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Crea F, Quagliata L, Michael A, Liu HH, Frumento P, Azad AA, Xue H, Pikor L, Watahiki A, Morant R, Eppenberger-Castori S, Wang Y, Parolia A, Lennox KA, Lam WL, Gleave M, Chi KN, Pandha H, Wang Y, Helgason CD. Integrated analysis of the prostate cancer small-nucleolar transcriptome reveals SNORA55 as a driver of prostate cancer progression. Mol Oncol 2016; 10:693-703. [PMID: 26809501 PMCID: PMC5423162 DOI: 10.1016/j.molonc.2015.12.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/13/2015] [Accepted: 12/07/2015] [Indexed: 12/12/2022] Open
Abstract
Metastasis is the primary cause of death in prostate cancer (PCa) patients. Small nucleolar RNAs (snoRNAs) have long been considered "housekeeping" genes with no relevance for cancer biology. Emerging evidence has challenged this assumption, suggesting that snoRNA expression is frequently modulated during cancer progression. Despite this, no study has systematically addressed the prognostic and functional significance of snoRNAs in PCa. We performed RNA Sequencing on paired metastatic/non-metastatic PCa xenografts derived from clinical specimens. The clinical significance of differentially expressed snoRNAs was further investigated in two independent primary PCa cohorts (131 and 43 patients, respectively). The snoRNA demonstrating the strongest association with clinical outcome was quantified in PCa patient-derived serum samples and its functional relevance was investigated in PCa cells via gene expression profiling, pathway analysis and gene silencing. Our comparison revealed 21 differentially expressed snoRNAs in the metastatic vs. non-metastatic xenografts. Of those, 12 were represented in clinical databases and were further analyzed. SNORA55 emerged as a predictor of shorter relapse-free survival (results confirmed in two independent databases). SNORA55 was reproducibly detectable in serum samples from PCa patients. SNORA55 silencing in PCa cell lines significantly inhibited cell proliferation and migration. Pathway analysis revealed that SNORA55 expression is significantly associated with growth factor signaling and pro-inflammatory cytokine expression in PCa. Our results demonstrate that SNORA55 up-regulation predicts PCa progression and that silencing this non-coding gene affects PCa cell proliferation and metastatic potential, thus positioning it as both a novel biomarker and therapeutic target.
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Affiliation(s)
- Francesco Crea
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada; The Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver BC, Canada; Department of Life, Health, and Chemical Sciences, The Open University, Milton Keynes, UK
| | - Luca Quagliata
- Molecular Pathology Unit, Institute of Pathology University Hospital Basel, Switzerland
| | - Agnieszka Michael
- Oncology, FHMS, School of Biosciences and Medicine, University of Surrey, UK
| | - Hui Hsuan Liu
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Paolo Frumento
- Karolinska Institutet, Institute of Environmental Medicine, Unit of Biostatistics, Stockholm, Sweden
| | - Arun A Azad
- Medical Oncology, BC Cancer Agency Vancouver Cancer Centre, Vancouver BC, Canada
| | - Hui Xue
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Larissa Pikor
- Genetics Unit, Integrative Oncology, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Akira Watahiki
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada; The Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver BC, Canada
| | - Rudolf Morant
- Cancer Center ZeTuP AG St.Gallen, St.Gallen, Switzerland
| | | | - Yuwei Wang
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Abhijit Parolia
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Kim A Lennox
- Integrated DNA Technologies, Coralville, IA, USA
| | - Wan L Lam
- Genetics Unit, Integrative Oncology, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
| | - Martin Gleave
- The Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver BC, Canada
| | - Kim N Chi
- The Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver BC, Canada; Medical Oncology, BC Cancer Agency Vancouver Cancer Centre, Vancouver BC, Canada
| | - Hardev Pandha
- Oncology, FHMS, School of Biosciences and Medicine, University of Surrey, UK
| | - Yuzhuo Wang
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada; The Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver BC, Canada.
| | - Cheryl D Helgason
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada.
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Sun X, Clermont PL, Jiao W, Helgason CD, Gout PW, Wang Y, Qu S. Elevated expression of the centromere protein-A(CENP-A)-encoding gene as a prognostic and predictive biomarker in human cancers. Int J Cancer 2016; 139:899-907. [PMID: 27062469 DOI: 10.1002/ijc.30133] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/09/2016] [Accepted: 03/23/2016] [Indexed: 01/08/2023]
Abstract
Centromere protein-A (CENP-A), a histone-H3 variant, plays an essential role in cell division by ensuring proper formation and function of centromeres and kinetochores. Elevated CENP-A expression has been associated with cancer development. This study aimed to establish whether elevated CENP-A expression can be used as a prognostic and predictive cancer biomarker. Molecular profiling of CENP-A in human cancers was investigated using genomic, transcriptomic and patient information from databases, including COSMIC, Oncomine, Kaplan-Meier plotter and cBioPortal. A network of CENP-A co-expressed genes was derived from cBioPortal and analyzed using Ingenuity Pathway Analysis (IPA) and Oncomine protocols to explore the function of CENP-A and its predictive potential. Transcriptional and post-transcriptional regulation of CENP-A expression was analyzed in silico. It was found that CENP-A expression was elevated in 20 types of solid cancer compared with normal counterparts. Elevated CENP-A expression highly correlated with cancer progression and poor patient outcome. Genomic analysis indicated that the elevated CENP-A expression was not due to alterations in the sequence or copy number of the CENP-A gene. Furthermore, CENP-A can be regulated by key oncogenic proteins and tumor-suppressive microRNAs. CENP-A co-expression network analysis indicated that CENP-A function is associated with cell cycle progression. Oncomine analysis showed a strong correlation between elevated CENP-A expression and oncolytic response of breast cancer patients to taxane-based chemotherapy. In conclusion, elevated CENP-A expression is coupled to malignant progression of numerous types of cancer. It may be useful as a biomarker of poor patient prognosis and as a predictive biomarker for taxane-based chemotherapy.
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Affiliation(s)
- Xia Sun
- Department of Pharmacology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Pier-Luc Clermont
- Department of Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada.,Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Wenlin Jiao
- Department of Pharmacology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Cheryl D Helgason
- Department of Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada.,Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Peter W Gout
- Department of Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada
| | - Yuzhuo Wang
- Department of Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada.,Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Vancouver Prostate Center, Vancouver, BC, Canada.,Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Sifeng Qu
- Department of Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada.,Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Vancouver Prostate Center, Vancouver, BC, Canada
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Clermont PL, Parolia A, Liu HH, Helgason CD. DNA methylation at enhancer regions: Novel avenues for epigenetic biomarker development. Front Biosci (Landmark Ed) 2016; 21:430-46. [PMID: 26709784 DOI: 10.2741/4399] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biomarkers are molecules or features which can provide clinically-relevant information about a particular disease state, thus providing useful tools for oncologists. Recently, a number of studies have demonstrated that DNA methylation holds great promise as a novel source of cancer biomarkers. Although promoter regions have been the focus of most investigations thus far, mounting evidence demonstrates that enhancer sequences also undergo extensive differential methylation in cancer cells. Moreover, enhancer methylation correlates with target gene expression better than promoter methylation, providing unexplored strategies for biomarker development. Here, we review important considerations associated with the clinical analysis of DNA methylation at distal regulatory regions. Notably, we highlight emerging literature addressing the methylation status of enhancers in development and cancer, and subsequently discuss how enhancer methylation can be exploited to guide disease management. While acknowledging current limitations, we propose that the methylation state of enhancer regions has the potential to headline the next generation of epigenetic biomarkers.
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Affiliation(s)
- Pier-Luc Clermont
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, British Columbia, Canada, V5Z 1L3
| | - Abhijit Parolia
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, British Columbia, Canada, V5Z 1L3
| | - Hui Hsuan Liu
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, British Columbia, Canada, V5Z 1L3
| | - Cheryl D Helgason
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, British Columbia, Canada, V5Z 1L3.,
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Crea F, Di Paolo A, Liu HH, Polillo M, Clermont PL, Guerrini F, Ciabatti E, Ricci F, Baratè C, Fontanelli G, Barsotti S, Morganti R, Danesi R, Wang Y, Petrini M, Galimberti S, Helgason CD. Polycomb genes are associated with response to imatinib in chronic myeloid leukemia. Epigenomics 2015; 7:757-65. [PMID: 26343356 DOI: 10.2217/epi.15.35] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AIM Imatinib is a tyrosine kinase inhibitor that has revolutionized the treatment of chronic myeloid leukemia (CML). Despite its efficacy, about a third of patients discontinue the treatment due to therapy failure or intolerance. The rational identification of patients less likely to respond to imatinib would be of paramount clinical relevance. We have shown that transmembrane transporter hOCT1 genotyping predicts imatinib activity. In parallel, Polycomb group genes (PcGs) are epigenetic repressors implicated in CML progression and in therapy resistance. PATIENTS & METHODS We measured the expression of eight PcGs in paired pre- and post-imatinib bone marrow samples from 30 CML patients. RESULTS BMI1, PHC3, CBX6 and CBX7 expression was significantly increased during imatinib treatment. Post-treatment levels of CBX6 and CBX7 predicted 3-month response rate. Measurement of post-treatment BMI1 levels improved the predictive power of hOCT1 genotyping. CONCLUSION These results suggest that the expression levels of PcGs might be useful for a more accurate risk stratification of CML patients.
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Affiliation(s)
- Francesco Crea
- Experimental Therapeutics, BCCA Research Centre, 675 W 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.,Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC, V6H 3Z6, Canada.,Department of Life Health & Chemical Sciences, The Open University, UK
| | - Antonello Di Paolo
- Department of Clinical & Experimental Medicine, Section of Pharmacology, University of Pisa, Pisa, Italy
| | - Hui Hsuan Liu
- Experimental Therapeutics, BCCA Research Centre, 675 W 10th Avenue, Vancouver, BC, V5Z 1L3, Canada
| | - Marialuisa Polillo
- Department of Clinical & Experimental Medicine, Section of Pharmacology, University of Pisa, Pisa, Italy
| | - Pier-Luc Clermont
- Experimental Therapeutics, BCCA Research Centre, 675 W 10th Avenue, Vancouver, BC, V5Z 1L3, Canada
| | - Francesca Guerrini
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Elena Ciabatti
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Federica Ricci
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Claudia Baratè
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Giulia Fontanelli
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Sara Barsotti
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Riccardo Morganti
- Department of Clinical & Experimental Medicine, Section of Statistics, University of Pisa, Pisa, Italy
| | - Romano Danesi
- Department of Clinical & Experimental Medicine, Section of Pharmacology, University of Pisa, Pisa, Italy
| | - Yuzhuo Wang
- Experimental Therapeutics, BCCA Research Centre, 675 W 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.,Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC, V6H 3Z6, Canada
| | - Mario Petrini
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Sara Galimberti
- Department of Clinical & Experimental Medicine, Section of Hematology, University of Pisa, Pisa, Italy
| | - Cheryl D Helgason
- Experimental Therapeutics, BCCA Research Centre, 675 W 10th Avenue, Vancouver, BC, V5Z 1L3, Canada
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Abstract
Since the discovery of microRNAs, non-coding RNAs (NC-RNAs) have increasingly attracted the attention of cancer investigators. Two classes of NC-RNAs are emerging as putative metastasis-related genes: long non-coding RNAs (lncRNAs) and small nucleolar RNAs (snoRNAs). LncRNAs orchestrate metastatic progression through several mechanisms, including the interaction with epigenetic effectors, splicing control and generation of microRNA-like molecules. In contrast, snoRNAs have been long considered “housekeeping” genes with no relevant function in cancer. However, recent evidence challenges this assumption, indicating that some snoRNAs are deregulated in cancer cells and may play a specific role in metastasis. Interestingly, snoRNAs and lncRNAs share several mechanisms of action, and might synergize with protein-coding genes to generate a specific cellular phenotype. This evidence suggests that the current paradigm of metastatic progression is incomplete. We propose that NC-RNAs are organized in complex interactive networks which orchestrate cellular phenotypic plasticity. Since plasticity is critical for cancer cell metastasis, we suggest that a molecular interactome composed by both NC-RNAs and proteins orchestrates cancer metastasis. Interestingly, expression of lncRNAs and snoRNAs can be detected in biological fluids, making them potentially useful biomarkers. NC-RNA expression profiles in human neoplasms have been associated with patients’ prognosis. SnoRNA and lncRNA silencing in pre-clinical models leads to cancer cell death and/or metastasis prevention, suggesting they can be investigated as novel therapeutic targets. Based on the literature to date, we critically discuss how the NC-RNA interactome can be explored and manipulated to generate more effective diagnostic, prognostic, and therapeutic strategies for metastatic neoplasms.
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Affiliation(s)
- Francesco Crea
- Experimental Therapeutics, BC Cancer Research Centre, Vancouver, BC, Canada,
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Clermont PL, Lin D, Crea F, Wu R, Xue H, Wang Y, Thu KL, Lam WL, Collins CC, Wang Y, Helgason CD. Polycomb-mediated silencing in neuroendocrine prostate cancer. Clin Epigenetics 2015; 7:40. [PMID: 25859291 PMCID: PMC4391120 DOI: 10.1186/s13148-015-0074-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [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: 11/12/2014] [Accepted: 03/13/2015] [Indexed: 02/06/2023] Open
Abstract
Background Neuroendocrine prostate cancer (NEPC) is a highly aggressive subtype of prostate cancer (PCa) for which the median survival remains less than a year. Current treatments are only palliative in nature, and the lack of suitable pre-clinical models has hampered previous efforts to develop novel therapeutic strategies. Addressing this need, we have recently established the first in vivo model of complete neuroendocrine transdifferentiation using patient-derived xenografts. Few genetic differences were observed between parental PCa and relapsed NEPC, suggesting that NEPC likely results from alterations that are epigenetic in nature. Thus, we sought to identify targetable epigenetic regulators whose expression was elevated in NEPC using genome-wide profiling of patient-derived xenografts and clinical samples. Results Our data indicate that multiple members of the polycomb group (PcG) family of transcriptional repressors were selectively upregulated in NEPC. Notably, CBX2 and EZH2 were consistently the most highly overexpressed epigenetic regulators across multiple datasets from clinical and xenograft tumor tissues. Given the striking upregulation of PcG genes and other transcriptional repressors, we derived a 185-gene list termed ‘neuroendocrine-associated repression signature’ (NEARS) by overlapping transcripts downregulated across multiple in vivo NEPC models. In line with the striking upregulation of PcG family members, NEARS was preferentially enriched with PcG target genes, suggesting a driving role for PcG silencing in NEPC. Importantly, NEARS was significantly associated with high-grade tumors, metastatic progression, and poor outcome in multiple clinical datasets, consistent with extensive literature linking PcG genes and aggressive disease progression. Conclusions We have explored the epigenetic landscape of NEPC and provided evidence of increased PcG-mediated silencing associated with aberrant transcriptional regulation of key differentiation genes. Our results position CBX2 and EZH2 as potential therapeutic targets in NEPC, providing opportunities to explore novel strategies aimed at reversing epigenetic alterations driving this lethal disease. Electronic supplementary material The online version of this article (doi:10.1186/s13148-015-0074-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pier-Luc Clermont
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Dong Lin
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Vancouver Prostate Centre, 899 West 12th Avenue, Vancouver, BC V5Z 1 M9 Canada
| | - Francesco Crea
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Vancouver Prostate Centre, 899 West 12th Avenue, Vancouver, BC V5Z 1 M9 Canada ; Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1 M9 Canada
| | - Rebecca Wu
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Hui Xue
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Yuwei Wang
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Kelsie L Thu
- Department of Integrative Oncology, Genetics Unit, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Wan L Lam
- Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Department of Integrative Oncology, Genetics Unit, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada
| | - Colin C Collins
- Vancouver Prostate Centre, 899 West 12th Avenue, Vancouver, BC V5Z 1 M9 Canada ; Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1 M9 Canada
| | - Yuzhuo Wang
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Vancouver Prostate Centre, 899 West 12th Avenue, Vancouver, BC V5Z 1 M9 Canada ; Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, 2775 Laurel Street, Vancouver, BC V5Z 1 M9 Canada
| | - Cheryl D Helgason
- Department of Experimental Therapeutics, British Columbia Cancer Research Centre, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, 675 W 10th Avenue, Vancouver, BC V5Z 1 L3 Canada ; Department of Surgery, University of British Columbia, 910 W 10th Avenue, Vancouver, BC V5Z 4E3 Canada
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7
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Parolia A, Crea F, Xue H, Wang Y, Mo F, Ramnarine VR, Liu HH, Lin D, Saidy NRN, Clermont PL, Cheng H, Collins C, Wang Y, Helgason CD. The long non-coding RNA PCGEM1 is regulated by androgen receptor activity in vivo. Mol Cancer 2015; 14:46. [PMID: 25744782 PMCID: PMC4342943 DOI: 10.1186/s12943-015-0314-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [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: 11/18/2014] [Accepted: 02/05/2015] [Indexed: 11/16/2022] Open
Abstract
Background Long non-coding RNAs (lncRNAs) can orchestrate oncogenic or tumor-suppressive functions in cancer biology. Accordingly, PCGEM1 and PRNCR1 were implicated in progression of prostate cancer (PCa) as transcriptional co-regulators of the androgen receptor (AR). However, these findings were recently refuted asserting that neither gene physically binds to the AR. Despite evidence for differing AR transcriptional programs in vivo and in vitro, studies investigating AR-regulation of these genes hitherto have only been conducted in vitro. Here, we further examine the relevance of PCGEM1 and PRNCR1 in PCa, and their relationship with AR signaling, using patient-derived xenograft models. Findings RNA sequencing of two distinct androgen-dependent models shows PCGEM1 to be considerably expressed, while PRNCR1 showed scant basal expression. PCGEM1 was sharply down-regulated following castration and up-regulated upon AR activation in vivo. However, we found no parallel evidence following AR stimulation in vitro. A PCGEM1-associated gene expression signature (PES) was significantly repressed in response to androgen ablation therapy and in hormone-refractory versus hormone-naïve PCa patients. Furthermore, we found PCGEM1 was uniformly distributed in PCa cell nucleus and cytoplasm which remained unaltered upon AR transcriptional activation. PCGEM1 was up-regulated in primary PCa but not in metastasized PCa. Accordingly, the PES was significantly down-regulated in advanced and higher grade PCa patients from multiple independent studies. Conclusion Our results demonstrate PCGEM1 as an in vivo androgen-regulated transcript with potential nuclear and/or cytoplasmic function(s). Importantly, the clinical expression profile of PCGEM1 implicates it in the early stages of PCa warranting further research in this direction. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0314-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abhijit Parolia
- Honours Biotechnology Program, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada. .,Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Francesco Crea
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada. .,Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.
| | - Hui Xue
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Yuwei Wang
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Fan Mo
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | | | - Hui Hsuan Liu
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.
| | - Dong Lin
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada. .,Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.
| | - Nur Ridzwan Nur Saidy
- Honours Biotechnology Program, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada. .,Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.
| | - Pier-Luc Clermont
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,Interdisciplinary Oncology Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Hongwei Cheng
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Colin Collins
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Yuzhuo Wang
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC, Canada.
| | - Cheryl D Helgason
- Experimental Therapeutics, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada. .,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
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8
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Crea F, Watahiki A, Quagliata L, Xue H, Pikor L, Parolia A, Wang Y, Lin D, Lam WL, Farrar WL, Isogai T, Morant R, Castori-Eppenberger S, Chi KN, Wang Y, Helgason CD. Identification of a long non-coding RNA as a novel biomarker and potential therapeutic target for metastatic prostate cancer. Oncotarget 2015; 5:764-74. [PMID: 24519926 PMCID: PMC3996663 DOI: 10.18632/oncotarget.1769] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [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] [Indexed: 12/15/2022] Open
Abstract
Metastatic prostate cancer (PCa) is still an incurable disease. Long non-coding RNAs (lncRNAs) may be an overlooked source of cancer biomarkers and therapeutic targets. We therefore performed RNA sequencing on paired metastatic/non-metastatic PCa xenografts derived from clinical specimens. The most highly up-regulated transcript was LOC728606, a lncRNA now designated PCAT18. PCAT18 is specifically expressed in the prostate compared to 11 other normal tissues (p<0.05) and up-regulated in PCa compared to 15 other neoplasms (p<0.001). Cancer-specific up-regulation of PCAT18 was confirmed on an independent dataset of PCa and benign prostatic hyperplasia samples (p<0.001). PCAT18 was detectable in plasma samples and increased incrementally from healthy individuals to those with localized and metastatic PCa (p<0.01). We identified a PCAT18-associated expression signature (PES), which is highly PCa-specific and activated in metastatic vs. primary PCa samples (p<1E-4, odds ratio>2). The PES was significantly associated with androgen receptor (AR) signalling. Accordingly, AR activation dramatically up-regulated PCAT18 expression in vitro and in vivo. PCAT18 silencing significantly (p<0.001) inhibited PCa cell proliferation and triggered caspase 3/7 activation, with no effect on non-neoplastic cells. PCAT18 silencing also inhibited PCa cell migration (p<0.01) and invasion (p<0.01). These results position PCAT18 as a potential therapeutic target and biomarker for metastatic PCa.
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Affiliation(s)
- Francesco Crea
- Experimental Therapeutics, BC Cancer Agency Cancer Research Centre, Vancouver BC, Canada
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Crea F, Clermont PL, Mai A, Helgason CD. Histone modifications, stem cells and prostate cancer. Curr Pharm Des 2014; 20:1687-97. [PMID: 23888964 DOI: 10.2174/13816128113199990522] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 07/18/2013] [Indexed: 11/22/2022]
Abstract
Prostate cancer (PCa) is a very common neoplasm, which is generally treated by chemo-, radio-, and/or hormonal-therapy. After a variable time, PCa becomes resistant to conventional treatment, leading to patient death. Prostate tumor-initiating cells (TICs) and cancer repopulating cells (CRCs) are stem-like populations, driving respectively cancer initiation and progression. Histone modifiers (HMs) control gene expression in normal and cancer cells, thereby orchestrating key physiological and pathological processes. In particular, Polycomb group genes (PcGs) are a set of HMs crucial for lineage-specific gene silencing and stem cell self renewal. PcG products are organized into two main Polycomb Repressive Complexes (PRCs). At specific loci, PRC2 catalyzes histone H3 Lys27 trimethylation, which triggers gene silencing by recruiting PRC1, histone deacetylases and DNA methyl transferases. PRC1 catalyzes addition of the repressive mark histone H2A ubiquitination. Recently, the catalytic component of PRC1 (BMI1) was shown to play critical roles in prostate CRC self-renewal and resistance to chemotherapy, resulting in poorer prognosis. Similarly, pharmacological disruption of PRC2 by a small molecule inhibitor reduced the tumorigenicity and metastatic potential of prostate CRCs. Along with PcGs, some histone lysine demethylases (KDMs) are emerging as critical regulators of TIC/CRC biology. KDMs may be inhibited by specific small molecules, some of which display antitumor activity in PCa cells at micromolar concentrations. Since epigenetic gene regulation is crucial for stem cell biology, exploring the role of HMs in prostate cancer is a promising path that may lead to novel treatments.
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Affiliation(s)
| | | | | | - Cheryl D Helgason
- Experimental Therapeutics, British Columbia Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, Canada, V5Z 1L3.
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10
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Nakamura H, Wang Y, Xue H, Romanish MT, Mager DL, Helgason CD, Wang Y. Genistein versus ICI 182, 780: an ally or enemy in metastatic progression of prostate cancer. Prostate 2013; 73:1747-60. [PMID: 24038102 DOI: 10.1002/pros.22712] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/20/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND Androgen signalling through the androgen receptor (AR) plays a critical role in prostate cancer (PCa) initiation and progression. Estrogen in synergy with androgen is essential for cell growth of the normal and malignant prostate. However, the exact role that estrogen and the estrogen receptor play in prostate carcinogenesis remains unclear. We have previously demonstrated the metastasis-promoting effect of an estrogen receptor beta (ERβ) agonist (genistein) in a patient-derived PCa xenograft model mimicking localized and metastatic disease. METHODS To test the hypothesis that the tumor-promoting activity of genistein was due to its estrogenic properties, we treated the xenograft-bearing mice with genistein and an anti-estrogen compound (ICI 182, 780) and compared the differential gene expression using microarrays. RESULTS Using a second xenograft model which was derived from another patient, we showed that genistein promoted disease progression in vivo and ICI 182, 780 inhibited metastatic spread. The microarray analysis revealed that the metallothionein (MT) gene family was differentially expressed in tumors treated by these compounds. Using qRT-PCR, the differences in expression levels were validated in the metastatic and non-metastatic LTL313 PCa xenograft tumor lines, both of which were originally derived from the same PCa patient. CONCLUSIONS Together our data provide evidence that genistein stimulates and ICI 182, 780 inhibits metastatic progression, suggesting that these effects may be mediated by ERβ signalling.
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Affiliation(s)
- Hisae Nakamura
- Experimental Therapeutics, BC Cancer Agency, Vancouver, British Columbia, Canada; Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, Canada; The Vancouver Prostate Centre, Vancouver, British Columbia, Canada
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11
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Watahiki A, Macfarlane RJ, Gleave ME, Crea F, Wang Y, Helgason CD, Chi KN. Plasma miRNAs as biomarkers to identify patients with castration-resistant metastatic prostate cancer. Int J Mol Sci 2013; 14:7757-70. [PMID: 23574937 PMCID: PMC3645714 DOI: 10.3390/ijms14047757] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 03/20/2013] [Accepted: 03/22/2013] [Indexed: 01/14/2023] Open
Abstract
MicroRNAs (miRNAs) have emerged as key regulators of numerous biological processes, and increasing evidence suggests that circulating miRNAs may be useful biomarkers of clinical disease. In this study, we sought to identify plasma miRNAs that differentiate patients with metastatic castration resistant prostate cancer (mCRPC) from those with localized prostate cancer (PCa). Pooled plasma samples from patients with localized PCa or mCRPC (25 per group) were assayed using the Exiqon miRNA qPCR panel, and the differential expression of selected candidates was validated using qRT-PCR. We identified 63 miRNAs upregulated in mCRPC versus localized PCa, while only four were downregulated. Pearson’s correlation analysis revealed two highly correlated groups: one consisting of miR-141, miR375 and miR-200c and the other including miR151-3p, miR423-3p, miR-126, miR152 and miR-21. A third group, containing miR-16 and miR-205, showed less correlation. One miRNA from each group (miR-141, miR151-3p and miR-16) was used for logistic regression analysis and proved to increase the sensitivity of the prostate-specific antigen (PSA) test alone. While no miRNA alone differentiated localized PCa and mCRPC, combinations had greater sensitivity and specificity. The expression of these 10 candidates was assayed for association with clinical parameters of disease progression through the cBio portal. Our results demonstrate that plasma levels of selected miRNAs are potential biomarkers to differentiate localized PCa and mCRPC.
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Affiliation(s)
- Akira Watahiki
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada; E-Mails: (A.W.); (M.E.G.); (K.N.C.)
- Departments of Experimental Therapeutics, Vancouver, BC V5Z 1L3, Canada; E-Mail:
| | - Robyn J. Macfarlane
- Departments of Medical Oncology, BC Cancer Agency, Vancouver, BC V5Z 4E6, Canada; E-Mail:
| | - Martin E. Gleave
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada; E-Mails: (A.W.); (M.E.G.); (K.N.C.)
- Departments of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Francesco Crea
- Departments of Experimental Therapeutics, Vancouver, BC V5Z 1L3, Canada; E-Mail:
| | - Yuzhuo Wang
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada; E-Mails: (A.W.); (M.E.G.); (K.N.C.)
- Departments of Experimental Therapeutics, Vancouver, BC V5Z 1L3, Canada; E-Mail:
- Departments of Urologic Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Authors to whom correspondence should be addressed; E-Mails: (Y.W.); (C.D.H.); Tel.: +1-604-675-8013 (Y.W.); +1-604-675-8011 (C.D.H.); Fax: +1-604-675-8019 (Y.W. & C.D.H.)
| | - Cheryl D. Helgason
- Departments of Experimental Therapeutics, Vancouver, BC V5Z 1L3, Canada; E-Mail:
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC V5Z 4E3, Canada
- Authors to whom correspondence should be addressed; E-Mails: (Y.W.); (C.D.H.); Tel.: +1-604-675-8013 (Y.W.); +1-604-675-8011 (C.D.H.); Fax: +1-604-675-8019 (Y.W. & C.D.H.)
| | - Kim N. Chi
- The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada; E-Mails: (A.W.); (M.E.G.); (K.N.C.)
- Departments of Experimental Therapeutics, Vancouver, BC V5Z 1L3, Canada; E-Mail:
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC V5Z 4E3, Canada
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Crea F, Sun L, Mai A, Chiang YT, Farrar WL, Danesi R, Helgason CD. The emerging role of histone lysine demethylases in prostate cancer. Mol Cancer 2012; 11:52. [PMID: 22867098 PMCID: PMC3441810 DOI: 10.1186/1476-4598-11-52] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [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: 02/02/2012] [Accepted: 07/17/2012] [Indexed: 01/22/2023] Open
Abstract
Early prostate cancer (PCa) is generally treatable and associated with good prognosis. After a variable time, PCa evolves into a highly metastatic and treatment-refractory disease: castration-resistant PCa (CRPC). Currently, few prognostic factors are available to predict the emergence of CRPC, and no curative option is available. Epigenetic gene regulation has been shown to trigger PCa metastasis and androgen-independence. Most epigenetic studies have focused on DNA and histone methyltransferases. While DNA methylation leads to gene silencing, histone methylation can trigger gene activation or inactivation, depending on the target amino acid residues and the extent of methylation (me1, me2, or me3). Interestingly, some histone modifiers are essential for PCa tumor-initiating cell (TIC) self-renewal. TICs are considered the seeds responsible for metastatic spreading and androgen-independence. Histone Lysine Demethylases (KDMs) are a novel class of epigenetic enzymes which can remove both repressive and activating histone marks. KDMs are currently grouped into 7 major classes, each one targeting a specific methylation site. Since their discovery, KDM expression has been found to be deregulated in several neoplasms. In PCa, KDMs may act as either tumor suppressors or oncogenes, depending on their gene regulatory function. For example, KDM1A and KDM4C are essential for PCa androgen-dependent proliferation, while PHF8 is involved in PCa migration and invasion. Interestingly, the possibility of pharmacologically targeting KDMs has been demonstrated. In the present paper, we summarize the emerging role of KDMs in regulating the metastatic potential and androgen-dependence of PCa. In addition, we speculate on the possible interaction between KDMs and other epigenetic effectors relevant for PCa TICs. Finally, we explore the role of KDMs as novel prognostic factors and therapeutic targets. We believe that studies on histone demethylation may add a novel perspective in our efforts to prevent and cure advanced PCa.
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Affiliation(s)
- Francesco Crea
- Experimental Therapeutics, British Columbia Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, Canada, V5Z 1L3.
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13
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Yang YHC, Szabat M, Bragagnini C, Kott K, Helgason CD, Hoffman BG, Johnson JD. Paracrine signalling loops in adult human and mouse pancreatic islets: netrins modulate beta cell apoptosis signalling via dependence receptors. Diabetologia 2011; 54:828-42. [PMID: 21212933 DOI: 10.1007/s00125-010-2012-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 11/08/2010] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS Adult pancreatic islets contain multiple cell types that produce and secrete well characterised hormones, including insulin, glucagon and somatostatin. Although it is increasingly apparent that islets release and respond to more secreted factors than previously thought, systematic analyses are lacking. We therefore sought to identify potential autocrine and/or paracrine islet growth factor loops, and to characterise the function of the netrin family of islet-secreted factors and their receptors, which have been previously unreported in adult islets. METHODS Gene expression databases, islet-specific tag sequencing libraries and microarray datasets of FACS purified beta cells were used to compile a list of secreted factors and receptors present in mouse or human islets. Netrins and their receptors were further assessed using RT-PCR, Western blot analysis and immunofluorescence staining. The roles of netrin-1 and netrin-4 in beta cell function, apoptosis and proliferation were also examined. RESULTS We identified 233 secreted factors and 234 secreted factor receptors in islets. The presence of netrins and their receptors was further confirmed. Downregulation of caspase-3 activation was observed when MIN6 cells were exposed to exogenous netrin-1 and netrin-4 under hyperglycaemic conditions. Reduction in caspase-3 cleavage was linked to the decrease in dependence receptors, neogenin and unc-5 homologue A, as well as the activation of Akt and extracellular signal-regulated protein kinase (ERK) signalling. CONCLUSIONS/INTERPRETATION Our results highlight the large number of potential islet growth factors and point to a context-dependent pro-survival role for netrins in adult beta cells. Since diabetes results from a deficiency in functional beta cell mass, these studies are important steps towards developing novel therapies to improve beta cell survival.
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Affiliation(s)
- Y H C Yang
- Department of Cellular and Physiological Sciences, University of British Columbia, 5358 Life Sciences Building, 2350 Health Sciences Mall, Vancouver, BC, Canada
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14
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Hoffman BG, Robertson G, Zavaglia B, Beach M, Cullum R, Lee S, Soukhatcheva G, Li L, Wederell ED, Thiessen N, Bilenky M, Cezard T, Tam A, Kamoh B, Birol I, Dai D, Zhao Y, Hirst M, Verchere CB, Helgason CD, Marra MA, Jones SJM, Hoodless PA. Locus co-occupancy, nucleosome positioning, and H3K4me1 regulate the functionality of FOXA2-, HNF4A-, and PDX1-bound loci in islets and liver. Genome Res 2010; 20:1037-51. [PMID: 20551221 DOI: 10.1101/gr.104356.109] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The liver and pancreas share a common origin and coexpress several transcription factors. To gain insight into the transcriptional networks regulating the function of these tissues, we globally identify binding sites for FOXA2 in adult mouse islets and liver, PDX1 in islets, and HNF4A in liver. Because most eukaryotic transcription factors bind thousands of loci, many of which are thought to be inactive, methods that can discriminate functionally active binding events are essential for the interpretation of genome-wide transcription factor binding data. To develop such a method, we also generated genome-wide H3K4me1 and H3K4me3 localization data in these tissues. By analyzing our binding and histone methylation data in combination with comprehensive gene expression data, we show that H3K4me1 enrichment profiles discriminate transcription factor occupied loci into three classes: those that are functionally active, those that are poised for activation, and those that reflect pioneer-like transcription factor activity. Furthermore, we demonstrate that the regulated presence of H3K4me1-marked nucleosomes at transcription factor occupied promoters and enhancers controls their activity, implicating both tissue-specific transcription factor binding and nucleosome remodeling complex recruitment in determining tissue-specific gene expression. Finally, we apply these approaches to generate novel insights into how FOXA2, PDX1, and HNF4A cooperate to drive islet- and liver-specific gene expression.
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Affiliation(s)
- Brad G Hoffman
- Department of Cancer Endocrinology, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada.
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15
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Antignano F, Ibaraki M, Kim C, Ruschmann J, Zhang A, Helgason CD, Krystal G. SHIP is required for dendritic cell maturation. J Immunol 2010; 184:2805-13. [PMID: 20154203 DOI: 10.4049/jimmunol.0903170] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although several groups have investigated the role of SHIP in macrophage (M) development and function, SHIP's contribution to the generation, maturation, and innate immune activation of dendritic cells (DCs) is poorly understood. We show herein that SHIP negatively regulates the generation of DCs from bone marrow precursors in vitro and in vivo, as illustrated by the enhanced expansion of DCs from SHIP(-/-) GM-CSF cultures, as well as increased numbers of DCs in the spleens of SHIP-deficient mice. Interestingly, however, these SHIP(-/-) DCs display a relatively immature phenotype and secrete substantially lower levels of IL-12 after TLR ligand stimulation than wild type DCs. This, in turn, leads to a dramatically reduced stimulation of Ag-specific T cell proliferation and Th1 cell responses in vitro and in vivo. This immature phenotype of SHIP(-/-) DCs could be reversed with the PI3K inhibitors LY294002 and wortmannin, suggesting that SHIP promotes DC maturation by reducing the levels of the PI3K second messenger phosphatidylinositol-3,4,5-trisphosphate. These results are consistent with SHIP being a negative regulator of GM-CSF-derived DC generation but a positive regulator of GM-CSF-derived DC maturation and function.
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Affiliation(s)
- Frann Antignano
- The Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
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16
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Morozova O, Morozov V, Hoffman BG, Helgason CD, Marra MA. A seriation approach for visualization-driven discovery of co-expression patterns in Serial Analysis of Gene Expression (SAGE) data. PLoS One 2008; 3:e3205. [PMID: 18787709 PMCID: PMC2527533 DOI: 10.1371/journal.pone.0003205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Accepted: 08/19/2008] [Indexed: 11/20/2022] Open
Abstract
Background Serial Analysis of Gene Expression (SAGE) is a DNA sequencing-based method for large-scale gene expression profiling that provides an alternative to microarray analysis. Most analyses of SAGE data aimed at identifying co-expressed genes have been accomplished using various versions of clustering approaches that often result in a number of false positives. Principal Findings Here we explore the use of seriation, a statistical approach for ordering sets of objects based on their similarity, for large-scale expression pattern discovery in SAGE data. For this specific task we implement a seriation heuristic we term ‘progressive construction of contigs’ that constructs local chains of related elements by sequentially rearranging margins of the correlation matrix. We apply the heuristic to the analysis of simulated and experimental SAGE data and compare our results to those obtained with a clustering algorithm developed specifically for SAGE data. We show using simulations that the performance of seriation compares favorably to that of the clustering algorithm on noisy SAGE data. Conclusions We explore the use of a seriation approach for visualization-based pattern discovery in SAGE data. Using both simulations and experimental data, we demonstrate that seriation is able to identify groups of co-expressed genes more accurately than a clustering algorithm developed specifically for SAGE data. Our results suggest that seriation is a useful method for the analysis of gene expression data whose applicability should be further pursued.
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Affiliation(s)
- Olena Morozova
- Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia, Canada.
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17
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Hoffman BG, Zavaglia B, Beach M, Helgason CD. Expression of Groucho/TLE proteins during pancreas development. BMC Dev Biol 2008; 8:81. [PMID: 18778483 PMCID: PMC2551604 DOI: 10.1186/1471-213x-8-81] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 09/08/2008] [Indexed: 11/28/2022]
Abstract
Background The full-length mammalian homologs of groucho, Tle1, 2, 3, and 4, act as transcriptional corepressors and are recruited by transcription factors containing an eh1 or WRPW/Y domain. Many transcription factors critical to pancreas development contain a Gro/TLE interaction domain and several have been shown to require Gro/TLE interactions for proper function during neuronal development. However, a detailed analysis of the expression patterns of the Gro/TLE proteins in pancreas development has not been performed. Moreover, little is known about the ability of Gro/TLE proteins to interact with transcription factors in the pancreas. Results We describe the expression of Gro/TLE family members, and of 34 different transcription factors that contain a Gro/TLE interaction motif, in the pancreas utilizing nine SAGE libraries created from the developing and adult pancreas, as well as the GenePaint database. Next, we show the dynamic expression of Tle1, 2, 3, 4, 5 and 6 during pancreas development by qRT-PCR. To further define the cell-type specificity of the expression of these proteins we use immunofluorescence to co-localize them with Pdx1 at embryonic day 12.5 (E12.5), Ngn3 at E14.5, Pdx1, Nkx2-2, Insulin, Glucagon, Pancreatic polypeptide and Somatostatin at E18.5, as well as Insulin and Glucagon in the adult. We then show that Tle2 can interact with Nkx2-2, Hes1, Arx, and Nkx6-1 which are all critical factors in pancreas development. Finally, we demonstrate that Tle2 modulates the repressive abilities of Arx in a β-cell line. Conclusion Although Tle1, 2, 3, and 4 show overlapping expression in pancreatic progenitors and in the adult islet, the expression of these factors is restricted to different cell types during endocrine cell maturation. Of note, Tle2 and Tle3 are co-expressed with Gro/TLE interaction domain containing transcription factors that are essential for endocrine pancreas development. We further demonstrate that Tle2 can interact with several of these factors and that Tle2 modulate Arx's repressive activity. Taken together our studies suggest that Gro/TLE proteins play a role in the repression of target genes during endocrine cell specification.
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Affiliation(s)
- Brad G Hoffman
- Department of Cancer Endocrinology, BC Cancer Research Center, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.
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18
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Hoffman BG, Zavaglia B, Witzsche J, Ruiz de Algara T, Beach M, Hoodless PA, Jones SJM, Marra MA, Helgason CD. Identification of transcripts with enriched expression in the developing and adult pancreas. Genome Biol 2008; 9:R99. [PMID: 18554416 PMCID: PMC2481431 DOI: 10.1186/gb-2008-9-6-r99] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [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: 04/02/2008] [Revised: 05/13/2008] [Accepted: 06/14/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite recent advances, the transcriptional hierarchy driving pancreas organogenesis remains largely unknown, in part due to the paucity of comprehensive analyses. To address this deficit we generated ten SAGE libraries from the developing murine pancreas spanning Theiler stages 17-26, making use of available Pdx1 enhanced green fluorescent protein (EGFP) and Neurog3 EGFP reporter strains, as well as tissue from adult islets and ducts. RESULTS We used a specificity metric to identify 2,536 tags with pancreas-enriched expression compared to 195 other mouse SAGE libraries. We subsequently grouped co-expressed transcripts with differential expression during pancreas development using K-means clustering. We validated the clusters first using quantitative real time PCR and then by analyzing the Theiler stage 22 pancreas in situ hybridization staining patterns of over 600 of the identified genes using the GenePaint database. These were then categorized into one of the five expression domains within the developing pancreas. Based on these results we identified a cascade of transcriptional regulators expressed in the endocrine pancreas lineage and, from this, we developed a predictive regulatory network describing beta-cell development. CONCLUSION Taken together, this work provides evidence that the SAGE libraries generated here are a valuable resource for continuing to elucidate the molecular mechanisms regulating pancreas development. Furthermore, our studies provide a comprehensive analysis of pancreas development, and insights into the regulatory networks driving this process are revealed.
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Affiliation(s)
- Brad G Hoffman
- Department of Cancer Endocrinology, BC Cancer Research Center, West 10th Ave, Vancouver, BC V5Z 1L3, Canada.
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Lu M, Glover CH, Tien AH, Humphries RK, Piret JM, Helgason CD. Involvement of tyrosine kinase signaling in maintaining murine embryonic stem cell functionality. Exp Hematol 2007; 35:1293-302. [PMID: 17562354 DOI: 10.1016/j.exphem.2007.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/13/2007] [Accepted: 04/16/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We previously demonstrated that c-kit expression decreases during murine embryonic stem cell (ESC) differentiation induced by leukemia inhibitory factor removal. In this study, we addressed the possibility that c-kit is a marker of undifferentiated murine ESC and, moreover, that it plays a role in maintaining the undifferentiated state of these cells. MATERIALS AND METHODS c-kit expression was analyzed under various differentiation conditions by flow cytometry and quantitative reverse transcription polymerase chain reaction. ESC were then sorted on the basis of c-kit expression and functionality was investigated using embryoid body and colony-forming cell assays. Imatinib (Gleevec) and ACK2 were used to block, and stem cell factor was used to stimulate, c-kit activity. RESULTS c-kit expression decreased in two murine ESC lines under various differentiation conditions. Sorting of ESC populations on the basis of c-kit expression revealed significant differences in the functional capacities and gene expression profiles of the sorted populations. The inhibition studies revealed an important role for tyrosine kinase activity in maintaining ESC viability and differentiation capacity, at least in part by preventing apoptosis and enhancing cell cycle progression. However, activation of c-kit alone is not sufficient for maintaining undifferentiated ESC. CONCLUSION The results suggest that c-kit may represent a useful marker for monitoring ESC functionality. Moreover, tyrosine kinase signaling plays an important role in maintaining undifferentiated ESC. This work provides valuable insights into the complex signaling pathways that synergize to maintain the undifferentiated state of murine ESC.
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Affiliation(s)
- Min Lu
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
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Neill L, Tien AH, Rey-Ladino J, Helgason CD. SHIP-deficient mice provide insights into the regulation of dendritic cell development and function. Exp Hematol 2007; 35:627-39. [PMID: 17379073 DOI: 10.1016/j.exphem.2007.01.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 01/22/2007] [Accepted: 01/22/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Dendritic cells (DC) play a critical role in establishment and maintenance of central and peripheral tolerance. Despite intensive research, our knowledge of the molecular mechanisms regulating DC development and function is limited, thus hindering our ability to generate appropriate DC populations for manipulating immune tolerance. We utilized mice deficient in the SH2-containing inositol-5-phosphatase (SHIP) to examine the role of cytokine signaling in DC development and function. METHODS We analyzed the phenotype of both primary and bone marrow (BM)-derived DC (BMDC) using flow cytometry. In addition, cytokine production was measured using cytometric bead arrays and the ability of DC to induce allogeneic T-cell proliferation was assessed using thymidine incorporation assays. RESULTS We demonstrated that spleen DC isolated from SHIP-deficient mice are increased in number and have an altered phenotype. In vitro analyses revealed that SHIP-deficient BM cells give rise to a higher frequency of myeloid, but not plasmacytoid, DC due to both an increased progenitor frequency and enhanced cytokine sensitivity. The BMDC exhibit an altered phenotype that correlates with a reduced capacity to induce allogeneic T-cell proliferation. Addition of interleukin-6 to WT BM cultures during DC differentiation partially induces a KO phenotype. CONCLUSION These studies suggest that myeloid and plasmacytoid DC progenitors are differentially sensitive to signaling pathways in which SHIP is involved. Moreover, they suggest that interleukin-6 may have an important role in regulating the phenotype and function of myeloid DC.
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Affiliation(s)
- Leanne Neill
- Department of Cancer Endocrinology, British Columbia Cancer Agency, 675 West 12th Avenue, Vancouver, BC, Canada
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Glover CH, Marin M, Eaves CJ, Helgason CD, Piret JM, Bryan J. Meta-analysis of differentiating mouse embryonic stem cell gene expression kinetics reveals early change of a small gene set. PLoS Comput Biol 2006; 2:e158. [PMID: 17121458 PMCID: PMC1664699 DOI: 10.1371/journal.pcbi.0020158] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 10/06/2006] [Indexed: 11/19/2022] Open
Abstract
Stem cell differentiation involves critical changes in gene expression. Identification of these should provide endpoints useful for optimizing stem cell propagation as well as potential clues about mechanisms governing stem cell maintenance. Here we describe the results of a new meta-analysis methodology applied to multiple gene expression datasets from three mouse embryonic stem cell (ESC) lines obtained at specific time points during the course of their differentiation into various lineages. We developed methods to identify genes with expression changes that correlated with the altered frequency of functionally defined, undifferentiated ESC in culture. In each dataset, we computed a novel statistical confidence measure for every gene which captured the certainty that a particular gene exhibited an expression pattern of interest within that dataset. This permitted a joint analysis of the datasets, despite the different experimental designs. Using a ranking scheme that favored genes exhibiting patterns of interest, we focused on the top 88 genes whose expression was consistently changed when ESC were induced to differentiate. Seven of these (103728_at, 8430410A17Rik, Klf2, Nr0b1, Sox2, Tcl1, and Zfp42) showed a rapid decrease in expression concurrent with a decrease in frequency of undifferentiated cells and remained predictive when evaluated in additional maintenance and differentiating protocols. Through a novel meta-analysis, this study identifies a small set of genes whose expression is useful for identifying changes in stem cell frequencies in cultures of mouse ESC. The methods and findings have broader applicability to understanding the regulation of self-renewal of other stem cell types.
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Affiliation(s)
- Clive H Glover
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael Marin
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Connie J Eaves
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
| | - Cheryl D Helgason
- Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cancer Endocrinology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
| | - James M Piret
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jennifer Bryan
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
- * To whom correspondence should be addressed. E-mail:
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22
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Hoffman BG, Williams KL, Tien AH, Lu V, de Algara TR, Ting JPY, Helgason CD. Identification of novel genes and transcription factors involved in spleen, thymus and immunological development and function. Genes Immun 2006; 7:101-12. [PMID: 16355110 DOI: 10.1038/sj.gene.6364270] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We constructed and analyzed six serial analysis of gene expression (SAGE) libraries to identify genes with previously uncharacterized roles in spleen or thymus development. A total of 625 070 tags were sequenced from the three spleen (embryonic day (E)15.5, E16.5 and adult) and three thymus (E15.5, E18.5 and adult) libraries. These tags corresponded to 83 182 tag types, which mapped unambiguously to 36 133 different genes. Genes over-represented in these libraries, compared to 115 mouse SAGE libraries (www.mouseatlas.org), included genes of known and unknown immunological or developmental relevance. The expression profiles of 11 genes with unknown roles in spleen and thymus development were validated using reverse transcription-qPCR. We further characterized the expression of one of these candidates, RIKEN cDNA 9230105E10 that encodes a murine homolog of Trim5alpha, in numerous adult tissues and immune cell types. In addition, we demonstrate that transcript levels are upregulated in response to TLR stimulation of plasmacytoid dendritic cells and macrophages. This work provides the first evidence of regulated and cell type-specific expression of this gene. In addition, these observations suggest that the SAGE libraries provide an important resource for further investigations into the molecular mechanisms regulating spleen and thymus organogenesis, as well as the development of immunological competence.
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23
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Marçal N, Patel H, Dong Z, Belanger-Jasmin S, Hoffman B, Helgason CD, Dang J, Stifani S. Antagonistic effects of Grg6 and Groucho/TLE on the transcription repression activity of brain factor 1/FoxG1 and cortical neuron differentiation. Mol Cell Biol 2006; 25:10916-29. [PMID: 16314515 PMCID: PMC1316978 DOI: 10.1128/mcb.25.24.10916-10929.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Groucho (Gro)/TLE transcriptional corepressors are involved in a variety of developmental mechanisms, including neuronal differentiation. They contain a conserved C-terminal WD40 repeat domain that mediates interactions with several DNA-binding proteins. In particular, Gro/TLE1 interacts with forkhead transcription factor brain factor 1 (BF-1; also termed FoxG1). BF-1 is an essential regulator of neuronal differentiation during cerebral cortex development and represses transcription together with Gro/TLE1. Gro/TLE-related gene product 6 (Grg6) shares with Gro/TLEs a conserved WD40 repeat domain but is more distantly related at its N-terminal half. We demonstrate that Grg6 is expressed in cortical neural progenitor cells and interacts with BF-1. In contrast to Gro/TLE1, however, Grg6 does not promote, but rather suppresses, BF-1-mediated transcriptional repression. Consistent with these observations, Grg6 interferes with the binding of Gro/TLE1 to BF-1 and does not repress transcription when targeted to DNA. Moreover, coexpression of Grg6 and BF-1 in cortical progenitor cells leads to a decrease in the number of proliferating cells and increased neuronal differentiation. Conversely, Grg6 knockdown by RNA interference causes decreased neurogenesis. These results identify a new role for Grg6 in cortical neuron development and establish a functional link between Grg6 and BF-1.
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Affiliation(s)
- Nathalie Marçal
- Center for Neuronal Survival, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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24
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Zhang TJ, Hoffman BG, Ruiz de Algara T, Helgason CD. SAGE reveals expression of Wnt signalling pathway members during mouse prostate development. Gene Expr Patterns 2005; 6:310-24. [PMID: 16378759 DOI: 10.1016/j.modgep.2005.07.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 07/05/2005] [Accepted: 07/15/2005] [Indexed: 12/29/2022]
Abstract
To identify genes and pathways not previously implicated in the mesenchymal-epithelial (M/E) interactions that are critical for normal mouse prostate development, we constructed six serial analysis of gene expression (SAGE) libraries. Bioinformatic analyses revealed expression of various members of numerous signalling pathways and the differential expression of several members of the wingless-related MMTV integration site (Wnt) signalling pathway. This pathway has not been previously implicated in prostate development thus expression of selected Wnt pathway members in the developing prostate was confirmed by RT-qPCR. Of particular interest, an antagonist of the Wnt pathway, secreted frizzled related protein 2 (Sfrp2), was highly expressed in the early prostate libraries and down regulated at later developmental stages. The expression levels of four Wnt ligands reported to interact with Sfrp2 were, therefore, examined by RT-qPCR. We found that only Wnt4 transcripts were detectable in the developing prostate. Expression of Sfrp2 was validated using RT-qPCR and localization of Sfrp2 transcripts and protein was carried out using in situ hybridization and immunofluorescence, respectively. These studies provide the first evidence that Wnt pathway members are expressed in the developing prostate. Functional analyses are now required to establish the biological significance of this observation.
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Affiliation(s)
- Tian-Jiao Zhang
- Department of Cancer Endocrinology, British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC, Canada V5Z 1L3
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25
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Siddiqui AS, Khattra J, Delaney AD, Zhao Y, Astell C, Asano J, Babakaiff R, Barber S, Beland J, Bohacec S, Brown-John M, Chand S, Charest D, Charters AM, Cullum R, Dhalla N, Featherstone R, Gerhard DS, Hoffman B, Holt RA, Hou J, Kuo BYL, Lee LLC, Lee S, Leung D, Ma K, Matsuo C, Mayo M, McDonald H, Prabhu AL, Pandoh P, Riggins GJ, de Algara TR, Rupert JL, Smailus D, Stott J, Tsai M, Varhol R, Vrljicak P, Wong D, Wu MK, Xie YY, Yang G, Zhang I, Hirst M, Jones SJM, Helgason CD, Simpson EM, Hoodless PA, Marra MA. A mouse atlas of gene expression: large-scale digital gene-expression profiles from precisely defined developing C57BL/6J mouse tissues and cells. Proc Natl Acad Sci U S A 2005; 102:18485-90. [PMID: 16352711 PMCID: PMC1311911 DOI: 10.1073/pnas.0509455102] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We analyzed 8.55 million LongSAGE tags generated from 72 libraries. Each LongSAGE library was prepared from a different mouse tissue. Analysis of the data revealed extensive overlap with existing gene data sets and evidence for the existence of approximately 24,000 previously undescribed genomic loci. The visual cortex, pancreas, mammary gland, preimplantation embryo, and placenta contain the largest number of differentially expressed transcripts, 25% of which are previously undescribed loci.
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Affiliation(s)
- Asim S Siddiqui
- Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Research Centre, British Columbia Cancer Agency, Vancouver, BC, Canada V5Z 4S6
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26
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Palmqvist L, Glover CH, Hsu L, Lu M, Bossen B, Piret JM, Humphries RK, Helgason CD. Correlation of Murine Embryonic Stem Cell Gene Expression Profiles with Functional Measures of Pluripotency. Stem Cells 2005; 23:663-80. [PMID: 15849174 DOI: 10.1634/stemcells.2004-0157] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Global gene expression profiling was performed on murine embryonic stem cells (ESCs) induced to differentiate by removal of leukemia inhibitory factor (LIF) to identify genes whose change in expression correlates with loss of pluripotency. To identify appropriate time points for the gene expression analysis, the dynamics of loss of pluripotency were investigated using three functional assays: chimeric mouse formation, embryoid body generation, and colony-forming ability. A rapid loss of pluripotency was detected within 24 hours, with very low residual activity in all assays by 72 hours. Gene expression profiles of undifferentiated ESCs and ESCs cultured for 18 and 72 hours in the absence of LIF were determined using the Affymetrix GeneChip U74v2. In total, 473 genes were identified as significantly differentially expressed, with approximately one third having unknown biological function. Among the 275 genes whose expression decreased with ESC differentiation were several factors previously identified as important for, or markers of, ESC pluripotency, including Stat3, Rex1, Sox2, Gbx2, and Bmp4. A significant number of the decreased genes also overlap with previously published mouse and human ESC data. Furthermore, several membrane proteins were among the 48 decreased genes correlating most closely with the functional assays, including the stem cell factor receptor c-Kit. Through identification of genes whose expression closely follows functional properties of ESCs during early differentiation, this study lays the foundation for further elucidating the molecular mechanisms regulating the maintenance of ESC pluripotency and facilitates the identification of more reliable molecular markers of the undifferentiated state.
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Affiliation(s)
- Lars Palmqvist
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC, Canada
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27
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Abstract
Increasing evidence suggests that altered immune function accompanies, and indeed may facilitate, cancer progression. In this study, we sought to determine the nature of, and cellular mechanisms underlying, changes in immune status during disease progression in a transgenic mouse model of prostate dysplasia. Immune cells in the tumor microenvironment, as well as in the secondary lymphoid tissues, displayed altered phenotypes. Although evidence of antitumor immunity was detected, there was a paradoxical decrease in the ability of T cells to proliferate in vitro at later stages of disease progression. Detailed analysis of the draining lumbar lymph nodes revealed an increased frequency and number of CD4(+)CD25(+) T cells and an enhanced production of inhibitory cytokines, which correlated with impaired T-cell function. Functional studies confirmed a role for CD4(+)CD25(+) regulatory T cells in suppressing T-cell proliferation as well as regulating the growth of transplanted prostate tumor cells. In addition, our studies show for the first time that anti-CD25 antibody treatment reduces, but does not prevent, tumor growth in a transgenic mouse model of prostate dysplasia. Taken together, this work provides compelling evidence that prostate tumor progression is accompanied by altered immune function and, moreover, that regulatory T cells play an important role in this process. These studies thus provide the impetus for development of specific and effective strategies to deplete regulatory T cells, or suppress their function, as an alternative or adjunct strategy for reducing tumor growth.
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Affiliation(s)
- Amy H Tien
- Department of Cancer Endocrinology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
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Abstract
Cell culture is an invaluable tool for investigators in numerous fields. It facilitates analysis of biological properties and processes that are not readily accessible at the level of the intact organism. Successful maintenance of cells in culture, whether primary or immortalized, requires knowledge and practice of a few essential techniques. The purpose of this chapter is to explain the basic principles of cell culture using the maintenance of a nonadherent cell line, the P815 mouse mastocytoma cell line, and the isolation and culture of adherent primary mouse embryonic fibroblasts (MEFs) as examples. Procedures for thawing, culture, determination of cell numbers and viability, and cryopreservation are described.
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Affiliation(s)
- Cheryl D Helgason
- Department of Cancer Endocrinology, British Columbia Cancer agency, Vancouver, Canada
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Moody JL, Xu L, Helgason CD, Jirik FR. Anemia, thrombocytopenia, leukocytosis, extramedullary hematopoiesis, and impaired progenitor function in Pten+/-SHIP-/- mice: a novel model of myelodysplasia. Blood 2004; 103:4503-10. [PMID: 15001465 DOI: 10.1182/blood-2003-09-3262] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The myeloproliferative disorder of mice lacking the Src homology 2 (SH2)-containing 5' phosphoinositol phosphatase, SHIP, underscores the need for closely regulating phosphatidylinositol 3-kinase (PI3K) pathway activity, and hence levels of phosphatidylinositol species during hematopoiesis. The role of the 3' phosphoinositol phosphatase Pten in this process is less clear, as its absence leads to embryonic lethality. Despite Pten heterozygosity being associated with a lymphoproliferative disorder, we found no evidence of a hematopoietic defect in Pten(+/-) mice. Since SHIP shares the same substrate (PIP(3)) with Pten, we hypothesized that the former might compensate for Pten haploinsufficiency in the marrow. Thus, we examined the effect of Pten heterozygosity in SHIP(-/-) mice, predicting that further dysregulation of PIP(3) metabolism would exacerbate the pheno-type of the latter. Indeed, compared with SHIP(-/-) mice, Pten(+/-)SHIP(-/-) animals developed a myelodysplastic phenotype characterized by increased hepatosplenomegaly, extramedullary hematopoiesis, anemia, and thrombocytopenia. Consistent with a marrow defect, clonogenic assays demonstrated reductions in committed myeloid and megakaryocytic progenitors in these animals. Providing further evidence of a Pten(+/-)SHIP(-/-) progenitor abnormality, reconstitution of irradiated mice with marrows from these mice led to a marked defect in short-term repopulation of peripheral blood by donor cells. These studies suggest that the regulation of the levels and/or ratios of PI3K-derived phosphoinositol species by these 2 phosphatases is critical to normal hematopoiesis.
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Affiliation(s)
- Jennifer L Moody
- Department of Biochemistry and Molecular Biology, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
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30
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Abstract
SH2-containing inositol 5-phosphatase (SHIP) is an important negative regulator of cytokine and immune receptor signaling. SHIP-deficient mice have a number of hematopoietic perturbations, including enhanced cytokine responsiveness. Because cytokines play an important role in the maintenance/expansion of the primitive hematopoietic cell pool, we investigated the possibility that SHIP also regulates the properties of cells in these compartments. Primitive hematopoietic cells were evaluated in SHIP-deficient mice and wild-type littermate controls using the colony-forming unit-spleen (CFU-S) and competitive repopulating unit (CRU) assays for multipotent progenitors and long-term lympho-myeloid repopulating cells, respectively. Absence of SHIP was found to affect homeostasis of CFU-S and CRU compartments. Numbers of primitive cells were increased in extramedullary sites such as the spleen of SHIP-deficient mice, although total body numbers were not significantly changed. In vivo cell cycle status of the CRU compartment was further evaluated using 5-fluorouracil (5-FU). SHIP-deficient CRUs were more sensitive to 5-FU killing, indicating a higher proliferative cell fraction. More strikingly, SHIP was found to regulate the ability of primitive cells to regenerate in vivo, as CRU recovery was approximately 30-fold lower in mice that received transplants of SHIP-deficient cells compared with controls. These results support a major role for SHIP in modulating pathways important in homeostasis and regeneration of hematopoietic stem cells, and emphasize the importance of negative cytokine regulation at the earliest stages of hematopoiesis.
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Affiliation(s)
- Cheryl D Helgason
- Department of Cancer Endocrinology, British Columbia Cancer Agency, 601 W 10th Ave, Vancouver, British Columbia Canada V5Z 1L3.
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31
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Baran CP, Tridandapani S, Helgason CD, Humphries RK, Krystal G, Marsh CB. The inositol 5'-phosphatase SHIP-1 and the Src kinase Lyn negatively regulate macrophage colony-stimulating factor-induced Akt activity. J Biol Chem 2003; 278:38628-36. [PMID: 12882960 DOI: 10.1074/jbc.m305021200] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Upon encountering macrophage colony-stimulating factor (M-CSF), human monocytes undergo a series of cellular signaling events leading to an increase in Akt activity. However, the regulation of these events is not completely understood. Because the inositol 5'-phosphatase SHIP-1 is an important regulator of intracellular levels of phosphatidylinositol 3,4,5-trisphosphate, an important second messenger necessary for Akt activation, we hypothesized that SHIP-1 was involved in the regulation of M-CSF receptor (M-CSF-R)-induced Akt activation. In the human monocytic cell line, THP-1, SHIP-1 became tyrosine-phosphorylated following M-CSF activation in a Src family kinase-dependent manner. Transfection of 3T3-Fms cells, which express the human M-CSF-R, with wild-type SHIP-1 showed that SHIP-1 was necessary for the negative regulation of M-CSF-induced Akt activation. In THP-1 cells, SHIP-1 bound Lyn, independent of the kinase activity of Lyn, following M-CSF activation. Utilizing a glutathione S-transferase fusion protein, we found that SHIP-1 bound to Lyn via the SHIP-1 Src homology 2 domain. Furthermore, transfection of THP-1 cells with a wild-type SHIP-1 construct reduced NF-kappaB-dependent transcriptional activation of a reporter gene, whereas a SHIP-1 Src homology 2 domain construct resulted in an increase in NF-kappaB activation. Additionally, in 3T3-Fms cells, Lyn enhanced the ability of SHIP-1 to regulate Akt activation by stabilizing SHIP-1 at the cellular membrane. Finally, macrophages isolated from both SHIP-1- and Lyn-deficient mice exhibited enhanced Akt phosphorylation following M-CSF stimulation. These data provide the first evidence of the involvement of both SHIP-1 and Lyn in the negative regulation of M-CSF-R-induced Akt activation.
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Affiliation(s)
- Christopher P Baran
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus 43210, USA
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32
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Crow AR, Song S, Freedman J, Helgason CD, Humphries RK, Siminovitch KA, Lazarus AH. IVIg-mediated amelioration of murine ITP via FcgammaRIIB is independent of SHIP1, SHP-1, and Btk activity. Blood 2003; 102:558-60. [PMID: 12649142 DOI: 10.1182/blood-2003-01-0023] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
It has been established that amelioration of murine immune thrombocytopenia purpura (ITP) by IVIg is dependent on the inhibitory receptor FcgammaRIIB. Co-cross-linking of the FcgammaRIIB with the B-cell receptor complex or with FcepsilonRI in mast cells results in cell inhibition, which is mediated by recruitment of the inositol phosphatase SHIP1 to the cytoplasmic tail of the FcgammaR. The FcgammaRIIB can also associate with protein tyrosine phosphatase SHP-1 as a potential secondary target of the receptor. Alternatively, homoaggregation of FcgammaRIIB can induce a proapoptotic state in B cells that is dependent on the presence of Bruton tyrosine kinase (Btk), a kinase also expressed in monocytes. We sought to determine if these signaling pathways may direct IVIg-mediated FcgammaRIIB-dependent regulation of in vivo monocyte function in a murine model of ITP in which IVIg functions in an FcgammaRIIB-dependent manner. We demonstrate that mice deficient in SHIP1, SHP-1, and Btk respond to the ameliorating effects of IVIg with the same kinetics as control mice. We conclude that IVIgmediated inhibitory pathways operating via monocyte FcgammaRIIB may involve a transmembrane signaling pathway different from that of B cells.
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MESH Headings
- Agammaglobulinaemia Tyrosine Kinase
- Animals
- Antigens, CD/physiology
- Autoimmune Diseases/enzymology
- Autoimmune Diseases/immunology
- Autoimmune Diseases/therapy
- B-Lymphocytes/enzymology
- B-Lymphocytes/immunology
- Immunoglobulins, Intravenous/therapeutic use
- Intracellular Signaling Peptides and Proteins
- Mast Cells/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Animal
- Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
- Phosphoric Monoester Hydrolases/deficiency
- Phosphoric Monoester Hydrolases/genetics
- Phosphoric Monoester Hydrolases/physiology
- Phosphorylation
- Protein Processing, Post-Translational
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/deficiency
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases/physiology
- Protein-Tyrosine Kinases/deficiency
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/physiology
- Purpura, Thrombocytopenic, Idiopathic/enzymology
- Purpura, Thrombocytopenic, Idiopathic/immunology
- Purpura, Thrombocytopenic, Idiopathic/therapy
- Receptors, IgG/physiology
- Signal Transduction/physiology
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Affiliation(s)
- Andrew R Crow
- Transfusion Medicine Research, St Michael's Hospital, Toronto, ON, Canada
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33
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Takeshita S, Namba N, Zhao JJ, Jiang Y, Genant HK, Silva MJ, Brodt MD, Helgason CD, Kalesnikoff J, Rauh MJ, Humphries RK, Krystal G, Teitelbaum SL, Ross FP. SHIP-deficient mice are severely osteoporotic due to increased numbers of hyper-resorptive osteoclasts. Nat Med 2002; 8:943-9. [PMID: 12161749 DOI: 10.1038/nm752] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The hematopoietic-restricted protein Src homology 2-containing inositol-5-phosphatase (SHIP) blunts phosphatidylinositol-3-kinase-initiated signaling by dephosphorylating its major substrate, phosphatidylinositol-3,4,5-trisphosphate. As SHIP(-/-) mice contain increased numbers of osteoclast precursors, that is, macrophages, we examined bones from these animals and found that osteoclast number is increased two-fold. This increased number is due to the prolonged life span of these cells and to hypersensitivity of precursors to macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kappa B ligand (RANKL). Similar to pagetic osteoclasts, SHIP(-/-) osteoclasts are enlarged, containing upwards of 100 nuclei, and exhibit enhanced resorptive activity. Moreover, as in Paget disease, serum levels of interleukin-6 are markedly increased in SHIP(-/-) mice. Consistent with accelerated resorptive activity, 3D trabecular volume fraction, trabecular thickness, number and connectivity density of SHIP(-/-) long bones are reduced, resulting in a 22% loss of bone-mineral density and a 49% decrease in fracture energy. Thus, SHIP negatively regulates osteoclast formation and function and the absence of this enzyme results in severe osteoporosis.
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Affiliation(s)
- Sunao Takeshita
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
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34
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Pineault N, Helgason CD, Lawrence HJ, Humphries RK. Differential expression of Hox, Meis1, and Pbx1 genes in primitive cells throughout murine hematopoietic ontogeny. Exp Hematol 2002; 30:49-57. [PMID: 11823037 DOI: 10.1016/s0301-472x(01)00757-3] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The Hox gene family of transcription factors is thought to be involved in the regulation of primitive hematopoietic cells, including stem cells and early committed progenitors, and has also been directly implicated in leukemia. To gain further insight into Hox gene-mediated regulation of hematopoiesis, we investigated the expression pattern of representative Hox genes and two of their cofactors, Pbx1 and Meis1, at different stages of murine hematopoiesis. METHODS Functionally distinct subpopulations of murine bone marrow (BM) and fetal liver day 14.5 (FL) cells were isolated by flow cytometry, and gene expression of various homeobox-containing genes was assessed by global cDNA amplification technique. RESULTS Hox genes were found preferentially expressed in hematopoietic stem cell (HSC)-enriched subpopulations and downregulated following differentiation and maturation. This profile of expression was observed at both adult and fetal stages of hematopoiesis. The Pbx1 and Meis1 genes had important differences in their expression pattern but were both detected in Hox expressing subpopulations. In particular, Meis1 consistently showed an expression profile closely resembling that of Hox genes. Finally, using the in vitro embryonic stem (ES) cell differentiation model to mimic embryonic hematopoiesis, we found coexpression of Hox genes and their cofactors coincided with the appearance of hematopoietic progenitor cells. CONCLUSION Together, these results further support the notion that Hox genes are involved in the regulation of early hematopoietic cells and provide strong evidence that they are involved in the regulation of hematopoiesis throughout ontogeny.
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Affiliation(s)
- Nicolas Pineault
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
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35
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Latour S, Gish G, Helgason CD, Humphries RK, Pawson T, Veillette A. Regulation of SLAM-mediated signal transduction by SAP, the X-linked lymphoproliferative gene product. Nat Immunol 2001; 2:681-90. [PMID: 11477403 DOI: 10.1038/90615] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) is a short intracellular molecule that is mutated in humans with X-linked lymphoproliferative (XLP) disease. Although the exact role and mechanism of action of SAP are not known, it has the capacity to interact with the cytoplasmic region of SLAM and other related immune cell receptors. As SAP is composed almost exclusively of a Src homology 2 (SH2) domain, it has been proposed that it functions as a natural blocker of SH2 domain--mediated interactions. We report here that the SLAM receptor is capable of triggering a protein tyrosine phosphorylation signal in T cells via a mechanism that is strictly dependent on SAP expression. This signal involves the SH2 domain--containing inositol phosphatase (SHIP); the adaptor molecules Dok2, Dok1 and Shc; and Ras GTPase--activating protein RasGAP. SAP is essential for this pathway because it facilitates the selective recruitment and activation of the Src-related protein tyrosine kinase FynT. We also show that signaling via the SLAM-SAP pathway in an established T cell line can alter the profile of cytokine production during T cell activation. These findings identify a mechanism by which a putative adaptor molecule is required for receptor-mediated signaling events in the immune system. They also provide insights into the pathophysiology of a severe human lymphoproliferative disease.
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Affiliation(s)
- S Latour
- Laboratory of Molecular Oncology, IRCM, 110 Pine Ave. West, Montréal, Québec, Canada H2W 1R7
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36
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Brauweiler A, Tamir I, Marschner S, Helgason CD, Cambier JC. Partially distinct molecular mechanisms mediate inhibitory FcgammaRIIB signaling in resting and activated B cells. J Immunol 2001; 167:204-11. [PMID: 11418650 DOI: 10.4049/jimmunol.167.1.204] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
FcgammaRIIB functions as an inhibitory receptor to dampen B cell Ag receptor signals and immune responses. Accumulating evidence indicates that ex vivo B cells require the inositol 5-phosphatase, Src homology domain 2-containing inositol 5-phosphatase (SHIP), for FcgammaRIIB-mediated inhibitory signaling. However, we report here that LPS-activated primary B cells do not require SHIP and thus differ from resting B cells. SHIP-deficient B cell blasts display efficient FcgammaRIIB-dependent inhibition of calcium mobilization as well as Akt and extracellular signal-related protein kinase phosphorylation. Surprisingly, FcgammaRIIB-dependent degradation of phosphatidylinositol 3,4,5-trisphosphate and conversion into phosphatidylinositol 3,4-bisphosphate occur in SHIP-deficient B cell blasts, demonstrating the function of an additional inositol 5-phosphatase. Further analysis reveals that while resting cells express only SHIP, B cell blasts also express the recently described inositol 5-phosphatase, SHIP-2. Finally, data suggest that both SHIP-2 and SHIP can mediate downstream biologic consequences of FcgammaRIIB signaling, including inhibition of the proliferative response.
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Affiliation(s)
- A Brauweiler
- Department of Immunology, National Jewish Medical and Research Center, Denver, CO 80206, USA
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37
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Wang R, Salem M, Yousef IM, Tuchweber B, Lam P, Childs SJ, Helgason CD, Ackerley C, Phillips MJ, Ling V. Targeted inactivation of sister of P-glycoprotein gene (spgp) in mice results in nonprogressive but persistent intrahepatic cholestasis. Proc Natl Acad Sci U S A 2001; 98:2011-6. [PMID: 11172067 PMCID: PMC29373 DOI: 10.1073/pnas.98.4.2011] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2000] [Indexed: 12/14/2022] Open
Abstract
Mutations in the sister of P-glycoprotein (Spgp) or bile salt export pump (BSEP) are associated with Progressive Familial Intrahepatic Cholestasis (PFIC2). Spgp is predominantly expressed in the canalicular membranes of liver. Consistent with in vitro evidence demonstrating the involvement of Spgp in bile salt transport, PFIC2 patients secrete less than 1% of biliary bile salts compared with normal infants. The disease rapidly progresses to hepatic failure requiring liver transplantation before adolescence. In this study, we show that the knockout of spgp gene in mice results in intrahepatic cholestasis, but with significantly less severity than PFIC2 in humans. Some unexpected characteristics are observed. Notably, although the secretion of cholic acid in mutant mice is greatly reduced (6% of wild-type), total bile salt output in mutant mice is about 30% of wild-type. Also, secretion of an unexpectedly large amount of tetra-hydroxylated bile acids (not detected in wild-type) is observed. These results suggest that hydroxylation and an alternative canalicular transport mechanism for bile acids compensate for the absence of Spgp function and protect the mutant mice from severe cholestatic damage. In addition, the spgp(-/-) mice display a significant increase in the secretion of cholesterol and phospholipids into the bile. This latter observation in spgp(-/-) mice suggests that intrahepatic, rather than intracanalicular, bile salts are the major driving force for the biliary lipid secretion. The spgp(-/-) mice thus provide a unique model for gaining new insights into therapeutic intervention for intrahepatic cholestasis and understanding mechanisms associated with lipid homeostasis.
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Affiliation(s)
- R Wang
- British Columbia Cancer Research Center, British Columbia Cancer Agency, Vancouver, BC, Canada V5Z 1L3
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38
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Cox D, Dale BM, Kashiwada M, Helgason CD, Greenberg S. A regulatory role for Src homology 2 domain-containing inositol 5'-phosphatase (SHIP) in phagocytosis mediated by Fc gamma receptors and complement receptor 3 (alpha(M)beta(2); CD11b/CD18). J Exp Med 2001; 193:61-71. [PMID: 11136821 PMCID: PMC2195884 DOI: 10.1084/jem.193.1.61] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The Src homology 2 domain-containing inositol 5'-phosphatase (SHIP) is recruited to immunoreceptor tyrosine-based inhibition motif (ITIM)-containing proteins, thereby suppressing phosphatidylinositol 3-kinase (PI 3-kinase)-dependent pathways. The role of SHIP in phagocytosis, a PI 3-kinase-dependent pathway, is unknown. Overexpression of SHIP in macrophages led to an inhibition of phagocytosis mediated by receptors for the Fc portion of IgG (Fc gamma Rs). In contrast, macrophages expressing catalytically inactive SHIP or lacking SHIP expression demonstrated enhanced phagocytosis. To determine whether SHIP regulates phagocytosis mediated by receptors that are not known to recruit ITIMs, we determined the effect of SHIP expression on complement receptor 3 (CR3; CD11b/CD18; alpha(M)beta(2))-dependent phagocytosis. Macrophages overexpressing SHIP demonstrated impaired CR3-mediated phagocytosis, whereas macrophages expressing catalytically inactive SHIP demonstrated enhanced phagocytosis. CR3-mediated phagocytosis in macrophages derived from SHIP(-/-) mice was up to 2.5 times as efficient as that observed in macrophages derived from littermate controls. SHIP was localized to Fc gamma R- and CR3-containing phagocytic cups and was recruited to the cytoskeleton upon clustering of CR3. In a transfected COS cell model of activation-independent CR3-mediated phagocytosis, catalytically active but not inactive SHIP also inhibited phagocytosis. We conclude that PI 3-kinase(s) and SHIP regulate multiple forms of phagocytosis and that endogenous SHIP plays a role in modulating beta(2) integrin outside-in signaling.
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Affiliation(s)
- Dianne Cox
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Benjamin M. Dale
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Masaki Kashiwada
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | | | - Steven Greenberg
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, New York 10032
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39
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Satterthwaite AB, Willis F, Kanchanastit P, Fruman D, Cantley LC, Helgason CD, Humphries RK, Lowell CA, Simon M, Leitges M, Tarakhovsky A, Tedder TF, Lesche R, Wu H, Witte ON. A sensitized genetic system for the analysis of murine B lymphocyte signal transduction pathways dependent on Bruton's tyrosine kinase. Proc Natl Acad Sci U S A 2000; 97:6687-92. [PMID: 10829070 PMCID: PMC18703 DOI: 10.1073/pnas.110146697] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Modifier screens have been powerful genetic tools to define signaling pathways in lower organisms. The identification of modifier loci in mice has begun to allow a similar dissection of mammalian signaling pathways. Transgenic mice (Btk(lo)) expressing 25% of endogenous levels of Bruton's tyrosine kinase (Btk) have B cell functional responses between those of wild-type and Btk(-/-) mice. We asked whether reduced dosage or complete deficiency of genes previously implicated as Btk regulators would modify the Btk(lo) phenotype. We used two independent assays of Btk-dependent B cell function. Proliferative response to B cell antigen receptor cross-linking in vitro was chosen as an example of a relatively simple, well-defined signaling system. In vivo response to type II T-independent antigens (TI-II) measures complex interactions among multiple cell types over time and may identify additional Btk pathways. All modifiers identified differentially affected these two assays, indicating that Btk mediates these processes via distinct mechanisms. Loss of Lyn, PTEN (phosphatase and tensin homolog), or SH2-containing inositol phosphatase suppressed the Btk(lo) phenotype in vitro but not in vivo, whereas CD19 and the p85alpha form of phosphoinositide 3-kinase behaved as Btk(lo) enhancers in vivo but not in vitro. Effects of Lyn, PTEN, or p85alpha haploinsufficiency were observed. Haploinsufficiency or complete deficiency of protein kinase C beta, Fyn, CD22, Galphaq, or Galpha11 had no detectable effect on the function of Btk(lo) B cells. A transgenic system creating a reduction in dosage of Btk can therefore be used to identify modifier loci that affect B cell responses and quantitatively rank their contribution to Btk-mediated processes.
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Affiliation(s)
- A B Satterthwaite
- Department of Microbiology, Immunology, and Molecular Genetics, and Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095, USA
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40
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Brauweiler A, Tamir I, Dal Porto J, Benschop RJ, Helgason CD, Humphries RK, Freed JH, Cambier JC. Differential regulation of B cell development, activation, and death by the src homology 2 domain-containing 5' inositol phosphatase (SHIP). J Exp Med 2000; 191:1545-54. [PMID: 10790429 PMCID: PMC2213431 DOI: 10.1084/jem.191.9.1545] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Although the Src homology 2 domain-containing 5' inositol phosphatase (SHIP) is a well-known mediator of inhibitory signals after B cell antigen receptor (BCR) coaggregation with the low affinity Fc receptor, it is not known whether SHIP functions to inhibit signals after stimulation through the BCR alone. Here, we show using gene-ablated mice that SHIP is a crucial regulator of BCR-mediated signaling, B cell activation, and B cell development. We demonstrate a critical role for SHIP in termination of phosphatidylinositol 3,4,5-triphosphate (PI[3,4,5]P(3)) signals that follow BCR aggregation. Consistent with enhanced PI(3,4,5)P(3) signaling, we find that splenic B cells from SHIP-deficient mice display enhanced sensitivity to BCR-mediated induction of the activation markers CD86 and CD69. We further demonstrate that SHIP regulates the rate of B cell development in the bone marrow and spleen, as B cell precursors from SHIP-deficient mice progress more rapidly through the immature and transitional developmental stages. Finally, we observe that SHIP-deficient B cells have increased resistance to BCR-mediated cell death. These results demonstrate a central role for SHIP in regulation of BCR signaling and B cell biology, from signal driven development in the bone marrow and spleen, to activation and death in the periphery.
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Affiliation(s)
- Anne Brauweiler
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
| | - Idan Tamir
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
| | - Joseph Dal Porto
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
| | - Robert J. Benschop
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
| | - Cheryl D. Helgason
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - R. Keith Humphries
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
- Department of Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - John H. Freed
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
| | - John C. Cambier
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206
- Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206
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41
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Helgason CD, Kalberer CP, Damen JE, Chappel SM, Pineault N, Krystal G, Humphries RK. A dual role for Src homology 2 domain-containing inositol-5-phosphatase (SHIP) in immunity: aberrant development and enhanced function of b lymphocytes in ship -/- mice. J Exp Med 2000; 191:781-94. [PMID: 10704460 PMCID: PMC2195854 DOI: 10.1084/jem.191.5.781] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In this report, we demonstrate that the Src homology 2 domain-containing inositol-5-phosphatase (SHIP) plays a critical role in regulating both B cell development and responsiveness to antigen stimulation. SHIP(-/-) mice exhibit a transplantable alteration in B lymphoid development that results in reduced numbers of precursor B (fraction C) and immature B cells in the bone marrow. In vitro, purified SHIP(-/)- B cells exhibit enhanced proliferation in response to B cell receptor stimulation in both the presence and absence of Fcgamma receptor IIB coligation. This enhancement is associated with increased phosphorylation of both mitogen-activated protein kinase and Akt, as well as with increased survival and cell cycling. SHIP(-/)- mice manifest elevated serum immunoglobulin (Ig) levels and an exaggerated IgG response to the T cell-independent type 2 antigen trinitrophenyl Ficoll. However, only altered B cell development was apparent upon transplantation into nonobese diabetic-severe combined immunodeficient (NOD/SCID) mice. The in vitro hyperresponsiveness, together with the in vivo findings, suggests that SHIP regulates B lymphoid development and antigen responsiveness by both intrinsic and extrinsic mechanisms.
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Affiliation(s)
- Cheryl D. Helgason
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Christian P. Kalberer
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Jacqueline E. Damen
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Suzanne M. Chappel
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Nicolas Pineault
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Gerald Krystal
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - R. Keith Humphries
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
- Department of Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
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42
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Tamir I, Stolpa JC, Helgason CD, Nakamura K, Bruhns P, Daeron M, Cambier JC. The RasGAP-binding protein p62dok is a mediator of inhibitory FcgammaRIIB signals in B cells. Immunity 2000; 12:347-58. [PMID: 10755621 DOI: 10.1016/s1074-7613(00)80187-9] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The low affinity receptor for IgG, FcgammaRIIB, functions to dampen the antibody response and reduce the risk of autoimmunity. This function is reportedly mediated in part by inhibition of B cell antigen receptor (BCR)-mediated p21ras activation, though the basis of this inhibition is unknown. We show here that FcgammaRIIB-BCR coaggregation leads to increased tyrosine phosphorylation of the RasGAP-binding protein p62dok, with a concomitant increase in its binding to RasGAP. These effects require the recruitment and tyrosine phosphorylation of the phosphatidylinositol 5-phosphatase SHIP, which further recruits p62dok via the latter's phosphotyrosine-binding domain. Using chimeric FcgammaRIIB containing the RasGAP-binding domain of p62dok, we demonstrate that p62dok contains all structural information required to mediate the inhibitory effect of FcgammaRIIB on Erk activation.
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Affiliation(s)
- I Tamir
- Department of Immunology, National Jewish Medical and Research Center and The University of Colorado Health Sciences Center, Denver 80206, USA
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43
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Metzler M, Helgason CD, Dragatsis I, Zhang T, Gan L, Pineault N, Zeitlin SO, Humphries RK, Hayden MR. Huntingtin is required for normal hematopoiesis. Hum Mol Genet 2000; 9:387-94. [PMID: 10655548 DOI: 10.1093/hmg/9.3.387] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease associated with polyglutamine expansion in huntingtin, a widely expressed protein. The function of huntingtin is unknown although huntingtin plays a fundamental role in development since gene targeted HD (-) (/-)mouse embryos die shortly after gastrulation. Expression of huntingtin is detected in spleen and thymus but its role in hematopoiesis has not been examined. To determine the function of huntingtin and to provide insight into potential pathologic mechanisms in HD, we analyzed the role of huntingtin in hematopoietic development. Expression of huntingtin was analyzed in a variety of hematopoietic cell types, and in vitro hematopoiesis was assessed using an HD ( +/-)and several HD( -) (/-)embryonic stem (ES) cell lines. Although wild-type, HD ( +/-)and HD( -) (/-)ES cell lines formed primary embryoid bodies (EBs) with similar efficiency, the numbers of hematopoietic progenitors detected at various stages of the in vitro differentiation were reduced in HD ( +/-)and HD( -/-)() ()ES cell lines examined. Expression analyses of hematopoietic markers within the EBs revealed that primitive and definitive hematopoiesis occurs in the absence of huntingtin. However, further analysis using a suspension culture in the presence of hematopoietic cytokines demonstrated a highly significant gene dosage-dependent decrease in proliferation and/or survival of HD ( +/-)and HD( -) (/-)cells. Enrichment for the CD34(+)cells within the EB confirmed that the impairment is intrinsic to the hematopoietic cells. These obser- vations suggest that huntingtin expression is required for the generation and expansion of hematopoietic cells and provides an alternative system in which to assess the function of huntingtin.
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Affiliation(s)
- M Metzler
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Department of Medical Genetics, 950 West 28th Avenue, Vancouver, British Columbia, Canada
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44
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Kim CH, Hangoc G, Cooper S, Helgason CD, Yew S, Humphries RK, Krystal G, Broxmeyer HE. Altered responsiveness to chemokines due to targeted disruption of SHIP. J Clin Invest 1999; 104:1751-9. [PMID: 10606629 PMCID: PMC409879 DOI: 10.1172/jci7310] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1999] [Accepted: 10/26/1999] [Indexed: 11/17/2022] Open
Abstract
SHIP has been implicated in negative signaling in a number of hematopoietic cell types and is postulated to downregulate phosphatidylinositol-3-kinase- (PI-3K-) initiated events in diverse receptor signaling pathways. Because PI-3K is implicated in chemokine signaling, we investigated whether SHIP plays any role in cellular responses to chemokines. We found that a number of immature and mature hematopoietic cells from SHIP-deficient mice manifested enhanced directional migration (chemotaxis) in response to the chemokines stromal cell-derived factor-1 (SDF-1) and B-lymphocyte chemoattractant (BLC). SHIP(-/-) cells were also more active in calcium influx and actin polymerization in response to SDF-1. However, colony formation by SHIP-deficient hematopoietic progenitor cell (HPCs) was not inhibited by 13 myelosuppressive chemokines that normally inhibit proliferation of HPCs. These altered biologic activities of chemokines on SHIP-deficient cells are not caused by simple modulation of chemokine receptor expression in SHIP-deficient mice, implicating SHIP in the modulation of chemokine-induced signaling and downstream effects.
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Affiliation(s)
- C H Kim
- Departments of Microbiology/Immunology and Medicine and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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45
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Krystal G, Damen JE, Helgason CD, Huber M, Hughes MR, Kalesnikoff J, Lam V, Rosten P, Ware MD, Yew S, Humphries RK. SHIPs ahoy. Int J Biochem Cell Biol 1999; 31:1007-10. [PMID: 10582334 DOI: 10.1016/s1357-2725(99)00072-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In 1996 three groups independently cloned a hemopoietic specific, src homology 2-containing inositol 5'-phosphatase which, based on its structure, was called SHIP. More recently, a second more widely expressed SHIP-like protein has been cloned and called SHIP2. Both specifically hydrolyze phosphatidylinositol-3,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate in vitro. Moreover, SHIP has been shown in vivo to be the primary enzyme responsible for breaking down phosphatidylinositol-3,4,5-trisphosphate to phosphatidylinositol-3,4-bisphosphate in normal mast cells and, as a result, limits normal and prevents inappropriate mast cell degranulation. Because of their ability to break down phosphatidylinositol-3,4,5-trisphosphate, the SHIPs have the potential to regulate many, if not all, phosphatidylinositol-3-kinase induced events including, proliferation, differentiation, apoptosis, end cell activation, cell movement and adhesion and will thus likely be the subject of intensive research over the next few years.
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Affiliation(s)
- G Krystal
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada.
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46
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Huber M, Helgason CD, Damen JE, Scheid MP, Duronio V, Lam V, Humphries RK, Krystal G. The role of the SRC homology 2-containing inositol 5'-phosphatase in Fc epsilon R1-induced signaling. Curr Top Microbiol Immunol 1999; 244:29-41. [PMID: 10453647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Affiliation(s)
- M Huber
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada
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47
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Huber M, Helgason CD, Damen JE, Scheid M, Duronio V, Liu L, Ware MD, Humphries RK, Krystal G. The role of SHIP in growth factor induced signalling. Prog Biophys Mol Biol 1999; 71:423-34. [PMID: 10354708 DOI: 10.1016/s0079-6107(98)00049-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The recently cloned, hemopoietic-specific, src homology 2 (SH2)-containing inositol phosphatase, SHIP, is rapidly gaining prominence as a potential regulator of all phosphatidylinositol (PI)-3 kinase mediated events since it has been shown both in vitro and in vivo to hydrolyze the 5' phosphate from phosphatidylinositol-3,4,5-trisphosphate (PI-3,4,5-P3). Thus SHIP, and its more widely expressed counterpart, SHIP2, could play a central role in determining PI-3,4,5-P3 and PI-3,4-P2 levels in many cell types. To explore the in vivo function of SHIP further we recently generated a SHIP knock out mouse and in this review we discuss experiments carried out with bone marrow derived mast cells (BMMCs) from these animals.
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Affiliation(s)
- M Huber
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada
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48
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Metzler M, Chen N, Helgason CD, Graham RK, Nichol K, McCutcheon K, Nasir J, Humphries RK, Raymond LA, Hayden MR. Life without huntingtin: normal differentiation into functional neurons. J Neurochem 1999; 72:1009-18. [PMID: 10037472 DOI: 10.1046/j.1471-4159.1999.0721009.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Huntington disease (HD) is a neurodegenerative disorder associated with polyglutamine expansion in a recently identified protein, huntingtin. Huntingtin is widely expressed and plays a crucial role in development, because gene-targeted HD-/- mouse embryos die early in embryogenesis. To analyze the function of normal huntingtin, we have generated HD-/- embryonic stem (ES) cells and used an in vitro model of ES cell differentiation to analyze their ability to develop into neuronal cells. Expression analysis of wild-type ES cells revealed that huntingtin is expressed at all stages during ES cell differentiation with high expression in neurons. Expression levels increased with the maturation of differentiating neurons, demonstrating that expression of huntingtin is developmentally regulated in cell culture and resembles the pattern of expression observed in differentiating neurons in the mouse brain. It is interesting that HD-/- ES cells could differentiate into mature postmitotic neurons that expressed functional voltage- and neurotransmitter-gated ion channels. Moreover, both excitatory and inhibitory spontaneous postsynaptic currents were observed, indicating the establishment of functional synapses in the absence of huntingtin. These results demonstrate that huntingtin is not required for the generation of functional neurons with features characteristic of postmitotic neurons in the developing mouse brain.
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Affiliation(s)
- M Metzler
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, Canada
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Huber M, Helgason CD, Scheid MP, Duronio V, Humphries RK, Krystal G. Targeted disruption of SHIP leads to Steel factor-induced degranulation of mast cells. EMBO J 1998; 17:7311-9. [PMID: 9857188 PMCID: PMC1171077 DOI: 10.1093/emboj/17.24.7311] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To investigate the role of the src homology 2 (SH2)-containing inositol 5' phosphatase (SHIP) in growth factor-mediated signalling, we compared Steel factor (SF)-induced events in bone marrow-derived mast cells (BMMCs) from SHIP-/- and SHIP+/+ littermates. We found SF alone stimulated massive degranulation from SHIP-/- but none from SHIP+/+ BMMCs. This SF-induced degranulation, which was not due to higher c-kit levels in SHIP-/- cells, correlated with higher intracellular calcium than that in SHIP+/+ cells and was dependent on the influx of extracellular calcium. Both this influx and subsequent degranulation were completely inhibited by PI-3-kinase inhibitors, indicating that SF-induced activation of PI-3-kinase was upstream of extracellular calcium entry. A comparison of phosphatidylinositol-3,4,5-trisphosphate (PIP3) levels following SF stimulation of SHIP+/+ and SHIP-/- BMMCs suggested that SHIP restricted this entry by hydrolyzing PIP3. Although PI-3-kinase inhibitors blocked the release of intracellular calcium, implicating PIP3, and PLCgamma-2 was slightly more tyrosine phosphorylated in SHIP-/- cells, the increase in inositol-1,4,5-trisphosphate (IP3) and intracellular calcium levels were identical in SHIP-/- and SHIP+/+ BMMCs. These results suggest that SHIP prevents SF from triggering degranulation of normal BMMCs, and does so by hydrolyzing PIP3, which in turn limits extracellular calcium entry at a step after the release of intracellular calcium.
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Affiliation(s)
- M Huber
- Terry Fox Laboratory, BC Cancer Agency, 601 West 10th Avenue, Vancouver, BC, V5Z IL3, Canada
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Huber M, Helgason CD, Damen JE, Liu L, Humphries RK, Krystal G. The src homology 2-containing inositol phosphatase (SHIP) is the gatekeeper of mast cell degranulation. Proc Natl Acad Sci U S A 1998; 95:11330-5. [PMID: 9736736 PMCID: PMC21642 DOI: 10.1073/pnas.95.19.11330] [Citation(s) in RCA: 264] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To clarify the role that the src homology 2-containing inositol phosphatase (SHIP) plays in mast cell degranulation, the gene for SHIP was disrupted by homologous recombination in embryonic stem cells. Bone-marrow-derived mast cells from SHIP+/+, +/-, and -/- F2 littermates were compared. SHIP-/- mast cells were found to be far more prone to degranulation, after the crosslinking of IgE preloaded cells, than SHIP+/- or +/+ cells. Intriguingly, IgE alone also stimulated massive degranulation in SHIP-/- but not in +/+ mast cells. This degranulation with IgE alone, which may be due to low levels of IgE aggregates, correlated with a higher and more sustained intracellular calcium level than that observed with SHIP+/+ cells and was dependent upon the entry of extracellular calcium. Immunoprecipitation studies revealed that the addition of IgE alone to normal mast cells stimulates multiple cascades, which are prevented from progressing to degranulation by SHIP. PI 3-kinase inhibitor studies suggested that IgE-induced activation of PI 3-kinase is upstream of the entry of extracellular calcium and that SHIP restricts this entry by hydrolyzing phosphatidylinositol 3,4, 5-trisphosphate. These results show the critical role that SHIP plays in setting the threshold for degranulation and that SHIP directly modulates a "positive-acting" receptor.
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Affiliation(s)
- M Huber
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada V5Z 1L3
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