Downregulation of ESRP2 Promotes Breast Cancer Cell Migration by Activating EMT Transcription Program Through Modulation of ENAH Variable Splicing

Epithelial splicing regulatory protein 2 (ESRP2) is a splicing regulator specific to epithelial cell types. Multiple studies have found that its expression is abnormal in various tumors, influencing their occurrence, development, or prognosis. Our previous research indicated that down-regulating ESRP2 can suppress the proliferation of breast cancer (BC) cells, specifically the MCF-7 line. To delve deeper into the role of ESRP2 in BC cells, we investigated its impact on the migration of BC cells in vitro and the underlying molecular mechanisms. The outcomes of the in vitro scratch assay and Transwell assay initially confirmed that ESRP2 hinders the migration of both MCF-7 and MDA-MB-231 cells, and that reducing ESRP2 expression enhances their migratory capacity. We demonstrated that the down-regulation of ESRP2 can boost the migration ability of MCF-7 cells, and increase the mRNA expression of epithelial-mesenchymal transition (EMT) transcription factor ZEB2 and related markers N-cadherin and Vimentin. This suggests that ESRP2 plays a potential regulatory role in inhibiting EMT transcription program. Additionally, results from RNA sequencing and agarose electrophoresis gel experiments predict that down-regulating ESRP2 may promote exon skipping of the ENAH gene by modulating the alternative splicing of genes associated with cell migration, driving the shift of MCF-7 cells from an epithelial to a mesenchymal phenotype. Our research reveals a novel mechanism by which ESRP2 affects BC metastasis through post-transcriptional regulation. ESRP2 may present as a promising biomarker in combating BC cell migration by targeting EMT.