The knowledge regarding the importance of long non-coding RNAs (lncRNAs), a new class of genes, is very sparse in osteosarcoma. In the present study, we describe the expression profile of lncRNAs in osteosarcomas compared with paired adjacent non-cancerous tissue (n = 7) using microarray analysis. A total of 25,733 lncRNAs were identified in osteosarcoma; 1995 lncRNAs were consistently upregulated and 2226 lncRNAs were consistently under-regulated in all samples analyzed (≥2.0-fold, p < 0.05). We have validated three over-regulated and three under-regulated lncRNAs in patient samples (n = 7). The antisense transcript of SATB2 protein (SATB2-AS1) was identified as one of the upregulated lncRNAs. The SATB2-AS1 is a 3197-bp lncRNA on chromosome 2. This is the first report, where we have documented the increased expression of SATB2-AS1 in osteosarcoma patients and in human osteosarcoma cancer cell lines (U2OS, HOS, MG63). SATB2-AS1 expression was significantly higher in the metastatic tumors compared to non-metastatic tumors. In vitro gain and loss of function approaches demonstrated that SATB2-AS1 regulates cell cycle, cell proliferation, and cell growth. In addition, SATB2-AS1 affects the translational expression of SATB2 gene. Our data demonstrate that an antisense non-coding RNA regulates the expression of its sense gene, and increases the cell growth, therefore pointing the pivotal functions of SATB2-AS1 in osteosarcoma.
Keywords: Antisense; Cell Cycle; Cell proliferation; LncRNA; Metastasis; Osteosarcoma.