Rapidly proliferating solid tumor cells are often dependent on glycolysis for ATP production even in normoxia (the Warburg effect), however it is not yet clear whether acute leukemias have a similarly increased dependence on aerobic glycolysis. We report that all leukemia subtypes (pre-B ALL, T-ALL and AML) demonstrated growth arrest and cell death when treated the novel glycolysis inhibitor 3-BrOP. Potentiated ATP depletion and pro-apoptotic effects were seen for 3-BrOP combinations with the cytochrome-C-reductase inhibitor antimycin A and the mTOR inhibitor rapamycin. These results reveal a potential role for glycolysis inhibition in acute leukemia subtypes and suggest potential combinations.

Summary Children with high-risk and recurrent neuroblastoma have poor survival rates, and novel therapies are needed. Many cancer cells have been found to preferentially employ the glycolytic pathway for energy generation, even in the presence of oxygen. 3-BrOP is a novel inhibitor of glycolysis, and has demonstrated efficacy against a wide range of tumor types. To determine whether human neuroblastoma cells are susceptible to glycolysis inhibition, we evaluated the role of 3-BrOP in neuroblastoma model systems. Neuroblastoma tumor cell lines demonstrated high rates of lactate accumulation and low rates of oxygen consumption, suggesting a potential susceptibility to inhibitors of glycolysis. In all ten human tested neuroblastoma tumor cell lines, 3-BrOP induced cell death via apoptosis in a dose and time dependent manner. Furthermore, 3-BrOP-induced depletion of ATP levels correlated with decreased neuroblastoma cell viability. In a mouse neuroblastoma xenograft model, glycolysis inhibition with 3-BrOP demonstrated significantly reduced final tumor weight. In neuroblastoma tumor cells, treatment with 3-BrOP induced mTOR activation, and the combination of 3-BrOP and mTOR inhibition with rapamycin demonstrated synergistic efficacy. Based on these results, neuroblastoma tumor cells are sensitive to treatment with inhibitors of glycolysis, and the demonstrated synergy with rapamycin suggests that the combination of glycolysis and mTOR inhibitors represents a novel therapeutic approach for neuroblastoma that warrants further investigation.

Objectives/Hypothesis: The purpose of this study is to develop consensus on key points that would support the use of systemic bevacizumab for the treatment of recurrent respiratory papillomatosis (RRP), and to provide preliminary guidance surrounding the use of this treatment modality.Study Design: Delphi method-based survey series. Methods: A multidisciplinary, multi-institutional panel of physicians with experience using systemic bevacizumab for the treatment of RRP was established. The Delphi method was used to identify and obtain consensus on characteristics associated with systemic bevacizumab use across five domains: 1) patient characteristics; 2) disease characteristics; 3) treating center characteristics; 4) prior treatment characteristics; and 5) prior work-up.Results: The international panel was composed of 70 experts from 12 countries, representing pediatric and adult otolaryngology, hematology/oncology, infectious diseases, pediatric surgery, family medicine, and epidemiology. A total of 189 items were identified, of which consensus was achieved on Patient Characteristics (9), Disease Characteristics (10), Treatment Center Characteristics ( 22), and Prior Workup Characteristics (18).Conclusion: This consensus statement provides a useful starting point for clinicians and centers hoping to offer systemic bevacizumab for RRP and may serve as a framework to assess the components of practices and centers currently using this therapy. We hope to provide a strategy to offer the treatment and also to provide a springboard for bevacizumab's use in combination with other RRP treatment protocols. Standardized delivery systems may facilitate research efforts and provide dosing regimens to help shape best-practice applications of systemic bevacizumab for patients with early-onset or less-severe disease phenotypes.