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Cook AL, Sur S, Dobbyn L, Watson E, Cohen JD, Ptak B, Lee BS, Paul S, Hsiue E, Popoli M, Vogelstein B, Papadopoulos N, Bettegowda C, Gabrielson K, Zhou S, Kinzler KW, Wyhs N. Identification of nonsense-mediated decay inhibitors that alter the tumor immune landscape. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.28.573594. [PMID: 38234817 PMCID: PMC10793421 DOI: 10.1101/2023.12.28.573594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Despite exciting developments in cancer immunotherapy, its broad application is limited by the paucity of targetable antigens on the tumor cell surface. As an intrinsic cellular pathway, nonsense-mediated decay (NMD) conceals neoantigens through the destruction of the RNA products from genes harboring truncating mutations. We developed and conducted a high throughput screen, based on the ratiometric analysis of transcripts, to identify critical mediators of NMD. This screen implicated disruption of kinase SMG1's phosphorylation of UPF1 as a potential disruptor of NMD. This led us to design a novel SMG1 inhibitor, KVS0001, that elevates the expression of transcripts and proteins resulting from truncating mutations in vivo and in vitro . Most importantly, KVS0001 concomitantly increased the presentation of immune-targetable HLA class I-associated peptides from NMD-downregulated proteins on the surface of cancer cells. KVS0001 provides new opportunities for studying NMD and the diseases in which NMD plays a role, including cancer and inherited diseases. One Sentence Summary Disruption of the nonsense-mediated decay pathway with a newly developed SMG1 inhibitor with in-vivo activity increases the expression of T-cell targetable cancer neoantigens resulting from truncating mutations.
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Cheruiyot A, Li S, Nonavinkere Srivatsan S, Ahmed T, Chen Y, Lemacon DS, Li Y, Yang Z, Wadugu BA, Warner WA, Pruett-Miller SM, Obeng EA, Link DC, He D, Xiao F, Wang X, Bailis JM, Walter MJ, You Z. Nonsense-Mediated RNA Decay Is a Unique Vulnerability of Cancer Cells Harboring SF3B1 or U2AF1 Mutations. Cancer Res 2021; 81:4499-4513. [PMID: 34215620 DOI: 10.1158/0008-5472.can-20-4016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 05/26/2021] [Accepted: 06/30/2021] [Indexed: 11/16/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is recognized as an RNA surveillance pathway that targets aberrant mRNAs with premature translation termination codons (PTC) for degradation, however, its molecular mechanisms and roles in health and disease remain incompletely understood. In this study, we developed a novel reporter system to accurately measure NMD activity in individual cells. A genome-wide CRISPR-Cas9 knockout screen using this reporter system identified novel NMD-promoting factors, including multiple components of the SF3B complex and other U2 spliceosome factors. Interestingly, cells with mutations in the spliceosome genes SF3B1 and U2AF1, which are commonly found in myelodysplastic syndrome (MDS) and cancers, have overall attenuated NMD activity. Compared with wild-type (WT) cells, SF3B1- and U2AF1-mutant cells were more sensitive to NMD inhibition, a phenotype that is accompanied by elevated DNA replication obstruction, DNA damage, and chromosomal instability. Remarkably, the sensitivity of spliceosome mutant cells to NMD inhibition was rescued by overexpression of RNase H1, which removes R-loops in the genome. Together, these findings shed new light on the functional interplay between NMD and RNA splicing and suggest a novel synthetic lethal strategy for the treatment of MDS and cancers with spliceosome mutations. SIGNIFICANCE: This study has developed a novel NMD reporter system and identified a potential therapeutic approach of targeting the NMD pathway to treat cancer with spliceosome gene mutations.
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Affiliation(s)
- Abigael Cheruiyot
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Shan Li
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Sridhar Nonavinkere Srivatsan
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Tanzir Ahmed
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Yuhao Chen
- Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Delphine S Lemacon
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Ying Li
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri.,Clinical Biobank, The Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, P.R. China
| | - Zheng Yang
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri.,Department of Urology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, China
| | - Brian A Wadugu
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Wayne A Warner
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Shondra M Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Esther A Obeng
- Molecular Oncology Division, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Daniel C Link
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Dalin He
- Department of Urology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, China
| | - Fei Xiao
- Clinical Biobank, The Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, P.R. China
| | - Xiaowei Wang
- Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | | | - Matthew J Walter
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, Washington University School in St. Louis, St. Louis, Missouri
| | - Zhongsheng You
- Department of Cell Biology and Physiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri.
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Repression of TERRA Expression by Subtelomeric DNA Methylation Is Dependent on NRF1 Binding. Int J Mol Sci 2019; 20:ijms20112791. [PMID: 31181625 PMCID: PMC6600276 DOI: 10.3390/ijms20112791] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 05/29/2019] [Accepted: 06/04/2019] [Indexed: 12/25/2022] Open
Abstract
Chromosome ends are transcribed into long noncoding telomeric repeat-containing RNA (TERRA) from subtelomeric promoters. A class of TERRA promoters are associated with CpG islands embedded in repetitive DNA tracts. Cytosines in these subtelomeric CpG islands are frequently methylated in telomerase-positive cancer cells, and demethylation induced by depletion of DNA methyltransferases is associated with increased TERRA levels. However, the direct evidence and the underlying mechanism regulating TERRA expression through subtelomeric CpG islands methylation are still to establish. To analyze TERRA regulation by subtelomeric DNA methylation in human cell line (HeLa), we used an epigenetic engineering tool based on CRISPR-dCas9 (clustered regularly interspaced short palindromic repeats - dead CRISPR associated protein 9) associated with TET1 (ten-eleven 1 hydroxylase) to specifically demethylate subtelomeric CpG islands. This targeted demethylation caused an up-regulation of TERRA, and the enhanced TERRA production depended on the methyl-sensitive transcription factor NRF1 (nuclear respiratory factor 1). Since AMPK (AMP-activated protein kinase) is a well-known activator of NRF1, we treated cells with an AMPK inhibitor (compound C). Surprisingly, compound C treatment increased TERRA levels but did not inhibit AMPK activity in these experimental conditions. Altogether, our results provide new insight in the fine-tuning of TERRA at specific subtelomeric promoters and could allow identifying new regulators of TERRA.
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