MiRNA expression analysis of cancer-associated fibroblasts and normal fibroblasts in breast cancer

[Display omitted] ► MiRNAs expression profile of cancer-associated fibroblasts and normal fibroblasts derived from breast cancer tissue and its paired normal tissue was systemically analyzed by using miRNA-microarray. ► Three up-regulated miRNAs were found in CAFs: miR-221-5p, miR-31-3p, miR-221-3p. Eight miRNAs were down-regulated in CAFs: miR-205, miR-200b, miR-200c, miR-141, miR-101, miR-342-3p, let-7g, miR-26b. ► The predicted target genes of disregulated miRNAs are involved in a variety of signaling pathways, such as IL-6 and TGF-β pathways, associated with differentiation and function of CAF. ► The activation of IL-6 and TGF-β signaling pathways were proved to play a role in cell migration of CAFs. Cancer-associated fibroblasts (CAFs) promote tumorigenesis, growth, invasion and metastasis of cancer, whereas normal fibroblasts (NFs) are thought to suppress tumor progression. Little is known about miRNAs expression differences between CAFs and NFs or the patient-to-patient variability in miRNAs expression in breast cancer. We established primary cultures of CAFs and paired NFs from six resected breast tumor tissues that had not previously received radiotherapy or chemotherapy treatment and analyzed with miRNAs microarrays. The array data were analyzed using paired SAM t-test and filtered according to α and q values. Pathway analysis was conducted using DAVID v6.7. We identified 11 dysregulated miRNAs in CAFs: three were up-regulated (miR-221-5p, miR-31-3p, miR-221-3p), while eight were down-regulated (miR-205, miR-200b, miR-200c, miR-141, miR-101, miR-342-3p, let-7g, miR-26b). Their target genes are known to affect cell differentiation, adhesion, migration, proliferation, secretion and cell–cell interaction. By our knowledge it is firstly identify the expression profiles of miRNAs between CAFs and NFs and revealed their regulation on the associated signaling pathways.