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Than MT, O'Hara M, Stanger BZ, Reiss KA. KRAS-Driven Tumorigenesis and KRAS-Driven Therapy in Pancreatic Adenocarcinoma. Mol Cancer Ther 2024; 23:1378-1388. [PMID: 39118358 PMCID: PMC11444872 DOI: 10.1158/1535-7163.mct-23-0519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/09/2024] [Accepted: 08/02/2024] [Indexed: 08/10/2024]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is associated with significant morbidity and mortality and is projected to be the second leading cause of cancer-related deaths by 2030. Mutations in KRAS are found in the vast majority of PDAC cases and plays an important role in the development of the disease. KRAS drives tumor cell proliferation and survival through activating the MAPK pathway to drive cell cycle progression and to lead to MYC-driven cellular programs. Moreover, activated KRAS promotes a protumorigenic microenvironment through forming a desmoplastic stroma and by impairing antitumor immunity. Secretion of granulocyte-macrophage colony-stimulating factor and recruitment of myeloid-derived suppressor cells and protumorigenic macrophages results in an immunosuppressive environment while secretion of secrete sonic hedgehog and TGFβ drive fibroblastic features characteristic of PDAC. Recent development of several small molecules to directly target KRAS marks an important milestone in precision medicine. Many molecules show promise in preclinical models of PDAC and in early phase clinical trials. In this review, we discuss the underlying cell intrinsic and extrinsic roles of KRAS in PDAC tumorigenesis, the pharmacologic development of KRAS inhibition, and therapeutic strategies to target KRAS in PDAC.
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Affiliation(s)
- Minh T Than
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Abramson Cancer Center and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mark O'Hara
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Abramson Cancer Center and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ben Z Stanger
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Abramson Cancer Center and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kim A Reiss
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Abramson Cancer Center and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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2
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Whitley MJ, Tran TH, Rigby M, Yi M, Dharmaiah S, Waybright TJ, Ramakrishnan N, Perkins S, Taylor T, Messing S, Esposito D, Nissley DV, McCormick F, Stephen AG, Turbyville T, Cornilescu G, Simanshu DK. Comparative analysis of KRAS4a and KRAS4b splice variants reveals distinctive structural and functional properties. SCIENCE ADVANCES 2024; 10:eadj4137. [PMID: 38354232 DOI: 10.1126/sciadv.adj4137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
KRAS, the most frequently mutated oncogene in human cancer, produces two isoforms, KRAS4a and KRAS4b, through alternative splicing. These isoforms differ in exon 4, which encodes the final 15 residues of the G-domain and hypervariable regions (HVRs), vital for trafficking and membrane localization. While KRAS4b has been extensively studied, KRAS4a has been largely overlooked. Our multidisciplinary study compared the structural and functional characteristics of KRAS4a and KRAS4b, revealing distinct structural properties and thermal stability. Position 151 influences KRAS4a's thermal stability, while position 153 affects binding to RAF1 CRD protein. Nuclear magnetic resonance analysis identified localized structural differences near sequence variations and provided a solution-state conformational ensemble. Notably, KRAS4a exhibits substantial transcript abundance in bile ducts, liver, and stomach, with transcript levels approaching KRAS4b in the colon and rectum. Functional disparities were observed in full-length KRAS variants, highlighting the impact of HVR variations on interaction with trafficking proteins and downstream effectors like RAF and PI3K within cells.
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Affiliation(s)
- Matthew J Whitley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Timothy H Tran
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Megan Rigby
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Ming Yi
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Srisathiyanarayanan Dharmaiah
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Timothy J Waybright
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Nitya Ramakrishnan
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Shelley Perkins
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Troy Taylor
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Simon Messing
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Frank McCormick
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3rd Street, San Francisco, CA, USA
| | - Andrew G Stephen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Thomas Turbyville
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Gabriel Cornilescu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
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3
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Maio G, Smith M, Bhawal R, Zhang S, Baskin JM, Li J, Lin H. Interactome Analysis Identifies the Role of BZW2 in Promoting Endoplasmic Reticulum-Mitochondria Contact and Mitochondrial Metabolism. Mol Cell Proteomics 2024; 23:100709. [PMID: 38154691 PMCID: PMC10835002 DOI: 10.1016/j.mcpro.2023.100709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 12/19/2023] [Accepted: 12/24/2023] [Indexed: 12/30/2023] Open
Abstract
Understanding the molecular functions of less-studied proteins is an important task of life science research. Despite reports of basic leucine zipper and W2 domain-containing protein 2 (BZW2) promoting cancer progression first emerging in 2017, little is known about its molecular function. Using a quantitative proteomic approach to identify its interacting proteins, we found that BZW2 interacts with both endoplasmic reticulum (ER) and mitochondrial proteins. We thus hypothesized that BZW2 localizes to and promotes the formation of ER-mitochondria contact sites and that such localization would promote calcium transport from ER to the mitochondria and promote ATP production. Indeed, we found that BZW2 localized to ER-mitochondria contact sites and that BZW2 knockdown decreased ER-mitochondria contact, mitochondrial calcium levels, and ATP production. These findings provide key insights into molecular functions of BZW2, the potential role of BZW2 in cancer progression, and highlight the utility of interactome data in understanding the function of less-studied proteins.
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Affiliation(s)
- George Maio
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Mike Smith
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Ruchika Bhawal
- Proteomics and Metabolomics Facility, Cornell University, Ithaca, New York, USA
| | - Sheng Zhang
- Proteomics and Metabolomics Facility, Cornell University, Ithaca, New York, USA
| | - Jeremy M Baskin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA; Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
| | - Jenny Li
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA; Howard Hughes Medical Institute, Cornell University, Ithaca, New York, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA.
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4
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Chiari R, Palladino S, Emili R, De Lisa M, Sarti D, Catalano V, Magnani M, Graziano F, Ruzzo A. KRAS4A and KRAS4B in liquid biopsy of metastatic lung adenocarcinoma patients treated with Pembrolizumab or chemotherapy plus Pembrolizumab. Sci Rep 2023; 13:21036. [PMID: 38030703 PMCID: PMC10687227 DOI: 10.1038/s41598-023-48304-0] [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: 06/06/2023] [Accepted: 11/24/2023] [Indexed: 12/01/2023] Open
Abstract
KRAS is involved in the stability and expression of PD-L1. We investigated the expression of circulating mRNA (cmRNA) of KRAS4A and KRAS4B and the possible impact on progression-free survival (PFS) of patients with metastatic lung adenocarcinoma treated with immunotherapy. Patients without driver mutations undergoing Pembrolizumab (P) or P plus chemotherapy (PC) were prospectively accrued for liquid biopsy analysis of KRAS4A, KRAS4B, and PD-L1 cmRNA. Both KRAS isoforms were also studied for association with PD-L1 cmRNA. Of 56 patients, 28 received P and 28 PC. Patients with high levels of both KRAS isoforms showed significantly better PFS. The median PFS for KRAS4A was 29 months (95% CI 22-29 months) and KRAS4B 24 months (95% CI 13-29 months), respectively. The median PFS of patients with low levels of both isoforms was 12 months (95% CI 6-15 months for KRAS4A and 95% CI 5-20 months for KRAS4B). High KRAS4A retained a significant positive association with PFS in the multivariate model. An exploratory analysis in treatment subgroups found a positive association between high KRAS4A and KRAS4B with PFS in patients treated with P. PD-L1 cmRNA was significantly higher in patients with high KRAS isoforms levels and this effect was pronounced for high KRAS4A carriers. KRAS4A deserves further investigation as a potential marker for defining patients who may benefit the most from immune checkpoint inhibitors therapy and improving personalized cancer immunotherapeutic strategies.
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Affiliation(s)
- Rita Chiari
- Oncology Unit, AST1 Pesaro e Urbino, Stabilimento di Muraglia - Via Lombroso 1, 61122, Pesaro, Italy
- Oncology Unit, AST1 Pesaro e Urbino, Fano, Italy
| | - Silvia Palladino
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Arco d'Augusto, 2, 61032, Fano, Italy
| | - Rita Emili
- Oncology Unit, AST1 Pesaro e Urbino, Urbino, Italy
| | | | | | | | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Arco d'Augusto, 2, 61032, Fano, Italy
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - Francesco Graziano
- Oncology Unit, AST1 Pesaro e Urbino, Stabilimento di Muraglia - Via Lombroso 1, 61122, Pesaro, Italy.
| | - Annamaria Ruzzo
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Arco d'Augusto, 2, 61032, Fano, Italy.
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5
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Nussinov R, Liu Y, Zhang W, Jang H. Protein conformational ensembles in function: roles and mechanisms. RSC Chem Biol 2023; 4:850-864. [PMID: 37920394 PMCID: PMC10619138 DOI: 10.1039/d3cb00114h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/02/2023] [Indexed: 11/04/2023] Open
Abstract
The sequence-structure-function paradigm has dominated twentieth century molecular biology. The paradigm tacitly stipulated that for each sequence there exists a single, well-organized protein structure. Yet, to sustain cell life, function requires (i) that there be more than a single structure, (ii) that there be switching between the structures, and (iii) that the structures be incompletely organized. These fundamental tenets called for an updated sequence-conformational ensemble-function paradigm. The powerful energy landscape idea, which is the foundation of modernized molecular biology, imported the conformational ensemble framework from physics and chemistry. This framework embraces the recognition that proteins are dynamic and are always interconverting between conformational states with varying energies. The more stable the conformation the more populated it is. The changes in the populations of the states are required for cell life. As an example, in vivo, under physiological conditions, wild type kinases commonly populate their more stable "closed", inactive, conformations. However, there are minor populations of the "open", ligand-free states. Upon their stabilization, e.g., by high affinity interactions or mutations, their ensembles shift to occupy the active states. Here we discuss the role of conformational propensities in function. We provide multiple examples of diverse systems, including protein kinases, lipid kinases, and Ras GTPases, discuss diverse conformational mechanisms, and provide a broad outlook on protein ensembles in the cell. We propose that the number of molecules in the active state (inactive for repressors), determine protein function, and that the dynamic, relative conformational propensities, rather than the rigid structures, are the hallmark of cell life.
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Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research Frederick MD 21702 USA
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University Tel Aviv 69978 Israel
- Cancer Innovation Laboratory, National Cancer Institute Frederick MD 21702 USA
| | - Yonglan Liu
- Cancer Innovation Laboratory, National Cancer Institute Frederick MD 21702 USA
| | - Wengang Zhang
- Cancer Innovation Laboratory, National Cancer Institute Frederick MD 21702 USA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research Frederick MD 21702 USA
- Cancer Innovation Laboratory, National Cancer Institute Frederick MD 21702 USA
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6
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Yan Y, Ren Y, Bao Y, Wang Y. RNA splicing alterations in lung cancer pathogenesis and therapy. CANCER PATHOGENESIS AND THERAPY 2023; 1:272-283. [PMID: 38327600 PMCID: PMC10846331 DOI: 10.1016/j.cpt.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/25/2023] [Accepted: 04/29/2023] [Indexed: 02/09/2024]
Abstract
RNA splicing alterations are widespread and play critical roles in cancer pathogenesis and therapy. Lung cancer is highly heterogeneous and causes the most cancer-related deaths worldwide. Large-scale multi-omics studies have not only characterized the mutational landscapes but also discovered a plethora of transcriptional and post-transcriptional changes in lung cancer. Such resources have greatly facilitated the development of new diagnostic markers and therapeutic options over the past two decades. Intriguingly, altered RNA splicing has emerged as an important molecular feature and therapeutic target of lung cancer. In this review, we provide a brief overview of splicing dysregulation in lung cancer and summarize the recent progress on key splicing events and splicing factors that contribute to lung cancer pathogenesis. Moreover, we describe the general strategies targeting splicing alterations in lung cancer and highlight the potential of combining splicing modulation with currently approved therapies to combat this deadly disease. This review provides new mechanistic and therapeutic insights into splicing dysregulation in cancer.
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Affiliation(s)
- Yueren Yan
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Yunpeng Ren
- Department of Cellular and Genetic Medicine, Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yufang Bao
- Department of Cellular and Genetic Medicine, Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yongbo Wang
- Department of Cellular and Genetic Medicine, Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
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7
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Nolan A, Raso C, Kolch W, von Kriegsheim A, Wynne K, Matallanas D. Proteomic Mapping of the Interactome of KRAS Mutants Identifies New Features of RAS Signalling Networks and the Mechanism of Action of Sotorasib. Cancers (Basel) 2023; 15:4141. [PMID: 37627169 PMCID: PMC10452836 DOI: 10.3390/cancers15164141] [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: 07/14/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
RAS proteins are key regulators of cell signalling and control different cell functions including cell proliferation, differentiation, and cell death. Point mutations in the genes of this family are common, particularly in KRAS. These mutations were thought to cause the constitutive activation of KRAS, but recent findings showed that some mutants can cycle between active and inactive states. This observation, together with the development of covalent KRASG12C inhibitors, has led to the arrival of KRAS inhibitors in the clinic. However, most patients develop resistance to these targeted therapies, and we lack effective treatments for other KRAS mutants. To accelerate the development of RAS targeting therapies, we need to fully characterise the molecular mechanisms governing KRAS signalling networks and determine what differentiates the signalling downstream of the KRAS mutants. Here we have used affinity purification mass-spectrometry proteomics to characterise the interactome of KRAS wild-type and three KRAS mutants. Bioinformatic analysis associated with experimental validation allows us to map the signalling network mediated by the different KRAS proteins. Using this approach, we characterised how the interactome of KRAS wild-type and mutants is regulated by the clinically approved KRASG12C inhibitor Sotorasib. In addition, we identified novel crosstalks between KRAS and its effector pathways including the AKT and JAK-STAT signalling modules.
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Affiliation(s)
- Aoife Nolan
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
| | - Cinzia Raso
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
| | - Walter Kolch
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Alex von Kriegsheim
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
- Edinburgh Cancer Research UK Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Kieran Wynne
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
| | - David Matallanas
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland; (A.N.); (C.R.); (W.K.); (A.v.K.); (K.W.)
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8
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Wojtyś W, Oroń M. How Driver Oncogenes Shape and Are Shaped by Alternative Splicing Mechanisms in Tumors. Cancers (Basel) 2023; 15:cancers15112918. [PMID: 37296881 DOI: 10.3390/cancers15112918] [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: 04/28/2023] [Revised: 05/20/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
The development of RNA sequencing methods has allowed us to study and better understand the landscape of aberrant pre-mRNA splicing in tumors. Altered splicing patterns are observed in many different tumors and affect all hallmarks of cancer: growth signal independence, avoidance of apoptosis, unlimited proliferation, invasiveness, angiogenesis, and metabolism. In this review, we focus on the interplay between driver oncogenes and alternative splicing in cancer. On one hand, oncogenic proteins-mutant p53, CMYC, KRAS, or PI3K-modify the alternative splicing landscape by regulating expression, phosphorylation, and interaction of splicing factors with spliceosome components. Some splicing factors-SRSF1 and hnRNPA1-are also driver oncogenes. At the same time, aberrant splicing activates key oncogenes and oncogenic pathways: p53 oncogenic isoforms, the RAS-RAF-MAPK pathway, the PI3K-mTOR pathway, the EGF and FGF receptor families, and SRSF1 splicing factor. The ultimate goal of cancer research is a better diagnosis and treatment of cancer patients. In the final part of this review, we discuss present therapeutic opportunities and possible directions of further studies aiming to design therapies targeting alternative splicing mechanisms in the context of driver oncogenes.
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Affiliation(s)
- Weronika Wojtyś
- Laboratory of Human Disease Multiomics, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland
| | - Magdalena Oroń
- Laboratory of Human Disease Multiomics, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland
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9
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Zhang Y, Zhao Q, Lin H. Identification of potential HDAC11 deacylase substrates by affinity pulldown MS. Methods Enzymol 2023; 685:43-55. [PMID: 37245910 DOI: 10.1016/bs.mie.2023.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Lysine fatty acylation is a protein posttranslational modification (PTM) that has been linked to various important biological processes. HDAC11, the sole member of class IV of histone deacetylases (HDACs), has been shown to have high lysine defatty-acylase activity. In order to better understand the functions of lysine fatty acylation and its regulation by HDAC11, it is important to identify the physiological substrates of HDAC11. This can be achieved through profiling the interactome of HDAC11 using a stable isotope labeling with amino acids in cell culture (SILAC) proteomics strategy. Here we describe a detailed method on using SILAC to identify the interactome of HDAC11. This method can be similarly used to identify the interactome, and thus potential substrates, of other PTM enzymes.
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Affiliation(s)
- Yandong Zhang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States
| | - Qian Zhao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States; Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States.
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10
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Adams LM, DeHart CJ, Drown BS, Anderson LC, Bocik W, Boja ES, Hiltke TM, Hendrickson CL, Rodriguez H, Caldwell M, Vafabakhsh R, Kelleher NL. Mapping the KRAS proteoform landscape in colorectal cancer identifies truncated KRAS4B that decreases MAPK signaling. J Biol Chem 2022; 299:102768. [PMID: 36470426 PMCID: PMC9808003 DOI: 10.1016/j.jbc.2022.102768] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/07/2022] Open
Abstract
The KRAS gene is one of the most frequently mutated oncogenes in human cancer and gives rise to two isoforms, KRAS4A and KRAS4B. KRAS post-translational modifications (PTMs) have the potential to influence downstream signaling. However, the relationship between KRAS PTMs and oncogenic mutations remains unclear, and the extent of isoform-specific modification is unknown. Here, we present the first top-down proteomics study evaluating both KRAS4A and KRAS4B, resulting in 39 completely characterized proteoforms across colorectal cancer cell lines and primary tumor samples. We determined which KRAS PTMs are present, along with their relative abundance, and that proteoforms of KRAS4A versus KRAS4B are differentially modified. Moreover, we identified a subset of KRAS4B proteoforms lacking the C185 residue and associated C-terminal PTMs. By confocal microscopy, we confirmed that this truncated GFP-KRAS4BC185∗ proteoform is unable to associate with the plasma membrane, resulting in a decrease in mitogen-activated protein kinase signaling pathway activation. Collectively, our study provides a reference set of functionally distinct KRAS proteoforms and the colorectal cancer contexts in which they are present.
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Affiliation(s)
- Lauren M. Adams
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Caroline J. DeHart
- NCI RAS Initiative, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Bryon S. Drown
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
| | - Lissa C. Anderson
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Tallahassee, Florida, USA
| | - William Bocik
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Emily S. Boja
- Office of Cancer Clinical Proteomics Research, National Cancer Institute, Bethesda Maryland, USA
| | - Tara M. Hiltke
- Office of Cancer Clinical Proteomics Research, National Cancer Institute, Bethesda Maryland, USA
| | | | - Henry Rodriguez
- Office of Cancer Clinical Proteomics Research, National Cancer Institute, Bethesda Maryland, USA
| | - Michael Caldwell
- Division of Hematology and Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA,Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA,Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Neil L. Kelleher
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA,Department of Chemistry, Northwestern University, Evanston, Illinois, USA,Division of Hematology and Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA,Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA,Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA,For correspondence: Neil L. Kelleher
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11
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Tolani B, Celli A, Yao Y, Tan YZ, Fetter R, Liem CR, de Smith AJ, Vasanthakumar T, Bisignano P, Cotton AD, Seiple IB, Rubinstein JL, Jost M, Weissman JS. Ras-mutant cancers are sensitive to small molecule inhibition of V-type ATPases in mice. Nat Biotechnol 2022; 40:1834-1844. [PMID: 35879364 PMCID: PMC9750872 DOI: 10.1038/s41587-022-01386-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 06/03/2022] [Indexed: 01/14/2023]
Abstract
Mutations in Ras family proteins are implicated in 33% of human cancers, but direct pharmacological inhibition of Ras mutants remains challenging. As an alternative to direct inhibition, we screened for sensitivities in Ras-mutant cells and discovered 249C as a Ras-mutant selective cytotoxic agent with nanomolar potency against a spectrum of Ras-mutant cancers. 249C binds to vacuolar (V)-ATPase with nanomolar affinity and inhibits its activity, preventing lysosomal acidification and inhibiting autophagy and macropinocytosis pathways that several Ras-driven cancers rely on for survival. Unexpectedly, potency of 249C varies with the identity of the Ras driver mutation, with the highest potency for KRASG13D and G12V both in vitro and in vivo, highlighting a mutant-specific dependence on macropinocytosis and lysosomal pH. Indeed, 249C potently inhibits tumor growth without adverse side effects in mouse xenografts of KRAS-driven lung and colon cancers. A comparison of isogenic SW48 xenografts with different KRAS mutations confirmed that KRASG13D/+ (followed by G12V/+) mutations are especially sensitive to 249C treatment. These data establish proof-of-concept for targeting V-ATPase in cancers driven by specific KRAS mutations such as KRASG13D and G12V.
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Affiliation(s)
- Bhairavi Tolani
- Thoracic Oncology Program, Department of Surgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.
| | - Anna Celli
- Laboratory for Cell Analysis Core Facility, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Yanmin Yao
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Yong Zi Tan
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Disease Intervention Technology Laboratory, Agency for Science, Technology and Research, Singapore, Singapore
| | - Richard Fetter
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Christina R Liem
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Division of Biological Sciences, the Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Adam J de Smith
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Thamiya Vasanthakumar
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
| | - Paola Bisignano
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Adam D Cotton
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Ian B Seiple
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
- Department of Medical Biophysics, The University of Toronto, Toronto, ON, Canada
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA.
- Department of Microbiology & Immunology, University of California, San Francisco, CA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
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12
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Nuevo-Tapioles C, Philips MR. The role of KRAS splice variants in cancer biology. Front Cell Dev Biol 2022; 10:1033348. [PMID: 36393833 PMCID: PMC9663995 DOI: 10.3389/fcell.2022.1033348] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/20/2022] [Indexed: 11/07/2022] Open
Abstract
The three mammalian RAS genes (HRAS, NRAS and KRAS) encode four proteins that play central roles in cancer biology. Among them, KRAS is mutated more frequently in human cancer than any other oncogene. The pre-mRNA of KRAS is alternatively spliced to give rise to two products, KRAS4A and KRAS4B, which differ in the membrane targeting sequences at their respective C-termini. Notably, both KRAS4A and KRAS4B are oncogenic when KRAS is constitutively activated by mutation in exon 2 or 3. Whereas KRAS4B is the most studied oncoprotein, KRAS4A is understudied and until recently considered relatively unimportant. Emerging work has confirmed expression of KRAS4A in cancer and found non-overlapping functions of the splice variants. The most clearly demonstrated of these is direct regulation of hexokinase 1 by KRAS4A, suggesting that the metabolic vulnerabilities of KRAS-mutant tumors may be determined in part by the relative expression of the splice variants. The aim of this review is to address the most relevant characteristics and differential functions of the KRAS splice variants as they relate to cancer onset and progression.
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13
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A proteomic approach identifies isoform-specific and nucleotide-dependent RAS interactions. Mol Cell Proteomics 2022; 21:100268. [PMID: 35839996 PMCID: PMC9396065 DOI: 10.1016/j.mcpro.2022.100268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 06/28/2022] [Accepted: 07/07/2022] [Indexed: 11/22/2022] Open
Abstract
Active mutations in the RAS genes are found in ∼30% of human cancers. Although thought to have overlapping functions, RAS isoforms show preferential activation in human tumors, which prompted us to employ a comparative and quantitative proteomics approach to generate isoform-specific and nucleotide-dependent interactomes of the four RAS isoforms, KRAS4A, KRAS4B, HRAS, and NRAS. Many isoform-specific interacting proteins were identified, including HRAS-specific CARM1 and CHK1 and KRAS-specific PIP4K2C and IPO7. Comparing the interactomes of WT and constitutively active G12D mutant of RAS isoforms, we identified several potential previously unknown effector proteins of RAS, one of which was recently reported while this article was in preparation, RADIL. These interacting proteins play important roles as knockdown or pharmacological inhibition leads to potent inhibition of cancer cells. The HRAS-specific interacting protein CARM1 plays a role in HRAS-induced senescence, with CARM1 knockdown or inhibition selectively increasing senescence in HRAS-transformed cells but not in KRAS4B-transformed cells. By revealing new isoform-specific and nucleotide-dependent RAS interactors, the study here provides insights to help understand the overlapping functions of the RAS isoforms. RAS interactome uncovers isoform-specific and nucleotide-dependent interactors. Potential novel RAS effector proteins are introduced. RAS interactors are possible new targets for RAS-driven cancer cells.
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14
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Aran V. K-RAS4A: Lead or Supporting Role in Cancer Biology? Front Mol Biosci 2021; 8:729830. [PMID: 34604308 PMCID: PMC8479197 DOI: 10.3389/fmolb.2021.729830] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/01/2021] [Indexed: 11/19/2022] Open
Abstract
The RAS oncogene is one of the most frequently mutated genes in human cancer, with K-RAS having a leading role in tumorigenesis. K-RAS undergoes alternative splicing, and as a result its transcript generates two gene products K-RAS4A and K-RAS4B, which are affected by the same oncogenic mutations, are highly homologous, and are expressed in a variety of human tissues at different levels. In addition, both isoforms localise to the plasma membrane by distinct targeting motifs. While some evidence suggests nonredundant functions for both splice variants, most work to date has focused on K-RAS4B, or even just K-RAS (i.e., without differentiating between the splice variants). This review aims to address the most relevant evidence published regarding K-RAS4A and to discuss if this “minor” isoform could also play a leading role in cancer, concluding that a significant body of evidence supports a leading role rather than a supporting (or secondary) role for K-RAS4A in cancer biology.
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Affiliation(s)
- Veronica Aran
- Laboratorio de Biomedicina Do Cérebro, Instituto Estadual Do Cérebro Paulo Niemeyer, Rio de Janeiro, Brazil
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15
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Tang D, Kroemer G, Kang R. Oncogenic KRAS blockade therapy: renewed enthusiasm and persistent challenges. Mol Cancer 2021; 20:128. [PMID: 34607583 PMCID: PMC8489073 DOI: 10.1186/s12943-021-01422-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 09/08/2021] [Indexed: 02/08/2023] Open
Abstract
Across a broad range of human cancers, gain-of-function mutations in RAS genes (HRAS, NRAS, and KRAS) lead to constitutive activity of oncoproteins responsible for tumorigenesis and cancer progression. The targeting of RAS with drugs is challenging because RAS lacks classic and tractable drug binding sites. Over the past 30 years, this perception has led to the pursuit of indirect routes for targeting RAS expression, processing, upstream regulators, or downstream effectors. After the discovery that the KRAS-G12C variant contains a druggable pocket below the switch-II loop region, it has become possible to design irreversible covalent inhibitors for the variant with improved potency, selectivity and bioavailability. Two such inhibitors, sotorasib (AMG 510) and adagrasib (MRTX849), were recently evaluated in phase I-III trials for the treatment of non-small cell lung cancer with KRAS-G12C mutations, heralding a new era of precision oncology. In this review, we outline the mutations and functions of KRAS in human tumors and then analyze indirect and direct approaches to shut down the oncogenic KRAS network. Specifically, we discuss the mechanistic principles, clinical features, and strategies for overcoming primary or secondary resistance to KRAS-G12C blockade.
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Affiliation(s)
- Daolin Tang
- The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, China. .,Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Guido Kroemer
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France. .,Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France. .,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
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16
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KRAS4A induces metastatic lung adenocarcinomas in vivo in the absence of the KRAS4B isoform. Proc Natl Acad Sci U S A 2021; 118:2023112118. [PMID: 34301865 DOI: 10.1073/pnas.2023112118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In mammals, the KRAS locus encodes two protein isoforms, KRAS4A and KRAS4B, which differ only in their C terminus via alternative splicing of distinct fourth exons. Previous studies have shown that whereas KRAS expression is essential for mouse development, the KRAS4A isoform is expendable. Here, we have generated a mouse strain that carries a terminator codon in exon 4B that leads to the expression of an unstable KRAS4B154 truncated polypeptide, hence resulting in a bona fide Kras4B-null allele. In contrast, this terminator codon leaves expression of the KRAS4A isoform unaffected. Mice selectively lacking KRAS4B expression developed to term but died perinatally because of hypertrabeculation of the ventricular wall, a defect reminiscent of that observed in embryos lacking the Kras locus. Mouse embryonic fibroblasts (MEFs) obtained from Kras4B-/- embryos proliferated less than did wild-type MEFs, because of limited expression of KRAS4A, a defect that can be compensated for by ectopic expression of this isoform. Introduction of the same terminator codon into a Kras FSFG12V allele allowed expression of an endogenous KRAS4AG12V oncogenic isoform in the absence of KRAS4B. Exposure of Kras +/FSF4AG12V4B- mice to Adeno-FLPo particles induced lung tumors with complete penetrance, albeit with increased latencies as compared with control Kras +/FSFG12V animals. Moreover, a significant percentage of these mice developed proximal metastasis, a feature seldom observed in mice expressing both mutant isoforms. These results illustrate that expression of the KRAS4AG12V mutant isoform is sufficient to induce lung tumors, thus suggesting that selective targeting of the KRAS4BG12V oncoprotein may not have significant therapeutic consequences.
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17
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Huang M, Wang Y. GLOBAL AND TARGETED PROFILING OF GTP-BINDING PROTEINS IN BIOLOGICAL SAMPLES BY MASS SPECTROMETRY. MASS SPECTROMETRY REVIEWS 2021; 40:215-235. [PMID: 32519381 PMCID: PMC7725852 DOI: 10.1002/mas.21637] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/04/2020] [Accepted: 05/15/2020] [Indexed: 05/05/2023]
Abstract
GTP-binding proteins are among the most important enzyme families that are involved in a plethora of biological processes. However, owing to the enormous diversity of the nucleotide-binding protein family, comprehensive analyses of the expression level, structure, activity, and regulatory mechanisms of GTP-binding proteins remain challenging with the use of conventional approaches. The many advances in mass spectrometry (MS) instrumentation and data acquisition methods, together with a variety of enrichment approaches in sample preparation, render MS a powerful tool for the comprehensive characterizations of the activities and expression levels of various GTP-binding proteins. We review herein the recent developments in the application of MS-based techniques, together with general and widely used affinity enrichment approaches, for the proteome-wide and targeted capture, identification, and quantification of GTP-binding proteins. The working principles, advantages, and limitations of various strategies for profiling the expression level, activity, posttranslational modifications, and interactome of GTP-binding proteins are discussed. It can be envisaged that future applications of MS-based proteomics will lead to a better understanding about the roles of GTP-binding proteins in different biological processes and human diseases. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Ming Huang
- Environmental Toxicology Graduate Program, University of California Riverside, Riverside, CA 92521, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California Riverside, Riverside, CA 92521, USA
- Department of Chemistry, University of California Riverside, Riverside, CA 92521, USA
- Correspondence author: Yinsheng Wang. Telephone: (951)827-2700;
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18
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Kiel C, Matallanas D, Kolch W. The Ins and Outs of RAS Effector Complexes. Biomolecules 2021; 11:236. [PMID: 33562401 PMCID: PMC7915224 DOI: 10.3390/biom11020236] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/31/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
RAS oncogenes are among the most commonly mutated proteins in human cancers. They regulate a wide range of effector pathways that control cell proliferation, survival, differentiation, migration and metabolic status. Including aberrations in these pathways, RAS-dependent signaling is altered in more than half of human cancers. Targeting mutant RAS proteins and their downstream oncogenic signaling pathways has been elusive. However, recent results comprising detailed molecular studies, large scale omics studies and computational modeling have painted a new and more comprehensive portrait of RAS signaling that helps us to understand the intricacies of RAS, how its physiological and pathophysiological functions are regulated, and how we can target them. Here, we review these efforts particularly trying to relate the detailed mechanistic studies with global functional studies. We highlight the importance of computational modeling and data integration to derive an actionable understanding of RAS signaling that will allow us to design new mechanism-based therapies for RAS mutated cancers.
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Affiliation(s)
- Christina Kiel
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
- UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland
| | - David Matallanas
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
| | - Walter Kolch
- Systems Biology Ireland, School of Medicine, University College Dublin, Dublin 4, Ireland; (C.K.); (D.M.)
- Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
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19
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Abstract
One of the mechanisms potentially explaining the discrepancy between the number of human genes and the functional complexity of organisms is generating alternative splice variants, an attribute of the vast majority of multi-exon genes. Members of the RAS family, such as NRAS, KRAS and HRAS, all of which are of significant importance in cancer biology, are no exception. The structural and functional differences of these splice variants, particularly if they contain the canonical (and therefore routinely targeted for diagnostic purposes) hot spot mutations, pose a significant challenge for targeted therapies. We must therefore consider whether these alternative splice variants constitute a minor component as originally thought and how therapies targeting the canonical isoforms affect these alternative splice variants and their overall functions.
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Affiliation(s)
- Erzsébet Rásó
- 2nd Department of Pathology, Semmelweis University, Budapest, Hungary.
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20
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Abstract
Precisely controlling the activation of transcription factors is crucial for physiology. After a transcription factor is activated and carries out its transcriptional activity, it also needs to be properly deactivated. Here, we report a deactivation mechanism of HIF-1 and several other oncogenic transcription factors. HIF-1 promotes the transcription of an ADP ribosyltransferase, TiPARP, which serves to deactivate HIF-1. Mechanistically, TiPARP forms distinct nuclear condensates or nuclear bodies in an ADP ribosylation-dependent manner. The TiPARP nuclear bodies recruit both HIF-1α and an E3 ubiquitin ligase HUWE1, which promotes the ubiquitination and degradation of HIF-1α. Similarly, TiPARP promotes the degradation of c-Myc and estrogen receptor. By suppressing HIF-1α and other oncogenic transcription factors, TiPARP exerts strong antitumor effects both in cell culture and in mouse xenograft models. Our work reveals TiPARP as a negative-feedback regulator for multiple oncogenic transcription factors, provides insights into the functions of protein ADP-ribosylation, and suggests activating TiPARP as an anticancer strategy.
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21
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Abdelkarim H, Banerjee A, Grudzien P, Leschinsky N, Abushaer M, Gaponenko V. The Hypervariable Region of K-Ras4B Governs Molecular Recognition and Function. Int J Mol Sci 2019; 20:ijms20225718. [PMID: 31739603 PMCID: PMC6888304 DOI: 10.3390/ijms20225718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/09/2019] [Accepted: 11/11/2019] [Indexed: 12/25/2022] Open
Abstract
The flexible C-terminal hypervariable region distinguishes K-Ras4B, an important proto-oncogenic GTPase, from other Ras GTPases. This unique lysine-rich portion of the protein harbors sites for post-translational modification, including cysteine prenylation, carboxymethylation, phosphorylation, and likely many others. The functions of the hypervariable region are diverse, ranging from anchoring K-Ras4B at the plasma membrane to sampling potentially auto-inhibitory binding sites in its GTPase domain and participating in isoform-specific protein-protein interactions and signaling. Despite much research, there are still many questions about the hypervariable region of K-Ras4B. For example, mechanistic details of its interaction with plasma membrane lipids and with the GTPase domain require further clarification. The roles of the hypervariable region in K-Ras4B-specific protein-protein interactions and signaling are incompletely defined. It is also unclear why post-translational modifications frequently found in protein polylysine domains, such as acetylation, glycation, and carbamoylation, have not been observed in K-Ras4B. Expanding knowledge of the hypervariable region will likely drive the development of novel highly-efficient and selective inhibitors of K-Ras4B that are urgently needed by cancer patients.
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Affiliation(s)
- Hazem Abdelkarim
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA; (H.A.); (P.G.); (N.L.); (M.A.)
| | - Avik Banerjee
- Department of Chemistry, University of Illinois at Chicago (UIC), Chicago, IL 60612, USA;
| | - Patrick Grudzien
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA; (H.A.); (P.G.); (N.L.); (M.A.)
| | - Nicholas Leschinsky
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA; (H.A.); (P.G.); (N.L.); (M.A.)
| | - Mahmoud Abushaer
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA; (H.A.); (P.G.); (N.L.); (M.A.)
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA; (H.A.); (P.G.); (N.L.); (M.A.)
- Correspondence: ; Tel.: +312-355-4839
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22
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Abstract
The three RAS genes - HRAS, NRAS and KRAS - are collectively mutated in one-third of human cancers, where they act as prototypic oncogenes. Interestingly, there are rather distinct patterns to RAS mutations; the isoform mutated as well as the position and type of substitution vary between different cancers. As RAS genes are among the earliest, if not the first, genes mutated in a variety of cancers, understanding how these mutation patterns arise could inform on not only how cancer begins but also the factors influencing this event, which has implications for cancer prevention. To this end, we suggest that there is a narrow window or 'sweet spot' by which oncogenic RAS signalling can promote tumour initiation in normal cells. As a consequence, RAS mutation patterns in each normal cell are a product of the specific RAS isoform mutated, as well as the position of the mutation and type of substitution to achieve an ideal level of signalling.
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Affiliation(s)
- Siqi Li
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
| | - Allan Balmain
- Helen Diller Family Comprehensive Cancer Center and Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Christopher M Counter
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA.
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