[Molecular characterization of osteosarcomas].

Osteosarcomas are rare with an estimated incidence of 5-6 cases per one million inhabitants per year. As the prognosis has not improved significantly over the last 30 years and more than 30 % of patients still die of the disease a better understanding of the molecular tumorigenesis is urgently needed to identify prognostic and predictive biomarkers as well as potential therapeutic targets. Using genome-wide SNP chip analyses we were able to detect a genetic signature enabling a prognostic prediction of patients already at the time of initial diagnosis. Furthermore, we found the microRNA cluster 17-92 to be constitutively overexpressed in osteosarcomas. The microRNAs included here are intermingled in a complex network of several oncogenes and tumor suppressors that have been described to be deregulated in osteosarcomas. Therefore, the microRNA cluster 17-92 could represent a central regulator in the development of osteosarcomas.