TAp73 is a marker of glutamine addiction in medulloblastoma.

Medulloblastoma is the most common solid primary brain tumor in children. Remarkable advancements in the understanding of the genetic and epigenetic basis of these tumors have informed their recent molecular classification. However, the genotype/phenotype correlation of the subgroups remains largely uncharacterized. In particular, the metabolic phenotype is of great interest because of its druggability, which could lead to the development of novel and more tailored therapies for a subset of medulloblastoma. p73 plays a critical role in a range of cellular metabolic processes. We show overexpression of p73 in a proportion of non-WNT medulloblastoma. In these tumors, p73 sustains cell growth and proliferation via regulation of glutamine metabolism. We validated our results in a xenograft model in which we observed an increase in survival time in mice on a glutamine restriction diet. Notably, glutamine starvation has a synergistic effect with cisplatin, a component of the current medulloblastoma chemotherapy. These findings raise the possibility that glutamine depletion can be used as an adjuvant treatment for p73-expressing medulloblastoma.

Anesthesia Exposure during Therapy Predicts Neurocognitive Outcomes in Survivors of Childhood Medulloblastoma.

OBJECTIVE: To examine the contribution of anesthesia exposure during treatment for childhood medulloblastoma to neurocognitive outcomes 3 years after tumor diagnosis. STUDY DESIGN: In this retrospective study, anesthesia data were abstracted from medical records for 111 patients treated with risk-adapted protocol therapy at St Jude Children's Research Hospital. Neurocognitive testing data were obtained for 90.9% of patients. RESULTS: For the 101 patients (62.4% male) who completed testing, mean age at diagnosis was 10.1 years, and 74.3% were staged to have average-risk disease. Anesthesia exposure during treatment ranged from 1 to 52 events (mean = 19.9); mean cumulative duration per patient was 21.1 hours (range 0.7-59.7). Compared with normative expectations (16%), the group had a significantly greater frequency of at-risk scores (<1 SD) on measures of intelligence (28.7%), attention (35.2%), working memory (26.6%), processing speed (46.7%), and reading (25.8%). Including anesthesia exposure duration to linear regression models accounting for age at diagnosis, treatment intensity, and baseline IQ significantly increased the predicted variance for intelligence (r2 = 0.59), attention (r2 = 0.29), working memory (r2 = 0.31), processing speed (r2 = 0.44), and reading (r2 = 0.25; all P values <.001). CONCLUSIONS: In survivors of childhood medulloblastoma, a neurodevelopmentally vulnerable population, greater exposure to anesthesia significantly and independently predicts deficits in neurocognitive and academic functioning. When feasible, anesthesia exposure during treatment should be reduced.

Voltage-gated potassium channel EAG2 controls mitotic entry and tumor growth in medulloblastoma via regulating cell volume dynamics.

Medulloblastoma (MB) is the most common pediatric CNS malignancy. We identify EAG2 as an overexpressed potassium channel in MBs across different molecular and histological subgroups. EAG2 knockdown not only impairs MB cell growth in vitro, but also reduces tumor burden in vivo and enhances survival in xenograft studies. Mechanistically, we demonstrate that EAG2 protein is confined intracellularly during interphase but is enriched in the plasma membrane during late G2 phase and mitosis. Disruption of EAG2 expression results in G2 arrest and mitotic catastrophe associated with failure of premitotic cytoplasmic condensation. While the tumor suppression function of EAG2 knockdown is independent of p53 activation, DNA damage checkpoint activation, or changes in the AKT pathway, this defective cell volume control is specifically associated with hyperactivation of the p38 MAPK pathway. Inhibition of the p38 pathway significantly rescues the growth defect and G2 arrest. Strikingly, ectopic membrane expression of EAG2 in cells at interphase results in cell volume reduction and mitotic-like morphology. Our study establishes the functional significance of EAG2 in promoting MB tumor progression via regulating cell volume dynamics, the perturbation of which activates the tumor suppressor p38 MAPK pathway, and provides clinical relevance for targeting this ion channel in human MBs.

Neurocognitive dysfunction in adult cerebellar medulloblastoma.

OBJECTIVE: Impaired neurocognitive function (NCF) is a well-established consequence of pediatric medulloblastoma (MB) and its treatments. However, the frequency and features of neurocognitive dysfunction in adult-onset MB patients are largely unknown. METHODS: Adult patients (≥ 18 years) with MB who had received formal neurocognitive evaluation (N = 27) were identified. Demographic, medical, and treatment histories were extracted from the medical record. Lesion properties on MRI were analyzed and used to evaluate lesion-symptom mapping further. Demographically adjusted z-scores were calculated for each neurocognitive test and used to assess impairment frequency. Regression analyses were conducted to identify clinical and paraclinical factors associated with impaired NCF. RESULTS: Mean age of the patient sample was 33 years (SD = 11) at the time of MB diagnosis. Prior therapy included surgical resection (89%), radiation (70%), and chemotherapy (26%). A significant proportion of patients were impaired on tests of verbal learning and memory (32%), executive function (29%), and naming (18%). Age, education, lesion size, time from surgery, and number of chemotherapy cycles had the greatest contribution to test performance in random-forest regression models. CONCLUSION: This study identifies frequent impairment of NCF in adult patients with MB, particularly in the domains of learning and memory and executive function. Neurocognitive impairment is influenced by patients' demographic, disease, and treatment history. Further study is warranted to characterize the clinical impact of adult MB more fully.

Triptolide inhibits the proliferation and migration of medulloblastoma Daoy cells by upregulation of microRNA-138.

Medulloblastoma is a primitive neuroectodermal-derived brain tumor and the most common malignant brain tumor in children. Triptolide (TPL) is the major active component extracted from Tripterygium wilfordii Hook F. This study aimed to explore the effects of TPL on medulloblastoma cell proliferation, migration, and apoptosis, as well as the underlying possible molecular mechanism. Viability, proliferation, and apoptosis of Daoy cells were measured using cell counting kit-8 assay, 5-bromo-2'-deoxyuridine incorporation assay, and Guava Nexin assay, respectively. Cell migration was detected using two-chamber transwell assay and wound healing assay. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to determine the relative expression of microRNA-138 (miR-138) in Daoy cells. Cell transfection was used to change the expression of miR-138 in cells. Western blot analysis was used to analyze the expression of key factors involved in cell apoptosis, cell migration, the phosphatidylinositol 3-kinase (PI3K)/protein kinase 3 (AKT) pathway, and the Notch pathway in Daoy cells. We found that TPL significantly inhibited the viability, proliferation, and migration of Daoy cells but promoted Daoy cell apoptosis. The expression levels of matrix metalloproteinases (MMP)-2 and MMP-9 after TPL treatment were decreased. The expression of miR-138 in Daoy cells after TPL treatment was increased. Suppression of miR-138 obviously reversed the TPL-induced Daoy cell proliferation, migration inhibition, and cell apoptosis enhancement, as well as the inactivation of the PI3K/AKT and Notch pathways. Cyclin-dependent kinase 6 (CDK6) was a direct target gene of miR-138, which might be involved in the antitumor effects of TPL on Daoy cells. In conclusion, our study verified that TPL exerted anticancer effects on medulloblastoma cells possibly via upregulating miR-138 and inactivating the PI3K/AKT and Notch pathways.

Aspm sustains postnatal cerebellar neurogenesis and medulloblastoma growth in mice.

Alterations in genes that regulate brain size may contribute to both microcephaly and brain tumor formation. Here, we report that Aspm, a gene that is mutated in familial microcephaly, regulates postnatal neurogenesis in the cerebellum and supports the growth of medulloblastoma, the most common malignant pediatric brain tumor. Cerebellar granule neuron progenitors (CGNPs) express Aspm when maintained in a proliferative state by sonic hedgehog (Shh) signaling, and Aspm is expressed in Shh-driven medulloblastoma in mice. Genetic deletion of Aspm reduces cerebellar growth, while paradoxically increasing the mitotic rate of CGNPs. Aspm-deficient CGNPs show impaired mitotic progression, altered patterns of division orientation and differentiation, and increased DNA damage, which causes progenitor attrition through apoptosis. Deletion of Aspm in mice with Smo-induced medulloblastoma reduces tumor growth and increases DNA damage. Co-deletion of Aspm and either of the apoptosis regulators Bax or Trp53 (also known as p53) rescues the survival of neural progenitors and reduces the growth restriction imposed by Aspm deletion. Our data show that Aspm functions to regulate mitosis and to mitigate DNA damage during CGNP cell division, causes microcephaly through progenitor apoptosis when mutated, and sustains tumor growth in medulloblastoma.

UAB30, a novel RXR agonist, decreases tumorigenesis and leptomeningeal disease in group 3 medulloblastoma patient-derived xenografts.

BACKGROUND: Group 3 tumors account for approximately 25-30% of medulloblastomas and have the worst prognosis. UAB30 is a novel synthetic rexinoid shown to have limited toxicities in humans and significant efficacy in the pediatric neuroectodermal tumor, neuroblastoma. We hypothesized that treatment with UAB30 would decrease tumorigenicity in medulloblastoma patient-derived xenografts (PDXs). METHODS: Three group 3 medulloblastoma PDXs (D341, D384 and D425) were utilized. Cell viability, proliferation, migration and invasion assays were performed after treatment with UAB30 or 13-cis-retinoic acid (RA). Cell cycle analysis was completed using flow cytometry. A flank model, a cerebellar model, and a model of leptomeningeal metastasis using human medulloblastoma PDX cells was used to assess the in vivo effects of UAB30 and RA. RESULTS: UAB30 treatment led to cell differentiation and decreased medulloblastoma PDX cell viability, proliferation, migration and invasion and G1 cell cycle arrest in all three PDXs similar to RA. UAB30 and RA treatment of mice bearing medulloblastoma PDX tumors resulted in a significant decrease in tumor growth and metastasis compared to vehicle treated animals. CONCLUSIONS: UAB30 decreased viability, proliferation, and motility in group 3 medulloblastoma PDX cells and significantly decreased tumor growth in vivo in a fashion similar to RA, suggesting that further investigations into the potential therapeutic application of UAB30 for medulloblastoma are warranted.

Pleiotropic role for MYCN in medulloblastoma.

Medulloblastoma (MB) is the most common malignant brain tumor of childhood. Sonic Hedgehog (SHH) signaling drives a minority of MB, correlating with desmoplastic pathology and favorable outcome. The majority, however, arises independently of SHH and displays classic or large cell anaplastic (LCA) pathology and poor prognosis. To identify common signaling abnormalities, we profiled mRNA, demonstrating misexpression of MYCN in the majority of human MB and negligible expression in normal cerebella. We clarified a role in pathogenesis by targeting MYCN (and luciferase) to cerebella of transgenic mice. MYCN-driven MB showed either classic or LCA pathologies, with Shh signaling activated in approximately 5% of tumors, demonstrating that MYCN can drive MB independently of Shh. MB arose at high penetrance, consistent with a role for MYCN in initiation. Tumor burden correlated with bioluminescence, with rare metastatic spread to the leptomeninges, suggesting roles for MYCN in both progression and metastasis. Transient pharmacological down-regulation of MYCN led to both clearance and senescence of tumor cells, and improved survival. Targeted expression of MYCN thus contributes to initiation, progression, and maintenance of MB, suggesting a central role for MYCN in pathogenesis.

Posterior fossa syndrome: Review of the behavioral and emotional aspects in pediatric cancer patients.

Medulloblastoma, the most common malignant brain tumor of childhood, occurs in the posterior fossa, the part of the intracranial cavity that contains the brainstem and the cerebellum. The cerebellum is involved in many complex aspects of human behavior and function, and when it is disrupted or insulted, this can lead to significant sequelae in children with posterior fossa tumors. A constellation of impairing and distressing symptoms, including mutism, ataxia/hypotonia, and emotional lability, develops in approximately 25% of children after the surgical resection of posterior fossa tumors. These symptoms may impede treatment and frequently require intervention in order for children to be able to participate in their care. The eventual recovery of speech occurs for most, but with slowly improving dysarthria over many months. Behavioral changes and emotional lability also occur. This phenomenon has been classified differently by different investigators over the past 35 years. For the purposes of this article, the term posterior fossa syndrome is used to refer to the neuropsychiatric and behavioral features that compose this condition. The current review summarizes the development of the clinical understanding of this phenomenon with a focus on near- and long-term psychosocial and psychiatric implications. Also, clinical examples of the presentation, management, and lasting implications of this syndrome are provided. This review is intended to be a resource for clinicians who treat affected children. Cancer 2017;123:551-559. © 2016 American Cancer Society.

Brain Perfusion and Diffusion Abnormalities in Children Treated for Posterior Fossa Brain Tumors.

OBJECTIVE: To compare cerebral perfusion and diffusion in survivors of childhood posterior fossa brain tumor with neurologically normal controls and correlate differences with cognitive dysfunction. STUDY DESIGN: We analyzed retrospectively arterial spin-labeled cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) in 21 patients with medulloblastoma (MB), 18 patients with pilocytic astrocytoma (PA), and 64 neurologically normal children. We generated ANCOVA models to evaluate treatment effects on the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, and cerebral white matter at time points an average of 5.7 years after original diagnosis. A retrospective review of patient charts identified 12 patients with neurocognitive data and in whom the relationship between IQ and magnetic resonance imaging variables was assessed for each brain structure. RESULTS: Patients with MB (all treated with surgery, chemotherapy, and radiation) had significantly lower global CBF relative to controls (10%-23% lower, varying by anatomic region, all adjusted P?

Societal preferences in the treatment of pediatric medulloblastoma: Balancing risk of death and quality of life.

PURPOSE: Medulloblastoma is the most prevalent childhood brain cancer. Children with medulloblastoma typically receive a combination of surgery, radiation, and chemotherapy. The survival rate is high but survivors often have sequelae from radiotherapy of the entire developing brain and spinal cord. Ongoing genetic studies have suggested that decreasing the dose of radiation might be possible among children with favorable molecular variants; however, this may result in an increased disease recurrence. As such, there is a need to investigate the nature of trade-offs that individuals are willing to make regarding the treatment of medulloblastoma. METHOD: We used best-worst scaling to estimate the importance of attributes affecting the general public's decision making around the treatment of medulloblastoma. After conducting focus groups, we selected three relevant attributes: (1) the accuracy of the genetic test; (2) the probability of serious adverse effects of the treatment(s); and (3) the survival rate. Using the paired method, we applied a conditional logit model to estimate preferences. RESULTS: In total, 3,006 respondents (51.3% female) with an average age of 43 years answered the questionnaires. All coefficients were statistically significantly different from zero and the attribute levels of adverse effects and the survival rate had the most impact on individuals' stated decision making. CONCLUSION: Overall, respondents showed high sensitivity to children experiencing disability particularly in the setting of a good prognosis. However, among children with poor prognostic molecular variants, participants showed tolerance about having a child with mild and partial disability compared to a low rate of survival.

Medulloblastoma initiation and spread: Where neurodevelopment, microenvironment and cancer cross pathways.

Medulloblastomas are the most common malignant pediatric brain tumors. Over the past several decades, a wide range of tumor-centric studies have identified genes and their regulators within signaling pathways that promote medulloblastoma growth. This review aims to raise awareness that transdisciplinary research between developmental neurobiology and cancer foundations can advance our current understanding of how the nervous system contributes to medulloblastomas. By leveraging current advances in neurodevelopment, microenvironment (including secreted neuropeptides), neurotransmitters, and axon guidance cues, we can uncover novel mechanisms used by the nervous system to promote medulloblastoma growth and spread. This will ultimately result in development of improved strategies for cancer prevention and treatment of pediatric patients with this devastating disease. © 2016 Wiley Periodicals, Inc.

Neurocognitive Function and Health-Related Quality of Life in Pediatric Korean Survivors of Medulloblastoma.

The neurocognitive function and quality of life of 58 Korean survivors of childhood medulloblastoma were assessed after surgery, cranial radiation and chemotherapy. All patients were evaluated with a battery of neurocognitive function tests and the Pediatric Functional Assessment of Cancer Therapy-Brain Tumor Survivors, which consists of self-report questionnaires on quality of life. The mean full-scale intelligence quotient (IQ), verbal IQ, and performance IQ scores were 90.2, 97.1, and 84.16, respectively. The mean memory quotient (MQ) score was 86.78, which was within 1 standard deviation of the average score of 100. Processing speed, attention, and executive function showed mild to moderate deficits. Intelligence, memory, executive function, visuospatial function, and simple motor function were significantly lower in the patients diagnosed before 8 years of age compared with those diagnosed after 8. The cognitive deficits in the patients diagnosed at younger ages might be related to earlier exposure to craniospinal irradiation and chemotherapy. The patient and parent proxy evaluations of attention, fine motor function, and quality of life did not differ. We found significant neurocognitive changes in a wide range of neurocognitive functional domains in Korean survivors of childhood medulloblastoma. Long-term follow-up studies of survivors of childhood medulloblastoma beginning at the time of their first diagnosis are required to better understand the deficits exhibited by survivors of childhood medulloblastoma, so that intervention strategies and treatment refinements that reduce the long-term neurocognitive decline can be developed.

Metastasis-associated gene 1 expression in human medulloblastoma and its association with invasion and metastasis in medulloblastoma Daoy cell lines.

This study aims to investigate the expression of metastasis-associated gene 1 (MTA1) in human medulloblastoma, and its significance in the invasion and metastasis in a medulloblastoma cell line. Positive expression rate of MTA1 protein in medulloblastoma and adjacent normal tissues collected from 29 medulloblastoma patients was detected by immunohistochemistry assay in vivo. In in vitro experiments, Daoy cells were transfected with MTA1-targeted small interfering RNA (siRNA, MTA1-siRNA group), niRNA (MTA1-niRNA group), and plasmid vectors (control group). Transfection efficiency was evaluated by PT-PCR and western blot; cell adhesion, migration, and invasion capacity was assessed by adhesion assays, scratch assays, and transwell chamber invasion assays, respectively. Results indicated that the positive expression rate of MTA1 protein in the medulloblastoma tissues was higher as compared with that of the adjacent normal tissues (P < 0.05). In addition, mRNA and protein expression of MTA1 in the MTA1-siRNA group was lower than that in the control and MTA1- niRNA groups (P < 0.05). Adhesion, migration, and invasion capacity of Daoy cells in the MTA1-siRNA group was inhibited as compared with the control and MTA1-niRNA groups (P < 0.05). In conclusion, MTA1 expression was increased in medulloblastoma cells, while MTA1 knockdown in medulloblastoma cells inhibited MTA1 expression. In addition, MTA1 knockdown inhibited the adhesion, migration, and invasive capabilities of medulloblastoma cells. It is possible that MTA1 can serve as a biomarker and a potential therapeutic target for medulloblastoma.

Evidence of high mortality in long term survivors of childhood medulloblastoma.

The diagnosis of pediatric medulloblastoma now carries a much improved overall survival; however as outcomes advance, late mortality, from causes such as disease recurrence and subsequent malignancies, are of increasing concern for these patients. Using the Surveillance, Epidemiology, and End Results database, the causes of late mortality in long term survivors of medulloblastoma were evaluated. Patients diagnosed with a medulloblastoma between the ages of 0-19 years who survived at least 5 years after diagnosis were included. Using U.S. population data, standardized mortality ratios (SMRs) were calculated. Cumulative incidence estimates and standardized incidence ratios (SIRs) of subsequent malignancies were calculated. A total of 455 patients were included in the analysis. All patients received radiation as part of therapy. Median age at diagnosis was 7 years, and mean follow-up was 16 years. By the time of last follow-up, 20.4 % of patients had died, representing an SMR of 24.0 (95 % CI 19.3-29.4). Overall survival at 30 years was 65.5 %. Primary recurrence accounted for 59 % of late deaths, while subsequent malignancy accounted for 11.8 %. SIR for subsequent malignancy in these patients was 10.4 (95 % CI 6.9-15.1). The most common secondary tumor was another brain tumor (32 %), followed by thyroid cancer (21 %). These data demonstrate that late mortality remains a significant problem in these patients. The causes of death are largely attributable to disease recurrence and secondary malignancies. Efforts to improve risk stratification and tailor therapy will help in reducing late mortality in this population.

Wnt activation affects proliferation, invasiveness and radiosensitivity in medulloblastoma.

Medulloblastomas (MBs) associated with the Wnt activation represent a subgroup with a favorable prognosis, but it remains unclear whether Wnt activation confers a less aggressive phenotype and/or enhances radiosensitivity. To investigate this issue, we evaluated the biological behavior of an MB cell line, UW228-1, stably transfected with human ß-catenin cDNA encoding a nondegradable form of ß-catenin (UW-B) in standard culture conditions and after radiation treatment. We evaluated the expression, transcriptional activity, and localization of ß-catenin in the stably transfected cells using immunofluorescence and WB. We performed morphological analysis using light and electron microscopy. We then analyzed changes in the invasiveness, growth, and mortality in standard culture conditions and after radiation. We demonstrated that (A) Wnt activation inhibited 97 % of the invasion capability of the cells, (B) the growth of the UW-B cells was statistically significantly lower than that of all the other control cells (p < 0.01), (C) the mortality of irradiated UW-B cells was statistically significantly higher than that of the controls and their nonirradiated counterparts (p < 0.05), and (D) morphological features of neuronal differentiation were observed in the Wnt-activated cells. In tissue samples, the Ki-67 labeling index (LI) was lower in ß-catenin-positive samples compared to non-ß-catenin positive ones. The Ki-67 LI median (LI = 40) of the nuclear ß-catenin-positive tumor samples was lower than that of non-nuclear ß-catenin-positive samples (LI = 50), but the difference was not statistically significant. Overall, our data suggest that activation of the Wnt pathway reduces the proliferation and invasion of MBs and increases the tumor's radiosensitivity.

Adult medulloblastoma: clinical characters, prognostic factors, outcomes and patterns of relapse.

To analyze the clinical characters, prognostic factors, patterns of relapse and treatment outcomes for medulloblastoma in adults. The clinical materials of 73 consecutive adult patients (age, ≥16 years) with medulloblastoma were analyzed retrospectively. Follow-up data were available in 62 patients, ranging from 10 to 142 months (median, 78.4 months). Outcome in survival was assessed by the progression-free survival (PFS) and overall survival (OS). Univariate and multivariate analysis were performed to determine the prognostic factors. Total or near-total tumor resection was achieved in 37 cases (59.7 %), subtotal in 19 cases (30.6 %), and partial resection in 6 cases (9.7 %).Twenty-two patients experienced recurrences, and 45 % percent of all recurrences occurred more than 4 years after initial surgery. The PFS rates at 5 and 8 years were 60.1 and 37.0 %, respectively. The OS rates at 5 and 8 years were 82.6 and 57.3 %, respectively. In univariate analysis, less tumor resection, non-desmoplastic pathology, and brainstem involvement were risk factors for worse PFS and OS (P < 0.05). High-risk category was associated with just lower PFS, but not OS. In multivariate analysis, complete resection and desmoplastic pathology were independently predictive factors of improved PFS and OS. In adult medulloblastoma, late relapse is common and therefore long-term follow-up is important for evaluating the real impact of treatments. Risk category had prognostic value just for PFS, but not for OS. Complete resection and desmoplastic histology are independently predictive factors for favorable outcomes.

Tumor necrosis-initiated complement activation stimulates proliferation of medulloblastoma cells.

OBJECTIVE AND DESIGN: We sought to determine the effect of necrosis-induced activation of the complement protein C3 in medulloblastoma. MATERIALS/METHODS: Twelve medulloblastoma surgical specimens were evaluated for complement activation using immunohistochemistry, with H&E stains performed on adjacent tissue sections to determine the relationship of complement activation to necrotic tissue. Flow cytometry and Western blot were performed on three established medulloblastoma lines and one surgically-procured cell culture to determine expression of C3a receptor (C3aR) in medulloblastoma. In vitro proliferation of siRNA C3aR knockdown cells was compared to that of control siRNA cells with cell line Daoy. RESULTS: Three surgical specimens were found to have necrosis on H&E sections. In each case, iC3b staining was identified on adjacent sections, limited to the necrotic region. In no case did necrosis occur without iC3b staining on adjacent sections. C3aR protein was demonstrated on both the three established cell lines and on the surgical culture. Proliferation assays of Daoy cells with siRNA knockdown vs. control siRNA revealed significantly reduced proliferation at 72 h (p = 0.001). CONCLUSIONS: Necrosis is associated with complement activation in medulloblastoma. Medulloblastoma cells express C3aR, and siRNA-mediated knockdown of C3aR inhibits proliferation of these cells in vitro.

The transcription factor Cux1 in cerebellar granule cell development and medulloblastoma pathogenesis.

Cux1, also known as Cutl1, CDP or Cut is a homeodomain transcription factor implicated in the regulation of normal and oncogenic development in diverse peripheral tissues and organs. We studied the expression and functional role of Cux1 in cerebellar granule cells and medulloblastoma. Cux1 is robustly expressed in proliferating granule cell precursors and in postmitotic, migrating granule cells. Expression is lost as postmigratory granule cells mature. Moreover, Cux1 is also strongly expressed in a well-established mouse model of medulloblastoma. In contrast, expression of CUX1 in human medulloblastoma tissue samples is lower than in normal fetal cerebellum. In these tumors, CUX1 expression tightly correlates with a set of genes which, when mapped on a global protein-protein interaction dataset, yields a tight network that constitutes a cell cycle control signature and may be related to p53 and the DNA damage response pathway. Antisense-mediated reduction of CUX1 levels in two human medulloblastoma cell lines led to a decrease in proliferation and altered motility. The developmental expression of Cux1 in the cerebellum and its action in cell lines support a role in granule cell and medulloblastoma proliferation. Its expression in human medulloblastoma shifts that perspective, suggesting that CUX1 is part of a network involved in cell cycle control and maintenance of DNA integrity. The constituents of this network may be rational targets to therapeutically approach medulloblastomas.

De-escalation of therapy for pediatric medulloblastoma: trade-offs between quality of life and survival.

BACKGROUND: Treatment intensity for pediatric medulloblastoma may vary depending on the type of medulloblastoma. In some cases, the dose of radiation may be reduced or eliminated. Correspondingly, there may be trade-offs between quality of life and survival. In this study, focus groups were conducted with parents and clinicians to explore their opinions about these trade-offs as well as the alignment/misalignment between parents and clinicians regarding the trade-offs. METHODS: One hour semi-structured focus groups were conducted with parents of children with medulloblastoma and health care providers who were involved in the care of these children. RESULTS: Parents and providers showed differences in which factors they believe have the greatest impact on quality of life for children with medulloblastoma and their families. For parents, the most important factor is social functioning and their child's ability to make friends and have a social life. In contrast, providers thought that parents cared most about their child's cognitive functioning and ability to attend and perform in school. CONCLUSION: Understanding parents' perspectives on quality of life is important in terms of providing support services that target the areas that the parents prioritize. The types of functioning that are most strongly correlated with quality of life from the parents' perspective may be the ones that should be targeted to protect during treatment. Pediatr Blood Cancer 2014;61:1300-1304. © 2014 Wiley Periodicals, Inc.