Comparative proteomics as a tool for identifying specific alterations within interferon response pathways in human glioblastoma multiforme cells.

Irina A Tarasova,Alena S Sidorenko,Frank Kjeldsen,Vladimir Gorshkov,Elizaveta M Solovyeva,Mikhail V Gorshkov,Sergei A Moshkovskii,Julia A Bubis,Mark V Ivanov,Anna A Lobas,Alesya V Tereshkova,Irina Y Ilina,Peter M Chumakov

doi:10.18632/oncotarget.22751

Abstract

An acquisition of increased sensitivity of cancer cells to viruses is a common outcome of malignant progression that justifies the development of oncolytic viruses as anticancer therapeutics. Studying molecular changes that underlie the sensitivity to viruses would help to identify cases where oncolytic virus therapy would be most effective. We quantified changes in protein abundances in two glioblastoma multiforme (GBM) cell lines that differ in the ability to induce resistance to vesicular stomatitis virus (VSV) infection in response to type I interferon (IFN) treatment. In IFN-treated samples we observed an up-regulation of protein products of some IFN-regulated genes (IRGs). In total, the proteome analysis revealed up to 20% more proteins encoded by IRGs in the glioblastoma cell line, which develops resistance to VSV infection after pre-treatment with IFN. In both cell lines protein-protein interaction and signaling pathway analyses have revealed a significant stimulation of processes related to type I IFN signaling and defense responses to viruses. However, we observed a deficiency in STAT2 protein in the VSV-sensitive cell line that suggests a de-regulation of the JAK/STAT/IRF9 signaling. The study has shown that the up-regulation of IRG proteins induced by the IFNα treatment of GBM cells can be detected at the proteome level. Similar analyses could be applied for revealing functional alterations within the antiviral mechanisms in glioblastoma samples, accompanying by acquisition of sensitivity to oncolytic viruses. The approach can be useful for discovering the biomarkers that predict a potential sensitivity of individual glioblastoma tumors to oncolytic virus therapy.

Highlights

Glioblastoma multiforme (GBM) is highly aggressive still incurable malignant brain tumor [1, 2]
Statistical analysis using paired t-test for dependent samples revealed 109 and 199 proteins with Benjamini-Hochberg false discovery rate fdrBH < 0.05 for A-172 and DBTRG-05MG, respectively
To understand how the calculated p-values are correlated with abundance fold changes (FC) for all proteins examined in t-test, the uncorrected protein p-values were plotted against the FC in logarithmic scale, −log2 vs. log10 (FC ) IFN/K (Figure 2)

Summary

Introduction

Glioblastoma multiforme (GBM) is highly aggressive still incurable malignant brain tumor [1, 2]. Besides the direct virus replication-dependent cell lysis, the infection initiates complex changes in tumor microenvironment and activation of both innate and adaptive branches of anticancer immunity that contribute to a long-term therapeutic effect even after the virus is cleared from tumor sites [21,22,23,24,25]. Another important advantage of oncolytic viruses is their ability to kill the cancer-initiating stem cells, limiting the probability of relapses [26,27,28,29]. The activity against GBM stem cells has been demonstrated for many oncolytic viruses [30,31,32,33,34,35], and some long-term remissions following GBM virotherapy in limited clinical trials [36,37,38,39] suggest that viruses could provide a long lasting cure for the patients

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Results