The European Network for Cancer Research in Children and Adolescents (ENCCA) provides an interaction platform for stakeholders in research and care of children with cancer. Among ENCCA objectives... Show moreThe European Network for Cancer Research in Children and Adolescents (ENCCA) provides an interaction platform for stakeholders in research and care of children with cancer. Among ENCCA objectives is the establishment of biology-based prioritization mechanisms for the selection of innovative targets, drugs, and prognostic markers for validation in clinical trials. Specifically for sarcomas, there is a burning need for novel treatment options, since current chemotherapeutic treatment protocols have met their limits. This is most obvious for metastatic Ewing sarcoma (ES), where long term survival rates are still below 20%. Despite significant progress in our understanding of ES biology, clinical translation of promising laboratory results has not yet taken place due to fragmentation of research and lack of an institutionalized discussion forum. To fill this gap, ENCCA assembled 30 European expert scientists and five North American opinion leaders in December 2011 to exchange thoughts and discuss the state of the art in ES research and latest results from the bench, and to propose biological studies and novel promising therapeutics for the upcoming European EWING2008 and EWING2012 clinical trials. Show less
Mackintosh, C.; Ordonez, J.L.; Garcia-Dominguez, D.J.; Sevillano, V.; Llombart-Bosch, A.; Szuhai, K.; ... ; Alava, E. de 2012
Chondrosarcomas are resistant to conventional chemo- and radiotherapy. A subset of chondrosarcomas arises secondarily in the benign tumour syndromes enchondromatosis (EC) and multiple... Show moreChondrosarcomas are resistant to conventional chemo- and radiotherapy. A subset of chondrosarcomas arises secondarily in the benign tumour syndromes enchondromatosis (EC) and multiple osteochondromas (MO), and prevention of tumour development would greatly improve prognosis. We therefore investigated the effect of selective COX-2 inhibition on chondrosarcoma growth. COX-2 expression was studied in central- and peripheral cartilaginous tumours. The effect of COX-2 inhibition was assessed in four high-grade chondrosarcoma cell lines using celecoxib and NS-398 treatment. COX-2 activity (prostaglandin E-2 (PGE(2)) ELISA) and cell viability were measured. The (prophylactic) effect of celecoxib on chondrosarcoma growth in vivo was studied for 8 weeks using a xenograft model of cell line CH2879 in immunoincompetent nude mice. High COX-2 protein expression was mainly found in solitary peripheral chondrosarcoma and in enchondromatosis-related central chondrosarcoma, which was confirmed by qPCR. After 72 h of celecoxib treatment, a significant decrease in cell viability was observed in three chondrosarcoma cell lines. in vivo, celecoxib initially slowed tumour growth in chondrosarcoma xenografts; however, after prolonged treatment relapsed tumour growth was observed. Tumour volume was negatively associated with celecoxib serum levels, and seemed smaller in the high-dose prophylactic treatment group. We confirmed the expression of COX-2 in 65% of chondrosarcomas, and COX-2 inhibition by celecoxib diminished cell viability in vitro. The initial response and the decrease in tumour volume with increased celecoxib serum levels in vivo supported a role for celecoxib, although relapsed tumour growth after 6 weeks was worrisome. Also the role of high-dose prophylactic celecoxib in preventing the development of benign and malignant cartilage tumours in EC and MO patients deserves further investigation. (C) 2009 Elsevier Ltd. All rights reserved. Show less
