UA68/6/2 Eulogy on Dr. Kinnaman

Part of a chapel presentation by members of the Congress Debating Club regarding the history of WKU and it\u27s founding faculty. This portion was given by Evon Howell regarding A.J. Kinnaman who taught at WKU from 1906 to 1926. Kinnaman died in 1928

Pegylated Interferon Pharmacokinetics and Self-Reported Depressive Symptoms During Antiviral Treatment for Chronic Hepatitis C

Pegylated interferon-2a (PegIFN-2a) + ribavirin treatment for chronic hepatitis C is often associated with depressive symptoms. Previous studies have failed to explore whether PegIFN-2a pharmacokinetic variability plays an etiologic role in PegIFN-2a-induced mood disorders. The objective of this investigation was to evaluate the association between trough PegIFN-2a concentration at treatment week 4 (“PegIFN-2a Cmin4”) and an increase in depressive symptoms

The biguanide polyamine analog verlindamycin promotes differentiation in neuroblastoma via induction of antizyme

Deregulated polyamine biosynthesis is emerging as a common feature of neuroblastoma and drugs targeting this metabolic pathway such as DFMO are in clinical and preclinical development. The polyamine analog verlindamycin inhibits the polyamine biosynthesis pathway enzymes SMOX and PAOX, as well as the histone demethylase LSD1. Based on our previous research in acute myeloid leukemia (AML), we reasoned verlindamycin may also unblock neuroblastoma differentiation when combined with all-trans-retinoic acid (ATRA). Indeed, co-treatment with verlindamycin and ATRA strongly induced differentiation regardless of MYCN status, but in MYCN-expressing cells, protein levels were strongly diminished. This process was not transcriptionally regulated but was due to increased degradation of MYCN protein, at least in part via ubiquitin-independent, proteasome-dependent destruction. Here we report that verlindamycin effectively induces the expression of functional tumor suppressor—antizyme via ribosomal frameshifting. Consistent with previous results describing the function of antizyme, we found that verlindamycin treatment led to the selective targeting of ornithine decarboxylase (the rate-limiting enzyme for polyamine biosynthesis) as well as key oncoproteins, such as cyclin D and Aurora A kinase. Retinoid-based multimodal differentiation therapy is one of the few interventions that extends relapse-free survival in MYCN-associated high-risk neuroblastoma and these results point toward the potential use of verlindamycin in this regimen.Output Status: Forthcoming/Available Onlin

Pegylated Interferon Pharmacokinetics and Self-Reported Depressive Symptoms During Antiviral Treatment for Chronic Hepatitis C

BACKGROUND: Pegylated interferon-2a (PegIFN-2a) + ribavirin treatment for chronic hepatitis C is often associated with depressive symptoms. Previous studies have failed to explore whether PegIFN-2a pharmacokinetic variability plays an etiologic role in PegIFN-2a-induced mood disorders. The objective of this investigation was to evaluate the association between trough PegIFN-2a concentration at treatment week 4 (“PegIFN-2a Cmin(4)”) and an increase in depressive symptoms. METHODS: Using data from Virahep-C, the association between PegIFN-2a Cmin(4) and the following depression outcomes were evaluated using the Center for Epidemiological Studies-Depression scale (CES-D): (1) change in CES-D score from baseline to week 12; (2) greatest difference in CES-D score between baseline and weeks 4, 12, or 24; and (3) occurrence of severe depressive symptoms (CES-D greater than 23) at weeks 4, 12, or 24. One post-hoc analysis examined whether PegIFN-2a exposure during the first week of treatment was associated with change in CES-D score from baseline to week 4. RESULTS: No significant associations between PegIFN-2a Cmin(4) and the depression outcomes were observed (p>0.05). Exploratory analyses suggest a possible relationship between PegIFN-2a exposure during the first week of therapy and CES-D score change from baseline to week 4 (p=0.03). CONCLUSIONS: PegIFN-2a concentration levels from baseline to week 4 do not predict the onset and severity of depressive symptoms during 24 weeks of antiviral therapy; however PegIFN-2a levels during the first week of treatment may predict depressive symptoms in the first 4 weeks, earlier than anticipated and warrants further exploration

Fatigue before, during and after antiviral therapy of chronic hepatitis C: Results from the Virahep-C study

BACKGROUND AND AIMS: Fatigue is the most frequent and often debilitating symptom of chronic hepatitis C. It is unclear whether successful therapy of hepatitis C leads to its clinical improvement. In the Virahep-C study, patients with hepatitis C virus (HCV) genotype 1 infection were treated with peginterferon alfa-2a and ribavirin for up to 48 weeks while undergoing assessment of viral kinetics and clinical symptoms. METHODS: Fatigue measurements were conducted, before, during and after therapy, as `presence' (yes/no) and `severity' (visual analogue scale: 0 to 100mm). The clinical, histologic and virologic features that correlated with the presence and degree of fatigue were assessed focusing upon changes associated with sustained virological response (SVR). RESULTS: At baseline, 52% (n= 401) participants reported having fatigue, which was more common in women than men (59% vs. 48%, p=0.02) and slightly more severe (30 vs. 22mm, p=0.056). Fatigue was frequent and worse in cirrhotics versus those with lesser fibrosis (66% vs. 49%; 34 vs. 24mm). Fatigue did not correlate with other parameters. The proportion of patients and median fatigue scores increased on treatment (52% to 78%; 25 to 40mm, p<0.0001) with higher fatigue noted amongst those who ultimately achieved SVR (p<0.0001). On achieving SVR, there was a significant decrease in both frequency and severity of fatigue compared to their baseline (53% to 33%; 27 to 13mm, both p<0.0001). CONCLUSION: Fatigue is common in patients with chronic hepatitis C but associated poorly with biochemical parameters. Sustained response is accompanied by substantial improvement of fatigue

Combined MYC and P53 Defects Emerge at Medulloblastoma Relapse and Define Rapidly Progressive, Therapeutically Targetable Disease

We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this group died of rapidly progressive disease postrelapse. To study this interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of p53 function in this model produced aggressive tumors that mimicked characteristics of relapsed human tumors with combined P53-MYC dysfunction. Restoration of p53 activity and genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53-MYC interactions at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically

Abstract LB-201: MYC and TP53 defects interact at medulloblastoma relapse to define rapidly progressive disease and can be targeted therapeutically.

Disease recurrence following multi-modal therapy is the single most adverse event in medulloblastoma (MB). Currently >90% of relapsing patients die, accounting for ∼10% of childhood cancer deaths. MB is heterogeneous at diagnosis, comprising four molecular subgroups with distinct clinicopathological and molecular features and outcomes. The relevance of these features at relapse is unknown, making characterisation, modelling and targeted therapy of relapse biology essential to improve outcomes. However, relapsed MBs are not routinely biopsied in clinical practice. We undertook a first comprehensive investigation of the molecular, clinical and pathological features of 29 relapsed MBs and paired tumour samples taken at diagnosis, including the assessment of features with established significance at diagnosis (e.g. chromosome 17 and TP53 pathway status, MYC family (MYC, MYCN) gene amplification, polyploidy, CTNNB1 mutation and molecular subgroup status). Molecular subgroup was concordant at diagnosis and relapse, however evidence of alteration of all other features examined was found in relapsed tumours, with the majority of changes (30/44) representing acquired high-risk events. Most notably, MYC family gene amplifications and TP53 pathway defects commonly emerged in combination at relapse following conventional multimodal treatment (P=0.02, 7/22, 32%) and predicted rapid progression to death (P=0.016). These observations suggested aberrant activation of MYC family genes synergizes with TP53 inactivation in the genesis of biologically aggressive MB. To investigate any such relationship, we examined Trp53 status in our transgenic mouse model of spontaneously-arising MYCN-driven MB (GTML; Glt1-tTA/TRE-MYCN-Luc). Somatic Trp53 mutations were found in 83% of tumors (n=10/12). Direct modelling of this interaction in GTML/Trp53KI/KI mice dramatically enhanced MB formation with 100% penetrance (43/43, median survival 47 days) in GTML/Trp53KI/KI versus 6% (3/50) in GTML; P<0.0001), faithfully mimicked clinicopathological characteristics of TP53-MYC family gene-associated relapsed human tumors, and validated the essential role of TP53 in potentiating the growth of MYCN-driven MB. Finally, therapeutic inhibition of Aurora-A kinase using MLN8237 in these tumours, and in derived neurospheres in vitro, promoted degradation of MYCN, reduced tumor growth and prolonged survival. In summary, while subgroup status remains stable, MBs display altered molecular, pathological and clinical features at relapse, and the emergence of combined TP53-MYC family gene defects is common following conventional therapy. Their association with rapid demise, coupled with their biological validation as driving and therapeutically exploitable events in a novel mouse MB model, strongly support further investigation and routine biopsy of relapse disease to drive future individualised therapeutic strategies

Abstract MB-013: MYC and TP53 defects interact at medulloblastoma relapse to define rapidly progressive disease and can be targeted therapeutically.

Relapse following multi-modal therapy is the most adverse event in medul- loblastoma. Currently .90% of relapsing patients die, accounting for ~10% of childhood cancer deaths. Medulloblastoma is heterogeneous at diagnosis, comprising four molecular subgroups with distinct clinicopathological and molecular features. The relevance of these features at relapse is unknown, making characterisation, modelling and targeted therapy of relapse biology essential to improve outcomes. We undertook a comprehensive investigation of the molecular and clinicopathological features of 29 relapsed medulloblastomas and paired tumour samples taken at diagnosis, including the assessment of features with established significance at diagnosis (e.g. TP53 pathway status, MYC/MYCN amplification and molecular subgroup status). Molecular subgroup was unchanged, however evidence of alteration of all other features examined was found at relapse, with the majority of changes (30/44) representing acquired high-risk events. Most notably, MYC gene family amplifications and TP53 pathway defects commonly emerged in combination at relapse following conventional multimodal treatment (P 1⁄4 0.02, 7/ 22, 32%) and predicted rapid progression to death (P 1⁄4 0.016). Spontaneous development of Trp53 inactivating mutations was similarly common in a transgenic model of MYCN driven medulloblastoma (GTML;Glt1-tTA/ TRE-MYCN-Luc). Direct modelling of this interaction in GTML/Trp53KI/KI mice enhanced medulloblastoma formation (100%, 43/43 vs. 6%, 3/50 in GTML; P , 0.0001), mimicked clinicopathological characteristics of TP53-MYC relapsed human tumours, and validated the role of TP53 in potentiating the growth of MYCN-driven medulloblastoma. Therapeutic inhibition of Aurora-A kinase using MLN8237 in these tumours, and in derived neurospheres in vitro, promoted degradation of MYCN, reduced tumour growth and prolonged survival. In summary, medulloblastomas display altered molecular, pathological and clinical features at relapse and the emergence of combined TP53-MYC gene family defects is common following conventional therapy. Their association with rapid demise, and their validation as driving and therapeutically exploitable events in a novel mouse model, strongly support routine biopsy at relapse to drive future therapeutic strategies

MEDULLOBLASTOMA

BACKGROUND: LMD in children with recurrent medulloblastoma and other PNETs carries a poor prognosis and novel therapies are urgently needed to improve disease control. Somatostatin receptor-2 (SSR-2)is overexpressed in medulloblastoma and other central PNETs and can serve as a target for radionuclide tagged somatostatin analogues like 177Lu-DOTA-TATE that has shown considerable efficacy in adults with SSR-2 positive neuro-endocrine tumors. As a preliminary step prior to testing this agent in children with LMD, we performed an efficacy study of i.t. 177Lu-DOTA-TATE in athymic rats bearing LMD from MBL. METHODS: The subarachnoid space was accessed through the animal's cervical spine and a catheter was threaded along the dorsal aspect of spinal cord to the lumbar region and injected with 1 x 107 D341 human MBL cells and treatment initiated 3 days later. Groups of 10 animals received a single i.t. dose of 2, 3, or 5 mCi of 177Lu- DOTA-TATE or saline control. Animals were followed 300 days for survival. RESULTS: Treatment with 2 mCi resulted in an increase in median survival of 58.3% compared with saline control (p &lt; 0.001). Treatment with 5.0 mCi of 177Lu-DOTA-TATE increased median survival by 75.0% compared with the saline control group while a single dose of 3.0 mCi 177Lu-DOTA-TATE increased median survival compared with saline controls by 519.4%. Long-term survivors were seen in 0 of 10 animals treated with saline, 4 of 11 treated with 3 mCi, and 3 of 12 treated with 5.0 mCi. CONCLUSION: Intrathecal 177Lu- DOTA TATE is efficacious in controlling LMD from medulloblastoma in athymic rats. A phase I trial of this agent is being planned in children with LMD from recurrent MBL and other CNS PNETs. INTRODUCTION: Medulloblastoma/PNET is the most common malignant brain tumor in children. For children older than 3 years, the treatment of high risk group includes surgery, craniospinal (CSI) radiation therapy (30-36 Gy) plus local boost radiotherapy (54-56 Gy) and adjuvant chemotherapy, such as cisplatinum, carboplatin, lomustine, cyclophosphamide, and vincristine. The results have demonstrated 5-year overall survival (OS) of 40-60%. This study aimed to evaluate the outcomes of high risk medulloblastoma/PNET patients who were treated with radiation and adjuvant chemotherapy. METHODS: Patients were diagnosed with high risk medulloblastoma/PNET according to the histopathology, medulloblastoma risk classification by an evidence of metastasis or the residual tumor more than 1.5 cm2 and evidence of residual tumor after surgery in PNET. Treatment protocol was CSI RT 36 Gy with local boost at tumor 54-56 Gy. Two to four weeks after RT, patients received 8 courses of chemotherapy consisting of cyclophosphamide 800 mg/m2, day 1-3 and vincristine 2 mg/m2, week 1-3, alternated with carboplatin 200 mg/m2, day 1-3 and etoposide 150 mg/m2, day 1-3. RESULTS: Total of 25 patients, male: female of 2.6:1 and mean ± SD for age of 9.7± 3.0 years, were enrolled. The 5-year progression free survival and OS were 41.6± 11.7% and 61.5± 12.9%,respectively. The age and sex did not determine the difference in outcomes. The hematotoxic side effect, according to the National Cancer Institute's Common Terminology Criteria, were grade 4 leucopenia 60%, grade 4 neutropenia 60%, grade 4 anemia 20%, grade 4 thrombocytopenia 16%, grade 3 leucopenia 20%, grade 3 neutropenia 20%, grade 3 anemia 40%, and grade 3 thrombocytopenia 36%. Febrile neutropenia was found in 11 patients (44%). CONCLUSION: The present study demonstrated the similar outcomes of high risk medulloblastoma/PNET with the previous studies. Although, the grade 3 and 4 hematologic toxicity was high, no treatment related death was found. OBJECTIVE: Recent investigations revealed an association between transcriptional subtypes and morphological features in medulloblastoma. Since both characteristics are of prognostic significance, a precise correlation between them should be well established. Therefore we re-examined paediatric nodular medulloblastoma tumours for correlation with molecular subtypes of disease. METHODS: Paediatric patients with previously diagnosed desmoplastic/nodular (D/N) or medulloblastoma with extensive nodularity (MBEN) histopathology were re-analysed by two neuropathologists. In addition to H&amp;E-stained slides, reticulin preparations were simultaneously analysed from the same FFPE blocks. For identification of transcriptional subtypes of tumours immunohistopathological analyses were performed using a panel of representative antibodies. MYCC amplification was detected by FISH. RESULTS: Altogether 28 tumours with original MBEN or D/N diagnosis where molecular subtypes could be determined were identified. All tumours with MBEN histology belonged to SHH group and displayed distinctive reticulin-positive internodular reaction. However, only ∼60% of tumours with original D/N diagnosis were reticulin-positive. They belonged to SHH type, were mainly infantile and patients are still alive. Among reticulin-negative tumours only two were of the SHH type and were subsequently reclassified as classic and anaplastic tumours with pseudonodules. Importantly, all remaining reticulin-negative tumours with a presence of nodules in H&amp;E staining belonged to the non-WNT,SHH type. Therefore the original diagnosis was again reclassified as classic or anaplastic tumours with pseudonodules. Patients from this group were only males, with median age 14 years old, one had MYCC amplification and two of them died because of disease. Therefore, non-WNT,SHH tumours did not display typical desmoplastic/nodular histology accompanied by reticulin positive reaction as opposite to truly D/N tumours being typical for SHH molecular group (p &lt; 0.001). CONCLUSION: Reticulin staining is necessary to distinguish two different biologically and clinically group of nodular tumours which appear morphologically similar under H&amp;E staining alone. BACKGROUND: In the PNET4 European randomised controlled trial, children with standard risk medulloblastoma were allocated to HFRT or to STRT. All received maintenance chemotherapy. Event-free survival was similar between the two treatment arms. HFRT was associated with worse growth and better questionnaire-based executive function 6.1 years post-diagnosis, especially in children aged &lt;8 years at diagnosis (Kennedy et al., IJROBP, 2014). Therefore the aim of this study was to compare cognitive outcomes between treatment arms. METHODS: Neuropsychological data was collected prospectively in 137 patients from Germany, France, Italy and Sweden. Using results of the Wechsler Intelligence Scales, Kaufman Assessment Battery for Children, and Raven's progressive matrices, we generated: Full scale IQ (FSIQ), Verbal IQ (VIQ), Performance IQ (PIQ), working memory index (WMI) and speed of processing index (PSI). RESULTS: Among the 137 participants, [n = 71 HFRT, n = 66 STRT, 63.5% males; mean (SD, range) age at diagnosis 9.3 years (3.2, 4 to 17.6), 40.9% aged &lt;8 years at diagnosis; age at assessment 15.6 years (3.7, 8.3 to 25). Mean (SD, range) FSIQ in all participants was 88 (19, 40-137); mean intergroup difference [95% CIs] (3.88, [-2.66 to 10.41], p = .24). No difference was found in children aged &gt; 8 years at diagnosis. In children aged &lt;8 at diagnosis, VIQ was significantly higher in children receiving HFRT compared to STRT; a similar trend was found for PSI but not for PIQ,WMI and FSIQ (mean inter-group differences [95% CIs]): VIQ 12.02 [2.37 to 21.67], p = 0.02; PIQ (2.73 [-7.89 to 13.35], p &gt; .10); WMI (5.20 [-2.07 to 12.47], p &gt; .10), PSI (10.91 [-1.54 to 23.36], p = .08; FSIQ (5.28 [-4.23 to 14.79], p &gt; .10). CONCLUSION: HFRT was associated with higher verbal IQ in children aged &lt;8 years at diagnosis, consistent with the previous report using questionnaire-based data. Effect sizes were small, albeit with 10 point inter-group differences within their 95% CIs. Preoperative chemotherapy is often used in pediatric oncology to treat metastatic disease and facilitate the surgery of the primary tumor, but not for brain tumors. A first pilot study showed in 2004 the feasibility and effectiveness of preoperative chemotherapy in treating high-risk medulloblastomas. Seventy-one patients were treated for a metastatic medulloblastoma between 2002 and 2010 at Gustave Roussy. Two strategies were compared in intention to treat. Forty-two children were operated at the time of the diagnosis (group A) and the 29 others children were treated with 2 courses of carboplatin and etoposide (group B) after histological diagnosis (biopsy) and before a delayed surgery. Children of group A received the two courses of carboplatin and etoposide afterwards. The rest of the protocol (high-dose chemotherapy and cranio-spinal irradiation) was similar in the both groups. Complete neuropsychological testing, including intelligence quotient measurements, was scheduled before surgery, before radiotherapy and every year thereafter. MRI performed after neo-adjuvant chemotherapy showed an objective response in 24 patients (83%) and a stable disease in 4 patients (14%). Complete excision rate was significantly higher in group B (100% versus 64%, p = 0.00248) without any difference in postoperative complication rate. Medulloblastoma cells could still be evidenced despite preoperative chemotherapy. The median Total Intelligence Quotient (TIQ) was 81 and 90 in group A and B respectively (p = 0.02543). This difference was even more significant in young children (77 vs 91 points for groupe A and B, respectively). Hydrocephalus and brain radiotherapy dose were not associated with TIQ. Neo-adjuvant chemotherapy had no negative impact on local disease control (79 versus 83%). Event-free survival and overall survival at 3 years were 54 versus 62% and 58 versus 68% respectively (p = NS). Neo-adjuvant chemotherapy in metastatic medulloblastoma is safe and could have a positive impact on neuropsychological outcome and completeness of surgery. BACKGROUND: We prospectively evaluated histopathological findings and molecular variables, which have shown to impact prognosis of medulloblastoma patients, for outcome prediction in homogenously treated metastatic medulloblastoma patients. METHODS: One hundred twenty-three patients aged 4-21 years, diagnosed from 2001 to 2007, received systemic induction chemotherapy and intraventricular methotrexate, followed by hyperfractionated radiotherapy, and maintenance chemotherapy. From 86 patients paraffin material was available for immunohistochemical analysis to determine the activation status of the wingless (WNT) pathway, by immunostaining for β-catenin and sequencing of CTNNB1. In 81 of those 86 patients, material was available for gene amplification assessment of MYCC and MYCN by multiplex ligation-dependent probe amplification. RESULTS: Tumors with nuclear β-catenin immunopositivity showed excellent outcome (n = 4, all classic histology, 3 / 4 with CTNNB1 mutation; 5-year event-free (EFS) and overall survival (OS): 100%) compared to patients with tumors lacking nuclear β-catenin staining (n = 82; 5-year rates: 63% and 72%, respectively; p = 0.134 for EFS, p = 0.213 for OS). Patients with tumors characterized by MYC amplification (n = 5; MYCC, n = 2; MYCN, n = 3; all classic histology despite one case with MYCC amplification showing large cell histology) had poor outcome (20% for EFS and OS, respectively) when compared to patients with non-MYCC/MYCN amplified tumors (n = 76; 5-year EFS and OS: 65% and 75%, respectively; p = 0.011 for EFS, p &lt; 0.001 for OS). Based on histopathological and molecular findings, we identified three risk groups: Favorable- (β-catenin nucleopositive and/or desmoplastic histology (n = 7; one death of disease), n = 11; 5-year EFS and OS 89 ± 11%), poor- (MYCC/MYCN amplification and/or anaplastic or large cell histology, n = 6; 5-year EFS and OS 33 ± 19%), and intermediate-risk group (n = 64; 5-year EFS and OS 61 ± 7%, and 72 ± 6%, respectively; p = 0.020 for EFS, and p = 0.002 for OS). CONCLUSION: Histopathological subtyping together with molecular features (WNT pathway and MYCC/MYCN amplification status) differentiate three risk groups in homogenously treated metastatic medulloblastoma patients. Supported by Deutsche Kinderkrebsstiftung. BACKGROUND: A number of different second neoplasms have been reported in patients with neuroblastoma including brain tumors. None of these second cancers have occurred with sufficient frequency to indicate a specific relationship between neuroblastoma and any other neoplasm except in rare cancer syndromes. OBJECTIVE: We report a case of medulloblastoma in a child 5 months after successful treatment of metastatic neuroblastoma. DESIGN AND METHOD: A MEDLINE search was conducted for queries including “Children”, “medulloblastoma” and ‘neuroblastoma”. Relevant papers were selected for literature review. RESULT: A 10 months old female presented with 2-month history of right eye proptosis. CT scan of the abdomen showed a right adrenal mass with liver metastasis. Brain MRI revealed disease at the right orbital fossa extends to middle cranial fossa with no intracranial disease. Pathology of the right adrenal mass confirmed neuroblastoma with non amplified N myc. The patient was classified as intermediate risk disease and started on chemotherapy consisted of vincristine, cyclophosphamide, cisplatin, dacarbazine, ifosphamide and Adriamycin followed by 5 cycles of Accutane. Surveillance MIBG revealed no evidence of residual disease. Five months later, she had a new onset of trouble walking. CT and MRI of the brain showed a mass in the right cerebellar hemisphere with hydrocephalus. Complete Surgical resection of the mass was done and pathology revealed anaplastic medullobastoma. The patient initiated chemoradiation treatment for medulloblastoma. Her treatment was stopped because of disseminated fungal infection. She is currently receiving metronomic therapy with cyclophosphamide and topotecan and has been clinically stable. Molecular genetic tests are pending for familial cancer syndromes. CONCLUSION: We report a case of metachronous medullobastoma after treatment of metastatic neuroblastoma in a two year-old child. The occurrence of metachronous neoplasms is rare and challenging to treat. Cancer familial syndromes like neurofibromatosis type 1 and Simpson-Golabi-Behmel syndrome need to be excluded. Group 3 medulloblastoma with elevated c-MYC has the worst prognoses of the four molecular subgroups. To generate a genetically defined model of this disease, we transformed human fetal cerebellar stem cells with MYC along with hTERT, dominant negative p53 and constitutively active AKT. The resulting xenografts showed morphological similarities to large cell/anaplastic medulloblastoma, leptomeningeal and spinal dissemination, and had a gene expression profile closely aligned with Group 3 primary tumors. Because MYC over-expression leads to increased glutamine metabolism and glutamine addiction in other cancers, we hypothesized that MYC-driven MB would exhibit increased glutamine metabolism and be sensitive inhibitors of glutamine metabolism. In both our human stem cell derived and established medulloblastoma cell lines, MYC expression positively correlates with increased expression of glutaminolytic enzymes. Inhibition of glutamine metabolism was achieved using two glutamine analogs, acivicin and 6-diazo-5-L-norleucine (DON). In our human stem cell models, MYC-transformed cells experienced a significant decrease in proliferation and an increase in apoptosis after acivicin treatment (p &lt; 0.005), while SV40-transformed cells were unaffected. Both compounds also significantly decreased growth and increased apoptosis of the high-MYC MB cell lines D425Med and D283Med. In xenograft experiments using D283Med, fewer mice receiving acivicin developed flank tumors, and the resulting tumors were significantly smaller (80.9 mm3 treated vs 273.8 mm3 untreated). Glutaminase knockdown using short hairpins also significantly decreased growth of D425Med and D283Med. In summary, we present a novel human cerebellar stem cell based model of Group 3 medulloblastoma, and data suggesting that glutamine metabolism may be a therapeutic target in MYC-driven MB