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Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

BACKGROUND: The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and norma...

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Autores principales: Rodríguez-Rigueiro, Teresa, Valladares-Ayerbes, Manuel, Haz-Conde, Mar, Aparicio, Luis A, Figueroa, Angélica
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229560/
https://www.ncbi.nlm.nih.gov/pubmed/22051109
http://dx.doi.org/10.1186/1471-2407-11-474
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author Rodríguez-Rigueiro, Teresa
Valladares-Ayerbes, Manuel
Haz-Conde, Mar
Aparicio, Luis A
Figueroa, Angélica
author_facet Rodríguez-Rigueiro, Teresa
Valladares-Ayerbes, Manuel
Haz-Conde, Mar
Aparicio, Luis A
Figueroa, Angélica
author_sort Rodríguez-Rigueiro, Teresa
collection PubMed
description BACKGROUND: The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. METHODS: Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. RESULTS: Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The expression of Paxillin was found to be regulated by a proteasome-independent mechanism, possibly due to the decreased abundance of E-cadherin. CONCLUSIONS: Taken together, these results suggest that Hakai may be involved in two hallmark aspects of tumour progression, the lowering cell-substratum adhesion and the enhancement of cell invasion.
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spelling pubmed-32295602011-12-03 Hakai reduces cell-substratum adhesion and increases epithelial cell invasion Rodríguez-Rigueiro, Teresa Valladares-Ayerbes, Manuel Haz-Conde, Mar Aparicio, Luis A Figueroa, Angélica BMC Cancer Research Article BACKGROUND: The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. METHODS: Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. RESULTS: Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The expression of Paxillin was found to be regulated by a proteasome-independent mechanism, possibly due to the decreased abundance of E-cadherin. CONCLUSIONS: Taken together, these results suggest that Hakai may be involved in two hallmark aspects of tumour progression, the lowering cell-substratum adhesion and the enhancement of cell invasion. BioMed Central 2011-11-03 /pmc/articles/PMC3229560/ /pubmed/22051109 http://dx.doi.org/10.1186/1471-2407-11-474 Text en Copyright ©2011 Rodríguez-Rigueiro et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Rodríguez-Rigueiro, Teresa
Valladares-Ayerbes, Manuel
Haz-Conde, Mar
Aparicio, Luis A
Figueroa, Angélica
Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title_full Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title_fullStr Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title_full_unstemmed Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title_short Hakai reduces cell-substratum adhesion and increases epithelial cell invasion
title_sort hakai reduces cell-substratum adhesion and increases epithelial cell invasion
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229560/
https://www.ncbi.nlm.nih.gov/pubmed/22051109
http://dx.doi.org/10.1186/1471-2407-11-474
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