Cells with One Stone: Pharmacologic BCL-2 Family Targeting for Cancer Cell Death and Immune Modulation. Front Pediatr 2016; 4:135. [PMID: 28066751 PMCID: PMC5174130 DOI: 10.3389/fped.2016.00135] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/30/2016] [Indexed: 12/31/2022] Open
Abstract
A crucial component of regulating organismal homeostasis is maintaining proper cell number and eliminating damaged or potentially malignant cells. Apoptosis, or programed cell death, is the mechanism responsible for this equilibrium. The intrinsic apoptotic pathway is also especially important in the development and maintenance of the immune system. Apoptosis is essential for proper positive and negative selection during B- and T-cell development and for efficient contraction of expanded lymphocytes following an immune response. Tight regulation of the apoptotic pathway is critical, as excessive cell death can lead to immunodeficiency while apoptotic resistance can lead to aberrant lymphoproliferation and autoimmune disease. Dysregulation of cell death is implicated in a wide range of hematological malignancies, and targeting various components of the apoptotic machinery in these cases is an attractive chemotherapeutic strategy. A wide array of compounds has been developed with the purpose of reactivating the intrinsic apoptotic pathway. These compounds, termed BH3 mimetics are garnering considerable attention as they gain greater clinical oncologic significance. As their use expands, it will be imperative to understand the effects these compounds have on immune homeostasis. Uncovering their potential immunomodulatory activity may allow for administration of BH3 mimetics for direct tumor cell killing as well as novel therapies for a wide range of immune-based directives. This review will summarize the major proteins involved in the intrinsic apoptotic pathway and define their roles in normal immune development and disease. Clinical and preclinical BH3 mimetics are described within the context of what is currently known about their ability to affect immune function. Prospects for future antitumor immune amplification and immune modulation are then proposed.
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Affiliation(s)
- Lindsey M Ludwig
- Section of Hematology, Oncology, Stem Cell Transplantation, Department of Pediatrics, University of Chicago, Comer Children's Hospital, Chicago, IL, USA; Committee on Cancer Biology, University of Chicago, Chicago, IL, USA
| | - Michele L Nassin
- Section of Hematology, Oncology, Stem Cell Transplantation, Department of Pediatrics, University of Chicago, Comer Children's Hospital , Chicago, IL , USA
| | - Abbas Hadji
- Section of Hematology, Oncology, Stem Cell Transplantation, Department of Pediatrics, University of Chicago, Comer Children's Hospital , Chicago, IL , USA
| | - James L LaBelle
- Section of Hematology, Oncology, Stem Cell Transplantation, Department of Pediatrics, University of Chicago, Comer Children's Hospital, Chicago, IL, USA; Committee on Cancer Biology, University of Chicago, Chicago, IL, USA
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