mRNA expression profiles of primary high-grade central osteosarcoma are preserved in cell lines and xenografts
1 Department of Pathology, Leiden University Medical Center, Albinusdreef 2, 2300RC Leiden, the Netherlands
2 Department of Tumor Biology, the Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0310 Oslo, Norway
3 Department of Pathology, University Hospitals Leuven, Minderbroedersstraat 12, 3000 Leuven, Belgium
4 Department of Pathology, Valencia University, Av de Vicente Blasco Ibáñez 17, 46010 Valencia, Spain
5 Laboratory of Experimental Oncology Research, Istituto Ortopedico Rizzoli, Via G.C.Pupilli 1, 40136 Bologna, Italy
6 Norwegian Microarray Consortium, Institute for Molecular Bioscience, University of Oslo, 0316 Oslo, Norway
BMC Medical Genomics 2011, 4:66 doi:10.1186/1755-8794-4-66Published: 20 September 2011
Conventional high-grade osteosarcoma is a primary malignant bone tumor, which is most prevalent in adolescence. Survival rates of osteosarcoma patients have not improved significantly in the last 25 years. Aiming to increase this survival rate, a variety of model systems are used to study osteosarcomagenesis and to test new therapeutic agents. Such model systems are typically generated from an osteosarcoma primary tumor, but undergo many changes due to culturing or interactions with a different host species, which may result in differences in gene expression between primary tumor cells, and tumor cells from the model system. We aimed to investigate whether gene expression profiles of osteosarcoma cell lines and xenografts are still comparable to those of the primary tumor.
We performed genome-wide mRNA expression profiling on osteosarcoma biopsies (n = 76), cell lines (n = 13), and xenografts (n = 18). Osteosarcoma can be subdivided into several histological subtypes, of which osteoblastic, chondroblastic, and fibroblastic osteosarcoma are the most frequent ones. Using nearest shrunken centroids classification, we generated an expression signature that can predict the histological subtype of osteosarcoma biopsies.
The expression signature, which consisted of 24 probes encoding for 22 genes, predicted the histological subtype of osteosarcoma biopsies with a misclassification error of 15%. Histological subtypes of the two osteosarcoma model systems, i.e. osteosarcoma cell lines and xenografts, were predicted with similar misclassification error rates (15% and 11%, respectively).
Based on the preservation of mRNA expression profiles that are characteristic for the histological subtype we propose that these model systems are representative for the primary tumor from which they are derived.