Epithelial-mesenchymal transition (EMT) describes a morphogenetic program which confers mesenchymal cell properties, such as reduced cell-cell contact and increased cell migration and invasion, to epithelial cells. Here we investigate the role of the pleiotropic transcription/splicing factor and RNA-binding protein nucleasesensitive element-binding protein 1 (YBX1/YB-1) in increasing the oncogenic potential of epithelial MDCK cells. Characterization of MDCK cells expressing YBX1 (MDCKYBX1 cells) revealed a partial EMT phenotype, including cytosolic relocalization of E-cadherin, increased cell scattering, and anchorage-independent growth. Subcutaneous injection of parental MDCK cells into NOD/SCID mice did not form tumours. Critically, MDCKYBX1 cells established viable tumour xenografts, and immunohistochemical staining indicated murine vascularization by CD31+ endothelial cells. We analysed the total secretome (containing soluble and extracellular vesicles) of MDCKYBX1 cells to investigate regulation of the tumour microenvironment. YBX1 expression elevated release of secreted factors known to enhance angiogenesis (TGF-β, CSF-1, NGF, VGF, ADAM9 and ADAM17), compared to MDCK cells. Importantly, treatment with MDCKYBX1 cell-derived secretome increased recipient 2F-2B endothelial cell motility. This defines YBX1 as an oncogenic enhancer that can regulate tumour angiogenesis via release of secreted modulators into the extracellular microenvironment.
Funding
The authors are supported, in part, by the National Health and Medical Research Council of Australia program grant 487922 (R.J.S.), project grant 1057741 (R.J.S), 628727 (HJ.Z), Melbourne Research Grant Support Scheme (Melbourne University, HJ.Z) and Early Career CJ Martin Fellowship APP1037043 (R.A.M.). S.K.G/A.R/M.C are supported by La Trobe University Postgraduate Scholarships. The authors would like to thank Dr. Jacqueline Orian for assistance with immunohistochemistry. Proteomics in this study was supported using the LIMS Mass Spectrometry and Proteomics facility.
History
Publication Date
2015-04-23
Journal
Oncotarget
Volume
6
Issue
15
Pagination
13p. (p. 13718-13730)
Publisher
Impact Journals
ISSN
1949-2553
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