Breast cancer-derived exosomal lncRNA SNHG14 induces normal fibroblast activation to cancer-associated fibroblasts via the EBF1/FAM171A1 axis

Background Exosomes released from cancer cells can activate normal fibroblasts (NFs) into cancer-associated fibroblasts (CAFs), which promotes cancer development. Our study aims to explore the role and potential mechanisms of breast cancer exosomes-delivered long non- coding RNA (lncRNA) SNHG14 in regulating CAFs transformation. Methods Adjacent normal tissues, cancerous and serum specimens were gathered in breast cancer patients. Exosomes and NFs were separated from breast cancer cells (SKBR-3) and normal tissues of patients, respectively. Cell viability and migration were measured with CCK-8 and Transwell assays. CAFs markers, fibroblast activation protein (FAP) and a-smooth muscle actin (alpha-SMA) were detected for assessing CAFs activation. The interactions between molecules were evaluated using dual luciferase reporter assay, RNA immunoprecipitation and chromatin immunoprecipitation. Results SNHG14 and FAM171A1 were upregulated in breast cancer. Exosomes secreted by SKBR-3 cells induced NFs activation in CAFs, as indicated by upregulating CAFs marker levels and facilitated cell viability and migration. Exosomal SNHG14 silencing in SKBR-3 cells inhibited CAFs activation. SNHG14 positively regulated FAM171A1 expression through EBF1. FAM171A1 overexpression eliminated the inhibition effect of exosomal SNHG14 silencing in CAFs transformation. Conclusion Breast cancer-derived exosomal SNHG14 contributed to NFs transformation into CAFs by the EBF1/FAM171A1 axis.