A Serum Proteomic Signature Predicting Survival in Patients with Glioblastoma

Endosome associated trafficking regulator 1 promotes tumor growth and invasion of glioblastoma multiforme via inhibiting TNF signaling pathway

PURPOSE

Endosome associated trafficking regulator 1 (ENTR1) is a novel endosomal protein, which can affect multiple cellular biological behavior by remodeling plasma membrane structures. However, little is known regarding its function and underlying mechanisms in glioblastoma multiforme.

METHODS

Expression profile and clinical signature were obtained from The Public Database of human tumor. Immunohistochemical staining and western blotting assays were used to measure ENTR1 expression level. Human primary GBM tumor cells and human GBM cell lines A172, U87 and U251 were used to clarify the precise role of ENTR1. CCK-8 assays, wound healing and transwell invasion assays were designed to investigate cell viability, invasion and migration of GBM cells, respectively. Underlying molecular mechanisms of ENTR1 were determined via RNA-seq analysis. Tumor formation assay was used to validate the influence of ENTR1 in vivo.

RESULTS

Compared with normal brain tissues, ENTR1 was highly expressed in gliomas and correlated with malignant grades of gliomas and poor overall survival time. The proliferation and invasion of GBM cells could be weaken and the sensitivity to temozolomide (TMZ) chemotherapy increased after knocking down ENTR1. Overexpression of ENTR1 could reverse this effect. RNA-seq analysis showed that tumor necrosis factor (TNF) signaling pathway might be a putative regulatory target of ENTR1. Tumor formation assay validated that ENTR1 was a significant factor in tumor growth.

CONCLUSION

Our results indicated that ENTR1 played an important role in cell proliferation, invasion and chemotherapeutic sensitivity of GBM, suggesting that ENTR1 might be a novel prognostic marker and significant therapeutic target for GBM.

Glioblastoma survival is associated with distinct proteomic alteration signatures post chemoirradiation in a large-scale proteomic panel

Background

Glioblastomas (GBM) are rapidly progressive, nearly uniformly fatal brain tumors. Proteomic analysis represents an opportunity for noninvasive GBM classification and biological understanding of treatment response.

Purpose

We analyzed differential proteomic expression pre vs. post completion of concurrent chemoirradiation (CRT) in patient serum samples to explore proteomic alterations and classify GBM by integrating clinical and proteomic parameters.

Materials and methods

82 patients with GBM were clinically annotated and serum samples obtained pre- and post-CRT. Serum samples were then screened using the aptamer-based SOMAScan® proteomic assay. Significant traits from uni- and multivariate Cox models for overall survival (OS) were designated independent prognostic factors and principal component analysis (PCA) was carried out. Differential expression of protein signals was calculated using paired t-tests, with KOBAS used to identify associated KEGG pathways. GSEA pre-ranked analysis was employed on the overall list of differentially expressed proteins (DEPs) against the MSigDB Hallmark, GO Biological Process, and Reactome databases with weighted gene correlation network analysis (WGCNA) and Enrichr used to validate pathway hits internally.

Results

3 clinical clusters of patients with differential survival were identified. 389 significantly DEPs pre vs. post-treatment were identified, including 284 upregulated and 105 downregulated, representing several pathways relevant to cancer metabolism and progression. The lowest survival group (median OS 13.2 months) was associated with DEPs affiliated with proliferative pathways and exhibiting distinct oppositional response including with respect to radiation therapy related pathways, as compared to better-performing groups (intermediate, median OS 22.4 months; highest, median OS 28.7 months). Opposite signaling patterns across multiple analyses in several pathways (notably fatty acid metabolism, NOTCH, TNFα via NF-κB, Myc target V1 signaling, UV response, unfolded protein response, peroxisome, and interferon response) were distinct between clinical survival groups and supported by WGCNA. 23 proteins were statistically signficant for OS with 5 (NETO2, CST7, SEMA6D, CBLN4, NPS) supported by KM.

Conclusion

Distinct proteomic alterations with hallmarks of cancer, including progression, resistance, stemness, and invasion, were identified in serum samples obtained from GBM patients pre vs. post CRT and corresponded with clinical survival. The proteome can potentially be employed for glioma classification and biological interrogation of cancer pathways.

To Explore the Stem Cells Homing to GBM: The Rise to the Occasion

Multiple efforts are currently underway to develop targeted therapeutic deliveries to the site of glioblastoma progression. The use of carriers represents advancement in the delivery of various therapeutic agents as a new approach in neuro-oncology. Mesenchymal stem cells (MSCs) and neural stem cells (NSCs) are used because of their capability in migrating and delivering therapeutic payloads to tumors. Two of the main properties that carrier cells should possess are their ability to specifically migrate from the bloodstream and low immunogenicity. In this article, we also compared the morphological and molecular features of each type of stem cell that underlie their migration capacity to glioblastoma. Thus, the major focus of the current review is on proteins and lipid molecules that are released by GBM to attract stem cells.