Proteins and Molecular Pathways Relevant for Stemness Properties of Tumor-Initiating Pancreatic Cancer Stem Cells Recognized by Differential Proteome-, Gene Expression-, and Functional Analysis

ABSTRACT: Cancer stem cells (CSCs), a small subset of the tumor bulk with highly malignant properties, are deemed responsible for tumor initiation, growth, metastasis, and relapse. In order to reveal molecular markers and determinants of stemness properties, pancreatic CSCs were enriched in three-dimensional spheroid cultures of two highly metastatic pancreatic cancer cell lines (L3.6sl and L3.6pl) and compared to bulk tumor cells using differential proteomics (PTX). We identified about 400 putative target proteins with significantly different expression in pancreatic CSCs and bulk tumor cells. By combining the unbiased PTX with gene expression analysis using quantitative polymerase chain reaction (qPCR) we nominated the two calcium binding proteins S100A8 (MRP8) and S100A9 (MRP14), as well as galactin-3-binding protein LGALS3BP (MAC-2-BP) as putative determinants of pancreatic CSCs. In silico pathway analysis followed by candidate-based RNA interference mediated functional analysis revealed a critical role of S100A8, S100A9, and LGALS3BP as molecular determinants of CSC proliferation, migration and in vivo tumor initiation. Our study highlights the power of combining unbiased proteomics with focused gene expression and functional analyses for the identification of key regulators of CSCs, an approach that warrants further application to identify CSCs proteins amenable to drug targeting.

INSTRUMENT(S): LTQ Orbitrap XL

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture, Pancreas

DISEASE(S): Pancreatic Cancer

SUBMITTER: Constantin Blöchl  

LAB HEAD: Christian G. Huber

PROVIDER: PXD018585 | Pride | 2020-06-25

REPOSITORIES: Pride