The MRTF-A/miR-155/SOX1 pathway mediates gastric cancer migration and invasion

Gastric cancer (GC) is the leading cause of death worldwide and is closely related to metastasis. MRTF-A is one of the most well-characterized genetic markers in cancer. However, the mechanism whereby MRTF-A mediate gastric cancer (GC) tumorigenesis is not fully clear. Increasing evidence has confirmed that miRNA dysregulation is involved in MRTF-A-mediated tumorigenesis, supporting their potential as therapeutic targets for cancer. Although miR-155 has been reported as an upregulated miRNA, the interplay between miR-155 and MRTF-A-mediated gastric cancer progression remain largely elusive.

Real-time PCR was performed to determine miR-155 expression after transfected with MRTF-A encoding plasmids and siRNA. Potential target genes were identified by Western blot and luciferase reporter assay. Chip assay was proved that MRTF-A binds in the promoter region of miR-155. Transwell assay and Scratch-healing migration assay was used to investigate the role of MRTF-A and SOX1 in gastric cancer cell migration and invasion.

MRTF-A can interact with the miR-155 promoter to promote histone acetylation and RNA polymerase II recruitment via the Wnt-β-catenin pathway. miR-155 promotes gastric cancer cell migration by suppressing SOX1 expressiom by targeting its 3'UTR in vitro and in vivo. MRTF-A inhibited the inhibitory effects of SOX1 on gastric cancer cell migration by promoting the express -ion of miR-155.

Our data therefore provide important and novel insights into how the MRTF-A/miR-155/SOX1 pathway mediates migration and invasion in GC.