ORCID Profile
0000-0002-7017-5215
Current Organisations
University of Chile
,
University of Liverpool
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Publisher: Cold Spring Harbor Laboratory
Date: 04-09-2018
DOI: 10.1101/405043
Abstract: Crosstalk between adhesion and growth factor receptors plays a critical role in tissue morphogenesis and repair, and aberrations contribute substantially to neoplastic disease. However, the mechanisms by which adhesion and growth factor receptor signalling are integrated, spatially and temporally, are unclear. We used adhesion complex enrichment coupled with quantitative proteomic analysis to identify rapid changes to adhesion complex composition and signalling following growth factor stimulation. Bioinformatic network and ontological analyses revealed a substantial decrease in the abundance of adhesion regulatory proteins and co-ordinators of endocytosis within 5 minutes of EGF stimulation. Together these data suggested a mechanism of EGF-induced receptor endocytosis and adhesion complex turnover. Combinatorial interrogation of the networks allowed a global and dynamic view of adhesion and growth factor receptor crosstalk to be assembled. By interrogating network topology we identified Eps8 as a putative node integrating α5β1 integrin and EGFR functions. Importantly, EGF stimulation promoted internalisation of both α5β1 and EGFR. However, perturbation of Eps8 increased constitutive internalisation of α5β1 and EGFR suggesting that Eps8 constrains α5β1 and EGFR endocytosis in the absence of EGF stimulation. Consistent with this, Eps8 regulated Rab5 activity and was required for maintenance of adhesion complex organisation and for EGF-dependent adhesion complex disassembly. Thus, by co-ordinating α5β1 and EGFR trafficking mechanisms, Eps8 is able to control adhesion receptor and growth factor receptor bioavailability and cellular contractility. We propose that during tissue morphogenesis and repair, Eps8 functions to spatially and temporally constrain endocytosis, and engagement, of α5β1 and EGFR in order to precisely co-ordinate adhesion disassembly, cytoskeletal dynamics and cell migration.
Publisher: Cold Spring Harbor Laboratory
Date: 04-09-2018
DOI: 10.1101/407908
Abstract: The mechanical properties of the extracellular matrix within tumours control multiple cellular functions that drive cancer invasion and metastasis. However, the mechanisms controlling microenvironmental force sensation and transmission, and how these regulate transcriptional reprogramming and invasion, are unclear. Our aim was to understand how mechanical inputs are transmitted bidirectionally and translated into biochemical and transcriptional outputs to drive breast cancer progression. We reveal that adhesion receptor and growth factor receptor crosstalk regulates a bidirectional feedback mechanism co-ordinating force-dependent transcriptional regulation and invasion. Integrin αVβ6 drives invasion in a range of carcinomas and is a potential therapeutic target. αVβ6 exhibits unique biophysical properties that promote force-generation and increase matrix rigidity. We employed an inter-disciplinary approach incorporating proteomics, biophysical techniques and multi-modal live-cell imaging to dissect the role of αVβ6-EGFR crosstalk on transmission of mechanical signals bidirectionally between the extracellular matrix and nucleus. We show that αVβ6 expression correlates with poor prognosis in triple-negative breast cancer (TNBC) and drives invasion of TNBC cells. Moreover, our data show that a complex regulatory mechanism exists involving crosstalk between αVβ6 integrin and EGFR that impacts matrix stiffness, force transmission to the nucleus, transcriptional reprogramming and microenvironment rigidity. αVβ6 engagement triggers EGFR & MAPK signalling and αVβ6-EGFR crosstalk regulates mutual receptor trafficking mechanisms. Consequently, EGF stimulation suppresses αVβ6-mediated force-application on the matrix and nuclear shuttling of force-dependent transcriptional co-activators YAP/TAZ. Finally, we show that crosstalk between αVβ6 & EGFR regulates TNBC invasion. We propose a model whereby αVβ6-EGFR crosstalk regulates matrix stiffening, but also the transmission of extracellular forces into the cell in order to co-ordinate transcriptional reprogramming and invasion. To exploit adhesion receptors and receptor tyrosine kinases therapeutically, it will be essential to understand the integration of their signalling functions and how crosstalk mechanisms influence invasion and the response of tumours to molecular therapeutics.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Horacio Maldonado.