Combination of metronomic cyclophosphamide and dietary intervention inhibits neuroblastoma growth in a CD1-nu mouse model

// Raphael Johannes Morscher 1, 4 , Sepideh Aminzadeh-Gohari 1 , Cornelia Hauser-Kronberger 2 , Rene Gunther Feichtinger 1 , Wolfgang Sperl 3 , Barbara Kofler 1 1 Laura Bassi Centre of Expertise-THERAPEP, Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria 2 Department of Pathology, Paracelsus Medical University, 5020 Salzburg, Austria 3 Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria 4 Division of Medical Genetics, Medical University Innsbruck, 6020 Innsbruck, Austria Correspondence to: Raphael Johannes Morscher, e-mail: raphael.morscher@pmu.ac.at Keywords: neuroblastoma, ketogenic diet, glucose, metronomic cyclophosphamide, anti-angiogenic Received: September 15, 2015 Accepted: February 05, 2016 Published: March 05, 2016 ABSTRACT Background: MYCN -amplification in high-grade Neuroblastoma (NB) tumors correlates with increased vascularization and therapy resistance. This study combines an anti-angiogenic approach with targeting NB metabolism for treatment. Methods and Results: Metronomic cyclophosphamide (MCP) monotherapy significantly inhibited NB growth and prolonged host survival. Growth inhibition was more pronounced in MYCN -amplified xenografts. Immunohistochemical evaluation of this subtype showed significant decrease in blood vessel density and intratumoral hemorrhage accompanied by blood vessel maturation and perivascular fibrosis. Up-regulation of VEGFA was not sufficient to compensate for the effects of the MCP regimen. Reduced Bcl-2 expression and increased caspase-3 cleavage were evident. In contrast non MYCN -amplified tumors developed resistance, which was accompanied by Bcl-2-up-regulation. Combining MCP with a ketogenic diet and/or calorie-restriction significantly enhanced the anti-tumor effect. Calorie-restricted ketogenic diet in combination with MCP resulted in tumor regression in all cases. Conclusions: Our data show efficacy of combining an anti-angiogenic cyclophosphamide dosing regimen with dietary intervention in a preclinical NB model. These findings might open a new front in NB treatment.