Biologic and clinical features of childhood gamma delta T-ALL: identification of STAG2/LMO2 γδ T-ALL as an extremely high risk leukemia in the very young.

PURPOSE: Gamma delta T-cell receptor-positive acute lymphoblastic leukemia (γδ T-ALL) is a high-risk but poorly characterized disease. METHODS: We studied clinical features of 200 pediatric γδ T-ALL, and compared the prognosis of 93 cases to 1,067 protocol-matched non-γδ T-ALL. Genomic features were defined by transcriptome and genome sequencing. Experimental modeling was used to examine the mechanistic impacts of genomic alterations. Therapeutic vulnerabilities were identified by high throughput drug screening of cell lines and xenografts. RESULTS: γδ T-ALL in children under three was extremely high-risk with 5-year event-free survival (33% v. 70% [age 3-<10] and 73% [age ≥10], P =9.5 x 10 -5 ) and 5-year overall survival (49% v. 78% [age 3-<10] and 81% [age ≥10], P =0.002), differences not observed in non-γδ T-ALL. γδ T-ALL in this age group was enriched for genomic alterations activating LMO2 activation and inactivating STAG2 inactivation ( STAG2/LMO2 ). Mechanistically, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping resulting in deregulation of gene expression associated with T-cell differentiation. Drug screening showed resistance to prednisolone, consistent with clinical slow treatment response, but identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which was efficaciously targeted by Poly(ADP-ribose) polymerase (PARP) inhibition, with synergism with HDAC inhibitors. Ex-vivo drug screening on PDX cells validated the efficacy of PARP inhibitors as well as other potential targets including nelarabine. CONCLUSION: γδ T-ALL in children under the age of three is extremely high-risk and enriched for STAG2/LMO2 ALL. STAG2 loss perturbs chromatin conformation and differentiation, and STAG2/LMO2 ALL is sensitive to PARP inhibition. These data provide a diagnostic and therapeutic framework for pediatric γδ T-ALL. SUPPORT: The authors are supported by the American and Lebanese Syrian Associated Charities of St Jude Children's Research Hospital, NCI grants R35 CA197695, P50 CA021765 (C.G.M.), the Henry Schueler 41&9 Foundation (C.G.M.), and a St. Baldrick's Foundation Robert J. Arceci Innovation Award (C.G.M.), Gabriella Miller Kids First X01HD100702 (D.T.T and C.G.M.) and R03CA256550 (D.T.T. and C.G.M.), F32 5F32CA254140 (L.M.), and a Garwood Postdoctoral Fellowship of the Hematological Malignancies Program of the St Jude Children's Research Hospital Comprehensive Cancer Center (S.K.). This project was supported by the National Cancer Institute of the National Institutes of Health under the following award numbers: U10CA180820, UG1CA189859, U24CA114766, U10CA180899, U10CA180866 and U24CA196173. DISCLAIMER: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The funding agencies were not directly involved in the design of the study, gathering, analysis and interpretation of the data, writing of the manuscript, or decision to submit the manuscript for publication.

Quantification of Methotrexate in Human Serum Using Surface-Enhanced Raman Scattering-Toward Therapeutic Drug Monitoring.

Therapeutic drug monitoring (TDM) can improve clinical care when using drugs with pharmacokinetic variability and a narrow therapeutic window. Rapid, reliable, and easy-to-use detection methods are required in order to decrease the time of analysis and can also enable TDM in resource-limited settings or even at bedside. Monitoring methotrexate (MTX), an anticancer drug, is critical since it is needed to follow the drug clearance rate and decide how to administer the rescue drug, leucovorin (LV), in order to avoid toxicity and even death. We show that with the optimized nanopillar-assisted separation (NPAS) method using surface-enhanced Raman scattering, we were able to measure MTX in PBS and serum in the linear range of 5-150 µM and confirmed that MTX detection can be carried out even in the presence of LV. Additionally, when NPAS was combined with centrifugal filtration, a quantification limit of 2.1 µM for MTX in human serum sample was achieved. The developed detection method enables fast detection (10 min) and quantification of MTX from human serum (>90% accuracy). Furthermore, we show the potential of the developed method for TDM, when quantifying MTX from clinical samples, collected from patients who are undergoing high-dose MTX therapy.

Bovine Colostrum Against Chemotherapy-Induced Gastrointestinal Toxicity in Children With Acute Lymphoblastic Leukemia: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: The toxic effect of chemotherapy on the gastrointestinal tract may lead to mucositis and is associated with the pathogenesis of other treatment-related complications. We hypothesized that nutrition supplementation with bovine colostrum, rich in bioactive factors, would ameliorate gastrointestinal toxicity and reduce the incidence of fever and infectious complications during induction treatment for childhood acute lymphoblastic leukemia (ALL). METHODS: Children with newly diagnosed ALL were included in a 2-center, randomized, double-blind, placebo-controlled clinical trial. Patients were randomized to receive a daily colostrum or placebo supplement during 4 weeks of induction treatment. Data on fever, bacteremia, need for antibiotics, and mucosal toxicity were prospectively collected. (Trial registration: www.clinicaltrials.gov NCT01766804). RESULTS: Sixty-two patients were included. No differences were found for the primary outcome (number of days with fever). No difference was observed for neutropenic fever, intravenous antibiotics, or incidence of bacteremia. Peak severity of oral mucositis was significantly reduced by colostrum (7/29 patients, 24% mild; 6/29, 21% moderate; 1/29, 3% severe) compared with placebo (12/31, 39% mild; 1/31, 3% moderate; 7/31, 23% severe) (P = 0.02). Among patients receiving at least 1 dose of supplement (colostrum: n = 22; placebo: n = 30), the peak weekly self-reported oral mucositis score was overall significantly less severe in the colostrum group (P = 0.009). CONCLUSION: The use of prophylactic bovine colostrum showed no effect on fever, infectious morbidity, or inflammatory responses. Nevertheless, these data may suggest protective effects on the oral mucosa during induction therapy in childhood ALL, encouraging additional studies confirming these findings.

Extremely low-frequency magnetic fields and risk of childhood leukemia: A risk assessment by the ARIMMORA consortium.

Exposure to extremely low-frequency magnetic fields (ELF-MF) was evaluated in an International Agency for Research on Cancer (IARC) Monographs as "possibly carcinogenic to humans" in 2001, based on increased childhood leukemia risk observed in epidemiological studies. We conducted a hazard assessment using available scientific evidence published before March 2015, with inclusion of new research findings from the Advanced Research on Interaction Mechanisms of electroMagnetic exposures with Organisms for Risk Assessment (ARIMMORA) project. The IARC Monograph evaluation scheme was applied to hazard identification. In ARIMMORA for the first time, a transgenic mouse model was used to mimic the most common childhood leukemia: new pathogenic mechanisms were indicated, but more data are needed to draw definitive conclusions. Although experiments in different animal strains showed exposure-related decreases of CD8+ T-cells, a role in carcinogenesis must be further established. No direct damage of DNA by exposure was observed. Overall in the literature, there is limited evidence of carcinogenicity in humans and inadequate evidence of carcinogenicity in experimental animals, with only weak supporting evidence from mechanistic studies. New exposure data from ARIMMORA confirmed that if the association is nevertheless causal, up to 2% of childhood leukemias in Europe, as previously estimated, may be attributable to ELF-MF. In summary, ARIMMORA concludes that the relationship between ELF-MF and childhood leukemia remains consistent with possible carcinogenicity in humans. While this scientific uncertainty is dissatisfactory for science and public health, new mechanistic insight from ARIMMORA experiments points to future research that could provide a step-change in future assessments. Bioelectromagnetics. 37:183-189, 2016. © 2016 Wiley Periodicals, Inc.

[Beta-thalassemia major in children and adolescents in Denmark]. / beta-thalassaemia major hos børn og unge i Danmark.

INTRODUCTION: Beta-thalassemia major occurs with increasing frequency among Danish children as a result of immigration. The aim of the study was to estimate the occurrence of beta-thalassemia major in Denmark, analyse the treatment and organ functions, and identify areas for an improved treatment strategy. MATERIAL AND METHODS: During 1998-99 all Danish pediatric departments were contacted for identification of children aged 0-18 years with beta-thalassemia major. Blood transfusions and chelation therapy were registered, and for Eastern Denmark clinical, endocrine, cardiac, and serologic parameters were performed. RESULTS: Twenty-six children had beta-thalassemia major. Out of these, 20 received blood transfusions, and 17 patients were chelated. Eight patients were not chelated owing to previous bone marrow transplantation, treatment with hydroxyurea or ferritin < 2000 micrograms/l and young age. One patient had died. The body height was between 1.5 and -5.4 SDS (median -1.7) and the sitting height was -0.6 to -5.6 SDS (median -2.3). The bone age was delayed 1-5 years (median -2.5) in six out of ten examined patients, and puberty delayed in four out of five. A dilated left ventricle was documented in one out of eight patients examined. All patients were HIV and hepatitis C negative. For 75% of the children, the parents were related. DISCUSSION: Children and adolescents with beta-thalassemia major in Denmark experience major heterogenicity with regard to treatment and late effects. An earlier and more effective iron chelation therapy together with improved patient support may reduce growth disturbances and endocrine and cardiac late effects.