engleski

Characterisation of the integrin αv adhesome in human melanoma cells RPMI-­7951

Integrins are transmembrane receptors often overexpressed in melanoma that can modulate response to antitumour therapy. They transmit signals from extracellular matrix (ECM) to cytoskeleton through a multimolecular complex of signalling and adaptor proteins called integrin adhesion complex (IAC). The total sum of proteins of the IAC (adhesome) represents a pool of insufficiently investigated potential targets for tumour therapy. Our previous results on human melanoma cells RPMI­7951 have shown that targeted knockdown of integrin subunit αv via siRNA increased sensitivity to antitumour drugs: cisplatin, paclitaxel or vincristine, and drastically decreased in vitro migration and invasion. The goal of this study was: a) to define adhesome of RPMI­7951 cells that have assembled their own ECM, b) to determine key integrins these cells use to form IACs and c) to define IAC components dependent on integrin αv in order to pinpoint proteins involved in the observed phenotype of increased sensitivity to drugs and decreased motility. IACs were isolated from RPMI­7951 cells transfected with control or integrin αv­ specific siRNA plated on uncoated Petri dishes, upon crosslinking with DTBP and analysed by mass spectrometry. We identified 344 proteins, with a minimum number of spectra 4, in at least one of the three replicas. 31.9% of proteins are focal adhesion­ and 25.5% ECM­ associated proteins. Data suggest that RPMI­7951 preferentially form IACs via integrin αvβ5. 88 proteins, whose expression was changed at least 2 times in RPMI­7951 cells after integrin αv knockdown, were defined as integrin αv adhesome. These proteins might have a role in the observed phenotype of increased sensitivity to antitumour drugs and reduced motility. Further studies of IAC proteins could lead to the identification of potential target molecules for combined use with antitumour drugs for the metastatic melanoma treatment.

integrin alphav ; adhesome ; integrin adhesion complex

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