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Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5

BACKGROUND AND AIMS: Adenomatous polyposis coli (APC) is a tumour suppressor gene mutated in the germline of patients with familial adenomatous polyposis (FAP) and somatically in most colorectal cancers. APC mutations impair β-catenin degradation, resulting in increased Wnt signalling. The most freq...

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Autores principales: Lewis, Annabelle, Segditsas, Stefania, Deheragoda, Maesha, Pollard, Patrick, Jeffery, Rosemary, Nye, Emma, Lockstone, Helen, Davis, Hayley, Clark, Susan, Stamp, Gordon, Poulsom, Richard, Wright, Nicholas, Tomlinson, Ian
Formato: Texto
Lenguaje:English
Publicado: BMJ Group 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002835/
https://www.ncbi.nlm.nih.gov/pubmed/20926645
http://dx.doi.org/10.1136/gut.2009.193680
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author Lewis, Annabelle
Segditsas, Stefania
Deheragoda, Maesha
Pollard, Patrick
Jeffery, Rosemary
Nye, Emma
Lockstone, Helen
Davis, Hayley
Clark, Susan
Stamp, Gordon
Poulsom, Richard
Wright, Nicholas
Tomlinson, Ian
author_facet Lewis, Annabelle
Segditsas, Stefania
Deheragoda, Maesha
Pollard, Patrick
Jeffery, Rosemary
Nye, Emma
Lockstone, Helen
Davis, Hayley
Clark, Susan
Stamp, Gordon
Poulsom, Richard
Wright, Nicholas
Tomlinson, Ian
author_sort Lewis, Annabelle
collection PubMed
description BACKGROUND AND AIMS: Adenomatous polyposis coli (APC) is a tumour suppressor gene mutated in the germline of patients with familial adenomatous polyposis (FAP) and somatically in most colorectal cancers. APC mutations impair β-catenin degradation, resulting in increased Wnt signalling. The most frequent APC mutation is a codon 1309 truncation that is associated with severe FAP. A previous study compared two mouse models of intestinal tumorigenesis, Apc(R850X) (Min) and Apc(1322T) (1322T), the latter a model of human codon 1309 changes. 1322T mice had more severe polyposis but, surprisingly, these tumours had lower levels of nuclear β-catenin than Min tumours. The consequences of these different β-catenin levels were investigated. METHODS: Enterocytes were isolated from 1322T and Min tumours by microdissection and gene expression profiling was performed. Differentially expressed Wnt targets and other stem cell markers were validated using quantitative PCR, in situ hybridisation and immunohistochemistry. RESULTS: As expected, lower nuclear β-catenin levels in 1322T lesions were associated with generally lower levels of Wnt target expression. However, expression of the Wnt target and stem cell marker Lgr5 was significantly higher in 1322T tumours than in Min tumours. Other stem cell markers (Musashi1, Bmi1 and the Wnt target Cd44) were also at higher levels in 1322T tumours. In addition, expression of the Bmp antagonist Gremlin1 was higher in 1322T tumours, together with lower Bmp2 and Bmp4 expression. CONCLUSIONS: The severe phenotype caused by truncation of Apc at codon 1322 is associated with an increased number of stem cells. Thus, a submaximal level of Wnt signalling favours the stem cell phenotype and this may promote tumorigenesis. A level of Wnt signalling exists that is too high for optimal tumour growth.
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spelling pubmed-30028352010-12-23 Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5 Lewis, Annabelle Segditsas, Stefania Deheragoda, Maesha Pollard, Patrick Jeffery, Rosemary Nye, Emma Lockstone, Helen Davis, Hayley Clark, Susan Stamp, Gordon Poulsom, Richard Wright, Nicholas Tomlinson, Ian Gut Colon Cancer BACKGROUND AND AIMS: Adenomatous polyposis coli (APC) is a tumour suppressor gene mutated in the germline of patients with familial adenomatous polyposis (FAP) and somatically in most colorectal cancers. APC mutations impair β-catenin degradation, resulting in increased Wnt signalling. The most frequent APC mutation is a codon 1309 truncation that is associated with severe FAP. A previous study compared two mouse models of intestinal tumorigenesis, Apc(R850X) (Min) and Apc(1322T) (1322T), the latter a model of human codon 1309 changes. 1322T mice had more severe polyposis but, surprisingly, these tumours had lower levels of nuclear β-catenin than Min tumours. The consequences of these different β-catenin levels were investigated. METHODS: Enterocytes were isolated from 1322T and Min tumours by microdissection and gene expression profiling was performed. Differentially expressed Wnt targets and other stem cell markers were validated using quantitative PCR, in situ hybridisation and immunohistochemistry. RESULTS: As expected, lower nuclear β-catenin levels in 1322T lesions were associated with generally lower levels of Wnt target expression. However, expression of the Wnt target and stem cell marker Lgr5 was significantly higher in 1322T tumours than in Min tumours. Other stem cell markers (Musashi1, Bmi1 and the Wnt target Cd44) were also at higher levels in 1322T tumours. In addition, expression of the Bmp antagonist Gremlin1 was higher in 1322T tumours, together with lower Bmp2 and Bmp4 expression. CONCLUSIONS: The severe phenotype caused by truncation of Apc at codon 1322 is associated with an increased number of stem cells. Thus, a submaximal level of Wnt signalling favours the stem cell phenotype and this may promote tumorigenesis. A level of Wnt signalling exists that is too high for optimal tumour growth. BMJ Group 2010-10-06 2010-12 /pmc/articles/PMC3002835/ /pubmed/20926645 http://dx.doi.org/10.1136/gut.2009.193680 Text en © 2010, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.
spellingShingle Colon Cancer
Lewis, Annabelle
Segditsas, Stefania
Deheragoda, Maesha
Pollard, Patrick
Jeffery, Rosemary
Nye, Emma
Lockstone, Helen
Davis, Hayley
Clark, Susan
Stamp, Gordon
Poulsom, Richard
Wright, Nicholas
Tomlinson, Ian
Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title_full Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title_fullStr Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title_full_unstemmed Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title_short Severe polyposis in Apc(1322T) mice is associated with submaximal Wnt signalling and increased expression of the stem cell marker Lgr5
title_sort severe polyposis in apc(1322t) mice is associated with submaximal wnt signalling and increased expression of the stem cell marker lgr5
topic Colon Cancer
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002835/
https://www.ncbi.nlm.nih.gov/pubmed/20926645
http://dx.doi.org/10.1136/gut.2009.193680
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