TY - JOUR A1 - Stromecki, Margaret A1 - Tatari, Nazanin A1 - Coudière Morrison, Ludivine A1 - Kaur, Ravinder A1 - Zagozewski, Jamie A1 - Palidwor, Gareth A1 - Ramaswamy, Vijay A1 - Skowron, Patryk A1 - Wölfl, Matthias A1 - Milde, Till A1 - Del Bigio, Marc R. A1 - Taylor, Michael D. A1 - Werbowetski-Ogilvie, Tamra E. T1 - Characterization of a novel OTX2-driven stem cell program in Group 3 and Group 4 medulloblastoma JF - Molecular Oncology N2 - Medulloblastoma (MB) is the most common malignant primary pediatric brain cancer. Among the most aggressive subtypes, Group 3 and Group 4 originate from stem/progenitor cells, frequently metastasize, and often display the worst prognosis, yet we know the least about the molecular mechanisms driving their progression. Here, we show that the transcription factor orthodenticle homeobox 2 (OTX2) promotes self-renewal while inhibiting differentiation in vitro and increases tumor initiation from MB stem/progenitor cells in vivo. To determine how OTX2 contributes to these processes, we employed complementary bioinformatic approaches to characterize the OTX2 regulatory network and identified novel relationships between OTX2 and genes associated with neuronal differentiation and axon guidance signaling in Group 3 and Group 4 MB stem/progenitor cells. In particular, OTX2 levels were negatively correlated with semaphorin (SEMA) signaling, as expression of 9 SEMA pathway genes is upregulated following OTX2 knockdown with some being potential direct OTX2 targets. Importantly, this negative correlation was also observed in patient samples, with lower expression of SEMA4D associated with poor outcome specifically in Group 4 tumors. Functional proof-of-principle studies demonstrated that increased levels of select SEMA pathway genes are associated with decreased self-renewal and growth in vitro and in vivo and that RHO signaling, known to mediate the effects of SEMA genes, is contributing to the OTX2 KD phenotype. Our study provides mechanistic insight into the networks controlled by OTX2 in MB stem/progenitor cells and reveals novel roles for axon guidance genes and their downstream effectors as putative tumor suppressors in MB. KW - axon guidance genes KW - medulloblastoma KW - orthodenticle homeobox 2 KW - RHO KW - semaphorin KW - stem cells Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240089 VL - 12 ER - TY - JOUR A1 - Adolph, Jonas E. A1 - Fleischhack, Gudrun A1 - Gaab, Christine A1 - Mikasch, Ruth A1 - Mynarek, Martin A1 - Rutkowski, Stefan A1 - Schüller, Ulrich A1 - Pfister, Stefan M. A1 - Pajtler, Kristian W. A1 - Milde, Till A1 - Witt, Olaf A1 - Bison, Brigitte A1 - Warmuth-Metz, Monika A1 - Kortmann, Rolf-Dieter A1 - Dietzsch, Stefan A1 - Pietsch, Torsten A1 - Timmermann, Beate A1 - Tippelt, Stephan T1 - Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies JF - Journal of Neuro-Oncology N2 - Purpose Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN. Methods Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated. Results Median age at first recurrence was 7.6 years (IQR: 4.0–13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3–20.0) and 36.9 months (CI 29.7–53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74–1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found. Conclusion No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation. KW - ependymoma KW - chemotherapy KW - recurrence KW - children KW - sirolimus Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-308302 SN - 0167-594X SN - 1573-7373 VL - 155 IS - 2 ER - TY - JOUR A1 - Nemes, Karolina A1 - Johann, Pascal D. A1 - Steinbügl, Mona A1 - Gruhle, Miriam A1 - Bens, Susanne A1 - Kachanov, Denis A1 - Teleshova, Margarita A1 - Hauser, Peter A1 - Simon, Thorsten A1 - Tippelt, Stephan A1 - Eberl, Wolfgang A1 - Chada, Martin A1 - Lopez, Vicente Santa-Maria A1 - Grigull, Lorenz A1 - Hernáiz-Driever, Pablo A1 - Eyrich, Matthias A1 - Pears, Jane A1 - Milde, Till A1 - Reinhard, Harald A1 - Leipold, Alfred A1 - van de Wetering, Marianne A1 - Gil-da-Costa, Maria João A1 - Ebetsberger-Dachs, Georg A1 - Kerl, Kornelius A1 - Lemmer, Andreas A1 - Boztug, Heidrun A1 - Furtwängler, Rhoikos A1 - Kordes, Uwe A1 - Vokuhl, Christian A1 - Hasselblatt, Martin A1 - Bison, Brigitte A1 - Kröncke, Thomas A1 - Melchior, Patrick A1 - Timmermann, Beate A1 - Gerss, Joachim A1 - Siebert, Reiner A1 - Frühwald, Michael C. T1 - Infants and newborns with atypical teratoid rhabdoid tumors (ATRT) and extracranial malignant rhabdoid tumors (eMRT) in the EU-RHAB registry: a unique and challenging population JF - Cancers N2 - Introduction: Malignant rhabdoid tumors (MRT) predominantly affect infants and young children. Patients below six months of age represent a particularly therapeutically challenging group. Toxicity to developing organ sites limits intensity of treatment. Information on prognostic factors, genetics, toxicity of treatment and long-term outcomes is sparse. Methods: Clinical, genetic, and treatment data of 100 patients (aged below 6 months at diagnosis) from 13 European countries were analyzed (2005–2020). Tumors and matching blood samples were examined for SMARCB1 mutations using FISH, MLPA and Sanger sequencing. DNA methylation subgroups (ATRT-TYR, ATRT-SHH, and ATRT-MYC) were determined using 450 k / 850 k-profiling. Results: A total of 45 patients presented with ATRT, 29 with extracranial, extrarenal (eMRT) and 9 with renal rhabdoid tumors (RTK). Seventeen patients demonstrated synchronous tumors (SYN). Metastases (M+) were present in 27% (26/97) at diagnosis. A germline mutation (GLM) was detected in 55% (47/86). DNA methylation subgrouping was available in 50% (31 / 62) with ATRT or SYN; for eMRT, methylation-based subgrouping was not performed. The 5-year overall (OS) and event free survival (EFS) rates were 23.5 ± 4.6% and 19 ± 4.1%, respectively. Male sex (11 ± 5% vs. 35.8 ± 7.4%), M+ stage (6.1 ± 5.4% vs. 36.2 ± 7.4%), presence of SYN (7.1 ± 6.9% vs. 26.6 ± 5.3%) and GLM (7.7 ± 4.2% vs. 45.7 ± 8.6%) were significant prognostic factors for 5-year OS. Molecular subgrouping and survival analyses confirm a previously described survival advantage for ATRT-TYR. In an adjusted multivariate model, clinical factors that favorably influence the prognosis were female sex, localized stage, absence of a GLM and maintenance therapy. Conclusions: In this cohort of homogenously treated infants with MRT, significant predictors of outcome were sex, M-stage, GLM and maintenance therapy. We confirm the need to stratify which patient groups benefit from multimodal treatment, and which need novel therapeutic strategies. Biomarker-driven tailored trials may be a key option. KW - atypical teratoid rhabdoid tumors KW - extracranial malignant rhabdoid tumor KW - RTPS1 KW - RTPS2 KW - germline mutation KW - EU-RHAB registry Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270730 SN - 2072-6694 VL - 14 IS - 9 ER - TY - JOUR A1 - Gaab, Christine A1 - Adolph, Jonas E. A1 - Tippelt, Stephan A1 - Mikasch, Ruth A1 - Obrecht, Denise A1 - Mynarek, Martin A1 - Rutkowski, Stefan A1 - Pfister, Stefan M. A1 - Milde, Till A1 - Witt, Olaf A1 - Bison, Brigitte A1 - Warmuth-Metz, Monika A1 - Kortmann, Rolf-Dieter A1 - Dietzsch, Stefan A1 - Pietsch, Torsten A1 - Timmermann, Beate A1 - Sträter, Ronald A1 - Bode, Udo A1 - Faldum, Andreas A1 - Kwiecien, Robert A1 - Fleischhack, Gudrun T1 - Local and systemic therapy of recurrent medulloblastomas in children and adolescents: results of the P-HIT-REZ 2005 Study JF - Cancers N2 - Recurrent medulloblastomas are associated with survival rates <10%. Adequate multimodal therapy is being discussed as having a major impact on survival. In this study, 93 patients with recurrent medulloblastoma treated in the German P-HIT-REZ 2005 Study were analyzed for survival (PFS, OS) dependent on patient, disease, and treatment characteristics. The median age at the first recurrence was 10.1 years (IQR: 6.9–16.1). Median PFS and OS, at first recurrence, were 7.9 months (CI: 5.7–10.0) and 18.5 months (CI: 13.6–23.5), respectively. Early relapses/progressions (<18 months, n = 30/93) found mainly in molecular subgroup 3 were associated with markedly worse median PFS (HR: 2.34) and OS (HR: 3.26) in regression analyses. A significant survival advantage was found for the use of volume-reducing surgery as well as radiotherapy. Intravenous chemotherapy with carboplatin and etoposide (ivCHT, n = 28/93) showed improved PFS and OS data and the best objective response rate (ORR) was 66.7% compared to oral temozolomide (oCHT, n = 47/93) which was 34.8%. Intraventricular (n = 43) as well as high-dose chemotherapy (n = 17) at first relapse was not related to a significant survival benefit. Although the results are limited due to a non-randomized study design, they may serve as a basis for future treatment decisions in order to improve the patients' survival. KW - medulloblastoma KW - refractory KW - recurrent KW - children KW - chemotherapy KW - surgery KW - radiotherapy KW - re-irradiation KW - intraventricular therapy Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254809 SN - 2072-6694 VL - 14 IS - 3 ER -