Differential Expression Profiles of the Transcriptome in Breast Cancer Cell Lines Revealed by Next Generation...

As MCF-7 and MDA-MB-231 cells are the typical cell lines of two clinical breast tumour subtypes, the aim of the present study was to elucidate the transcriptome differences between MCF-7 and MDA-MB-231 breast cancer cell lines.

The mRNA, miRNA (MicroRNA) and lncRNA (Long non-coding RNA) expression profiles were examined using NGS (next generation sequencing) instrument Illumina HiSeq-2500. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses were performed to identify the biological functions of differentially expressed coding RNAs. Subsequently, we constructed an mRNA-ncRNA (non-coding RNA) targeting regulatory network. Finally, we performed RT-qPCR (real-time quantitative PCR) to confirm the NGS results.

There are sharp distinctions of the coding and non-coding RNA profiles between MCF-7 and MDA-MB-231 cell lines. Among the mRNAs and ncRNAs with the most differential expression, SLPI, SOD2, miR-7, miR-143 and miR-145 were highly expressed in MCF-7 cells, while CD55, KRT17, miR-21, miR-10b, miR-9, NEAT1 and PICSAR were over-expressed in MDA-MB-231 cells. Differentially expressed mRNAs are primarily involved in biological processes of locomotion, biological adhesion, ECM-receptor interaction pathway and focal adhesion. In the targeting regulatory network of differentially expressed RNAs, mRNAs and miRNAs are primarily associated with tumour metastasis, but the functions of lncRNAs remain uncharacterized.

These results provide a basis for future studies of breast cancer metastasis and drug resistance.