Longitudinal Bottom-Up Proteomics of Serum, Serum Extracellular Vesicles, and Cerebrospinal Fluid Reveals Candidate Biomarkers for Early Detection of Glioblastoma in a Murine Model.

Francesco Greco,Eleonora Vannini,Federica Anastasi,Matteo Caleo,Liam A Mcdonnell,Luca Fidia Pardini,Marialaura Dilillo,Laura Baroncelli

doi:10.3390/molecules26195992

Abstract

Glioblastoma Multiforme (GBM) is a brain tumor with a poor prognosis and low survival rates. GBM is diagnosed at an advanced stage, so little information is available on the early stage of the disease and few improvements have been made for earlier diagnosis. Longitudinal murine models are a promising platform for biomarker discovery as they allow access to the early stages of the disease. Nevertheless, their use in proteomics has been limited owing to the low sample amount that can be collected at each longitudinal time point. Here we used optimized microproteomics workflows to investigate longitudinal changes in the protein profile of serum, serum small extracellular vesicles (sEVs), and cerebrospinal fluid (CSF) in a GBM murine model. Baseline, pre-symptomatic, and symptomatic tumor stages were determined using non-invasive motor tests. Forty-four proteins displayed significant differences in signal intensities during GBM progression. Dysregulated proteins are involved in cell motility, cell growth, and angiogenesis. Most of the dysregulated proteins already exhibited a difference from baseline at the pre-symptomatic stage of the disease, suggesting that early effects of GBM might be detectable before symptom onset.

Highlights

Glioblastoma Multiforme (GBM, World Health Organization (WHO) grade IV astrocytoma [1]) is the most malignant glial tumor and is associated with a very poor prognosis, with a median survival of just 15 months [2]
The results from Grip strength and Rotarod tests are shown in Figure 1 and were consistent with previous findings, namely a decrease in grip strength and motor performance with tumor progression [25]
Mouse cerebrospinal fluid (CSF) proteomics is usually limited by the low sample amount [36] and by the presence of CSF high-abundance proteins [41]; in the case of longitudinal studies, the sample amount is reduced even further because of issues related to sampling invasiveness

Summary

Introduction

Glioblastoma Multiforme (GBM, World Health Organization (WHO) grade IV astrocytoma [1]) is the most malignant glial tumor and is associated with a very poor prognosis, with a median survival of just 15 months [2]. It is widely established that tumor stage and grade determine patient outcomes and patient treatment [5,6] in many types of tumors. Earlier diagnosis of breast cancer allows the tumor to be treated in the initial stage, significantly improving patient prognosis [7]; the introduction of screening for the prostate-specific antigen has decreased prostate cancer lethality by 21% [8,9]; and screening for α-fetoprotein [10,11] has enabled earlier detection and concomitant improvements in the outcome of hepatocellular carcinoma [12,13]. A lack of biomarkers for earlier-stage GBM has impeded any investigation of possible beneficial effects of early diagnosis in terms of treatment outcome

Methods

Results

Discussion

Conclusion