The identification of cell surface accessible biomarkers enabling diagnosis, disease monitoring, and treatment of renal cell carcinoma (RCC) is as challenging as the biology and progression of RCC is unpredictable.
A hallmark of most RCC is the loss-of-function of the von Hippel-Lindau (pVHL) protein by mutation of its gene (VHL). Using the cell surface capturing (CSC) technology, we screened and identified cell surface N-glycoproteins in pVHL-negative and positive 786-O cells. One hundred six cell surface N-glycoproteins were identified. Stable isotope labeling with amino acids in cell culture-based quantification of the CSC screen revealed 23 N-glycoproteins whose abundance seemed to change in a pVHL-dependent manner. Targeted validation experiments using transcriptional profiling of primary RCC samples revealed that nine glycoproteins, including CD10 and AXL, could be directly linked to pVHL-mediated transcriptional regulation. Subsequent human tumor tissue analysis of these cell surface candidate markers showed a correlation between epithelial AXL expression and aggressive tumor phenotype, indicating that pVHL-dependent regulation of glycoproteins may influence the biologic behavior of RCC. Functional characterization of the metalloprotease CD10 in cell invasion assays demonstrated a diminished penetrating behavior of pVHL-negative 786-O cells on treatment with the CD10-specific inhibitor thiorphan. Our proteomic surfaceome screening approach in combination with transcriptional profiling and functional validation suggests pVHL-dependent cell surface glycoproteins as potential diagnostic markers for therapeutic targeting and RCC patient monitoring.
Written by:
Boysen G, Bausch-Fluck D, Thoma CR, Nowicka AM, Stiehl DP, Cima I, Luu VD, von Teichman A, Hermanns T, Sulser T, Ingold-Heppner B, Fankhauser N, Wenger RH, Krek W, Schraml P, Wollscheid B, Moch H. Are you the author?
Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland.
Reference: Neoplasia. 2012 Jun;14(6):535-46.
PubMed Abstract
PMID: 22806541
UroToday.com Investigative Urology Section
