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Lam AJ, Haque M, Ward-Hartstonge KA, Uday P, Wardell CM, Gillies JK, Speck M, Mojibian M, Klein Geltink RI, Levings MK. PTEN is required for human Treg suppression of costimulation in vitro. Eur J Immunol 2022; 52:1482-1497. [PMID: 35746855 DOI: 10.1002/eji.202249888] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/18/2022] [Accepted: 06/10/2022] [Indexed: 11/07/2022]
Abstract
Regulatory T cell (Treg) therapy is under clinical investigation for the treatment of transplant rejection, autoimmune disease, and graft-versus-host disease. With the advent of genome editing, attention has turned to reinforcing Treg function for therapeutic benefit. A hallmark of Tregs is dampened activation of PI3K-AKT signalling, of which PTEN is a major negative regulator. Loss-of-function studies of PTEN, however, have not conclusively shown a requirement for PTEN in upholding Treg function and stability. Using CRISPR-based genome editing in human Tregs, we show that PTEN ablation does not cause a global defect in Treg function and stability; rather, it selectively blocks their ability to suppress antigen-presenting cells. PTEN-KO Tregs exhibit elevated glycolytic activity, upregulate FOXP3, maintain a Treg phenotype, and have no discernable defects in lineage stability. Functionally, PTEN is dispensable for human Treg-mediated inhibition of T cell activity in vitro and in vivo, but is required for suppression of costimulatory molecule expression by antigen-presenting cells. These data are the first to define a role for a signalling pathway in controlling a subset of human Treg activity. Moreover, they point to the functional necessity of PTEN-regulated PI3K-AKT activity for optimal human Treg function. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Avery J Lam
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Manjurul Haque
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Kirsten A Ward-Hartstonge
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Prakruti Uday
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Christine M Wardell
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Jana K Gillies
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Madeleine Speck
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Majid Mojibian
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada
| | - Ramon I Klein Geltink
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, V6T 2B5, Canada.,Department of Molecular Oncology, BC Cancer Research, Vancouver, BC, V5Z 1L3, Canada
| | - Megan K Levings
- BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, V6T 1Z3, Canada
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Lam AJ, Uday P, Gillies JK, Levings MK. Helios is a marker, not a driver, of human Treg stability. Eur J Immunol 2021; 52:75-84. [PMID: 34561855 DOI: 10.1002/eji.202149318] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 08/24/2021] [Accepted: 09/13/2021] [Indexed: 12/13/2022]
Abstract
Treg therapy holds promise as a potentially curative approach to establish immune tolerance in transplantation and autoimmune disease. An outstanding question is whether therapeutic Tregs have the potential to transdifferentiate into effector T-cells and, thus, exacerbate rather than suppress immune responses. In mice, the transcription factor Helios is thought to promote Treg lineage stability in a range of inflammatory contexts. In humans, the role of Helios in Tregs is less clear, in part, due to the inability to enrich and study subsets of Helios-positive versus Helios-negative Tregs. Using an in vitro expansion system, we found that loss of high Helios expression and emergence of an intermediate Helios (Heliosmid )-expressing population correlated with Treg destabilization. We used CRISPR/Cas9 to genetically ablate Helios expression in human naive or memory Tregs and found that Helios-KO and unedited Tregs were equivalent in their suppressive function and stability in inflammation. Thus, high Helios expression is a marker, but not a driver, of human Treg stability in vitro. These data highlight the importance of monitoring Helios expression in therapeutic Treg manufacturing and provide new insight into the biological function of this transcription factor in human T-cells.
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Affiliation(s)
- Avery J Lam
- Department of Surgery, University of British Columbia, Vancouver, Canada.,BC Children's Hospital Research Institute, Vancouver, Canada
| | - Prakruti Uday
- Department of Surgery, University of British Columbia, Vancouver, Canada.,BC Children's Hospital Research Institute, Vancouver, Canada
| | - Jana K Gillies
- Department of Surgery, University of British Columbia, Vancouver, Canada.,BC Children's Hospital Research Institute, Vancouver, Canada
| | - Megan K Levings
- Department of Surgery, University of British Columbia, Vancouver, Canada.,BC Children's Hospital Research Institute, Vancouver, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
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Lam AJ, Lin DTS, Gillies JK, Uday P, Pesenacker AM, Kobor MS, Levings MK. Optimized CRISPR-mediated gene knockin reveals FOXP3-independent maintenance of human Treg identity. Cell Rep 2021; 36:109494. [PMID: 34348163 DOI: 10.1016/j.celrep.2021.109494] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [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: 02/01/2021] [Revised: 06/28/2021] [Accepted: 07/14/2021] [Indexed: 12/30/2022] Open
Abstract
Regulatory T cell (Treg) therapy is a promising curative approach for a variety of immune-mediated conditions. CRISPR-based genome editing allows precise insertion of transgenes through homology-directed repair, but its use in human Tregs has been limited. We report an optimized protocol for CRISPR-mediated gene knockin in human Tregs with high-yield expansion. To establish a benchmark of human Treg dysfunction, we target the master transcription factor FOXP3 in naive and memory Tregs. Although FOXP3-ablated Tregs upregulate cytokine expression, effects on suppressive capacity in vitro manifest slowly and primarily in memory Tregs. Moreover, FOXP3-ablated Tregs retain their characteristic protein, transcriptional, and DNA methylation profile. Instead, FOXP3 maintains DNA methylation at regions enriched for AP-1 binding sites. Thus, although FOXP3 is important for human Treg development, it has a limited role in maintaining mature Treg identity. Optimized gene knockin with human Tregs will enable mechanistic studies and the development of tailored, next-generation Treg cell therapies.
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Affiliation(s)
- Avery J Lam
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - David T S Lin
- BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC V6H 3N1, Canada
| | - Jana K Gillies
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Prakruti Uday
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Anne M Pesenacker
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Michael S Kobor
- BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC V6H 3N1, Canada
| | - Megan K Levings
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; BC Children's Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada; School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Cook L, Reid KT, Häkkinen E, de Bie B, Tanaka S, Smyth DJ, White MP, Wong MQ, Huang Q, Gillies JK, Ziegler SF, Maizels RM, Levings MK. Induction of stable human FOXP3 + Tregs by a parasite-derived TGF-β mimic. Immunol Cell Biol 2021; 99:833-847. [PMID: 33929751 PMCID: PMC8453874 DOI: 10.1111/imcb.12475] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/31/2021] [Accepted: 04/27/2021] [Indexed: 12/14/2022]
Abstract
Immune homeostasis in the intestine is tightly controlled by FOXP3+ regulatory T cells (Tregs), defects of which are linked to the development of chronic conditions, such as inflammatory bowel disease (IBD). As a mechanism of immune evasion, several species of intestinal parasites boost Treg activity. The parasite Heligmosomoides polygyrus is known to secrete a molecule (Hp-TGM) that mimics the ability of TGF-β to induce FOXP3 expression in CD4+ T cells. The study aimed to investigate whether Hp-TGM could induce human FOXP3+ Tregs as a potential therapeutic approach for inflammatory diseases. CD4+ T cells from healthy volunteers were expanded in the presence of Hp-TGM or TGF-β. Treg induction was measured by flow cytometric detection of FOXP3 and other Treg markers, such as CD25 and CTLA-4. Epigenetic changes were detected using ChIP-Seq and pyrosequencing of FOXP3. Treg phenotype stability was assessed following inflammatory cytokine challenge and Treg function was evaluated by cellular co-culture suppression assays and cytometric bead arrays for secreted cytokines. Hp-TGM efficiently induced FOXP3 expression (> 60%), in addition to CD25 and CTLA-4, and caused epigenetic modification of the FOXP3 locus to a greater extent than TGF-β. Hp-TGM-induced Tregs had superior suppressive function compared with TGF-β-induced Tregs, and retained their phenotype following exposure to inflammatory cytokines. Furthermore, Hp-TGM induced a Treg-like phenotype in in vivo differentiated Th1 and Th17 cells, indicating its potential to re-program memory cells to enhance immune tolerance. These data indicate Hp-TGM has potential to be used to generate stable human FOXP3+ Tregs to treat IBD and other inflammatory diseases.
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Affiliation(s)
- Laura Cook
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kyle T Reid
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Elmeri Häkkinen
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Brett de Bie
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Shigeru Tanaka
- Department of Translational Research, Benaroya Research Institute, Virginia Mason, Seattle, WA, USA
| | - Danielle J Smyth
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Madeleine Pj White
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - May Q Wong
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Qing Huang
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Jana K Gillies
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Steven F Ziegler
- Department of Translational Research, Benaroya Research Institute, Virginia Mason, Seattle, WA, USA
| | - Rick M Maizels
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Megan K Levings
- BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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Cook L, Munier CML, Seddiki N, van Bockel D, Ontiveros N, Hardy MY, Gillies JK, Levings MK, Reid HH, Petersen J, Rossjohn J, Anderson RP, Zaunders JJ, Tye-Din JA, Kelleher AD. Circulating gluten-specific FOXP3 +CD39 + regulatory T cells have impaired suppressive function in patients with celiac disease. J Allergy Clin Immunol 2017; 140:1592-1603.e8. [PMID: 28283419 DOI: 10.1016/j.jaci.2017.02.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 02/03/2017] [Accepted: 02/16/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Celiac disease is a chronic immune-mediated inflammatory disorder of the gut triggered by dietary gluten. Although the effector T-cell response in patients with celiac disease has been well characterized, the role of regulatory T (Treg) cells in the loss of tolerance to gluten remains poorly understood. OBJECTIVE We sought to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3)+ Treg cells. METHODS Treated patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. Peripheral blood was collected before and after challenge. To comprehensively measure the gluten-specific CD4+ T-cell response, we paired traditional IFN-γ ELISpot with an assay to detect antigen-specific CD4+ T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation but rather on antigen-induced coexpression of CD25 and OX40 (CD134). RESULTS Numbers of circulating gluten-specific Treg cells and effector T cells both increased significantly after oral wheat challenge, peaking at day 6. Surprisingly, we found that approximately 80% of the ex vivo circulating gluten-specific CD4+ T cells were FOXP3+CD39+ Treg cells, which reside within the pool of memory CD4+CD25+CD127lowCD45RO+ Treg cells. Although we observed normal suppressive function in peripheral polyclonal Treg cells from patients with celiac disease, after a short in vitro expansion, the gluten-specific FOXP3+CD39+ Treg cells exhibited significantly reduced suppressive function compared with polyclonal Treg cells. CONCLUSION This study provides the first estimation of FOXP3+CD39+ Treg cell frequency within circulating gluten-specific CD4+ T cells after oral gluten challenge of patients with celiac disease. FOXP3+CD39+ Treg cells comprised a major proportion of all circulating gluten-specific CD4+ T cells but had impaired suppressive function, indicating that Treg cell dysfunction might be a key contributor to disease pathogenesis.
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Affiliation(s)
- Laura Cook
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
| | - C Mee Ling Munier
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia
| | - Nabila Seddiki
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia
| | - David van Bockel
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia
| | - Noé Ontiveros
- Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Melinda Y Hardy
- Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Jana K Gillies
- Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Megan K Levings
- Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hugh H Reid
- Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia
| | - Jan Petersen
- Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia
| | - Jamie Rossjohn
- Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia; Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Robert P Anderson
- Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; ImmusanT, Cambridge, Mass
| | - John J Zaunders
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia
| | - Jason A Tye-Din
- Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; Department of Gastroenterology, Royal Melbourne Hospital, Parkville, Australia
| | - Anthony D Kelleher
- Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia
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Baldwin RM, Barrett GM, Parolin DAE, Gillies JK, Paget JA, Lavictoire SJ, Gray DA, Lorimer IAJ. Coordination of glioblastoma cell motility by PKCι. Mol Cancer 2010; 9:233. [PMID: 20815904 PMCID: PMC2941485 DOI: 10.1186/1476-4598-9-233] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [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: 02/22/2010] [Accepted: 09/03/2010] [Indexed: 11/26/2022] Open
Abstract
Background Glioblastoma is one of the deadliest forms of cancer, in part because of its highly invasive nature. The tumor suppressor PTEN is frequently mutated in glioblastoma and is known to contribute to the invasive phenotype. However the downstream events that promote invasion are not fully understood. PTEN loss leads to activation of the atypical protein kinase C, PKCι. We have previously shown that PKCι is required for glioblastoma cell invasion, primarily by enhancing cell motility. Here we have used time-lapse videomicroscopy to more precisely define the role of PKCι in glioblastoma. Results Glioblastoma cells in which PKCι was either depleted by shRNA or inhibited pharmacologically were unable to coordinate the formation of a single leading edge lamellipod. Instead, some cells generated multiple small, short-lived protrusions while others generated a diffuse leading edge that formed around the entire circumference of the cell. Confocal microscopy showed that this behavior was associated with altered behavior of the cytoskeletal protein Lgl, which is known to be inactivated by PKCι phosphorylation. Lgl in control cells localized to the lamellipod leading edge and did not associate with its binding partner non-muscle myosin II, consistent with it being in an inactive state. In PKCι-depleted cells, Lgl was concentrated at multiple sites at the periphery of the cell and remained in association with non-muscle myosin II. Videomicroscopy also identified a novel role for PKCι in the cell cycle. Cells in which PKCι was either depleted by shRNA or inhibited pharmacologically entered mitosis normally, but showed marked delays in completing mitosis. Conclusions PKCι promotes glioblastoma motility by coordinating the formation of a single leading edge lamellipod and has a role in remodeling the cytoskeleton at the lamellipod leading edge, promoting the dissociation of Lgl from non-muscle myosin II. In addition PKCι is required for the transition of glioblastoma cells through mitosis. PKCι therefore has a role in both glioblastoma invasion and proliferation, two key aspects in the malignant nature of this disease.
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Affiliation(s)
- R Mitchell Baldwin
- Centre for Cancer Therapeutics, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa K1H 8L6, Canada
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Abstract
Levels of p27(Kip1), a key negative regulator of the cell cycle, are often decreased in cancer. In most cancers, levels of p27(Kip1) mRNA are unchanged and increased proteolysis of the p27(Kip1) protein is thought to be the primary mechanism for its downregulation. Here we show that p27(Kip1) protein levels are also downregulated by microRNAs in cancer cells. We used RNA interference to reduce Dicer levels in human glioblastoma cell lines and found that this caused an increase in p27(Kip1) levels and a decrease in cell proliferation. When the coding sequence for the 3'UTR of the p27(Kip1) mRNA was inserted downstream of a luciferase reporter gene, Dicer depletion also enhanced expression of the reporter gene product. The microRNA target site software TargetScan predicts that the 3'UTR of p27(Kip1) mRNA contains multiple sites for microRNAs. These include two sites for microRNA 221 and 222, which have been shown to be upregulated in glioblastoma relative to adjacent normal brain tissue. The genes for microRNA 221 and microRNA 222 occupy adjacent sites on the X chromosome; their expression appears to be coregulated and they also appear to have the same target specificity. Antagonism of either microRNA 221 or 222 in glioblastoma cells also caused an increase in p27(Kip1) levels and enhanced expression of the luciferase reporter gene fused to the p27(Kip1) 3'UTR. These data show that p27(Kip1) is a direct target for microRNAs 221 and 222, and suggest a role for these microRNAs in promoting the aggressive growth of human glioblastoma.
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Affiliation(s)
- Jana K Gillies
- Ottawa Health Research Institute, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
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