In vivo effects of rosiglitazone in a human neuroblastoma xenograft

Abstract

Background: Neuroblastoma (NB) is the most common extra-cranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. There is in vitro evidence that the peroxisome proliferator-activated receptor γ (PPARγ) might be a target for pharmacological intervention in NB. We have previously demonstrated that the PPARγ agonist rosiglitazone (RGZ) exerts strong anti-tumoural effects in the human NB cell line, SK-N-AS. The aim of this study was to evaluate whether RGZ maintains its anti-tumoural effects against SK-N-AS NB cells in vivo. Methods and results: For this purpose, tumour cells were subcutaneously implanted in nude mice, and RGZ (150 mg kg-1) was administered by gavage daily for 4 weeks. At the end of treatment, a significant tumour weight inhibition (70%) was observed in RGZ-treated mice compared with control mice. The inhibition of tumour growth was supported by a strong anti-angiogenic activity, as assessed by CD-31 immunostaining in tumour samples. The number of apoptotic cells, as determined by cleaved caspase-3 immunostaining, seemed lower in RGZ-treated animals at the end of the treatment period than in control mice, likely because of the large tumour size observed in the latter group. Conclusions To our knowledge, this is the first demonstration that RGZ effectively inhibits tumour growth in a human NB xenograft and our results suggest that PPARγ agonists may have a role in anti-tumoural strategies against NB. © 2010 Cancer Research UK All rights reserved.