Wnt/Fgf crosstalk is required for the specification of basal cells in the mouse trachea
DEVELOPMENT
Authors: Hou, Zhili; Wu, Qi; Sun, Xin; Chen, Huaiyong; Li, Yu; Zhang, Yongchun; Mori, Munemasa; Yang, Ying; Que, Jianwen; Jiang, Ming
Abstract
Basal progenitor cells are crucial for the establishment and maintenance of the tracheal epithelium. However, it remains unclear how these progenitor cells are specified during foregut development. Here, we found that ablation of the Wnt chaperone protein Gpr177 (also known as Wntless) in mouse tracheal epithelium causes a significant reduction in the number of basal progenitor cells accompanied by cartilage loss in Shh-Cre; Gpr177(loxp/loxp) mutants. Consistent with the association between cartilage and basal cell development, Nkx2.1(+) p63(+) basal cells are co-present with cartilage nodules in Shh-Cre; Ctnnb1(DM/loxp) mutants, which maintain partial cellcell adhesion but not the transcription regulation function of beta-catenin. More importantly, deletion of Ctnnb1 in the mesenchyme leads to the loss of basal cells and cartilage, concomitant with reduced transcript levels of Fgf10 in Dermo1-Cre; Ctnnb1loxp/loxp mutants. Furthermore, deletion of Fgf receptor 2 (Fgfr2) in the epithelium also leads to significantly reduced numbers of basal cells, supporting the importance of Wnt/Fgf crosstalk in early tracheal development.
Predisposition of Wingless Subgroup Medulloblastoma for Primary Tumor Hemorrhage
NEUROSURGERY
Authors: Reisinger, Dominik; Gojo, Johannes; Kasprian, Gregor; Haberler, Christine; Peyrl, Andreas; Azizi, Amedeo A.; Mayr, Lisa; Chocholous, Monika; Kool, Marcel; Czech, Thomas; Slavc, Irene
Abstract
BACKGROUND: Primary intratumoral hemorrhage as a presenting sign is rare in children with medulloblastomas but may result in severe complications. Given the distinct properties of molecular medulloblastoma subgroups, the impact on neurosurgical practice has still to be defined. OBJECTIVE: To investigate both clinical and radiological presentation of intratumoral hemorrhage in medulloblastoma patients in the context of molecular subgroups. METHODS: Data of all consecutive medulloblastoma patients treated at our institution between 1993 and 2018 (n = 104) were retrospectively reviewed in respect of clinical and radiological presentation as well as molecular subgroups. For cases with available tumor tissue (n = 86), subgroups were assigned by either 450 K methylation array or immunohistochemistry and CTNNB1 sequencing. Available imaging at diagnosis (n = 62) was reviewed by an experienced neuroradiologist. RESULTS: Within the entire cohort, 4 patients (4%) presented with massive spontaneous hemorrhage. Although no patient died as a direct consequence of hemorrhage, all suffered from serious sequelae. Moreover, 3 additional patients displayed radiological evidence of significant hemorrhage. Interestingly, all 7 cases belonged to the wingless (WNT) subgroup (n = 13), resulting in intratumoral hemorrhage in 54% (7/13) of pediatric WNT medulloblastomas. In contrast, significant hemorrhage was absent in all other molecular subgroups. CONCLUSION: Our results suggest that a substantial proportion of pediatric WNT medulloblastomas display significant intratumoral hemorrhage at the time of diagnosis. Consequently, the presence of significant hemorrhage in fourth ventricle childhood tumors is suggestive of WNT medulloblastoma and should lead to a less aggressive attempt for total resection in this prognostically favorable tumor type.