OCT 12, 2017 9:00 AM PDT

Profiling the cell surface of cancer cell lines for biomarker/drug target discovery using MS-based proteomics

Speaker
  • Josip Blonder, MD

    Senior Scientist, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research (FNLCR)
    BIOGRAPHY

Abstract

In order to expand the treatment options of cancers driven by oncogenic RAS, new cell surface targets need to be identified and characterized. Here, we describe mass spectrometry based phenotyping of the KRASG12V cell surface using MCF10A-KRASG12V as a cell line model of constitutively activated KRAS. Extensive view of the MCF10A-KRASG12V surface proteome was achieved by applying concurrently targeted hydrazide-based cell surface capturing (CSC) technology and global shotgun membrane (GSM) proteomics. Our combined approach revealed 666 plasma membrane proteins unique to the MCF10A-KRASG12V cell surface. Of these, 104 were cell surface glycoproteins identified by CSC technology while 562 cell surface proteins were identified using GSM proteomics. K-Ras was exclusively identified by GSM proteomics in the membrane fraction of MCF10A-KRASG12V cells and subsequently cross-validated by Western blot (WB) analysis. Subtractive proteomics, spectral counting-based based quantitation of changes in protein abundances, and Ingenuity Pathway Analysis showed that this investigation reliably revealed expected K-Ras induced changes at the surface of MCF10A-KRASG12V cells as well as alterations in cell surface protein expression with very little prior information. This analysis uncovered a subset of eight proteins identified exclusively at the cell surface of MCF10A-KRASG12V cells by both CSC and GSM technologies. Of these, two were further cross-validated using immunofluorescence and WB analysis. Furthermore, scanning electron microscopy and functional cell assays showed extensive changes at the KRASG12V cell surface consistent with widespread epithelial to mesenchymal transformation (EMT). Taken together, this dataset greatly extends the known molecular phenotype of the MCF10A-KRASG12V cell surface and reveals the important role of EMT in the pathophysiology of the KRASG12V driven malignant transformation in MCF10A- KRASG12V model cell line.


OCT 12, 2017 9:00 AM PDT

Profiling the cell surface of cancer cell lines for biomarker/drug target discovery using MS-based proteomics