According to United Nations reports, from 1992 to 2007 the number of undernourished people in the world grew by 80 million. In 2008, that number grew by an additional 40 million, bringing the total ...number of undernourished to 963 million people, or nearly one in every six people on the planet. While the US does provide the majority of global food aid, it does so very inefficiently and often ineffectively. The US spends too much of its foreign food aid budget procuring its food and transportation, and often the food aid arrives too late to be entirely effective. Having an effective and efficient US food aid policy is important for the US Government's image in the world, for its national security, and, most importantly, for saving lives. Congress is beginning to recognize the inefficiencies of US foreign food aid efforts. Pres Obama also has made notable public statements conveying a desire to reform the food aid procurement process.
Abstract
Atypical teratoid rhabdoid tumors (ATRT) are aggressive, malignant tumors of the central nervous system (CNS) that develop due to a loss-of-function mutation in the SMARCB1 gene. Rhabdoid ...tumor predisposition syndrome (RTPS) is characterized by familial cases as a result of pathogenic germline variants of this gene and an increased risk of developing ATRT within the first 2 years of life, which carries a poor prognosis. Genetic penetrance is incomplete with variable expressivity but the patient's age at time of diagnosis remains the most significant indicator of survival. We present a case of RTPS in a sibship born to unaffected parents, one of which was a carrier. The first sibling was diagnosed at 8 months of age after presenting with vomiting, developmental regression, and CN VI palsy for 3 months. Imaging revealed a posterior fossa mass, acquired obstructive hydrocephalus, and spinal metastasis. Four years later, her 3-month-old sister was brought in for evaluation due to vomiting, irritability, and macrocephaly for 2 months, along with a new vertical gaze palsy. Imaging findings also showed a posterior fossa mass and acquired obstructive hydrocephalus but without metastasis. Both siblings underwent craniotomy with subtotal tumor resection and ventriculoperitoneal shunt placement. Chemotherapy was promptly initiated but despite active treatment, they had rapid disease progression and ultimately passed away. Whole exome sequencing of both patients revealed an in-frame deletion involving the SNF5 homology domain of SMARCB1, with consistent findings on whole transcriptome sequencing, and evidence of loss of a single copy of chromosome 22. In this case report, we present a family faced with the devastating outcomes of RTPS and emphasize the importance of genetic testing and counseling for these families after diagnosis in the first child. Families should also be streamlined to a fertility specialist prior to subsequent pregnancies as an opportunity for familial screening.
Abstract
2-hydroxyoleic acid (2OHOA) is the first potential anti-cancer drug to act by modification of cell membrane lipid content. Through its unique mechanism, 2OHOA targets the membrane lipid ...composition and organization of cancer cells, altering downstream signaling cascades that promote tumor cell proliferation. Cancer cells demonstrate an abnormal membrane lipid microdomain phenotype rich in phosphatidylethanolamine (PE) and phosphatidylcholine (PC) and relatively sphingomyelin-poor when compared to non-malignant cells. Through its direct activity on sphingomyelin synthase 1, 2OHOA is able to alter the lipid membrane composition of cancer cells and restore the membrane to a normal sphingomyelin-rich phenotype. Ras is only able to propagate its signal cascade when located near the cell membrane and demonstrates an affinity for PE/PC microdomains. 2OHOA exposure results in replacement of PC and PE domains with sphingomyelin, thereby displacing Ras from the cell membrane to the cytoplasm where it is inert. Thus through normalization of the lipid membrane composition, 2OHOA is able to effectively downregulate the Ras signaling cascade, resulting in decreased tumor cell proliferation. A European phase I/IIa trial of 2OHOA in adult patients with high-grade glioma and other advanced solid tumors has recently been completed. The results are promising with five refractory malignant glioma patients demonstrating objective clinical benefit by RANO criteria for six or more months, including one glioblastoma patient with a sustained partial response (93% regression from baseline) of the primary lesion for over thirty-three months of therapy. The drug has been very well-tolerated in adult patients with minimal toxicity. A European phase IIb trial for adult patients with newly diagnosed high-grade glioma combining 2OHOA with standard therapy (radiotherapy and temozolomide) is being planned. A pediatric phase I trial of 2OHOA for children with high-grade glioma and other advanced solid tumors is due to open in the United States in 2018.
Introduction: Polyamines (PAs) are cationic metabolites that enhance pro-tumorigenic cellular processes including the stimulation of cell division and proliferation, pro-survival gene expression, DNA ...and protein synthesis, regulation of apoptosis, oxidative stress and angiogenesis. Spermidine is a particularly important polyamine because it acts as an essential substrate of hypusine biosynthesis. Hypusination is required for the post-transcriptional activation of eukaryotic initiation factor 5A (eIF5A) which is critical to cell growth and protein synthesis. Spermidine production is highly regulated through the rate-limiting enzyme ornithine decarboxylase (ODC). Polyamines and eIF5A have been shown to be critical growth promoters in various pediatric cancers. Thus, targeted inhibition of ODC has therapeutic potential for this unique group of currently incurable pediatric malignancies.
The anti-protozoan drug α-difluoromethylornithine (DFMO) is a suicide inhibitor of ODC and its effect may be potentiated by GC7 and Aurothioglucose. Previous mechanism based studies indicate that DFMO effectively reduces polyamine levels in neuroblastoma (NB) and provides rationale for ongoing Phase I and II clinical trials. To our knowledge, the effects of DFMO, GC7 and aurothioglucose have not yet been tested in pediatric leukemias. In this report, we evaluate the effectiveness of these therapeutic agents as a novel treatment of refractory hematological malignancies in the pediatric population.
Methods: The recently published TARGET 2018 dataset was analyzed to determine the relationship between ODC expression and patient survival. Demographic data from this study was used to identify patients populations who may benefit from an ODC targeted therapy. Western blot analyses were then used to screen a comprehensive panel of pediatric cancer cell lines for ODC expression. Infant and pediatric leukemia cell lines were selected to represent the various subtypes including AML (TIB202, KASUMI) as well as B ALL (SUP-B15, MV411, RS4-11, CCRF-SB ) and T ALL (CEM/C1, MOLT-3). These cells were derived from children with relapsed disease and have varying degrees of resistance to conventional chemotherapy. Drug combination studies were used to define drug candidates having potential synergistic activity when combined with DFMO.
Results: A Kaplan-Meier evaluation determined that high expression of ODC was associated with significantly lower patient survival and this finding was confirmed via cox regression analysis. The demographic analysis determined that females were significantly overrepresented in the high expression group whereas no variation was seen between race and ethnicity groups. Furthermore, a correlation was observed between high expression of eIF5A and younger diagnosis, indicating that ODC targeted therapy may be more effective in infant populations. DFMO-induced cytotoxicity was detected in many of the tumor cells including infant AML (TIB202) at an approximate physiologically achievable IC50 value of 200 uM. This was representative of values previously published for neuroblastoma. In infant AML, a western blot analysis determined that DFMO increased the abundance of cleaved PARP, cleaved caspase 3 and cleaved caspase 7 which serve as mechanistic markers of apoptosis. Probing for caspase 8 and caspase 9 showed no difference between treated cells and control. A combination screen of over 80 biologically active compounds was conducted to identify potential synergistic treatment partners of DFMO where GC7 and aurothioglucose (AuTG) ranked among the most promising. Further experimentation determined that doses of GC7 and AuTG, which were not effective as a singular treatment, were able to enhance the ability of DFMO to kill tumor cells.
Discussion: The preclinical studies discussed here offer the first proof-of-concept data on a novel treatment approach for refractory leukemia in children. We provide mechanistic evidence to show the ability of DFMO to effectively kill polyamine-dependent tumor cells at physiologically attainable concentrations. In addition, effective drug combinations have been identified to further enhance their clinical utility. Our findings provide key preclinical information on the utility of these drugs as treatment for refractory hematological malignancies in the pediatric population.
No relevant conflicts of interest to declare.
Abstract BACKGROUND CPC are childhood cancers in which the loss of TP53 function defines unfavorable disease. CPC-free survival rates have remained poor in patients with TP53 mutations and recent ...data revealed CPC-free survival of 29% with a non-marrow-ablative chemotherapy strategy. Previously reported results of the “Head Start” (HS) HDCT approach were limited by small patient numbers and incomplete TP53 mutation data. Consequently, the role of HDCT in TP53-mutated CPC remains unclear. METHODS We have analyzed data on TP53 status, CPC-free survival and second cancers from the largest cohort of patients who received initial therapy with the intent of undergoing HDCT. RESULTS Twenty-seven children with CPC received HS-like induction chemotherapy and 23 completed HDCT consolidation. Somatic or germline TP53 mutations were identified in 17 patients, 4 exhibited TP53 wild type (TP53wt); TP53 status remained untested in 6. Five-year CPC-free survival was 66% for patients with TP53 germline mutations (n=12), 40% for those with somatic tumor TP53 mutations (n=5) and 50% with confirmed TP53wt (n=4). Among patients with germline TP53 mutations, only 4/12 experienced CPC recurrences, 4 died from secondary cancers and 4 are currently alive. The 5-year CPC-free survival for 23 patients who underwent HDCT was 52%. All six survivors with TP53 mutations had undergone HDCT, and 5/6 avoided irradiation. Eight/12 patients with TP53 germline mutations and Li-Fraumeni Syndrome (LFS) developed second malignancies, including 6 patients in HDCT group and the remaining 2 patients who did not undergo consolidative HDCT. CONCLUSIONS Our data indicate that HDCT consolidation is associated with improved CPC-free survival compared with historical reports in children with TP53 mutated CPC. The ultimate development of second cancers affects outcomes for those with LFS, irrespective of HDCT treatment. These data justify the inclusion of HDCT in the prospective international trial under development for young children with newly diagnosed TP53 mutated CPC.
Abstract Embryonal tumors with multilayered rosettes (ETMR) are aggressive central nervous system neoplasms with unfavorable prognosis, exhibiting rapid disease progression and frequent ...post-therapeutic relapse. The rarity of ETMR necessitates global collaboration to advance therapies. Radiotherapy (RT) has been associated with improved survival outcomes in ETMR with case series revealing that nearly half of ETMR patients treated without RT relapse within six months of diagnosis. However, RT is often withheld due to young patient age and neurodevelopmental considerations. This high-rate of on-treatment relapse is unique to ETMR and suggests that radiation-sparing regimens may be suboptimal. PNOC031 is an international collaboration, establishing a global clinical trial to innovate and improve therapeutic interventions for children with ETMR. Eligible patients with newly-diagnosed ETMR are stratified into three cohorts: Cohort 1 - gross total resection/RT-eligible patients to receive early focal radiotherapy (RT); Cohort 2 – gross total resection/not RT-eligible to receive high-dose chemotherapy with autologous stem cell rescue; and Cohort 3 – less than gross total resection or with metastatic disease to receive RT or high-dose chemotherapy per RT eligibility, based on age and tumor location. Cohort 1 will test the hypothesis if early RT improves outcomes in a pilot cohort of 20 patients. Patients will receive six weeks of induction chemotherapy, followed by focal irradiation and an additional six weeks of chemotherapy. Six-month progression-free survival will be assessed to determine the impact of radiotherapy on the rate of early relapse. Cohorts 2 and 3 will allow collection of uniform prospective clinical data using a common treatment backbone, to inform future clinical trial design for ETMR. Incorporating a myriad of correlative studies, including next-generation sequencing, cerebrospinal fluid analyses, microbiome profiles, and evaluations of social determinants of health alongside cognitive outcomes, will enhance comprehensive understanding of clinical responses and advance therapeutic options for this high risk disease.
Long-term survival in high-risk neuroblastoma (HRNB) is approximately 50%, with mortality primarily driven by relapse. Eflornithine (DFMO) to reduce risk of relapse after completion of immunotherapy ...was investigated previously in a single-arm, phase II study (NMTRC003B; ClinicalTrials.gov identifier: NCT02395666) that suggested improved event-free survival (EFS) and overall survival (OS) compared with historical rates in a phase III trial (Children Oncology Group ANBL0032; ClinicalTrials.gov identifier: NCT00026312). Using patient-level data from ANBL0032 as an external control, we present new analyses to further evaluate DFMO as HRNB postimmunotherapy maintenance.
NMTRC003B (2012-2016) enrolled patients with HRNB (N = 141) after standard up-front or refractory/relapse treatment who received up to 2 years of continuous treatment with oral DFMO (750 ± 250 mg/m
twice a day). ANBL0032 (2001-2015) enrolled patients with HRNB postconsolidation, 1,328 of whom were assigned to dinutuximab (ch.14.18) treatment. Selection rules identified 92 NMTRC003B patients who participated in (n = 87) or received up-front treatment consistent with (n = 5) ANBL0032 (the DFMO/treated group) and 852 patients from ANBL0032 who could have been eligible for NMTRC003B after immunotherapy, but did not enroll (the NO-DFMO/control group). The median follow-up time for DFMO/treated patients was 6.1 years (IQR, 5.2-7.2) versus 5.0 years (IQR, 3.5-7.0) for NO-DFMO/control patients. Kaplan-Meier and Cox regression compared EFS and OS for overall groups, 3:1 (NO-DFMO:DFMO) propensity score-matched cohorts balanced on 11 baseline demographic and disease characteristics with exact matching on
, and additional sensitivity analyses.
DFMO after completion of immunotherapy was associated with improved EFS (hazard ratio HR, 0.50 95% CI, 0.29 to 0.84;
= .008) and OS (HR, 0.38 95% CI, 0.19 to 0.76;
= .007). The results were confirmed with propensity score-matched cohorts and sensitivity analyses.
The externally controlled analyses presented show a relapse risk reduction in patients with HRNB treated with postimmunotherapy DFMO.
Placental growth factor (PlGF) and its receptor neuropilin 1 are elevated in malignant embryonal tumors and mediate tumor progression by promoting cell proliferation, survival, and metastasis. TB-403 ...is a blocking monoclonal antibody against PlGF that inhibits tumor growth and increases survival in orthotopic medulloblastoma models.
We conducted a phase I, open-label, multicenter, dose-escalation study of TB-403 in pediatric subjects with relapsed or refractory cancers. The study involved four dose levels (20 mg/kg, 50 mg/kg, 100 mg/kg, 175 mg/kg) using a 3 + 3 dose-escalation scheme. Subjects received two doses of TB-403 (days 1 and 15) per cycle. After cycle 1, temozolomide or etoposide could be added. The primary objective was to determine the maximum tolerated dose (MTD) of TB-403 monotherapy during a dose-limiting toxicity assessment period. The secondary and exploratory objectives included efficacy, drug pharmacokinetics, and detection of pharmacodynamic biomarkers.
Fifteen subjects were treated in four dose levels. All subjects received two doses of TB-403 in cycle 1. Five serious treatment-emergent adverse events were reported in 3 subjects, but MTD was not reached. While no complete nor partial responses were observed, 7 of 11 relapsed subjects with medulloblastoma experienced stable disease, which persisted for more than 100 days in 4 of 7 subjects.
TB-403 was safe and well tolerated at all dose levels. No MTD was reached. The results look encouraging and therefore warrant further evaluation of efficacy in pediatric subjects with medulloblastoma.
Abstract
INTRODUCTION: Elevated levels of LIN28A expression in AT/RT samples provide the rationale to search for agents that may interfere with cellular pathways regulated by this molecule. Ornithine ...decarboxylase (ODC) modulates eIF-5A through polyamines production and has been shown to directly influence the LIN28/Let-7 axis. The anti-protozoan drug α-difluoromethylornithine (DFMO) irreversibly inhibits ODC and its activity is potentiated by GC7 and Aurothioglucose (AuTG). METHODS: Bioinformatics: ATRT Pediatric Patient Dataset from Children’s Brain Tumour Tissue Consortium was evaluated (n=32). In-vitro studies: Expression levels of LIN28 and ODC in three CNS ATRT cell lines, BT12, BT16 and KCCF1, were examined by western blotting. Cells were treated with increasing concentrations of DFMO, GC7 and AuTG and viability was measured by alamar blue assay. RESULTS: mRNA expression profile of patients suggest strong evidence of co-expression between three proteins: LIN28A – ODC1: 0.37 Pearson Coefficient (p = 0.037), ODC1 – EIF5A: 0.35 Pearson Coefficient (p = 0.049) and LIN28A – EIF5A: 0.54 Pearson Coefficient (p = 0.001). Drug sensitivity studies indicated DFMO, GC7 and AuTG were cytotoxic in-vitro. IC50 values of DFMO for BT12, BT16 and KCCF1 were 80uM, 50uM and 80uM respectively. GC-7 was cytotoxic at IC50 of 115uM, 25uM and 25uM and AuTG displayed IC50 of 15uM, 42 uM and 50uM. Markers of apoptosis, including PARP cleavage, were present at 48 hours although kinetics varied between cell lines. Drug combination studies showed significant synergy between DMFO and GC7. DISCUSSION: Data from this study identified alterations in expression and activity of components in LIN28 mediated pathways in ATRT. Interference in the LIN28 pathway by the tested drugs leads to apoptosis at physiologically attainable concentrations. Therapeutic efficacy can be further enhanced by mechanistically validated drug combinations. We discuss in detail the implications of these findings with respect to the biology and novel therapeutics development for ATRT.
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