Cell line analysis is an important element of cancer research. Despite the progress in glioblastoma cell culturing, the cells isolated from the majority of specimens cannot be propagated infinitely in vitro. The aim of this study was to identify the processes responsible for the stabilization failure. Therefore, we analyzed 56 primary GB cultures, 7 of which were stabilized. Our results indicate that senescence is primarily responsible for the glioblastoma cell line stabilization failure, while mitotic catastrophe and apoptosis play a minor role. Moreover, a new technical approach allowed for a more profound analysis of the senescent cells in primary cultures, including the distinction between tumor and normal cells. In addition, we observed that glioblastoma cells in primary cultures have a varied potential to undergo spontaneous in vitro senescence, which is often higher than that of the normal cells infiltrating the tumor. Thus, this is the first report of GB cells in primary cell cultures (including both monolayer and spheroid conditions) rapidly and spontaneously becoming senescent. Intriguingly, our data also suggest that nearly half of GB cell lines have a combination of TP53 mutation and CDKN2A homozygous deletion, which are considered as mutually exclusive in glioblastoma. Moreover, recognition of the mechanisms of senescence and mitotic catastrophe in glioblastoma cells may be a step towards a potential new therapeutic approach.

Glioblastoma is a highly aggressive tumour of the central nervous system, characterised by poor prognosis irrespective of the applied treatment. The aim of our study was to analyse whether the molecular markers of glioblastoma (i.e. TP53 and IDH1 mutations, CDKN2A deletion, EGFR amplification, chromosome 7 polysomy and EGFRvIII expression) could be associated with distinct prognosis and/or response to the therapy. Moreover, we describe a method which allows for a reliable, as well as time- and cost-effective, screening for EGFR amplification and chromosome 7 polysomy with quantitative Real-Time PCR at DNA level. In the clinical data, only the patient’s age had prognostic significance (continuous: HR = 1.04; p<0.01). At the molecular level, EGFRvIII expression was associated with a better prognosis (HR = 0.37; p = 0.04). Intriguingly, EGFR amplification was associated with a worse outcome in younger patients (HR = 3.75; p<0.01) and in patients treated with radiotherapy (HR = 2.71; p = 0.03). We did not observe any difference between the patients with the amplification treated with radiotherapy and the patients without such a treatment. Next, EGFR amplification was related to a better prognosis in combination with the homozygous CDKN2A deletion (HR = 0.12; p = 0.01), but to a poorer prognosis in combination with chromosome 7 polysomy (HR = 14.88; p = 0.01). Importantly, the results emphasise the necessity to distinguish both mechanisms of the increased EGFR gene copy number (amplification and polysomy). To conclude, although the data presented here require validation in different groups of patients, they strongly advocate the consideration of the patient’s tumour molecular characteristics in the selection of the therapy.

Introduction. The aim of this study was to evaluate whether Anterior Communicating Artery (AComA) complex rotation in axial plane may influence the ease of surgical exploration in this region and safety of clip positioning when left vs right-sided approach is compared. Materials and methods. This is a retrospective study based on analysis of patients operated due to AComA aneurysm, both ruptured and unruptured. AComA complex position in relation to coronal plane was evaluated using 3D-CTA VR reconstructions. Next, comparison between surgical approach from the side where A1-A2 junction (angle) was located anterior and posterior to coronal plane was performed in relation to surgical difficulties and intra- and postoperative complications. Results. Subgroup statistical analysis revealed that there is a strong and statistically significant correlation between AComA complex rotation and surgical difficulties expressed by the need of repeated temporary clip application and brain transgression. When anterior vs posterior angle side approach was compared in relation to surgical difficulties and complications, there was a statistically significant difference with strong correlation (p <0,05) in favour of posterior angle side approach. Interestingly, in 72,7% and 45,5% of patients that were operated from the side where A1-A2 junction was located posterior to coronal plane, the approach was performed form the side of a non-dominant A1 and aneurysm dome projection side, respectively. Conclusions. Despite its limitations, our results suggest that microsurgical clipping strategy of AComA aneurysms should at least include AComA complex rotation in axial plane, besides well acknowledged factors, when deciding from which side these lesions will be approached.

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