Comprehensive analysis of differentially expressed long noncoding RNAs, miRNAs and mRNAs in breast cancer brain metastasis.

Aim: To delineate the transcriptomic landscape and potential molecular mechanisms of breast cancer brain metastasis (BCBM). Materials & methods: Whole-transcriptome sequencing was performed to identify long noncoding RNA (lncRNA), miRNA and mRNA expression profiles associated with BCBM. Results: A total of 739 differentially expressed lncRNAs, 115 differentially expressed miRNAs and 5749 differentially expressed mRNAs were identified in 231-BR cells compared with MDA-MB-231 cells. Real-time quantitative PCR results revealed the expression levels of candidate molecules were consistent with their correspondence RNA-seq data. Protein-protein interaction analysis identified some hub genes associated with BCBM, such as PTBP1, NUP98 and HYOU1. LncRNA-miRNA-mRNA network highlighted a potential mechanism of BCBM in which lncRNA FIRRE and RP11-169F17.1 sponging hsa-miR-501-5p to regulate the expression of MMS19, PTBP1 and NUP98. Conclusion: This study provides a framework for better understanding molecular mechanisms of BCBM.