Wnt signaling plays important roles in tumorigenesis, invasiveness and therapeutic resistance of glioblastoma (GBM). We simultaneously investigated six Wnt pathway markers (Wnt5a, Fzd-2, beta-catenin, Wnt3a, Wnt7b, Fzd-10) at epigenetic and protein levels in 21 sequential formalin-fixed paraffin-embedded GBM pairs and controls. Expression levels of Wnt5a, beta-catenin and Wnt3a proteins either moderately or significantly increased, while those of Fzd-2, Wnt7b and Fzd-10 decreased in the primary (GBM-P) and recurrent (GBM-R) tumors compared to the controls. Methylation levels within promoters and genes showed corresponding decreases for Wnt5a, beta-catenin and Wnt3a in tumors vs. controls, while that of Fzd-10 was uniformly high. Comparing the GBM-P and GBM-R pairs, proteins of Fzd-2, beta-catenin and Wnt3a were either moderately or significantly up-, while that of Wnt7b was downregulated in GBM-R, but these patterns were not accompanied by inverse methylation patterns in the corresponding promoters and genes over time. No methylation differences were noted within promoters and genes of the same markers in 112 pairs of primary and recurrent GBMs in a database, suggesting that the observed changes in protein expression levels may not be explained by CpG methylation status alone. The promoter and gene methylation rate was the highest for Fzd-10 in the database cohort too, supporting the noted low Fzd-10 protein expression. These analyses underscore the relevance of Wnt pathway molecules in the context of their methylation profiles in the development and evolution of GBM, and suggest that Wnt pathway regulation as a potential treatment target merits further studies.

Background: Immune evasion in glioblastoma (GBM) shields cancer cells from cytotoxic immune response. Methods: We investigated CpG methylation in promoters, genes, and pathways in 22 pairs of formalin-fixed paraffin-embedded sequential (FFPE) GBM using restricted resolution bisulfite sequencing (RRBS) and bioinformatic analyses. Results: Gene ontology revealed hypermethylation in elements of the innate and adaptive immune system when recurrent GBM samples (GBM^rec) were compared to control (CG) and primary GBM samples (GBM^prim). Higher methylation levels of the IL-7 signaling pathway and response to IL-7 were found in GBM^rec suggesting a progressive blockade of the IL-7 driven T cell response in sequential GBM. Analyses of the Cancer Genome Atlas array-based data confirmed hypermethylation of the IL-7 pathway in recurrent compared with primary GBM. We also quantified DNA CpG methylation in promoter and gene regions of the IL-7 ligand and IL-7 α-receptor subunit in individual samples of a large RRBS-based sequential cohort of GBM in a Viennese database and found significantly higher methylation levels in the IL-7 receptor α-subunit in GBM^rec compared with GBM^prim. Conclusions: This study revealed the progressive suppression of the IL-7 receptor-mediated pathway as a means of immune evasion by GBM and thereby highlighted it as a new treatment target.

Purpose: Glioblastoma is the most aggressive form of brain tumors. A better understanding of the molecular mechanisms leading to its evolution is essential for the development of treatments more effective than the available modalities. Here, we aim to identify molecular drivers of glioblastoma development and recurrence by analyzing DNA CpG methylation patterns in sequential samples. Methods: DNA was isolated from 22 pairs of primary and recurrent formalin-fixed, paraffin-embedded glioblastoma specimens, and subjected to reduced representation bisulfite sequencing. Bioinformatic analyses were conducted to identify differentially methylated sites and pathways, and biostatistics was used to test correlations among clinical and pathological parameters. Results: Differentially methylated pathways likely involved in primary tumor development included those of neuronal differentiation, myelination, metabolic processes, synapse organization and endothelial cell proliferation, while pathways differentially active during glioblastoma recurrence involved those associated with cell processes and differentiation, immune response, Wnt regulation and catecholamine secretion and transport. Conclusion: DNA CpG methylation analyses in sequential clinical specimens revealed hypomethylation in certain pathways such as neuronal tissue development and angiogenesis likely involved in early tumor development and growth, while suggested altered regulation in catecholamine secretion and transport, Wnt expression and immune response contributing to glioblastoma recurrence. These pathways merit further investigations and may represent novel therapeutic targets.

Competitive athletes are often exposed to extreme physiological loading, resulting in over excessive mechanotransduction during their acute intensive training sessions and competitions. Individual differences in their genetics often affect how they cope with these challenges, as reflected in their high performances. Olympic Medalists are prohibited from providing atypical values in the Hematological Module of the Athlete Biological Passport. Since there was no aphysiological result and the Athlete maintained his innocence, a whole genome sequence analysis was carried out on him and his parents, with the primary focus on the PIEZO ion channels encoding gene. PIEZO1 is known to participate in homeostatic regulation even on a whole-body level, including the regulation of physical performance, circulatory longevity of red blood cells and cell fate determination of mesenchymal stem cells in relation to hydrostatic pressure. However, PIEZO2 was found to be the principal mechanosensory ion channel for proprioception. These regulatory mechanisms play a pivotal role in mechanotransduction and intensive exercise moments. Interestingly, two variances of uncertain significance of PIEZO1 were found that may explain the atypical values of the Athlete. Furthermore, two additional variances in SDC2, the syndcan-2 encoding gene, were identified in trans position that may influence the crosstalk between PIEZO2 and PIEZO1, with more likely relevance to the detected atypical values. After all, based on the found variances of PIEZO1 and syndecan-2, it cannot be ruled out that these VUS variants may have caused or impacted the exhibited outlier findings of the ABP Hematological Module of the Athlete.