Long noncoding RNAs (IncRNAs) are pervasively transcribed and have a critical role in genome regulation. Alterations in the expression of several IncRNAs have been observed in some types of cancers; however, the contributions of IncRNAs to osteosarcoma remain unknown. Here, we describe the expression profile of IncRNAs in osteosarcomas compared with paired adjacent noncancerous tissue using microarray analysis. In our study, 25,733 IncRNAs were expressed in osteosarcoma; 403 IncRNAs were consistently over-regulated and 798 IncRNAs were consistently under-regulated in all samples analyzed (>= 2.0-fold, p < 0.05). Quantitative real-time polymerase chain reaction (PCR) was used to validate six over-regulated and four under-regulated IncRNAs. Bioinformatic analysis (gene ontology analysis, pathway analysis and network analysis) was used for further research. Pathway analysis indicated that 32 pathways corresponded to under-regulated transcripts and that 34 pathways corresponded to over-regulated transcripts (p-value cut-off is 0.05). Our results are the first to reveal differentially expressed IncRNAs in osteosarcoma and suggest that IncRNAs may be novel candidate biomarkers for the diagnosis of osteosarcoma and potential targets for therapy. (C) 2013 Elsevier Inc. All rights reserved.