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Wang L, Bitar M, Lu X, Jacquelin S, Nair S, Sivakumaran H, Hillman KM, Kaufmann S, Ziegman R, Casciello F, Gowda H, Rosenbluh J, Edwards SL, French JD. CRISPR-Cas13d screens identify KILR, a breast cancer risk-associated lncRNA that regulates DNA replication and repair. Mol Cancer 2024; 23:101. [PMID: 38745269 PMCID: PMC11094906 DOI: 10.1186/s12943-024-02021-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/09/2024] [Indexed: 05/16/2024] Open
Abstract
BACKGROUND Long noncoding RNAs (lncRNAs) have surpassed the number of protein-coding genes, yet the majority have no known function. We previously discovered 844 lncRNAs that were genetically linked to breast cancer through genome-wide association studies (GWAS). Here, we show that a subset of these lncRNAs alter breast cancer risk by modulating cell proliferation, and provide evidence that a reduced expression on one lncRNA increases breast cancer risk through aberrant DNA replication and repair. METHODS We performed pooled CRISPR-Cas13d-based knockdown screens in breast cells to identify which of the 844 breast cancer-associated lncRNAs alter cell proliferation. We selected one of the lncRNAs that increased cell proliferation, KILR, for follow-up functional studies. KILR pull-down followed by mass spectrometry was used to identify binding proteins. Knockdown and overexpression studies were performed to assess the mechanism by which KILR regulates proliferation. RESULTS We show that KILR functions as a tumor suppressor, safeguarding breast cells against uncontrolled proliferation. The half-life of KILR is significantly reduced by the risk haplotype, revealing an alternative mechanism by which variants alter cancer risk. Mechanistically, KILR sequesters RPA1, a subunit of the RPA complex required for DNA replication and repair. Reduced KILR expression promotes breast cancer cell proliferation by increasing the available pool of RPA1 and speed of DNA replication. Conversely, KILR overexpression promotes apoptosis in breast cancer cells, but not normal breast cells. CONCLUSIONS Our results confirm lncRNAs as mediators of breast cancer risk, emphasize the need to annotate noncoding transcripts in relevant cell types when investigating GWAS variants and provide a scalable platform for mapping phenotypes associated with lncRNAs.
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Affiliation(s)
- Lu Wang
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Mainá Bitar
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Faculty of Health, Queensland University of Technology, Brisbane, Australia
- Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Xue Lu
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Sebastien Jacquelin
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Macrophage Biology Laboratory, Mater Research, Brisbane, Australia
| | - Sneha Nair
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Haran Sivakumaran
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Kristine M Hillman
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Susanne Kaufmann
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Rebekah Ziegman
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Francesco Casciello
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Harsha Gowda
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Joseph Rosenbluh
- Cancer Research Program, Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Functional Genomics Platform, Monash University, Clayton, Australia
| | - Stacey L Edwards
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
- Faculty of Health, Queensland University of Technology, Brisbane, Australia.
- Faculty of Medicine, The University of Queensland, Brisbane, Australia.
| | - Juliet D French
- Cancer Research Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
- Faculty of Health, Queensland University of Technology, Brisbane, Australia.
- Faculty of Medicine, The University of Queensland, Brisbane, Australia.
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Casciello F, Kelly GM, Ramarao-Milne P, Kamal N, Stewart TA, Mukhopadhyay P, Kazakoff SH, Miranda M, Kim D, Davis FM, Hayward NK, Vertino PM, Waddell N, Gannon F, Lee JS. Combined inhibition of G9a and EZH2 suppresses tumor growth via synergistic induction of IL24-mediated apoptosis. Cancer Res 2022; 82:1208-1221. [PMID: 35149587 DOI: 10.1158/0008-5472.can-21-2218] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 12/07/2021] [Accepted: 02/09/2022] [Indexed: 11/16/2022]
Abstract
G9a and EZH2 are two histone methyltransferases commonly upregulated in several cancer types, yet the precise roles that these enzymes play cooperatively in cancer is unclear. We demonstrate here that frequent concurrent upregulation of both G9a and EZH2 occurs in several human tumors. These methyltransferases cooperatively repressed molecular pathways responsible for tumor cell death. In genetically distinct tumor subtypes, concomitant inhibition of G9a and EZH2 potently induced tumor cell death, highlighting the existence of tumor cell survival dependency at the epigenetic level. G9a and EZH2 synergistically repressed expression of genes involved in the induction of endoplasmic reticulum (ER) stress and the production of reactive oxygen species. IL24 was essential for the induction of tumor cell death and was identified as a common target of G9a and EZH2. Loss-of-function of G9a and EZH2 activated the IL24-ER stress axis and increased apoptosis in cancer cells while not affecting normal cells. These results indicate that G9a and EZH2 promotes the evasion of ER stress-mediated apoptosis by repressing IL24 transcription, therefore suggesting that their inhibition may represent a potential therapeutic strategy for solid cancers.
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Affiliation(s)
| | | | - Priya Ramarao-Milne
- Transformational Bioinformatics, Commonwealth Scientific and Industrial Research Organisation
| | - Nabilah Kamal
- Epigenetics and Disease Laboratory, QIMR Berghofer Medical Research Institute
| | | | | | | | | | - Dorim Kim
- Epigenetics and Disease Laboratory, QIMR Berghofer Medical Research Institute
| | - Felicity M Davis
- School of Medical Sciences, EMBL Australia Node in Single Molecule Science
| | | | - Paula M Vertino
- School of Medicine and Dentistry, University of Rochester Medical Center
| | - Nicola Waddell
- Medical Genomics Laboratory, QIMR Berghofer Medical Research Institute
| | - Frank Gannon
- Cancer, QIMR Berghofer Medical Research Institute
| | - Jason S Lee
- Epigenetics and Disease Laboratory, QIMR Berghofer Medical Research Institute
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Kelly GM, Al-Ejeh F, McCuaig R, Casciello F, Ahmad Kamal N, Ferguson B, Pritchard AL, Ali S, Silva IP, Wilmott JS, Long GV, Scolyer RA, Rao S, Hayward NK, Gannon F, Lee JS. G9a Inhibition Enhances Checkpoint Inhibitor Blockade Response in Melanoma. Clin Cancer Res 2021; 27:2624-2635. [PMID: 33589432 DOI: 10.1158/1078-0432.ccr-20-3463] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/24/2020] [Accepted: 02/05/2021] [Indexed: 11/16/2022]
Abstract
PURPOSE G9a histone methyltransferase exerts oncogenic effects in several tumor types and its inhibition promotes anticancer effects. However, the impact on checkpoint inhibitor blockade response and the utility of G9a or its target genes as a biomarker is poorly studied. We aimed to examine whether G9a inhibition can augment the efficacy of checkpoint inhibitor blockade and whether LC3B, a G9a target gene, can predict treatment response. EXPERIMENTAL DESIGN Clinical potential of LC3B as a biomarker of checkpoint inhibitor blockade was assessed using patient samples including tumor biopsies and circulating tumor cells from liquid biopsies. Efficacy of G9a inhibition to enhance checkpoint inhibitor blockade was examined using a mouse model. RESULTS Patients with melanoma who responded to checkpoint inhibitor blockade were associated with not only a higher level of tumor LC3B but also a higher proportion of cells expressing LC3B. A higher expression of MAP1LC3B or LC3B protein was associated with longer survival and lower incidence of acquired resistance to checkpoint inhibitor blockade, suggesting LC3B as a potential predictive biomarker. We demonstrate that G9a histone methyltransferase inhibition is able to not only robustly induce LC3B level to augment the efficacy of checkpoint inhibitor blockade, but also induces melanoma cell death. CONCLUSIONS Checkpoint inhibitor blockade response is limited to a subset of the patient population. These results have implications for the development of LC3B as a predictive biomarker of checkpoint inhibitor blockade to guide patient selection, as well as G9a inhibition as a strategy to extend the proportion of patients responding to immunotherapy.
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Affiliation(s)
- Gregory M Kelly
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia.,School of Medicine, University of Queensland, Herston, Queensland, Australia
| | - Fares Al-Ejeh
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Robert McCuaig
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Francesco Casciello
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | | | - Blake Ferguson
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | | | - Sayed Ali
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australia.,St John of God Midland Public and Private Hospitals, Midland, Western Australia, Australia
| | - Ines P Silva
- Melanoma Institute Australia, University of Sydney, Wollstonecraft, New South Wales, Australia.,Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia
| | - James S Wilmott
- Melanoma Institute Australia, University of Sydney, Wollstonecraft, New South Wales, Australia.,Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia
| | - Georgina V Long
- Melanoma Institute Australia, University of Sydney, Wollstonecraft, New South Wales, Australia.,Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia.,Royal North Shore Hospital, St Leonards, New South Wales, Australia.,Mater Hospital, North Sydney, New South Wales, Australia
| | - Richard A Scolyer
- Melanoma Institute Australia, University of Sydney, Wollstonecraft, New South Wales, Australia.,Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia.,Royal North Shore Hospital, St Leonards, New South Wales, Australia.,Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
| | - Sudha Rao
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Nicholas K Hayward
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Frank Gannon
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Jason S Lee
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia. .,School of Medicine, University of Queensland, Herston, Queensland, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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Casciello F, Al-Ejeh F, Miranda M, Kelly G, Baxter E, Windloch K, Gannon F, Lee JS. G9a-mediated repression of CDH10 in hypoxia enhances breast tumour cell motility and associates with poor survival outcome. Am J Cancer Res 2020; 10:4515-4529. [PMID: 32292512 PMCID: PMC7150496 DOI: 10.7150/thno.41453] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/25/2020] [Indexed: 12/13/2022] Open
Abstract
Rationale: Epigenetic mechanisms are fundamental processes that can modulate gene expression, allowing cellular adaptation to environmental conditions. Hypoxia is an important factor known to initiate the metastatic cascade in cancer, activating cell motility and invasion by silencing cell adhesion genes. G9a is a histone methyltransferase previously shown to accumulate in hypoxic conditions. While its oncogenic activity has been previously reported, not much is known about the role G9a plays in the hypoxia-mediated metastatic cascade. Methods: The role of G9a in cell motility in hypoxic condition was determined by inhibiting G9a either by short-hairpin mediated knock down or pharmacologically using a small molecule inhibitor. Through gene expression profiling, we identified CDH10 to be an important G9a target that regulates breast cancer cell motility. Lung metastasis assay in mice was used to determine the physiological significance of G9a. Results: We demonstrate that, while hypoxia enhances breast cancer migratory capacity, blocking G9a severely reduces cellular motility under both normoxic and hypoxic conditions and prevents the hypoxia-mediated induction of cellular movement. Moreover, inhibition of G9a histone methyltransferase activity in mice using a specific small molecule inhibitor significantly reduced growth and colonisation of breast cancer cells in the lung. We identify the type-II cadherin CDH10 as being a novel hypoxia-dependent gene, directly repressed by G9a through histone methylation. CDH10 overexpression significantly reduces cellular movements in breast cancer cell lines and prevents the hypoxia-mediated increase in cell motility. In addition, we show that CDH10 expression is prognostic in breast cancer and that it is inversely correlated to EHMT2 (G9a) transcript levels in many tumor-types, including breast cancer. Conclusion: We propose that G9a promotes cellular motility during hypoxic stress through the silencing of the cell adhesion molecule CDH10 and we describe CDH10 as a novel prognostic biomarker for breast cancer.
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Borchert G, Casciello F, Kelly G, Baxter E, Gannon F, Lee J. Re-sensitising endocrine resistant ER+ breast cancer by targeting epigenetic modifying enzymes. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy047.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Affiliation(s)
- Francesco Casciello
- a Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston Rd, Herston , QLD , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , QLD , Australia
| | - Jason S Lee
- a Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston Rd, Herston , QLD , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , QLD , Australia
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Casciello F, Windloch K, Gannon F, Lee JS. Functional Role of G9a Histone Methyltransferase in Cancer. Front Immunol 2015; 6:487. [PMID: 26441991 PMCID: PMC4585248 DOI: 10.3389/fimmu.2015.00487] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/07/2015] [Indexed: 11/13/2022] Open
Abstract
Post-translational modifications of DNA and histones are epigenetic mechanisms, which affect the chromatin structure, ultimately leading to gene expression changes. A number of different epigenetic enzymes are actively involved in the addition or the removal of various covalent modifications, which include acetylation, methylation, phosphorylation, ubiquitination, and sumoylation. Deregulation of these processes is a hallmark of cancer. For instance, G9a, a histone methyltransferase responsible for histone H3 lysine 9 (H3K9) mono- and dimethylation, has been observed to be upregulated in different types of cancer and its overexpression has been associated with poor prognosis. Key roles played by these enzymes in various diseases have led to the hypothesis that these molecules represent valuable targets for future therapies. Several small molecule inhibitors have been developed to specifically block the epigenetic activity of these enzymes, representing promising therapeutic tools in the treatment of human malignancies, such as cancer. In this review, the role of one of these epigenetic enzymes, G9a, is discussed, focusing on its functional role in regulating gene expression as well as its implications in cancer initiation and progression. We also discuss important findings from recent studies using epigenetic inhibitors in cell systems in vitro as well as experimental tumor growth and metastasis assays in vivo.
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Affiliation(s)
- Francesco Casciello
- Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD , Australia ; School of Natural Sciences, Griffith University , Nathan, QLD , Australia
| | - Karolina Windloch
- Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD , Australia
| | - Frank Gannon
- Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD , Australia
| | - Jason S Lee
- Control of Gene Expression Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD , Australia ; Faculty of Health, School of Biomedical Sciences, Queensland University of Technology , Kelvin Grove, QLD , Australia ; School of Chemistry and Molecular Biosciences, University of Queensland , Brisbane, QLD , Australia
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