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Di Nisio E, Licursi V, Mannironi C, Buglioni V, Paiardini A, Robusti G, Noberini R, Bonaldi T, Negri R. A truncated and catalytically inactive isoform of KDM5B histone demethylase accumulates in breast cancer cells and regulates H3K4 tri-methylation and gene expression. Cancer Gene Ther 2023:10.1038/s41417-022-00584-w. [PMID: 36697763 DOI: 10.1038/s41417-022-00584-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 01/27/2023]
Abstract
KDM5B histone demethylase is overexpressed in many cancers and plays an ambivalent role in oncogenesis, depending on the specific context. This ambivalence could be explained by the expression of KDM5B protein isoforms with diverse functional roles, which could be present at different levels in various cancer cell lines. We show here that one of these isoforms, namely KDM5B-NTT, accumulates in breast cancer cell lines due to remarkable protein stability relative to the canonical PLU-1 isoform, which shows a much faster turnover. This isoform is the truncated and catalytically inactive product of an mRNA with a transcription start site downstream of the PLU-1 isoform, and the consequent usage of an alternative ATG for translation initiation. It also differs from the PLU-1 transcript in the inclusion of an additional exon (exon-6), previously attributed to other putative isoforms. Overexpression of this isoform in MCF7 cells leads to an increase in bulk H3K4 methylation and induces derepression of a gene cluster, including the tumor suppressor Cav1 and several genes involved in the interferon-alpha and -gamma response. We discuss the relevance of this finding considering the hypothesis that KDM5B may possess regulatory roles independent of its catalytic activity.
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Affiliation(s)
- Elena Di Nisio
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, via dei Sardi 70, 00185, Rome, Italy.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Sir James Black Centre, Dow Street, DD1 5EH, Dundee, Scotland, UK
| | - Valerio Licursi
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) of Italy, Via degli Apuli 4, 00185, Rome, Italy
| | - Cecilia Mannironi
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) of Italy, Via degli Apuli 4, 00185, Rome, Italy
| | - Valentina Buglioni
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, via dei Sardi 70, 00185, Rome, Italy
| | - Alessandro Paiardini
- Department of Biochemical Sciences, Sapienza University of Rome, p.le Aldo Moro 5, 00185, Rome, Italy
| | - Giulia Robusti
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
| | - Roberta Noberini
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy
| | - Tiziana Bonaldi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Via Adamello 16, 20139, Milan, Italy.,Department of Oncology and Hematology-Oncology, University of Milan, Milan, 20122, Italy
| | - Rodolfo Negri
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, via dei Sardi 70, 00185, Rome, Italy. .,Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) of Italy, Via degli Apuli 4, 00185, Rome, Italy.
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Kuźbicki Ł, Lange D, Stanek-Widera A, Chwirot BW. Prognostic significance of RBP2-H1 variant of JARID1B in melanoma. BMC Cancer 2017; 17:854. [PMID: 29246117 PMCID: PMC5731204 DOI: 10.1186/s12885-017-3836-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 11/23/2017] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Histone demethylase JARID1B plays several context dependent roles in epigenetic regulation of cellular differentiation in normal development and is highly expressed in multiple human cancers. The protein is a strong transcriptional repressor capable of downregulating numerous genes. There are three splicing isoforms of JARID1B, however the links between the protein structure and function are not clear. The expression pattern of JARID1B in human melanoma seems to be different from observed in other cancers. Moreover, up to now no data on the impact of JARID1B expression in cutaneous melanoma on the patients' prognosis have been reported. METHODS We investigated immunohistochemically the association of intratumoral expression of total JARID1B protein and its RBP2-H1 isoform in primary and metastatic melanomas with prognosis for the patients. RESULTS Expression of both total JARID1B protein and its RBP2-H1 variant was found in all the melanomas investigated. Our results indicate, however, that only high (above 90% of the cells) intratumoral expression of RBP2-H1 can be considered prognostic factor associated with worse overall survival of the patients. CONCLUSIONS Such results if considered together with data demonstrating a switch to enhanced expression of RBP2-H1 at early stages of malignant transformation of melanocytes are in agreement with hypothetical crucial role of JARID1B in the course of melanoma development and progression and suggest that altered splicing of JARID1B may be important factor increasing melanoma aggressiveness.
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Affiliation(s)
- Łukasz Kuźbicki
- Department of Medical Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland
| | - Dariusz Lange
- Department of Tumor Pathology, Oncology Center - Maria Skłodowska-Curie Institute, Wybrzeże Armii Krajowej 15, 44-101, Gliwice, Poland
| | - Agata Stanek-Widera
- Department of Tumor Pathology, Oncology Center - Maria Skłodowska-Curie Institute, Wybrzeże Armii Krajowej 15, 44-101, Gliwice, Poland
| | - Barbara W Chwirot
- Department of Medical Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland.
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