@article{FeldheimKesslerFeldheimetal.2022, author = {Feldheim, Jonas and Kessler, Almuth F. and Feldheim, Julia J. and Schulz, Ellina and Wend, David and Lazaridis, Lazaros and Kleinschnitz, Christoph and Glas, Martin and Ernestus, Ralf-Ingo and Brandner, Sebastian and Monoranu, Camelia M. and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Effects of long-term temozolomide treatment on glioblastoma and astrocytoma WHO grade 4 stem-like cells}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {9}, issn = {1422-0067}, doi = {10.3390/ijms23095238}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284417}, year = {2022}, abstract = {Glioblastoma leads to a fatal course within two years in more than two thirds of patients. An essential cornerstone of therapy is chemotherapy with temozolomide (TMZ). The effect of TMZ is counteracted by the cellular repair enzyme O\(^6\)-methylguanine-DNA methyltransferase (MGMT). The MGMT promoter methylation, the main regulator of MGMT expression, can change from primary tumor to recurrence, and TMZ may play a significant role in this process. To identify the potential mechanisms involved, three primary stem-like cell lines (one astrocytoma with the mutation of the isocitrate dehydrogenase (IDH), CNS WHO grade 4 (HGA)), and two glioblastoma (IDH-wildtype, CNS WHO grade 4) were treated with TMZ. The MGMT promoter methylation, migration, proliferation, and TMZ-response of the tumor cells were examined at different time points. The strong effects of TMZ treatment on the MGMT methylated cells were observed. Furthermore, TMZ led to a loss of the MGMT promoter hypermethylation and induced migratory rather than proliferative behavior. Cells with the unmethylated MGMT promoter showed more aggressive behavior after treatment, while HGA cells reacted heterogenously. Our study provides further evidence to consider the potential adverse effects of TMZ chemotherapy and a rationale for investigating potential relationships between TMZ treatment and change in the MGMT promoter methylation during relapse.}, language = {en} } @article{FeldheimKesslerMonoranuetal.2019, author = {Feldheim, Jonas and Kessler, Almuth F. and Monoranu, Camelia M. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Changes of O\(^6\)-Methylguanine DNA Methyltransferase (MGMT) promoter methylation in glioblastoma relapse—a meta-analysis type literature review}, series = {Cancers}, volume = {11}, journal = {Cancers}, number = {12}, issn = {2072-6694}, doi = {10.3390/cancers11121837}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193040}, year = {2019}, abstract = {Methylation of the O6-methylguanine DNA methyltransferase (MGMT) promoter has emerged as strong prognostic factor in the therapy of glioblastoma multiforme. It is associated with an improved response to chemotherapy with temozolomide and longer overall survival. MGMT promoter methylation has implications for the clinical course of patients. In recent years, there have been observations of patients changing their MGMT promoter methylation from primary tumor to relapse. Still, data on this topic are scarce. Studies often consist of only few patients and provide rather contrasting results, making it hard to draw a clear conclusion on clinical implications. Here, we summarize the previous publications on this topic, add new cases of changing MGMT status in relapse and finally combine all reports of more than ten patients in a statistical analysis based on the Wilson score interval. MGMT promoter methylation changes are seen in 115 of 476 analyzed patients (24\%; CI: 0.21-0.28). We discuss potential reasons like technical issues, intratumoral heterogeneity and selective pressure of therapy. The clinical implications are still ambiguous and do not yet support a change in clinical practice. However, retesting MGMT methylation might be useful for future treatment decisions and we encourage clinical studies to address this topic}, language = {en} } @article{KesslerFeldheimSchmittetal.2020, author = {Kessler, Almuth F. and Feldheim, Jonas and Schmitt, Dominik and Feldheim, Julia J. and Monoranu, Camelia M. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Monopolar Spindle 1 Kinase (MPS1/TTK) mRNA Expression is Associated with Earlier Development of Clinical Symptoms, Tumor Aggressiveness and Survival of Glioma Patients}, series = {Biomedicines}, volume = {8}, journal = {Biomedicines}, number = {7}, doi = {10.3390/biomedicines8070192}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236105}, year = {2020}, abstract = {Inhibition of the protein kinase MPS1, a mitotic spindle-checkpoint regulator, reinforces the effects of multiple therapies against glioblastoma multiforme (GBM) in experimental settings. We analyzed MPS1 mRNA-expression in gliomas WHO grade II, III and in clinical subgroups of GBM. Data were obtained by qPCR analysis of tumor and healthy brain specimens and correlated with the patients' clinical data. MPS1 was overexpressed in all gliomas on an mRNA level (ANOVA, p < 0.01) and correlated with tumor aggressiveness. We explain previously published conflicting results on survival: high MPS1 was associated with poorer long term survival when all gliomas were analyzed combined in one group (Cox regression: t < 24 months, p = 0.009, Hazard ratio: 8.0, 95\% CI: 1.7-38.4), with poorer survival solely in low-grade gliomas (LogRank: p = 0.02, Cox regression: p = 0.06, Hazard-Ratio: 8.0, 95\% CI: 0.9-66.7), but not in GBM (LogRank: p > 0.05). This might be due to their lower tumor volume at the therapy start. GBM patients with high MPS1 mRNA-expression developed clinical symptoms at an earlier stage. This, however, did not benefit their overall survival, most likely due to the more aggressive tumor growth. Since MPS1 mRNA-expression in gliomas was enhanced with increasing tumor aggressiveness, patients with the worst outcome might benefit best from a treatment directed against MPS1.}, language = {en} }