N6-methyladenosine-modified microRNA-675 advances the development of gastrointestinal stromal tumors via inhibiting myosin phosphatase targeting protein 1

RNA N6-methyladenosine (m6A) modifications influence gastrointestinal stromal tumors (GISTs) development, but the detailed molecular mechanisms have not been fully studied. Here, microRNA-675 was found to be aberrantly elevated in cancerous tissues and cells of GISTs, compared to the corresponding normal counterparts, and GISTs patients with high-expressed microRNA-675 have worse outcomes. Additional experiments confirmed that silencing of microRNA-675 hindered cell division, mobility and tumorigenesis in vitro and in vivo, whereas triggered apoptotic cell death in GISTs cells. Furthermore, microRNA-675-ablation increased the expression levels of myosin phosphatase targeting protein 1 (MYPT1) to inactivate the tumor-initiating RhoA/NF2/YAP1 signal pathway, and downregulation of MYPT1 recovered the malignant phenotypes in microRNA-675-silenced GISTs cells. In addition, we evidenced that METTL3-mediated m6A modifications were essential for sustaining the stability of microRNA-675, and silencing of METTL3 restrained tumorigenesis of GISTs cells by regulating the microRNA-675/MYPT1 axis. To summarize, theMETTL3/m6A/microRNA-675/MYPT1 axis could be used as novel biomarkers for the diagnosis and treatment of GISTs.