Diffuse astrocytoma of World Health Organization (WHO) grade II has an inherent tendency to spontaneously progress to anaplastic astrocytoma WHO grade III or secondary glioblastoma WHO grade IV. We explored the role of microRNAs (miRNAs) in glioma progression by investigating the expression profiles of 157 miRNAs in four patients with primary WHO grade II gliomas that spontaneously progressed to WHO grade IV secondary glioblastomas. Thereby, we identified 12 miRNAs (miR-9, miR-15a, miR-16, miR-17, miR-19a, miR-20a, miR-21, miR-25, miR-28, miR-130b, miR-140 and miR-210) showing increased expression, and two miRNAs (miR-184 and miR-328) showing reduced expression upon progression. Validation experiments on independent series of primary low-grade and secondary high-grade astrocytomas confirmed miR-17 and miR-184 as promising candidates, which were selected for functional analyses. These studies revealed miRNAspecific influences on the viability, proliferation, apoptosis and invasive growth properties of A172 and T98G glioma cells in vitro. Using mRNA and protein expression profiling, we identified distinct sets of transcripts and proteins that were differentially expressed after inhibition of miR-17 or overexpression of miR-184 in glioma cells. Taken together, our results support an important role of altered miRNA expression in gliomas, and suggest miR-17 and miR-184 as interesting candidates contributing to glioma progression.

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Current classification of gliomas is based on histological criteria according to the World Health Organization (WHO) classification of tumors of the central nervous system. Over the past years, characteristic genetic profiles have been identified in various glioma types. These can refine tumor diagnostics and provide important prognostic and predictive information. We report on the establishment and validation of gene panel next generation sequencing (NGS) for the molecular diagnostics of gliomas. We designed a glioma-tailored gene panel covering 660 amplicons derived from 20 genes frequently aberrant in different glioma types. Sensitivity and specificity of glioma gene panel NGS for detection of DNA sequence variants and copy number changes were validated by single gene analyses. NGS-based mutation detection was optimized for application on formalin-fixed paraffin-embedded tissue specimens including small stereotactic biopsy samples. NGS data obtained in a retrospective analysis of 121 gliomas allowed for their molecular classification into distinct biological groups, including (i) isocitrate dehydrogenase gene (IDH) 1 or 2 mutant astrocytic gliomas with frequent α-thalassemia/mental retardation syndrome X-linked (ATRX) and tumor protein p53 (TP53) gene mutations, (ii) IDH mutant oligodendroglial tumors with 1p/19q codeletion, telomerase reverse transcriptase (TERT) promoter mutation and frequent Drosophila homolog of capicua (CIC) gene mutation, as well as (iii) IDH wildtype glioblastomas with frequent TERT promoter mutation, phosphatase and tensin homolog (PTEN) mutation and/or epidermal growth factor receptor (EGFR) amplification. Oligoastrocytic gliomas were genetically assigned to either of these groups. Our findings implicate gene panel NGS as a promising diagnostic technique that may facilitate integrated histological and molecular glioma classification.

We summarize the relevant changes in the revised WHO classification of gliomas, outline the integrated approach, and discuss its practical implications and potential challenges.

Due to comprehensive social distancing measures related to the COVID-19 pandemic, medical faculties worldwide have made a virtue of necessity in resorting to online teaching. Medical faculties grapple with how to convey clinical competencies to students in this context. There is a need for research not only to map but also to explain the effect of these secondary measures on students' learning and mental wellbeing. During a period of ongoing comprehensive social distancing measures in Germany, we translated a competency-based curriculum including obstetrics, paediatrics, and human genetics to an e-learning course based on online patient and teacher encounters. In our qualitative study on students' and teachers' views, we identify potential enablers and drivers as well as barriers and challenges to undergraduate medical education under lockdown. In summer 2020, we conducted six focus group interviews to investigate medical students' and teachers' perspectives, experiences and attitudes. All focus groups were videotaped, transcribed verbatim and coded. To guide our deductive and inductive analysis, we applied the theoretical framework of Regmi and Jones. Content analysis was performed in a multi-perspective group. We identified five major themes contributing to a successful use of clinical competency-based e-learning under lockdown: Communication (with teachers, students, and patients), Mental wellbeing, Structure and self-organization, Technical issues, and Learning and commitment. We discuss enablers and potential barriers within all themes and their overlap and link them in an explanatory model. In our setting, students and teachers find e-learning holds strong potential and especially in times of COVID-19 it is greatly appreciated. We broaden the understanding of the impact of distant learning on acquiring competencies, on attitudes, and on mental wellbeing. Our model may serve for a thoughtful, necessary transition to future e-learning and hybrid programs for a competency-based medical education with ongoing social distancing measures.