Author/Editor     Vidak, Marko; Jovchevska, Ivana; Šamec, Neja; Zottel, Alja; Liović, Mirjana; Rozman, Damjana; Džeroski, Sašo; Juvan, Peter; Komel, Radovan
Title     Meta-analysis and experimental validation identified FREM2 and SPRY1 as new glioblastoma marker candidates
Type     članek
Vol. and No.     Letnik 19, št. 5
Publication year     2018
Volume     str. 1-24
ISSN     1422-0067 - International journal of molecular sciences
Language     eng
Abstract     Glioblastoma (GB) is the most aggressive brain malignancy. Although some potential glioblastoma biomarkers have already been identified, there is a lack of cell membrane-bound biomarkers capable of distinguishing brain tissue from glioblastoma and/or glioblastoma stem cells (GSC), which are responsible for the rapid post-operative tumor reoccurrence. In order to find new GB/GSC marker candidates that would be cell surface proteins (CSP), we have performed meta-analysis of genome-scale mRNA expression data from three data repositories (GEO, ArrayExpress and GLIOMASdb). The search yielded ten appropriate datasets, and three (GSE4290/GDS1962, GSE23806/GDS3885, and GLIOMASdb) were used for selection of new GB/GSC marker candidates, while the other seven (GSE4412/GDS1975, GSE4412/GDS1976, E-GEOD-52009, E-GEOD-68848, E-GEOD-16011, E-GEOD-4536, and E-GEOD-74571) were used for bioinformatic validation. The selection identified four new CSP-encoding candidate genes-CD276, FREM2, SPRY1, and SLC47A1-and the bioinformatic validation confirmed these findings. A review of the literature revealed that CD276 is not a novel candidate, while SLC47A1 had lower validation test scores than the other new candidates and was therefore not considered for experimental validation. This validation revealed that the expression of FREM2-but not SPRY1-is higher in glioblastoma cell lines when compared to non-malignant astrocytes. In addition, FREM2 gene and protein expression levels are higher in GB stem-like cell lines than in conventional glioblastoma cell lines. FREM2 is thus proposed as a novel GB biomarker and a putative biomarker of glioblastoma stem cells. Both FREM2 and SPRY1 are expressed on the surface of the GB cells, while SPRY1 alone was found overexpressed in the cytosol of non-malignant astrocytes.
Keywords     glioblastom
23/5000 matične celice glioblastoma
biomarkerji
glioblastoma
glioblastoma stem cells
biomarkers