Summary Medulloblastoma, the most common malignant pediatric brain tumour, is currently treated with non-specific cytotoxic therapies including surgery, whole brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, prior attempts to identify targets for therapy have been underpowered due to small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup enriched. The most common region of focal copy number gain is a tandem duplication of the Parkinson’s disease gene SNCAIP, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1 that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGFβ signaling in Group 3, and NF-κB signaling in Group 4 suggest future avenues for rational, targeted therapy.

Purpose: Medulloblastoma, a malignant pediatric brain tumor, is incurable in about one third of patients despite multimodal treatments. In addition, current therapies can lead to long-term disabilities. Based on studies of the extensive tropism of neural stem cells (NSC) toward malignant gliomas and the secretion of growth factors common to glioma and medulloblastoma, we hypothesized that NSCs could target medulloblastoma and be used as a cellular therapeutic delivery system. Experimental Design: The migratory ability of HB1.F3 cells (an immortalized, clonal human NSC line) to medulloblastoma was studied both in vitro and in vivo. As proof-of-concept, we used HB1.F3 cells engineered to secrete the prodrug activating enzyme cytosine deaminase. We investigated the potential of human NSCs to deliver a therapeutic gene and reduce tumor growth. Results: The migratory capacity of HB1.F3 cells was confirmed by an in vitro migration assay, and corroborated in vivo by injecting chloromethylbenzamido-Dil^labeled HB1.F3 cells into the hemisphere contralateral to established medulloblastoma in nude mice. In vitro studies showed the therapeutic efficacy of HB1.F3-CD on Daoy cells in coculture experiments. In vitro therapeutic studies were conducted in which animals bearing intracranial medulloblastoma were injected ipsilaterally with HB1.F3-CD cells followed by systemic 5-flourocytosine treatment. Histologic analyses showed that human NSCs migrate to the tumor bed and its boundary, resulting in a 76% reduction of tumor volume in the treatment group (P < 0.01).Conclusion: These studies show for the first time the potential of human NSCs as an effective delivery system to target and disseminate therapeutic agents to medulloblastoma.Medulloblastoma is the most common childhood malignant brain tumor. Although multimodal treatments, including radical surgical resection followed by radiation and chemotherapy, have substantially improved the survival rate for this disease, it remains incurable in about one third of patients.These treatments are also toxic and can lead to long-term disabilities (1, 2). The main cause of death is recurrence associated with tumor dissemination, at which point current therapeutic options have little efficacy (3, 4). Consequently, there is substantial need for novel, effective, low-toxicity therapies for children with medulloblastoma.The discovery of the inherent tumor-tropic properties of neural stem cells (NSC) could serve as a novel adjuvant strategy to current medulloblastoma treatments. Recent studies have shown that NSCs have the capacity to target therapeutic genes to brain tumors, such as malignant glioma (5 -13) and melanoma brain metastasis (14). We have expanded these investigations to determine whether NSCs are capable of targeting medulloblastoma in an orthotopic xenograft animal model. Therapeutic proof-of-concept studies were done using cytosine deaminase (CD) -producing NSCs and systemic 5-fluorocytosine (5-FC) prodrug administration. Our results show for the first time the pote...

Our results indicate that an early diagnosis and active intervention before establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome in children with MMD.

There were distinctive expression patterns of matrixins, cytokines and angiogenic factors in MMD patients, which seemed to correlate with disease pathogenesis. The balance between MMPs and TIMPs was disrupted in MMD and correlated with disease pathogenesis. Increased plasma levels of MCP-1 and VEGF in MMD patients may play a role in the recruitment of vascular progenitor cells and in the formation of collateral vessels.

Young-age MMD demonstrates rapid disease progression and results in poor clinical outcomes. These findings indicate the necessity of early surgery for young patients with MMD; however, the actual benefits should be verified with additional controlled studies, with long-term follow-up monitoring.

Purpose: Brainstem gliomas are usually inoperable and have a dismal prognosis.Based on the robust tropisms of neural stem cells (NSC) and mesenchymal stem cells (MSC) to brain tumors, we compared the tumor-tropic migratory capacities of these stem cells and evaluated the therapeutic potential of genetically engineered human NSCs encoding cytosine deaminase (CD) and IFNβ against brainstem gliomas. Experimental Design: The directed migratory capacities of NSCs and MSCs to brainstem glioma (F98) were evaluated both in vitro and in vivo. The human NSCs (HB1. F3) and various human MSCs, such as bone marrow-derived MSCs (HM3.B10), adipose tissue-derived MSCs, and umbilical cord blood-derived MSCs, were tested. Human fibroblast cells (HFF-1) were used as the negative control. As a proof of concept, the bioactivity of HB1.F3-CD-IFNβ was analyzed with a cell viability assay, and animals with brainstem gliomas were injected with HB1.F3-CD-IFNβ cells followed by systemic 5-fluorocytosine treatment.Results: In an in vitro modified Transwell migration assay and in vivo stem cell injection into established brainstem gliomas in rats, all the stem cells showed a significant migratory capacity compared with that of the control (P < 0.01). Histologic analysis showed a 59% reduction in tumor volume in the HB1.F3-CD-IFNβ-treated group (P < 0.05). Apoptotic cells were increased 2.33-fold in animals treated with HB1.F3-CD-IFNβ compared with the respective control groups (P < 0.01). Conclusion: The brainstem glioma-tropic migratory capacities of MSCs from various sources were similar to those of NSCs. Genetically engineered NSCs show therapeutic efficacy against brainstem gliomas.

The authors demonstrated that headaches can persist or develop after indirect bypass surgery despite successful prevention of cerebral ischemia. In addition to decreased cerebral blood flow, progressive recruitment and redistribution of blood flow should be considered as a cause of headaches in patients with moyamoya disease.

Sox2 is a key transcription factor that maintains the proliferation of neuroglial stem cells and inhibits neuronal fate commitment. Moreover, it was recently found that brain tumors contain stem cells that resemble normal neuroglial stem cells in many respects. This study was undertaken to describe Sox2 expression in various brain tumors, and to determine whether Sox2 expression is a universal feature of brain tumors, or whether its expression is limited to a specific lineage of brain tumors. Sox2 immunohistochemistry was performed on 194 brain tumor tissues of various kinds. Fetal and adult normal brain tissues obtained by autopsy and brain tissues of epilepsy patients with cortical dysplasia were used as controls. Semiquantitative reverse transcription polymerase chain reaction was used to confirm the immunohistochemical results. Double immunofluorescence was performed to characterize the lineage of Sox2-positive cells. Sox2 was found to be expressed in various glial tumors, including those with astroglial, oligodendroglial, and ependymal lineages, and in the glial components of mixed neuroglial tumors, regardless of pathologic grade. In brain tumors of embryonal origin, supratentorial primitive neuroectodermal tumors showed robust Sox2 expression, whereas medulloblastomas and pineoblastomas did not. The majority of Sox2-positive tumor cells coexpressed glial fibrillary acidic protein, and most Sox2-negative cells in medulloblastomas and pineoblastomas showed neuronal differentiation. This study suggest that Sox2 may be a tumor marker of glial lineages rather than a universal brain tumor stem cell marker, because its expression pattern was found to correspond to differentiation pathways. On the other hand, the aberrant coexpressions of Sox2 and of a neuronal marker were widely observed in glioblastomas, which reflects a disorganized differentiation pattern that characterizes highly malignant tumors.