An ERK5-PFKFB3 axis regulates glycolysis and represents a therapeutic vulnerability in pediatric diffuse midline glioma

Metabolic reprogramming in pediatric diffuse midline glioma is driven by gene expression changes induced by the hallmark histone mutation H3K27M, which results in aberrantly permissive activation of oncogenic signaling pathways. Previous studies of diffuse midline glioma with altered H3K27 (DMG-H3K27a) have shown that the RAS pathway, specifically through its downstream kinase, extracellular-signal-related kinase 5 (ERK5), is critical for tumor growth. Further downstream effectors of ERK5 and their role in DMG-H3K27a metabolic reprogramming have not been explored. We establish that ERK5 is a critical regulator of cell proliferation and glycolysis in DMG-H3K27a. We demonstrate that ERK5 mediates glycolysis through activation of transcription factor MEF2A, which subsequently modulates expression of glycolytic enzyme PFKFB3. We show that in vitro and mouse models of DMG-H3K27a are sensitive to the loss of PFKFB3. Multi-targeted drug therapy against the ERK5-PFKFB3 axis, such as with small-molecule inhibitors, may represent a promising therapeutic approach in patients with pediatric diffuse midline glioma.

B-Cell Acute Lymphoblastic Leukemia with iAMP21 in a Patient with Constitutional Ring Chromosome 21

Pediatric B-cell acute lymphoblastic leukemia (B-ALL) is associated with various specific cytogenetic and molecular markers that significantly influence treatment and prognosis. Intrachromosomal amplification of chromosome 21 (iAMP21) defines a rare distinct cytogenetic subgroup of childhood B-ALL, which is characterized by amplification of region 21q22.12 comprising the RUNX1 gene. Constitutional structural chromosomal abnormalities involving chromosome 21 confer an increased risk for B-ALL with iAMP21. Here, we report the development of B-ALL with iAMP21 in a 9-year-old child with a constitutional ring chromosome 21, r(21)c, uncovered after B-ALL diagnosis. Cytogenetic and microarray analysis of the post-therapy sample revealed an abnormal chromosome 21 lacking a satellite and having a deletion of the terminal 22q22.3 region, consistent with a constitutional ring chromosome 21, r(21)(p11.2q22). On a retrospective analysis, this ring chromosome was observed in the normal cells in the pre-treatment diagnostic specimen. Constitutional ring chromosome 21 may remain undetected in patients with mild or no neurodevelopmental phenotype, posing an unknown lifelong risk of developing B-ALL with iAMP21. Individuals with constitutional structural chromosome 21 rearrangements such as ring 21 require a close surveillance and long-term follow-up studies to establish their risk of B-ALL relapse and possibility of developing other malignancies. Germline analysis is recommended to all pediatric patients with iAMP21-related B-ALL to rule out structural chromosome 21 rearrangements and to elucidate molecular mechanisms of iAMP21 formation.

TMET-09. LOSS OF MAT2A COMPROMISES METHIONINE METABOLISM AND REPRESENTS A VULNERABILITY IN H3K27M MUTANT GLIOMAS

H3K27-mutant diffuse midline gliomas (DMGs) are defined as grade IV tumors by the World Health Organization. DMGs are inoperable and resistant to chemo/radio therapies. Median survival ranges from 8-11 months, with 2% of patients surviving beyond 5 years. H3K27M mutations lead to global epigenetic and transcriptional reprogramming driven by global loss of negative transcriptional regulator H3K27 trimethylation (H3K27me3). Loss of H3K27me3 is an initiating event in gliomagenesis. This disease lacks appropriate models to predict disease biology and response to treatment. Therefore, we developed a novel syngeneic H3K27M mouse model. An unbiased integrated systems biology approach identified that H3K27M but not isogenic controls relied on the amino acid methionine and the enzyme Methionine Adenosyltransferase 2A (MAT2A). MAT2A is a central regulator of one-carbon metabolism by converting methionine to S-adenosylmethionine (SAM), the universal methyl-donor for protein and nucleotide methylation reactions. In complementary genetic approaches, we applied these findings to patient-derived cell lines with the H3K27M mutation. We hypothesize that MAT2A abrogation, genetic/pharmacological, would alter DMG viability by disrupting the methylome. The current MAT2A sensitivity paradigm is based on Methylthioadenosine Phosphorylase (MTAP) deletion through a synthetic lethal mechanism. We provide a novel mechanism whereby H3K27M cells are sensitive to MAT2A loss, independent of MTAP and through Adenosylmethionine Decarboxylase 1 (AMD1) overexpression disrupting MAT2A regulation. This results in H3K27M cells having lower MAT2A protein levels, conferring a sensitivity by inhibiting residual MAT2A. Genetic/pharmacological aberrations to MAT2A resulted in reduced proliferation. Parallel H3K36me3 ChIP and RNA-sequencing identified loss of oncogenic and developmental transcriptional programs associated with MAT2A loss. In vivo syngeneic and patient-derived xenograft models with both inducible MAT2A knockdown or methionine restricted diets showed extended survival. These results suggest novel interactions between methionine metabolism and the epigenome of H3K27M gliomas and provide evidence that MAT2A, presents exploitable therapeutic vulnerabilities in histone mutant gliomas.

Living in an online world: Social media experiences of adolescents and young adults with cancer

BACKGROUND

Despite widespread use, little is known about how adolescents and young adults (AYA) with cancer use social media (SM). This research characterized use and self-reported SM experiences among AYA with cancer.

PROCEDURE

AYA, aged 12-26 years, receiving cancer care completed a mixed-methods survey regarding SM experiences. Clinical information was obtained from the electronic medical record. Data were analyzed with descriptive statistics, t tests, and qualitative content analysis.

RESULTS

Thirty-nine AYA with average age 16 (SD = 3.2) years participated. Most were Caucasian (92%) males (54%). Participants had leukemia/lymphoma (56%), solid tumors (33%), and brain tumors (10%). Nearly all (97%) used SM, with YouTube, Snapchat, and Instagram being the most popular. AYA self-reported lower SM use than their smartphone data indicated (2.8 hours/day, SD = 1.2 vs 3.4 hours/day, SD = 1.3; P < 0.001). Participants used SM to obtain information about their cancer (45%), post about cancer (47%), and read about others' cancer experience (50%). One-third made a friend with cancer through SM (32%). Qualitative results indicated that AYA had positive cancer-related SM experiences, including feelings of support (54%), community (27%), distraction (8%), and inspiration (8%). Most denied negative experiences (78%); however, 17% reported cyberbullying related to cancer.

CONCLUSIONS

AYA with cancer avidly use SM, noting it provides a sense of support and community. However, one-sixth reported cancer-related cyberbullying. AYA oncology providers have an opportunity to enhance positive and blunt negative SM interactions by addressing and guiding SM use in AYA patients.

Loss of MAT2A compromises methionine metabolism and represents a vulnerability in H3K27M mutant glioma by modulating the epigenome

Diffuse midline gliomas (DMGs) bearing driver mutations of histone 3 lysine 27 (H3K27M) are incurable brain tumors with unique epigenomes. Here, we generated a syngeneic H3K27M mouse model to study the amino acid metabolic dependencies of these tumors. H3K27M mutant cells were highly dependent on methionine. Interrogating the methionine cycle dependency through a short-interfering RNA screen identified the enzyme methionine adenosyltransferase 2A (MAT2A) as a critical vulnerability in these tumors. This vulnerability was not mediated through the canonical mechanism of MTAP deletion; instead, DMG cells have lower levels of MAT2A protein, which is mediated by negative feedback induced by the metabolite decarboxylated S-adenosyl methionine. Depletion of residual MAT2A induces global depletion of H3K36me3, a chromatin mark of transcriptional elongation perturbing oncogenic and developmental transcriptional programs. Moreover, methionine-restricted diets extended survival in multiple models of DMG in vivo. Collectively, our results suggest that MAT2A presents an exploitable therapeutic vulnerability in H3K27M gliomas.

Emerging indications for stereotactic laser interstitial thermal therapy in pediatric neurosurgery

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery.

Impact of respiratory viral panel testing on length of stay in pediatric cancer patients admitted with fever and neutropenia

BACKGROUND

Polymerase chain reaction (PCR) respiratory viral panel (RVP) testing is often used in evaluation of pediatric cancer patients with febrile neutropenia (FN), but correlation with adverse outcomes has not been well characterized.

PROCEDURE

A retrospective cohort of all children ages 0-21 years with cancer admitted to Children's Healthcare of Atlanta for FN from January 2013 to June 2016 was identified. Patient demographic and clinical variables such as age, RVP results, length of stay (LOS), and deaths were abstracted. Relationship between RVP testing and positivity and LOS, highest temperature (Tmax), hypotension and intensive care unit (ICU) admission were compared using Wilcoxon rank sums, chi-square, or Fisher's exact tests adjusting for age, sex, bacteremia, and diagnosis.

RESULTS

The 404 patients identified had 787 total FN admissions. RVPs were sent in 38% of admissions and were positive in 59%. Patients with RVPs sent were younger (median 5.5 vs 8.0 years, P < .0001) with higher Tmax (39.2° vs 39.1°, P = .016). The most common virus identified was rhinovirus/Enterovirus (61%). There were no significant differences in highest temperature or lowest blood pressure based on RVP positivity. Patients admitted to the ICU were more likely to have RVPs sent (odds ratio [OR] = 3.19, P < .002); however, neither having RVP testing nor RVP positivity were significantly associated with increased LOS or death. Coinfection with bacteremia and a respiratory virus was identified in 9.1% of patients.

CONCLUSIONS

These data raise the question of the utility of sending potentially costly RVP testing as RVP positivity during febrile neutropenia does not impact LOS, degree of hypotension, or ICU admission.

Improving long-term survival in diffuse intrinsic pontine glioma

INTRODUCTION

Diffuse intrinsic pontine glioma (DIPG) is an almost universally fatal pediatric brain cancer. There has been no improvement in event-free survival (EFS) or overall survival (OS) despite immense effort through a multitude of clinical trials to find a cure. Recently, there has been a surge in the knowledge of DIPG biology, including the discovery of a recurrent H3F3A mutation in over 80% of these tumors.

AREAS COVERED

The authors review the most recent approaches to diagnosis and treatment of DIPG including chemotherapy, biologics, surgical approaches, and immunotherapy.

EXPERT OPINION

The authors propose four main opportunities to improve long-term survival. First, patients should be enrolled in scientifically sound clinical trials that include molecularly profiling either via stereotactic biopsy or liquid biopsy. Second, clinical trials should include more innovative endpoints other than traditional EFS and OS such as MRI/PET imaging findings combined with surrogates of activity (e.g. serial liquid biopsies) to better ascertain biologically active treatments. Third, innovative clinical trial approaches are needed to help allow for the rapid development of combination therapies to be tested. Finally, effort should be concentrated on reversing the effects of the histone mutation, as this malfunctioning development program seems to be key to DIPG relentlessness.

Familial Cerebral Cavernous Malformation Syndrome with Concomitant Fourth Ventricular Ependymoma: True Association or Mere Coincidence?

Familial cerebral cavernous malformation syndromes are most commonly caused by mutations in one of three genes. The overlap of these genetic malformations with other acquired neoplastic lesions and congenital malformations is still under investigation. To the best of our knowledge, the concurrent occurrence of familial cavernous malformations and ependymoma has not been previously reported in the literature. Herein, we describe a patient with familial cerebral cavernous malformation syndrome and posterior fossa ependymoma. A 17-year-old asymptomatic male was referred to our outpatient neurosurgery clinic after genetic testing identified a familial KRIT1 (CCM1) mutation. The patient's sister had presented with a seizure disorder previously; multiple cavernous malformations were discovered, and a symptomatic large cavernous malformation required a craniotomy for resection. Two years later, she was diagnosed with follicular thyroid cancer due to HRAS (c.182A>G) mutation. The patient and his sister were found to have a novel germline KRIT1 disease-causing variant (c.1739deletion, p.ASN580Ilefs*2) and a variant of uncertain significance, potentially pathogenic (c.1988 A>G, p.Asn663Ser) in cis in CCM1 (KRIT1), of paternal inheritance. Due to the presence of genetic abnormalities, the patient underwent screening imaging of his neuraxis. Multiple cavernous malformations were identified, as was an incidental fourth ventricular mass. Resection of the fourth ventricular lesion was performed, and histopathological examination was consistent with ependymoma. We report a unique case of posterior fossa ependymoma in an individual with a familial cerebral cavernous malformation syndrome and a novel genetic abnormality in KRIT1. The association of these two findings may be valuable in determining a potential genetic association between the two pathologies and elucidating the pathogenesis of both cavernous malformations and ependymomas.

Successful treatment of a child with a prolactin secreting macroadenoma with temozolomide

Prolactinomas are a rare subset of brain tumors in pediatrics. We report a child with a prolactin secreting macroadenoma which was refractory to initial treatment with a dopamine antagonist. Given the location of her tumor she was ineligible for surgical resection. Temozolomide (200 mg/m2×5 days each month) was administered with a dramatic and prolonged response in tumor size, prolactin level, and symptoms, with no side effects from treatment. We demonstrate the benefit of temozolomide in the treatment of a pediatric patient with prolactinoma.

Splenectomy and spleen autotransplantation due to splenic cyst

Splenectomy is known to increase the risk of Overwhelming Postsplenectomy Infection (OPSI). Autotransplantation is one of the possibilities to preserve splenic functions. The authors performed spleen autotransplantations in two cases after the splenectomy of cystigerous spleens. Ten pieces from the intact spleens each sized 10 x 20 x 2 mm were implanted in between the plates of the great omentum according to Furka's spleen apron method. The function of the reimplanted splenic tissue was demonstrated by scintigraphic investigations.

An intervention for preventing alcohol use among inner-city middle school students

OBJECTIVE

To examine the effectiveness of a brief, school-based intervention for preventing alcohol use.

DESIGN AND SETTING

Randomized, control trial assigning inner-city public school students to an intervention program or a comparison program.

PARTICIPANTS

Sixth, seventh, and eighth grade students in Jacksonville, Fla (N=104).

INTERVENTIONS

Students assigned to the intervention program were given a self-instructional module and corresponding audiotape, a health consultation with a physician or nurse, and a follow-up consultation with a trained peer health model.

MAIN OUTCOME MEASURES

Alcohol consumption during the month after the intervention and students' assessments of the interventions were measured.

RESULTS

Students' t tests showed participants were more satisfied with physician or nurse consultations than with peer consultations or the self-instructional module and audiotapes (P=.05). Analysis of covariance tests showed significant main effects for 30-day quantity of alcohol use (F=5.15, P=.02), with intervention students reporting less alcohol consumption at follow-up than comparison students, and for 30-day frequency of alcohol use (F=5.92,P=.01) with intervention students again showing less frequent use at follow-up.

CONCLUSIONS

A multicomponent, school-based intervention using print and audiotape media, brief physician or nurse consultations, and follow-up peer contacts holds promise in altering short-term alcohol use and selected behavioral factors among inner-city youth.

Factors associated with the stages of alcohol use among inner city school youth

This study explored stages of alcohol acquisition and risk-factors associated with stages based on the Multi-Component Motivational Stages model. Two hundred fifty-four sixth-eighth grade students from an urban school completed a confidential questionnaire. Most students were in a precontemplation stage (86%), preparation stage (6%), or action stage (5%) for alcohol use. Significant differences were found across stage status on 11 of 22 risk factors. Discriminant analysis results indicated alcohol use, perceived prevalence of alcohol consumption, and intentions to drink in the future successfully discriminated youth in action and preparation from those in precontemplation and contemplation stages. Meanwhile, tobacco use discriminated students in preparation and action stages. Multiple regression analysis showed alcohol use was the most powerful predictor of acquisition stage status, followed by intentions, influenceability, and perceived severity of alcohol use. Implications for school-aged youth alcohol use prevention are discussed.