Genome-wide analysis of long non-coding RNA expression profile in lung adenocarcinoma compared to spinal metastasis

BACKGROUND: Long non-coding RNAs (lncRNAs) play important roles in tumor metastasis. The aim of the present study was to investigate their expression profile and potential functions in spinal metastasis (SM) of lung adenocarcinoma. METHODS: We conducted lncRNA and mRNA expression in lung adenocarcinoma and its SM tissue using microarray analysis. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) revealed 10 differentially expressed lncRNAs. Gene ontology and pathway analysis were performed to test the gene effect. Possible target genes of lncRNAs were predicted based on precise algorithms. RESULTS: Microarray analysis found many significantly differentially expressed lncRNAs and mRNAs in lung adenocarcinoma compared with SM. qRT-PCR results aligned with those of the microarray analysis. The expression level of 10 lncRNAs showed the same trend (P<0.05). Biologic pathways known to be involved in cancer were identified among the differentially expressed mRNAs; these include cell adhesion molecules (related to 42 genes), focal adhesion (related to 31 genes), cytokine-cytokine receptor interaction (related to 48 genes), and extracellular matrix-receptor interaction (related to 23 genes). About 9,458 lncRNAs were found to have cis- or trans-genes. A total of 2,317 cis target genes were discovered to be abnormally expressed and could be regulated by lncRNAs in SM of lung adenocarcinoma. CONCLUSIONS: Our results offer a genome-wide differential expression of lncRNA in lung adenocarcinoma and SM, as well as laying the foundation for further investigations of lncRNAs correlated with lung adenocarcinoma metastasis.