1
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Riaud M, Maxwell J, Soria-Bretones I, Dankner M, Li M, Rose AAN. The role of CRAF in cancer progression: from molecular mechanisms to precision therapies. Nat Rev Cancer 2024; 24:105-122. [PMID: 38195917 DOI: 10.1038/s41568-023-00650-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/27/2023] [Indexed: 01/11/2024]
Abstract
The RAF family of kinases includes key activators of the pro-tumourigenic mitogen-activated protein kinase pathway. Hyperactivation of RAF proteins, particularly BRAF and CRAF, drives tumour progression and drug resistance in many types of cancer. Although BRAF is the most studied RAF protein, partially owing to its high mutation incidence in melanoma, the role of CRAF in tumourigenesis and drug resistance is becoming increasingly clinically relevant. Here, we summarize the main known regulatory mechanisms and gene alterations that contribute to CRAF activity, highlighting the different oncogenic roles of CRAF, and categorize RAF1 (CRAF) mutations according to the effect on kinase activity. Additionally, we emphasize the effect that CRAF alterations may have on drug resistance and how precision therapies could effectively target CRAF-dependent tumours. Here, we discuss preclinical and clinical findings that may lead to improved treatments for all types of oncogenic RAF1 alterations in cancer.
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Affiliation(s)
- Melody Riaud
- Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
| | - Jennifer Maxwell
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Isabel Soria-Bretones
- Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Matthew Dankner
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Quebec, Canada
| | - Meredith Li
- Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec, Canada
| | - April A N Rose
- Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec, Canada.
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada.
- Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
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2
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Huang Y, Zhen Y, Chen Y, Sui S, Zhang L. Unraveling the interplay between RAS/RAF/MEK/ERK signaling pathway and autophagy in cancer: From molecular mechanisms to targeted therapy. Biochem Pharmacol 2023; 217:115842. [PMID: 37802240 DOI: 10.1016/j.bcp.2023.115842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/08/2023]
Abstract
RAS/RAF/MEK/ERK signaling pathway is one of the most important pathways of Mitogen-activated protein kinases (MAPK), which widely participate in regulating cell proliferation, differentiation, apoptosis and signaling transduction. Autophagy is an essential mechanism that maintains cellular homeostasis by degrading aged and damaged organelles. Recently, some studies revealed RAS/RAF/MEK/ERK signaling pathway is closely related to autophagy regulation and has a dual effect in tumor cells. However, the specific mechanism by which RAS/RAF/MEK/ERK signaling pathway participates in autophagy regulation is not fully understood. This article provides a comprehensive review of the research progress with regard to the RAS/RAF/MEK/ERK signaling pathway and autophagy, as well as their interplay in cancer therapy. The impact of small molecule inhibitors that target the RAS/RAF/MEK/ERK signaling pathway on autophagy is discussed in this study. The advantages and limitations of the clinical combination of these small molecule inhibitors with autophagy inhibitors are also explored. The findings from this study may provide additional perspectives for future cancer treatment strategies.
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Affiliation(s)
- Yunli Huang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Yongqi Zhen
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yanmei Chen
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shaoguang Sui
- Emergency Department, The Second Hospital, Dalian Medical University, Dalian 116000, China.
| | - Lan Zhang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
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3
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Singh S, Tian W, Severance ZC, Chaudhary SK, Anokhina V, Mondal B, Pergu R, Singh P, Dhawa U, Singha S, Choudhary A. Proximity-inducing modalities: the past, present, and future. Chem Soc Rev 2023; 52:5485-5515. [PMID: 37477631 DOI: 10.1039/d2cs00943a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Living systems use proximity to regulate biochemical processes. Inspired by this phenomenon, bifunctional modalities that induce proximity have been developed to redirect cellular processes. An emerging example of this class is molecules that induce ubiquitin-dependent proteasomal degradation of a protein of interest, and their initial development sparked a flurry of discovery for other bifunctional modalities. Recent advances in this area include modalities that can change protein phosphorylation, glycosylation, and acetylation states, modulate gene expression, and recruit components of the immune system. In this review, we highlight bifunctional modalities that perform functions other than degradation and have great potential to revolutionize disease treatment, while also serving as important tools in basic research to explore new aspects of biology.
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Affiliation(s)
- Sameek Singh
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Wenzhi Tian
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Zachary C Severance
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Santosh K Chaudhary
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Viktoriya Anokhina
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Basudeb Mondal
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Rajaiah Pergu
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Prashant Singh
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Uttam Dhawa
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Santanu Singha
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Amit Choudhary
- Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
- Divisions of Renal Medicine and Engineering, Brigham and Women's Hospital, Boston, MA 02115, USA
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4
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Liu X, Ciulli A. Proximity-Based Modalities for Biology and Medicine. ACS CENTRAL SCIENCE 2023; 9:1269-1284. [PMID: 37521793 PMCID: PMC10375889 DOI: 10.1021/acscentsci.3c00395] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Indexed: 08/01/2023]
Abstract
Molecular proximity orchestrates biological function, and blocking existing proximities is an established therapeutic strategy. By contrast, strengthening or creating neoproximity with chemistry enables modulation of biological processes with high selectivity and has the potential to substantially expand the target space. A plethora of proximity-based modalities to target proteins via diverse approaches have recently emerged, opening opportunities for biopharmaceutical innovation. This Outlook outlines the diverse mechanisms and molecules based on induced proximity, including protein degraders, blockers, and stabilizers, inducers of protein post-translational modifications, and agents for cell therapy, and discusses opportunities and challenges that the field must address to mature and unlock translation in biology and medicine.
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5
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Rohrer L, Spohr C, Beha C, Griffin R, Braun S, Halbach S, Brummer T. Analysis of RAS and drug induced homo- and heterodimerization of RAF and KSR1 proteins in living cells using split Nanoluc luciferase. Cell Commun Signal 2023; 21:136. [PMID: 37316874 DOI: 10.1186/s12964-023-01146-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 04/27/2023] [Indexed: 06/16/2023] Open
Abstract
The dimerization of RAF kinases represents a key event in their activation cycle and in RAS/ERK pathway activation. Genetic, biochemical and structural approaches provided key insights into this process defining RAF signaling output and the clinical efficacy of RAF inhibitors (RAFi). However, methods reporting the dynamics of RAF dimerization in living cells and in real time are still in their infancy. Recently, split luciferase systems have been developed for the detection of protein-protein-interactions (PPIs), incl. proof-of-concept studies demonstrating the heterodimerization of the BRAF and RAF1 isoforms. Due to their small size, the Nanoluc luciferase moieties LgBiT and SmBiT, which reconstitute a light emitting holoenzyme upon fusion partner promoted interaction, appear as well-suited to study RAF dimerization. Here, we provide an extensive analysis of the suitability of the Nanoluc system to study the homo- and heterodimerization of BRAF, RAF1 and the related KSR1 pseudokinase. We show that KRASG12V promotes the homo- and heterodimerization of BRAF, while considerable KSR1 homo- and KSR1/BRAF heterodimerization already occurs in the absence of this active GTPase and requires a salt bridge between the CC-SAM domain of KSR1 and the BRAF-specific region. We demonstrate that loss-of-function mutations impairing key steps of the RAF activation cycle can be used as calibrators to gauge the dynamics of heterodimerization. This approach identified the RAS-binding domains and the C-terminal 14-3-3 binding motifs as particularly critical for the reconstitution of RAF mediated LgBiT/SmBiT reconstitution, while the dimer interface was less important for dimerization but essential for downstream signaling. We show for the first time that BRAFV600E, the most common BRAF oncoprotein whose dimerization status is controversially portrayed in the literature, forms homodimers in living cells more efficiently than its wildtype counterpart. Of note, Nanoluc activity reconstituted by BRAFV600E homodimers is highly sensitive to the paradox-breaking RAFi PLX8394, indicating a dynamic and specific PPI. We report the effects of eleven ERK pathway inhibitors on RAF dimerization, incl. third-generation compounds that are less-defined in terms of their dimer promoting abilities. We identify Naporafenib as a potent and long-lasting dimerizer and show that the split Nanoluc approach discriminates between type I, I1/2 and II RAFi. Video Abstract.
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Affiliation(s)
- Lino Rohrer
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
| | - Corinna Spohr
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
| | - Carina Beha
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
| | - Ricarda Griffin
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
| | - Sandra Braun
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
| | - Sebastian Halbach
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany
- German Cancer Consortium (DKTK), Partner Site Freiburg and German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Tilman Brummer
- Institute of Molecular Medicine and Cell Research (IMMZ), Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Faculty of Medicine, University of Freiburg, Stefan-Meier-Str. 17, Freiburg, 79104, Germany.
- German Cancer Consortium (DKTK), Partner Site Freiburg and German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.
- Comprehensive Cancer Center Freiburg (CCCF), Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, 79106, Germany.
- Center for Biological Signalling Studies BIOSS, University of Freiburg, Freiburg, 79104, Germany.
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6
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Nadendla K, Simpson GG, Becher J, Journeaux T, Cabeza-Cabrerizo M, Bernardes GJL. Strategies for Conditional Regulation of Proteins. JACS AU 2023; 3:344-357. [PMID: 36873677 PMCID: PMC9975842 DOI: 10.1021/jacsau.2c00654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
Design of the next-generation of therapeutics, biosensors, and molecular tools for basic research requires that we bring protein activity under control. Each protein has unique properties, and therefore, it is critical to tailor the current techniques to develop new regulatory methods and regulate new proteins of interest (POIs). This perspective gives an overview of the widely used stimuli and synthetic and natural methods for conditional regulation of proteins.
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Affiliation(s)
- Karthik Nadendla
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
| | - Grant G. Simpson
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
| | - Julie Becher
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
| | - Toby Journeaux
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
| | - Mar Cabeza-Cabrerizo
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
| | - Gonçalo J. L. Bernardes
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, CB2 1EW, Cambridge, U.K.
- Instituto
de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
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7
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Zhao J, Luo Z. Discovery of Raf Family Is a Milestone in Deciphering the Ras-Mediated Intracellular Signaling Pathway. Int J Mol Sci 2022; 23:ijms23095158. [PMID: 35563547 PMCID: PMC9101324 DOI: 10.3390/ijms23095158] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 01/27/2023] Open
Abstract
The Ras-Raf-MEK-ERK signaling pathway, the first well-established MAPK pathway, plays essential roles in cell proliferation, survival, differentiation and development. It is activated in over 40% of human cancers owing to mutations of Ras, membrane receptor tyrosine kinases and other oncogenes. The Raf family consists of three isoforms, A-Raf, B-Raf and C-Raf. Since the first discovery of a truncated mutant of C-Raf as a transforming oncogene carried by a murine retrovirus, forty years of extensive studies have provided a wealth of information on the mechanisms underlying the activation, regulation and biological functions of the Raf family. However, the mechanisms by which activation of A-Raf and C-Raf is accomplished are still not completely understood. In contrast, B-Raf can be easily activated by binding of Ras-GTP, followed by cis-autophosphorylation of the activation loop, which accounts for the fact that this isoform is frequently mutated in many cancers, especially melanoma. The identification of oncogenic B-Raf mutations has led to accelerated drug development that targets Raf signaling in cancer. However, the effort has not proved as effective as anticipated, inasmuch as the mechanism of Raf activation involves multiple steps, factors and phosphorylation of different sites, as well as complex interactions between Raf isoforms. In this review, we will focus on the physiological complexity of the regulation of Raf kinases and their connection to the ERK phosphorylation cascade and then discuss the role of Raf in tumorigenesis and the clinical application of Raf inhibitors in the treatment of cancer.
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Affiliation(s)
- Jingtong Zhao
- Queen Mary School, Nanchang University, Nanchang 330031, China;
| | - Zhijun Luo
- Queen Mary School, Nanchang University, Nanchang 330031, China;
- Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Nanchang University, Nanchang 330031, China
- NCU-QMUL Joint Research Institute of Precision Medical Science, Nanchang 330031, China
- Correspondence:
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8
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Yap J, Deepak RNVK, Tian Z, Ng WH, Goh KC, Foo A, Tee ZH, Mohanam MP, Sim YRM, Degirmenci U, Lam P, Chen Z, Fan H, Hu J. The stability of R-spine defines RAF inhibitor resistance: A comprehensive analysis of oncogenic BRAF mutants with in-frame insertion of αC-β4 loop. SCIENCE ADVANCES 2021; 7:7/24/eabg0390. [PMID: 34108213 PMCID: PMC8189578 DOI: 10.1126/sciadv.abg0390] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
Although targeting BRAF mutants with RAF inhibitors has achieved promising outcomes in cancer therapy, drug resistance remains a remarkable challenge, and underlying molecular mechanisms are not fully understood. Here, we characterized a previously unknown group of oncogenic BRAF mutants with in-frame insertions (LLRins506 or VLRins506) of αC-β4 loop. Using structure modeling and molecular dynamics simulation, we found that these insertions formed a large hydrophobic network that stabilizes R-spine and thus triggers the catalytic activity of BRAF. Furthermore, these insertions disrupted BRAF dimer interface and impaired dimerization. Unlike BRAF(V600E), these BRAF mutants with low dimer affinity were strongly resistant to all RAF inhibitors in clinic or clinical trials, which arises from their stabilized R-spines. As predicted by molecular docking, the stabilized R-spines in other BRAF mutants also conferred drug resistance. Together, our data indicated that the stability of R-spine but not dimer affinity determines the RAF inhibitor resistance of oncogenic BRAF mutants.
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Affiliation(s)
- Jiajun Yap
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - R N V Krishna Deepak
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
| | - Zizi Tian
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wan Hwa Ng
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Kah Chun Goh
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Alicia Foo
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Zi Heng Tee
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Manju Payini Mohanam
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Yuen Rong M Sim
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Ufuk Degirmenci
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
| | - Paula Lam
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9, Singapore 117593, Singapore
- Cellvec Pte. Ltd., 100 Pasir Panjang Road, #04-02, Singapore 118518, Singapore
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Hao Fan
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore.
| | - Jiancheng Hu
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore.
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescen, Singapore 169610, Singapore
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9
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Morgan CW, Dale IL, Thomas AP, Hunt J, Chin JW. Selective CRAF Inhibition Elicits Transactivation. J Am Chem Soc 2021; 143:4600-4606. [PMID: 33750116 PMCID: PMC8041278 DOI: 10.1021/jacs.0c11958] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Discovering molecules that regulate
closely related protein isoforms
is challenging, and in many cases the consequences of isoform-specific
pharmacological regulation remains unknown. RAF isoforms are commonly
mutated oncogenes that serve as effector kinases in MAP kinase signaling.
BRAF/CRAF heterodimers are believed to be the primary RAF signaling
species, and many RAF inhibitors lead to a “paradoxical activation”
of RAF kinase activity through transactivation of the CRAF protomer;
this leads to resistance mechanisms and secondary tumors. It has been
hypothesized that CRAF-selective inhibition might bypass paradoxical
activation, but no CRAF-selective inhibitor has been reported and
the consequences of pharmacologically inhibiting CRAF have remained
unknown. Here, we use bio-orthogonal ligand tethering (BOLT) to selectively
target inhibitors to CRAF. Our results suggest that selective CRAF
inhibition promotes paradoxical activation and exemplify how BOLT
may be used to triage potential targets for drug discovery before
any target-selective small molecules are known.
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Affiliation(s)
- Charles W Morgan
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ian L Dale
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - Andrew P Thomas
- Medicinal Chemistry, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - James Hunt
- Antibody Discovery & Protein Engineering, R&D, AstraZeneca, Cambridge CB21 6GH, United Kingdom
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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10
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Cook FA, Cook SJ. Inhibition of RAF dimers: it takes two to tango. Biochem Soc Trans 2021; 49:237-251. [PMID: 33367512 PMCID: PMC7924995 DOI: 10.1042/bst20200485] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
The RAS-regulated RAF-MEK1/2-ERK1/2 pathway promotes cell proliferation and survival and RAS and BRAF proteins are commonly mutated in cancer. This has fuelled the development of small molecule kinase inhibitors including ATP-competitive RAF inhibitors. Type I and type I½ ATP-competitive RAF inhibitors are effective in BRAFV600E/K-mutant cancer cells. However, in RAS-mutant cells these compounds instead promote RAS-dependent dimerisation and paradoxical activation of wild-type RAF proteins. RAF dimerisation is mediated by two key regions within each RAF protein; the RKTR motif of the αC-helix and the NtA-region of the dimer partner. Dimer formation requires the adoption of a closed, active kinase conformation which can be induced by RAS-dependent activation of RAF or by the binding of type I and I½ RAF inhibitors. Binding of type I or I½ RAF inhibitors to one dimer partner reduces the binding affinity of the other, thereby leaving a single dimer partner uninhibited and able to activate MEK. To overcome this paradox two classes of drug are currently under development; type II pan-RAF inhibitors that induce RAF dimer formation but bind both dimer partners thus allowing effective inhibition of both wild-type RAF dimer partners and monomeric active class I mutant RAF, and the recently developed "paradox breakers" which interrupt BRAF dimerisation through disruption of the αC-helix. Here we review the regulation of RAF proteins, including RAF dimers, and the progress towards effective targeting of the wild-type RAF proteins.
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Affiliation(s)
- Frazer A. Cook
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, U.K
| | - Simon J. Cook
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, U.K
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11
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The 14-3-3 Proteins as Important Allosteric Regulators of Protein Kinases. Int J Mol Sci 2020; 21:ijms21228824. [PMID: 33233473 PMCID: PMC7700312 DOI: 10.3390/ijms21228824] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/20/2020] [Accepted: 11/20/2020] [Indexed: 12/14/2022] Open
Abstract
Phosphorylation by kinases governs many key cellular and extracellular processes, such as transcription, cell cycle progression, differentiation, secretion and apoptosis. Unsurprisingly, tight and precise kinase regulation is a prerequisite for normal cell functioning, whereas kinase dysregulation often leads to disease. Moreover, the functions of many kinases are regulated through protein–protein interactions, which in turn are mediated by phosphorylated motifs and often involve associations with the scaffolding and chaperon protein 14-3-3. Therefore, the aim of this review article is to provide an overview of the state of the art on 14-3-3-mediated kinase regulation, focusing on the most recent mechanistic insights into these important protein–protein interactions and discussing in detail both their structural aspects and functional consequences.
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12
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Degirmenci U, Wang M, Hu J. Targeting Aberrant RAS/RAF/MEK/ERK Signaling for Cancer Therapy. Cells 2020; 9:E198. [PMID: 31941155 PMCID: PMC7017232 DOI: 10.3390/cells9010198] [Citation(s) in RCA: 281] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 12/29/2019] [Accepted: 01/10/2020] [Indexed: 12/13/2022] Open
Abstract
The RAS/RAF/MEK/ERK (MAPK) signaling cascade is essential for cell inter- and intra-cellular communication, which regulates fundamental cell functions such as growth, survival, and differentiation. The MAPK pathway also integrates signals from complex intracellular networks in performing cellular functions. Despite the initial discovery of the core elements of the MAPK pathways nearly four decades ago, additional findings continue to make a thorough understanding of the molecular mechanisms involved in the regulation of this pathway challenging. Considerable effort has been focused on the regulation of RAF, especially after the discovery of drug resistance and paradoxical activation upon inhibitor binding to the kinase. RAF activity is regulated by phosphorylation and conformation-dependent regulation, including auto-inhibition and dimerization. In this review, we summarize the recent major findings in the study of the RAS/RAF/MEK/ERK signaling cascade, particularly with respect to the impact on clinical cancer therapy.
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Affiliation(s)
- Ufuk Degirmenci
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescent, Singapore 169610, Singapore
| | - Mei Wang
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Jiancheng Hu
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Crescent, Singapore 169610, Singapore
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
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13
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Barklis E, Stephen AG, Staubus AO, Barklis RL, Alfadhli A. Organization of Farnesylated, Carboxymethylated KRAS4B on Membranes. J Mol Biol 2019; 431:3706-3717. [PMID: 31330153 PMCID: PMC6733658 DOI: 10.1016/j.jmb.2019.07.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/10/2019] [Accepted: 07/12/2019] [Indexed: 11/24/2022]
Abstract
Mutations of the Ras proteins HRAS, KRAS4A, KRAS4B, and NRAS are associated with a high percentage of all human cancers. The proteins are composed of highly homologous N-terminal catalytic or globular domains, plus C-terminal hypervariable regions (HVRs). Post-translational modifications of all RAS HVRs helps target RAS proteins to cellular membrane locations where they perform their signaling functions. For the predominant KRAS4 isoform, KRAS4B, post-translational farnesylation and carboxymethylation, along with a patch of HVR basic residues help foster membrane binding. Recent investigations implicate membrane-bound RAS dimers, oligomers, and nanoclusters as landing pads for effector proteins that relay RAS signals. The details of these RAS signaling platforms have not been elucidated completely, in part due to the difficulties in preparing modified proteins. We have employed properly farnesylated and carboxymethylated KRAS4B in lipid monolayer incubations to examine how the proteins assemble on membranes. Our results reveal novel insights into to how KRAS4B may organize on membranes.
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Affiliation(s)
- Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA.
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21072, USA
| | - August O Staubus
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
| | - Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health & Sciences University, 3181 SW Sam Jackson Park Road, Portland, 97239, OR, USA
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14
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Deng Y, Jiang B, Rankin CL, Toyo-Oka K, Richter ML, Maupin-Furlow JA, Moskovitz J. Methionine sulfoxide reductase A (MsrA) mediates the ubiquitination of 14-3-3 protein isotypes in brain. Free Radic Biol Med 2018; 129:600-607. [PMID: 30096435 PMCID: PMC6249068 DOI: 10.1016/j.freeradbiomed.2018.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022]
Abstract
The methionine sulfoxide reductase (Msr) system is known for its function in reducing protein-methionine sulfoxide to methionine. Recently, we showed that one member of the Msr system, MsrA, is involved in the ubiquitination-like process in Archaea. Here, the mammalian MsrA is demonstrated to mediate the ubiquitination of the 14-3-3 zeta protein and to promote the binding of 14-3-3 proteins to alpha synuclein in brain. MsrA was also found to enhance the ubiquitination and phosphorylation of Ser129 of alpha synuclein in brain. Furthermore, we demonstrate that, similarly to the archaeal MsrA, the mammalian MsrA can compete for capturing ubiquitin using the same active site it contains for methionine sulfoxide binding. Based on our previous observations showing that MsrA knockout mice have elevated expression levels of dopamine and 14-3-3 zeta and our current data, we propose that MsrA-dependent 14-3-3 zeta ubiquitination affects the regulation of alpha synuclein degradation and dopamine synthesis in the brain.
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Affiliation(s)
- Yue Deng
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Beichen Jiang
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Carolyn L Rankin
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, 66045, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Kazuhito Toyo-Oka
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Room 186, Philadelphia, PA 19129, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Mark L Richter
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, 66045, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Julie A Maupin-Furlow
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Room 186, Philadelphia, PA 19129, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA
| | - Jackob Moskovitz
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611-0700, USA.
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15
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Hymowitz SG, Malek S. Targeting the MAPK Pathway in RAS Mutant Cancers. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031492. [PMID: 29440321 DOI: 10.1101/cshperspect.a031492] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Despite decades of extensive drug discovery efforts, there are currently no targeted therapies approved to treat KRAS mutant cancers. In this review, we highlight the challenges and opportunities in targeting KRAS mutant tumors through inhibition of mitogen-activated protein kinase (MAPK) signaling with conformation-specific kinase inhibitors. Through structural analysis and mechanistic studies with BRAF and mitogen-activated protein kinase (MEK) inhibitors, we describe how kinase-dependent and -independent functions of MAPK signaling components regulate KRAS-driven tumorigenesis and how these insights can be used to treat RAS mutant cancers with small molecule kinase inhibitors.
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Affiliation(s)
- Sarah G Hymowitz
- Department of Structural Biology, Genentech Inc., South San Francisco, California 94080
| | - Shiva Malek
- Department of Discovery Oncology, Genentech Inc., South San Francisco, California 94080
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16
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Ammar UM, Abdel-Maksoud MS, Oh CH. Recent advances of RAF (rapidly accelerated fibrosarcoma) inhibitors as anti-cancer agents. Eur J Med Chem 2018; 158:144-166. [PMID: 30216849 DOI: 10.1016/j.ejmech.2018.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 09/01/2018] [Accepted: 09/03/2018] [Indexed: 12/19/2022]
Abstract
Frequent oncogenic mutations have been identified in MAPK (mitogen-activated protein kinase) signaling pathway components. As a result, MAPK pathway is associated with human cancer initiation, in particular RAF (rapidly accelerated fibrosarcoma) component. The mutation in RAF component leads to auto-activation of MAPK signaling pathway, stimulating the uncontrolled cell growth and proliferation. In last few years, diverse chemical scaffolds have been identified as RAF inhibitors. Most of these scaffolds show potent anti-cancer activity. The present review highlights the recent investigations of RAF inhibitors during the last five years.
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Affiliation(s)
- Usama M Ammar
- Center for Biomaterials, Korea Institute of Science & Technology (KIST), Seoul, Seongbuk-gu, 02792, Republic of Korea; Department of Biomolecular Science, University of Science & Technology (UST), Daejeon, Yuseong-gu, 34113, Republic of Korea; Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ahram Canadian University, Giza, 12566, Egypt
| | - Mohammed S Abdel-Maksoud
- Medicinal & Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Division, National Research Centre (NRC), Dokki, Giza, 12622, Egypt
| | - Chang-Hyun Oh
- Center for Biomaterials, Korea Institute of Science & Technology (KIST), Seoul, Seongbuk-gu, 02792, Republic of Korea; Department of Biomolecular Science, University of Science & Technology (UST), Daejeon, Yuseong-gu, 34113, Republic of Korea.
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17
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Cermakova K, Hodges HC. Next-Generation Drugs and Probes for Chromatin Biology: From Targeted Protein Degradation to Phase Separation. Molecules 2018; 23:molecules23081958. [PMID: 30082609 PMCID: PMC6102721 DOI: 10.3390/molecules23081958] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/01/2018] [Accepted: 08/01/2018] [Indexed: 12/31/2022] Open
Abstract
Chromatin regulation is a critical aspect of nuclear function. Recent advances have provided detailed information about dynamic three-dimensional organization of chromatin and its regulatory factors. Mechanisms crucial for normal nuclear function and epigenetic control include compartmentalization of biochemical reactions by liquid-phase separated condensates and signal-dependent regulation of protein stability. Synthetic control of these phenomena by small molecules provides deep insight into essential activities such as histone modification, BAF (SWI/SNF) and PBAF remodeling, Polycomb repression, enhancer looping by cohesin and CTCF, as well as many other processes that contribute to transcription. As a result, a complete understanding of the spatiotemporal mechanisms that underlie chromatin regulation increasingly requires the use of fast-acting drugs and chemical probes. Here, we provide a comprehensive review of next-generation chemical biology tools to interrogate the chromatin regulatory landscape, including selective PROTAC E3 ubiquitin ligase degraders, degrons, fluorescent ligands, dimerizers, inhibitors, and other drugs. These small molecules provide important insights into the mechanisms that govern gene regulation, DNA repair, development, and diseases like cancer.
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Affiliation(s)
- Katerina Cermakova
- Department of Molecular & Cellular Biology, Center for Precision Environmental Health, and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA.
| | - H Courtney Hodges
- Department of Molecular & Cellular Biology, Center for Precision Environmental Health, and Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA.
- Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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18
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Schneider T, Martinez-Martinez A, Cubillos-Rojas M, Bartrons R, Ventura F, Rosa JL. The E3 ubiquitin ligase HERC1 controls the ERK signaling pathway targeting C-RAF for degradation. Oncotarget 2018; 9:31531-31548. [PMID: 30140388 PMCID: PMC6101136 DOI: 10.18632/oncotarget.25847] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 07/12/2018] [Indexed: 12/14/2022] Open
Abstract
The RAF/MEK/ERK cascade is a conserved intracellular signaling pathway that controls fundamental cellular processes including growth, proliferation, differentiation, survival and migration. Aberrant regulation of this signaling pathway has long been associated with human cancers. A major point of regulation of this pathway occurs at the level of the serine/threonine protein kinase C-RAF. Here, we show how the E3 ubiquitin ligase HERC1 regulates ERK signaling. HERC1 knockdown induced cellular proliferation, which is associated with an increase in ERK phosphorylation and in C-RAF protein levels. We demonstrate that overexpression of wild-type C-RAF is sufficient to increase ERK phosphorylation. Experiments with pharmacological inhibitors of RAF activity, or with interference RNA, show that the regulation of ERK phosphorylation by HERC1 is RAF-dependent. Immunoprecipitation, pull-down and confocal fluorescence microscopy experiments demonstrate an interaction between HERC1 and C-RAF proteins. Mechanistically, HERC1 controls C-RAF stability by regulating its polyubiquitylation in a lysine 48-linked chain. In vitro ubiquitylation assays indicate that C-RAF is a substrate of the E3 ubiquitin ligase HERC1. Altogether, we show how HERC1 can regulate cell proliferation through the activation of ERK signaling by a mechanism that affects C-RAF’s stability.
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Affiliation(s)
- Taiane Schneider
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Arturo Martinez-Martinez
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Monica Cubillos-Rojas
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Ramon Bartrons
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Francesc Ventura
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jose Luis Rosa
- Departament de Ciències Fisiològiques, IDIBELL, Campus Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
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19
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Yuan J, Ng WH, Yap J, Chia B, Huang X, Wang M, Hu J. The AMPK inhibitor overcomes the paradoxical effect of RAF inhibitors through blocking phospho-Ser-621 in the C terminus of CRAF. J Biol Chem 2018; 293:14276-14284. [PMID: 30030377 PMCID: PMC6139560 DOI: 10.1074/jbc.ra118.004597] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/17/2018] [Indexed: 11/15/2022] Open
Abstract
The dimerization-driven paradoxical activation of RAF proto-oncogene Ser/Thr kinase (RAF) is the predominant cause of drug resistance and toxicity in cancer therapies with RAF inhibitors. The scaffold protein 14-3-3, which binds to the RAF C terminus, is essential for RAF activation under physiological conditions, but the molecular basis is unclear. Here we investigated whether and how 14-3-3 regulates the dimerization-driven transactivation of the RAF isoform CRAF by RAF inhibitors and affects drug resistance and toxicity by virtue of the dominant role of CRAF in these processes. We demonstrated that 14-3-3 enhances the dimerization-driven transactivation of CRAF by stabilizing CRAF dimers. Further, we identified AMP-activated protein kinase (AMPK) and CRAF itself as two putative kinases that redundantly phosphorylate CRAF's C terminus and thereby control its association with 14-3-3. Next, we determined whether the combinatory inhibition of AMPK and CRAF could overcome the paradoxical effect of RAF inhibitors. We found that the AMPK inhibitor (AMPKi) not only blocked the RAF inhibitor–driven paradoxical activation of ERK signaling and cellular overgrowth in Ras-mutated cancer cells by blocking phosphorylation of Ser-621 in CRAF but also reduced the formation of drug-resistant clones of BRAFV600E-mutated cancer cells. Last, we investigated whether 14-3-3 binding to the C terminus of CRAF is required for CRAF catalytic activity and observed that it was dispensable in vivo. Altogether, our study unravels the molecular mechanism by which 14-3-3 regulates dimerization-driven RAF activation and identified AMPKi as a potential agent to counteract drug resistance and adverse effects of RAF inhibitors in cancer therapies.
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Affiliation(s)
- Jimin Yuan
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and
| | - Wan Hwa Ng
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and
| | - Jiajun Yap
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and
| | - Brandon Chia
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and
| | - Xuchao Huang
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and
| | - Mei Wang
- the Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Jiancheng Hu
- From the Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore and .,the Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
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20
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Yuan J, Ng WH, Lam PYP, Wang Y, Xia H, Yap J, Guan SP, Lee ASG, Wang M, Baccarini M, Hu J. The dimer-dependent catalytic activity of RAF family kinases is revealed through characterizing their oncogenic mutants. Oncogene 2018; 37:5719-5734. [PMID: 29930381 PMCID: PMC6202329 DOI: 10.1038/s41388-018-0365-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 05/18/2018] [Accepted: 05/21/2018] [Indexed: 12/19/2022]
Abstract
Although extensively studied for three decades, the molecular mechanisms that regulate the RAF/MEK/ERK kinase cascade remain ambiguous. Recent studies identified the dimerization of RAF as a key event in the activation of this cascade. Here, we show that in-frame deletions in the β3-αC loop activate ARAF as well as BRAF and other oncogenic kinases by enforcing homodimerization. By characterizing these RAF mutants, we find that ARAF has less allosteric and catalytic activity than the other two RAF isoforms, which arises from its non-canonical APE motif. Further, these RAF mutants exhibit a strong oncogenic potential, and a differential inhibitor resistance that correlates with their dimer affinity. Using these unique mutants, we demonstrate that active RAFs, including the BRAF(V600E) mutant, phosphorylate MEK in a dimer-dependent manner. This study characterizes a special category of oncogenic kinase mutations, and elucidates the molecular basis that underlies the differential ability of RAF isoforms to stimulate MEK-ERK pathway. Further, this study reveals a unique catalytic feature of RAF family kinases that can be exploited to control their activities for cancer therapies.
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Affiliation(s)
- Jimin Yuan
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Wan Hwa Ng
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Paula Y P Lam
- Division of Cellular and Molecular Research, Singapore, Singapore.,Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, 169857, Singapore, Singapore
| | - Yu Wang
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Hongping Xia
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Jiajun Yap
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Shou Ping Guan
- Division of Cellular and Molecular Research, Singapore, Singapore
| | - Ann S G Lee
- Division of Medical Sciences, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore.,Office of Clinical & Academic Faculty Affairs, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.,Department of Physiology, National University of Singapore, 2 Medical Drive, 117597, Singapore, Singapore
| | - Mei Wang
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, 169857, Singapore, Singapore
| | - Manuela Baccarini
- Max F. Perutz Laboratories, University of Vienna, Doktor-Bohr-Gasse 9, 1030, Vienna, Austria
| | - Jiancheng Hu
- Division of Cellular and Molecular Research, Singapore, Singapore. .,Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, 169857, Singapore, Singapore.
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21
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Stanton BZ, Chory EJ, Crabtree GR. Chemically induced proximity in biology and medicine. Science 2018; 359:359/6380/eaao5902. [PMID: 29590011 DOI: 10.1126/science.aao5902] [Citation(s) in RCA: 226] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Proximity, or the physical closeness of molecules, is a pervasive regulatory mechanism in biology. For example, most posttranslational modifications such as phosphorylation, methylation, and acetylation promote proximity of molecules to play deterministic roles in cellular processes. To understand the role of proximity in biologic mechanisms, chemical inducers of proximity (CIPs) were developed to synthetically model biologically regulated recruitment. Chemically induced proximity allows for precise temporal control of transcription, signaling cascades, chromatin regulation, protein folding, localization, and degradation, as well as a host of other biologic processes. A systematic analysis of CIPs in basic research, coupled with recent technological advances utilizing CRISPR, distinguishes roles of causality from coincidence and allows for mathematical modeling in synthetic biology. Recently, induced proximity has provided new avenues of gene therapy and emerging advances in cancer treatment.
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Affiliation(s)
- Benjamin Z Stanton
- Departments of Pathology and Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Emma J Chory
- Departments of Pathology and Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Gerald R Crabtree
- Departments of Pathology and Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA. .,Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
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22
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Abstract
Metastatic melanoma is associated with poor outcome and is largely refractory to the historic standard of care. In recent years, the development of targeted small-molecule inhibitors and immunotherapy has revolutionised the care and improved the overall survival of these patients. Therapies targeting BRAF and MEK to block the mitogen-activated protein kinase (MAPK) pathway were the first to show unprecedented clinical responses. Following these encouraging results, antibodies targeting immune checkpoint inhibition molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death (PD)-1, and PD-ligand1(PD-L1) demonstrated sustained tumour regression in a significant subset of patients by enabling an anti-tumour immunologic response. Despite these landmark changes in practice, the majority of patients are either intrinsically resistant or rapidly acquire resistance to MAPK pathway inhibitors and immune checkpoint blockade treatment. The lack of response can be driven by mutations and non-mutational events in tumour cells, as well as by changes in the surrounding tumour microenvironment. Common resistance mechanisms bypass the dependence of tumour cells on initial MAPK pathway driver mutations during targeted therapy, and permit evasion of the host immune system to allow melanoma growth and survival following immunotherapy. This highlights the requirement for personalised treatment regimens that take into account patient-specific genetic and immunologic characteristics. Here we review the mechanisms by which melanomas display intrinsic resistance or acquire resistance to targeted therapy and immunotherapy.
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Affiliation(s)
- Matthew Winder
- Skin Cancer and Ageing, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK
| | - Amaya Virós
- Skin Cancer and Ageing, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK. .,Salford Royal NHS Foundation Trust, Manchester, UK.
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23
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Chen M, Peters A, Huang T, Nan X. Ras Dimer Formation as a New Signaling Mechanism and Potential Cancer Therapeutic Target. Mini Rev Med Chem 2016; 16:391-403. [PMID: 26423697 PMCID: PMC5421135 DOI: 10.2174/1389557515666151001152212] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/31/2015] [Accepted: 09/18/2015] [Indexed: 12/12/2022]
Abstract
The K-, N-, and HRas small GTPases are key regulators of cell physiology and are frequently mutated in human cancers. Despite intensive research, previous efforts to target hyperactive Ras based on known mechanisms of Ras signaling have been met with little success. Several studies have provided compelling evidence for the existence and biological relevance of Ras dimers, establishing a new mechanism for regulating Ras activity in cells additionally to GTP-loading and membrane localization. Existing data also start to reveal how Ras proteins dimerize on the membrane. We propose a dimer model to describe Ras-mediated effector activation, which contrasts existing models of Ras signaling as a monomer or as a 5-8 membered multimer. We also discuss potential implications of this model in both basic and translational Ras biology.
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Affiliation(s)
| | | | | | - Xiaolin Nan
- Department of Biomedical Engineering, Knight Cancer Institute, and OHSU Center for Spatial Systems Biomedicine (OCSSB), Oregon Health and Science University, Portland, OR.
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24
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Mitra S, Ghosh B, Gayen N, Roy J, Mandal AK. Bipartite Role of Heat Shock Protein 90 (Hsp90) Keeps CRAF Kinase Poised for Activation. J Biol Chem 2016; 291:24579-24593. [PMID: 27703006 DOI: 10.1074/jbc.m116.746420] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/21/2016] [Indexed: 01/27/2023] Open
Abstract
CRAF kinase maintains cell viability, growth, and proliferation by participating in the MAPK pathway. Unlike BRAF, CRAF requires continuous chaperoning by Hsp90 to retain MAPK signaling. However, the reason behind the continuous association of Hsp90 with CRAF is still elusive. In this study, we have identified the bipartite role of Hsp90 in chaperoning CRAF kinase. Hsp90 facilitates Ser-621 phosphorylation of CRAF and prevents the kinase from degradation. Co-chaperone Cdc37 assists in this phosphorylation event. However, after folding, the stability of the kinase becomes insensitive to Hsp90 inhibition, although the physical association between Hsp90 and CRAF remains intact. We observed that overexpression of Hsp90 stimulates MAPK signaling by activating CRAF. The interaction between Hsp90 and CRAF is substantially increased under an elevated level of cellular Hsp90 and in the presence of either active Ras (RasV12) or EGF. Surprisingly, enhanced binding of Hsp90 to CRAF occurs prior to the Ras-CRAF association and facilitates actin recruitment to CRAF for efficient Ras-CRAF interaction, which is independent of the ATPase activity of Hsp90. However, monomeric CRAF (CRAFR401H) shows abrogated interaction with both Hsp90 and actin, thereby affecting Hsp90-dependent CRAF activation. This finding suggests that stringent assemblage of Hsp90 keeps CRAF kinase equipped for participating in the MAPK pathway. Thus, the role of Hsp90 in CRAF maturation and activation acts as a limiting factor to maintain the function of a strong client like CRAF kinase.
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Affiliation(s)
- Shahana Mitra
- From the Division of Molecular Medicine, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Baijayanti Ghosh
- From the Division of Molecular Medicine, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Nilanjan Gayen
- From the Division of Molecular Medicine, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Joydeep Roy
- From the Division of Molecular Medicine, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Atin K Mandal
- From the Division of Molecular Medicine, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India.
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25
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de Langen AJ, Smit EF. Therapeutic approach to treating patients with BRAF-mutant lung cancer: latest evidence and clinical implications. Ther Adv Med Oncol 2016; 9:46-58. [PMID: 28203297 DOI: 10.1177/1758834016670555] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lung adenocarcinoma is known for its high rate of somatic mutations and genomic rearrangements. The identification of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements that sensitize tumors to specific drugs has changed the therapeutic approach and prognosis in these molecularly-defined subgroups. Several other key genetic alterations have been identified, of which BRAF mutations are found in 4% of non-small cell lung cancer (NSCLC) cases. Targeted drugs against BRAF and downstream MEK were recently approved for the treatment of BRAF-positive melanoma and have entered clinical evaluation in NSCLC. In this review we discuss the latest evidence on the treatment of BRAF-mutated NSCLC, including tumor biology, targeted treatment with BRAF and MEK inhibitors, therapeutic resistance and strategies to overcome resistance.
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Affiliation(s)
- Adrianus J de Langen
- Department of Pulmonary Diseases, VU University Medical Center, De Boelelaan 1117, 1007 MB Amsterdam, The Netherlands
| | - Egbert F Smit
- Department of Pulmonary Diseases, VU University Medical Center, and Department of Thoracic Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
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26
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JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships. Microbiol Mol Biol Rev 2016; 80:793-835. [PMID: 27466283 DOI: 10.1128/mmbr.00043-14] [Citation(s) in RCA: 309] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states.
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27
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Zhang L, Wang X, Lai M. Modulation of epithelial-to-mesenchymal cancerous transition by natural products. Fitoterapia 2015; 106:247-55. [PMID: 26386389 DOI: 10.1016/j.fitote.2015.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/13/2015] [Accepted: 09/15/2015] [Indexed: 12/11/2022]
Abstract
Metastasis is mainly responsible for poor prognosis of cancer, and epithelial-to-mesenchymal transition (EMT) is a significant process often activated during cancer invasion and metastasis. Therefore EMT could be an effective target of chemotherapy to inhibit cancer metastasis and improve prognosis. Considering that many chemotherapeutics are plant-based, we reviewed recent reports about natural products extracted from plants and cancer EMT prevention.
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Affiliation(s)
- Lei Zhang
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
| | - Xue Wang
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
| | - Maode Lai
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China; Department of Pathology, School of Medicine, Zhejiang University, Hangzhou 310058, China.
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28
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Yao Z, Torres NM, Tao A, Gao Y, Luo L, Li Q, de Stanchina E, Abdel-Wahab O, Solit DB, Poulikakos PI, Rosen N. BRAF Mutants Evade ERK-Dependent Feedback by Different Mechanisms that Determine Their Sensitivity to Pharmacologic Inhibition. Cancer Cell 2015; 28:370-83. [PMID: 26343582 PMCID: PMC4894664 DOI: 10.1016/j.ccell.2015.08.001] [Citation(s) in RCA: 339] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 07/21/2015] [Accepted: 08/03/2015] [Indexed: 12/29/2022]
Abstract
ERK signaling requires RAS-induced RAF dimerization and is limited by feedback. Activated BRAF mutants evade feedback inhibition of RAS by either of two mechanisms. BRAF V600 mutants are activated monomers when RAS activity is low; all other activating BRAF mutants function as constitutive RAS-independent dimers. RAF inhibitors effectively inhibit mutant monomers, but not dimers; their binding to one site in the dimer significantly reduces their affinity for the second. Tumors with non-V600E BRAF mutants are insensitive to these drugs, and increased expression of BRAF V600E dimers causes acquired resistance. A compound that equally inhibits both sites of mutant RAF dimers inhibits tumors driven by either class of mutants or those BRAF V600E tumors with dimer-dependent acquired resistance to monomer-specific inhibitors.
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Affiliation(s)
- Zhan Yao
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Neilawattie M Torres
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Anthony Tao
- College of Arts and Sciences, New York University, New York, NY 10003, USA
| | - Yijun Gao
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Lusong Luo
- BeiGene (Beijing) Co., Ltd., No. 30 Science Park Road, Zhong-Guan-Cun Life Science Park, Changping District, Beijing 102206, China
| | - Qi Li
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Elisa de Stanchina
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Omar Abdel-Wahab
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - David B Solit
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | | | - Neal Rosen
- Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Center for Mechanism Based Therapeutics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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29
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Peng SB, Henry JR, Kaufman MD, Lu WP, Smith BD, Vogeti S, Rutkoski TJ, Wise S, Chun L, Zhang Y, Van Horn RD, Yin T, Zhang X, Yadav V, Chen SH, Gong X, Ma X, Webster Y, Buchanan S, Mochalkin I, Huber L, Kays L, Donoho GP, Walgren J, McCann D, Patel P, Conti I, Plowman GD, Starling JJ, Flynn DL. Inhibition of RAF Isoforms and Active Dimers by LY3009120 Leads to Anti-tumor Activities in RAS or BRAF Mutant Cancers. Cancer Cell 2015; 28:384-98. [PMID: 26343583 DOI: 10.1016/j.ccell.2015.08.002] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 06/29/2015] [Accepted: 08/03/2015] [Indexed: 12/19/2022]
Abstract
LY3009120 is a pan-RAF and RAF dimer inhibitor that inhibits all RAF isoforms and occupies both protomers in RAF dimers. Biochemical and cellular analyses revealed that LY3009120 inhibits ARAF, BRAF, and CRAF isoforms with similar affinity, while vemurafenib or dabrafenib have little or modest CRAF activity compared to their BRAF activities. LY3009120 induces BRAF-CRAF dimerization but inhibits the phosphorylation of downstream MEK and ERK, suggesting that it effectively inhibits the kinase activity of BRAF-CRAF heterodimers. Further analyses demonstrated that LY3009120 also inhibits various forms of RAF dimers including BRAF or CRAF homodimers. Due to these unique properties, LY3009120 demonstrates minimal paradoxical activation, inhibits MEK1/2 phosphorylation, and exhibits anti-tumor activities across multiple models carrying KRAS, NRAS, or BRAF mutation.
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Affiliation(s)
| | | | | | - Wei-Ping Lu
- Deciphera Pharmaceuticals, LLC, Lawrence, KS 66044, USA
| | - Bryan D Smith
- Deciphera Pharmaceuticals, LLC, Lawrence, KS 66044, USA
| | - Subha Vogeti
- Deciphera Pharmaceuticals, LLC, Lawrence, KS 66044, USA
| | | | - Scott Wise
- Deciphera Pharmaceuticals, LLC, Lawrence, KS 66044, USA
| | - Lawrence Chun
- Emerald Biostructures, Bainbridge Island, WA 98110, USA
| | - Youyan Zhang
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | - Tinggui Yin
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Xiaoyi Zhang
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Vipin Yadav
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | - Xueqian Gong
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Xiwen Ma
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Yue Webster
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | | | | | - Lisa Kays
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | | | - Denis McCann
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Phenil Patel
- Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Ilaria Conti
- Eli Lilly and Company, Indianapolis, IN 46285, USA
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30
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Luke JJ, Ott PA, Shapiro GI. The biology and clinical development of MEK inhibitors for cancer. Drugs 2015; 74:2111-28. [PMID: 25414119 DOI: 10.1007/s40265-014-0315-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mitogen-activated protein kinase kinases (MAPKK) MEK1 and MEK2 are integral members of the MAPK/ERK signaling pathway and are of interest in the development of anti-cancer therapeutics. The MAPK/ERK pathway is dysregulated in more than 30 % of cancers, predominately by mutations in RAS and BRAF proteins, and MEK serves as a potential downstream target for both of these. The biology of MEK inhibition is complex, as the molecule is differentially regulated by upstream RAS or RAF. This has impacted on the past development of MEK inhibitors as treatments for cancer and may be exploited in more rational, molecularly selected drug development plans in the future. The role of MEK in cancer and the mechanism of action of MEK inhibitors is reviewed. Furthermore, MEK inhibitors that are available in standard practice, as well as those most advanced in clinical development, are discussed. Finally, next steps in the development of MEK inhibitors are considered.
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Affiliation(s)
- Jason J Luke
- Melanoma and Developmental Therapeutics Clinics, University of Chicago Cancer Center, University of Chicago, 5841 S. Maryland Ave., MC2115, Chicago, IL, 60637, USA,
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31
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Abstract
RAF family kinases were among the first oncoproteins to be described more than 30 years ago. They primarily act as signalling relays downstream of RAS, and their close ties to cancer have fuelled a large number of studies. However, we still lack a systems-level understanding of their regulation and mode of action. The recent discovery that the catalytic activity of RAF depends on an allosteric mechanism driven by kinase domain dimerization is providing a vital new piece of information towards a comprehensive model of RAF function. The fact that current RAF inhibitors unexpectedly induce ERK signalling by stimulating RAF dimerization also calls for a deeper structural characterization of this family of kinases.
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32
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Thevakumaran N, Lavoie H, Critton DA, Tebben A, Marinier A, Sicheri F, Therrien M. Crystal structure of a BRAF kinase domain monomer explains basis for allosteric regulation. Nat Struct Mol Biol 2014; 22:37-43. [PMID: 25437913 DOI: 10.1038/nsmb.2924] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/03/2014] [Indexed: 12/14/2022]
Abstract
Reported RAF kinase domain structures adopt a side-to-side dimer configuration reflective of an 'on' state that underpins an allosteric mechanism of regulation. Atomic details of the monomer 'off' state have been elusive. Reinspection of the BRAF kinase domain structures revealed that sulfonamide inhibitors induce features of an off state, primarily a laterally displaced helix αC stabilized by the activation segment helix 1 (AS-H1). These features correlated with the ability of sulfonamides to disrupt human BRAF homodimers in cells, in vitro and in crystals yielding a structure of BRAF in a monomer state. The crystal structure revealed exaggerated, nonproductive positions of helix αC and AS-H1, the latter of which is the target of potent BRAF oncogenic mutations. Together, this work provides formal proof of an allosteric link between the RAF dimer interface, the activation segment and the catalytic infrastructure.
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Affiliation(s)
- Neroshan Thevakumaran
- 1] Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada. [2] Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Hugo Lavoie
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - David A Critton
- Molecular Structure &Design Group, Molecular Discovery Technologies Department, Bristol-Myers Squibb Research, Princeton, New Jersey, USA
| | - Andrew Tebben
- Molecular Structure &Design Group, Molecular Discovery Technologies Department, Bristol-Myers Squibb Research, Princeton, New Jersey, USA
| | - Anne Marinier
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada
| | - Frank Sicheri
- 1] Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada. [2] Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada. [3] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Marc Therrien
- 1] Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada. [2] Département de Pathologie et Biologie Cellulaire, Université de Montréal, Montréal, Québec, Canada
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33
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Beyer HM, Naumann S, Weber W, Radziwill G. Optogenetic control of signaling in mammalian cells. Biotechnol J 2014; 10:273-83. [DOI: 10.1002/biot.201400077] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/16/2014] [Accepted: 08/13/2014] [Indexed: 11/08/2022]
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34
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Girotti MR, Saturno G, Lorigan P, Marais R. No longer an untreatable disease: how targeted and immunotherapies have changed the management of melanoma patients. Mol Oncol 2014; 8:1140-58. [PMID: 25178978 PMCID: PMC5528622 DOI: 10.1016/j.molonc.2014.07.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 07/31/2014] [Indexed: 12/23/2022] Open
Abstract
The discovery that BRAF is a driver oncogene in cancer, and complementary improvements in our understanding of the immune system have resulted in new targeted and immune-therapies for metastatic melanoma. Targeted therapies achieve impressive clinical results in carefully selected patients but the development of resistance seems inevitable in most cases. Conversely, immune-checkpoints inhibitors can achieve long-term remission and cures, but in a smaller proportion of patients, and biomarkers to predict which patients will respond are not available. Nevertheless, melanoma has led the evolution of cancer treatment from relatively nonspecific cytotoxic agents to highly selective therapies and here we review the lessons from this paradigm shift in treatment and the opportunities for further improvements in outcomes for melanoma patients.
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Affiliation(s)
- Maria Romina Girotti
- Molecular Oncology Group, Cancer Research UK Manchester Institute, Manchester, UK
| | - Grazia Saturno
- Molecular Oncology Group, Cancer Research UK Manchester Institute, Manchester, UK
| | - Paul Lorigan
- University of Manchester, Christie NHS Foundation Trust, Manchester, UK
| | - Richard Marais
- Molecular Oncology Group, Cancer Research UK Manchester Institute, Manchester, UK.
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35
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El-Nassan HB. Recent progress in the identification of BRAF inhibitors as anti-cancer agents. Eur J Med Chem 2014; 72:170-205. [DOI: 10.1016/j.ejmech.2013.11.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/05/2013] [Accepted: 11/18/2013] [Indexed: 12/26/2022]
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36
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Lito P, Rosen N, Solit DB. Tumor adaptation and resistance to RAF inhibitors. Nat Med 2013; 19:1401-9. [DOI: 10.1038/nm.3392] [Citation(s) in RCA: 446] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 10/07/2013] [Indexed: 12/12/2022]
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37
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Single-molecule superresolution imaging allows quantitative analysis of RAF multimer formation and signaling. Proc Natl Acad Sci U S A 2013; 110:18519-24. [PMID: 24158481 DOI: 10.1073/pnas.1318188110] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The RAF serine/threonine kinases regulate cell growth through the MAPK pathway, and are targeted by small-molecule RAF inhibitors (RAFis) in human cancer. It is now apparent that protein multimers play an important role in RAF activation and tumor response to RAFis. However, the exact stoichiometry and cellular location of these multimers remain unclear because of the lack of technologies to visualize them. In the present work, we demonstrate that photoactivated localization microscopy (PALM), in combination with quantitative spatial analysis, provides sufficient resolution to directly visualize protein multimers in cells. Quantitative PALM imaging showed that CRAF exists predominantly as cytoplasmic monomers under resting conditions but forms dimers as well as trimers and tetramers at the cell membrane in the presence of active RAS. In contrast, N-terminal truncated CRAF (CatC) lacking autoinhibitory domains forms constitutive dimers and occasional tetramers in the cytoplasm, whereas a CatC mutant with a disrupted CRAF-CRAF dimer interface does not. Finally, artificially forcing CRAF to the membrane by fusion to a RAS CAAX motif induces multimer formation but activates RAF/MAPK only if the dimer interface is intact. Together, these quantitative results directly confirm the existence of RAF dimers and potentially higher-order multimers and their involvement in cell signaling, and showed that RAF multimer formation can result from multiple mechanisms and is a critical but not sufficient step for RAF activation.
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38
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Freeman AK, Ritt DA, Morrison DK. The importance of Raf dimerization in cell signaling. Small GTPases 2013; 4:180-5. [PMID: 23985533 DOI: 10.4161/sgtp.26117] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The Raf family of protein kinases are key signaling intermediates, acting as a central link between the membrane-bound Ras GTPases and the downstream kinases MEK and ERK. Raf kinase regulation is well-known for its complexity but only recently has it been realized that many of the mechanisms involved in Raf regulation also modulate Raf dimerization, now acknowledged to be a required step for Raf signaling in multiple cellular contexts. Recent studies have shown that Raf dimerization is necessary for normal Ras-dependent Raf kinase activation and contributes to the pathogenic function of disease-associated mutant Raf proteins with all but high intrinsic kinase activity. Raf dimerization has also been found to alter therapeutic responses and disease progression in patients treated with ATP-competitive Raf inhibitors as well as certain other kinase-targeted drugs. This demonstration of clinical significance has stimulated the recent development of biosensor assays that can monitor inhibitor-induced Raf dimerization as well as studies demonstrating the therapeutic potential of blocking Raf dimerization.
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Affiliation(s)
- Alyson K Freeman
- Laboratory of Cell and Developmental Signaling; Center for Cancer Research; National Cancer Institute-Frederick; Frederick, MD USA
| | - Daniel A Ritt
- Laboratory of Cell and Developmental Signaling; Center for Cancer Research; National Cancer Institute-Frederick; Frederick, MD USA
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling; Center for Cancer Research; National Cancer Institute-Frederick; Frederick, MD USA
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39
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Baljuls A, Kholodenko BN, Kolch W. It takes two to tango--signalling by dimeric Raf kinases. MOLECULAR BIOSYSTEMS 2013; 9:551-8. [PMID: 23212737 DOI: 10.1039/c2mb25393c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Raf kinases function downstream of Ras proteins to activate the MEK-ERK pathway which is deregulated in a large number of human cancers. Raf inhibitors are clinically highly effective for the treatment of cancer and melanoma in particular, but have unexpected side effects that include a paradoxical activation of the ERK pathway. These effects seem to be related to the heterodimerization of Raf-1 and B-Raf kinases. Here, we discuss the role of Raf dimerization as part of the physiological activation mechanism of Raf kinases, the mechanism of Raf dimerization induced by drugs, and the implications of dimerization for drug therapies targeting Raf kinases.
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Affiliation(s)
- Angela Baljuls
- Systems Biology Ireland, University College Dublin, Dublin 4, Ireland.
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40
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Peel N, Larijani B, Parker PJ. Localised interventions in cellular processes. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1834:1364-70. [PMID: 23403146 DOI: 10.1016/j.bbapap.2013.01.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 01/30/2013] [Indexed: 12/11/2022]
Abstract
The once linear view of cell regulatory processes is now changing as we begin to overlay spatial and temporal characteristics onto signalling pathways and dynamic membranous events. To better understand the properties of these spatially restricted processes we must refine our targeting of these events with acute localised manipulations. We review here the diverse application of a dimerisation system, which exploits immunosuppressor/immunophilin biology to provide a route to drug-inducible subdomain interventions. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases (2012).
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Affiliation(s)
- Nick Peel
- Protein Phosphorylation Laboratory London Research Institute, London, UK.
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41
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Abstract
The clinical benefits of BRAF inhibition in patients with advanced-stage BRAF-mutant melanoma are now well established. Although the emergence of cutaneous squamous-cell carcinomas (SCCs) and secondary melanomas in patients on BRAF-inhibitor therapy have been well described, reports are emerging of additional secondary premalignant and malignant events, including RAS-mutant leukaemia, the metastatic recurrence of RAS-mutant colorectal cancer and the development of gastric and colonic polyps. In most cases, paradoxical MAPK activation--resulting from the BRAF-inhibitor-mediated homodimerization and heterodimerization of nonmutant RAF isoforms--seems to underlie the development of these secondary tumours. Although evidence supports that therapy with the simultaneous administration of BRAF and MEK inhibitors abrogates the onset of treatment-induced SCCs, whether combination treatment will limit the emergence of all BRAF-inhibitor-driven pathologies is unclear. In this Review, we describe the clinical and mechanistic manifestations of secondary cancers that have thus far been observed to arise as a consequence of BRAF inhibition. We discuss the concept of pre-existing populations of partly transformed cells with malignant potential that might be present in various organ systems, and the rationale for novel therapeutic strategies for the management of BRAF-inhibitor-induced neoplasia.
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42
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MEK-1 activates C-Raf through a Ras-independent mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:976-86. [PMID: 23360980 DOI: 10.1016/j.bbamcr.2013.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/29/2012] [Accepted: 01/15/2013] [Indexed: 12/16/2022]
Abstract
C-Raf is a member of the Ras-Raf-MEK-ERK mitogen-activated protein kinase (MAPK) signaling pathway that plays key roles in diverse physiological processes and is upregulated in many human cancers. C-Raf activation involves binding to Ras, increased phosphorylation and interactions with co-factors. Here, we describe a Ras-independent in vivo pathway for C-Raf activation by its downstream target MEK. Using (32)P-metabolic labeling and 2D-phosphopeptide mapping experiments, we show that MEK increases C-Raf phosphorylation by up-to 10-fold. This increase was associated with C-Raf kinase activation, matching the activity seen with growth factor stimulation. Consequently, coexpression of wildtype C-Raf and MEK was sufficient for full and constitutive activation of ERK. Notably, the ability of MEK to activate C-Raf was completely Ras independent, since mutants impaired in Ras binding that are irresponsive to growth factors or Ras were fully activated by MEK. The ability of MEK to activate C-Raf was only partially dependent on MEK kinase activity but required MEK binding to C-Raf, suggesting that the binding results in a conformational change that increases C-Raf susceptibility to phosphorylation and activation or in the stabilization of the phosphorylated-active form. These findings propose a novel Ras-independent mechanism for activating the C-Raf and the MAPK pathway without the need for mutations in the pathway. This mechanism could be of significance in pathological conditions or cancers overexpressing C-Raf and MEK or in conditions where C-Raf-MEK interaction is enhanced due to the down-regulation of RKIP and MST2.
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43
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Knight JDR, Pawson T, Gingras AC. Profiling the kinome: current capabilities and future challenges. J Proteomics 2012; 81:43-55. [PMID: 23099349 DOI: 10.1016/j.jprot.2012.10.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 10/09/2012] [Accepted: 10/14/2012] [Indexed: 01/08/2023]
Abstract
Protein kinases are the second largest human protein family, but in terms of research interest, both basic and applied, they are surely the most popular. Over the past decade, many techniques and approaches for studying the kinome have been described and the pace of development is ever increasing. Presently, a molecular biologist can approach the kinome from many different angles: what kinases are active during a specific cell state of interest or become activated in response to a specific stimulus? What are the effects of controlling the activation status of an individual kinase? What substrates are targeted by a particular kinase, either in general or under particular conditions? And what kinase is responsible for targeting a specific phosphorylation site of interest? These are some of the more commonly asked questions during any kinase-centric research project and different strategies have been devised for answering such queries. In this review, we outline the most promising of these approaches, particularly those with a capacity for high-throughput studies. This article is part of a Special Issue entitled: From protein structures to clinical applications.
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Affiliation(s)
- James D R Knight
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
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44
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Bollag G, Tsai J, Zhang J, Zhang C, Ibrahim P, Nolop K, Hirth P. Vemurafenib: the first drug approved for BRAF-mutant cancer. Nat Rev Drug Discov 2012; 11:873-86. [PMID: 23060265 DOI: 10.1038/nrd3847] [Citation(s) in RCA: 539] [Impact Index Per Article: 44.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The identification of driver oncogenes has provided important targets for drugs that can change the landscape of cancer therapies. One such example is the BRAF oncogene, which is found in about half of all melanomas as well as several other cancers. As a druggable kinase, oncogenic BRAF has become a crucial target of small-molecule drug discovery efforts. Following a rapid clinical development path, vemurafenib (Zelboraf; Plexxikon/Roche) was approved for the treatment of BRAF-mutated metastatic melanoma in the United States in August 2011 and the European Union in February 2012. This Review describes the underlying biology of BRAF, the technology used to identify vemurafenib and its clinical development milestones, along with future prospects based on lessons learned during its development.
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Affiliation(s)
- Gideon Bollag
- Plexxikon, 91 Bolivar Drive, Berkeley, California 94710, USA.
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45
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Affiliation(s)
- Xiaolun Wang
- Takeda California , 10410 Science Center Drive, San Diego, California 92121, USA.
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46
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Rutkowska A, Schultz C. Protein Tango: The Toolbox to Capture Interacting Partners. Angew Chem Int Ed Engl 2012; 51:8166-76. [DOI: 10.1002/anie.201201717] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Indexed: 11/07/2022]
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47
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48
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Targeting Raf/MEK/ERK pathway in pituitary adenomas. Eur J Cancer 2012; 48:389-95. [DOI: 10.1016/j.ejca.2011.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 10/01/2011] [Accepted: 11/02/2011] [Indexed: 12/11/2022]
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Osborne JK, Zaganjor E, Cobb MH. Signal control through Raf: in sickness and in health. Cell Res 2011; 22:14-22. [PMID: 22143568 DOI: 10.1038/cr.2011.193] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The extracellular signal-regulated kinase 1/2 (ERK1/2) cascade is the prototype mammalian mitogen-activated protein kinase (MAPK) signaling cascade that regulates a number of processes, including proliferation, differentiation, survival, migration, stress responses and apoptosis. How this seemingly linear cascade is modulated to achieve a specific cellular function has been a main focus of the field. In this review, we describe new as well as old findings in the regulation of the ERK1/2 pathway in normal and disease states via MAP3Ks.
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Affiliation(s)
- Jihan K Osborne
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041, USA
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Watanabe K, Thandavarayan RA, Harima M, Sari FR, Gurusamy N, Veeraveedu PT, Mito S, Arozal W, Sukumaran V, Laksmanan AP, Soetikno V, Kodama M, Aizawa Y. Role of differential signaling pathways and oxidative stress in diabetic cardiomyopathy. Curr Cardiol Rev 2011; 6:280-90. [PMID: 22043204 PMCID: PMC3083809 DOI: 10.2174/157340310793566145] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 09/03/2010] [Accepted: 09/15/2010] [Indexed: 12/20/2022] Open
Abstract
Diabetes mellitus increases the risk of heart failure independently of underlying coronary artery disease, and many believe that diabetes leads to cardiomyopathy. The underlying pathogenesis is partially understood. Several factors may contribute to the development of cardiac dysfunction in the absence of coronary artery disease in diabetes mellitus. There is growing evidence that excess generation of highly reactive free radicals, largely due to hyperglycemia, causes oxidative stress, which further exacerbates the development and progression of diabetes and its complications. Hyperglycemia-induced oxidative stress is a major risk factor for the development of micro-vascular pathogenesis in the diabetic myocardium, which results in myocardial cell death, hypertrophy, fibrosis, abnormalities of calcium homeostasis and endothelial dysfunction. Diabetes-mediated biochemical changes show cross-interaction and complex interplay culminating in the activation of several intracellular signaling molecules. Diabetic cardiomyopathy is characterized by morphologic and structural changes in the myocardium and coronary vasculature mediated by the activation of various signaling pathways. This review focuses on the oxidative stress and signaling pathways in the pathogenesis of the cardiovascular complications of diabetes, which underlie the development and progression of diabetic cardiomyopathy.
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Affiliation(s)
- Kenichi Watanabe
- Department of Clinical Pharmacology, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata City, Japan
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