miRNA551b-3p Activates an Oncostatin Signaling Module for the Progression of Triple-Negative Breast Cancer.

Genomic amplification of 3q26.2 locus leads to the increased expression of microRNA 551b-3p (miR551b-3p) in triple-negative breast cancer (TNBC). Our results demonstrated that the nuclear translocation of miR551b-3p activates the transcription of STAT3 oncogene. We further demonstrated that Importin-8 (IPO8) facilitates the translocation of miR551b-3p from the cytoplasm to the nucleus. As a consequence, miR551b upregulates the expression of Oncostatin M receptor (OSMR) and Interleukin-31 receptor (IL31RA) as well as their ligands Oncostatin-M (OSM) and Interleukin 31 (IL31) through STAT3 transcription factor for breast cancer growth and progression