1
|
Knutsen E, Lellahi SM, Aure MR, Nord S, Fismen S, Larsen KB, Gabriel MT, Hedberg A, Bjørklund SS, Bofin AM, Mælandsmo GM, Sørlie T, Mortensen ES, Perander M. The expression of the long NEAT1_2 isoform is associated with human epidermal growth factor receptor 2-positive breast cancers. Sci Rep 2020; 10:1277. [PMID: 31992741 PMCID: PMC6987222 DOI: 10.1038/s41598-020-57759-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 12/21/2019] [Indexed: 12/21/2022] Open
Abstract
The long non-coding RNA NEAT1 locus is transcribed into two overlapping isoforms, NEAT1_1 and NEAT1_2, of which the latter is essential for the assembly of nuclear paraspeckles. NEAT1 is abnormally expressed in a wide variety of human cancers. Emerging evidence suggests that the two isoforms have distinct functions in gene expression regulation, and recently it was shown that NEAT1_2, but not NEAT1_1, expression predicts poor clinical outcome in cancer. Here, we report that NEAT1_2 expression correlates with HER2-positive breast cancers and high-grade disease. We provide evidence that NEAT1_1 and NEAT1_2 have distinct expression pattern among different intrinsic breast cancer subtypes. Finally, we show that NEAT1_2 expression and paraspeckle formation increase upon lactation in humans, confirming what has previously been demonstrated in mice.
Collapse
Affiliation(s)
- Erik Knutsen
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Seyed Mohammad Lellahi
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Miriam Ragle Aure
- Department of Cancer Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Silje Nord
- Department of Cancer Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Silje Fismen
- Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway
| | - Kenneth Bowitz Larsen
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Marta Tellez Gabriel
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Annica Hedberg
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Sunniva Stordal Bjørklund
- Department of Cancer Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | | | - Anna Mary Bofin
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Gunhild Mari Mælandsmo
- Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Therese Sørlie
- Department of Cancer Genetics, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Elin Synnøve Mortensen
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.,Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway
| | - Maria Perander
- Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
| |
Collapse
|
2
|
Adriaens C, Rambow F, Bervoets G, Silla T, Mito M, Chiba T, Asahara H, Hirose T, Nakagawa S, Jensen TH, Marine JC. The long noncoding RNA NEAT1_1 is seemingly dispensable for normal tissue homeostasis and cancer cell growth. RNA 2019; 25:1681-1695. [PMID: 31551298 PMCID: PMC6859857 DOI: 10.1261/rna.071456.119] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/30/2019] [Indexed: 05/27/2023]
Abstract
NEAT1 is one of the most studied lncRNAs, in part because its silencing in mice causes defects in mammary gland development and corpus luteum formation and protects them from skin cancer development. Moreover, depleting NEAT1 in established cancer cell lines reduces growth and sensitizes cells to DNA damaging agents. However, NEAT1 produces two isoforms and because the short isoform, NEAT1_1, completely overlaps the 5' part of the long NEAT1_2 isoform; the respective contributions of each of the isoforms to these phenotypes has remained unclear. Whereas NEAT1_1 is highly expressed in most tissues, NEAT1_2 is the central architectural component of paraspeckles, which are nuclear bodies that assemble in specific tissues and cells exposed to various forms of stress. Using dual RNA-FISH to detect both NEAT1_1 outside of the paraspeckles and NEAT1_2/NEAT1 inside this nuclear body, we report herein that NEAT1_1 levels are dynamically regulated during the cell cycle and targeted for degradation by the nuclear RNA exosome. Unexpectedly, however, cancer cells engineered to lack NEAT1_1, but not NEAT1_2, do not exhibit cell cycle defects. Moreover, Neat1_1-specific knockout mice do not exhibit the phenotypes observed in Neat1-deficient mice. We propose that NEAT1 functions are mainly, if not exclusively, attributable to NEAT1_2 and, by extension, to paraspeckles.
Collapse
Affiliation(s)
- Carmen Adriaens
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, VIB, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Oncology Department, KU Leuven, 3000 Leuven, Belgium
| | - Florian Rambow
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, VIB, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Oncology Department, KU Leuven, 3000 Leuven, Belgium
| | - Greet Bervoets
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, VIB, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Oncology Department, KU Leuven, 3000 Leuven, Belgium
| | - Toomas Silla
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Mari Mito
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, 351-0198 Saitama, Japan
| | - Tomoki Chiba
- Department of Systems BioMedicine, Tokyo Medical and Dental University, 113-8510 Tokyo, Japan
| | - Hiroshi Asahara
- Department of Systems BioMedicine, Tokyo Medical and Dental University, 113-8510 Tokyo, Japan
| | - Tetsuro Hirose
- Institute for Genetic Medicine, Hokkaido University, 060-0808 Sapporo, Japan
| | - Shinichi Nakagawa
- Faculty of Pharmaceutical Sciences, Hokkaido University, 060-0812 Sapporo, Japan
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Jean-Christophe Marine
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, VIB, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Oncology Department, KU Leuven, 3000 Leuven, Belgium
| |
Collapse
|