Analysis of the expression profile of serum exosomal lncRNA in breast cancer patients

BACKGROUND: Breast cancer (BC) is a common tumor that seriously affects women’s physical/mental health and even life. BC invasion and metastasis are still the main causes of mortality in BC patients. Exosomal long non-coding RNAs (exo-lncRNA) play an important role in cell communication and can help to understand better the physiological and pathological conditions that result from BC. This study investigates new potential targets and functions of the expression profiles of exo-lncRNAs in BC patients through high-throughput screening and bioinformatics. METHODS: Samples were collected from two BC patients and one healthy subject. The serum exosomal RNAs were subsequently purified, and a library was established for quality inspection and sequencing. The resultant data was compared with the reference data to obtain the differential expression of exo-lncRNAs, and predict the target genes. To obtain the final results, Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to annotate the function and pathway of the differentially expressed genes. RESULTS: After a comprehensive comparison of the BC patients and healthy subjects, we discovered five up-regulated exo-lncRNAs and six down-regulated exo-lncRNAs of interest. Combining our results with a literature review and screening, we found that VIM-AS1, SNHG8, and ELDR play a role in the progression of BC, with VIM-AS1 predicting 35 target miRNAs; SNHG8 predicting 12 target miRNAs, and ELDR predicting 24 target miRNAs. Target prediction considered that the target gene of VIM-AS1 was VIM and that the target gene of SNHG8 was PRSS12. GO enrichment analysis showed that VIM mainly played a role in cell processes, biological regulation, metabolic regulation, and molecular adhesion, while PRSS12 was enriched through cell metabolism, catalytic activity, and hydrolase activity. KEGG pathway enrichment results also indicated how the VIM protein functions in cancer development through the viral infection signaling pathway and miRNA signaling pathway. CONCLUSIONS: There is a significant difference in the expression profiles of serum exo-lncRNAs between BC patients and healthy individuals. This may be closely related to BC’s occurrence, development, and metastasis, and therefore provides a theoretical basis for more in-depth studies into exo-lncRNA.