Identification of Moesin (MSN) as a Potential Therapeutic Target for Colorectal Cancer via the β-Catenin-RUNX2 Axis

Abstract

CRC is the second leading cause of cancer-related death. The complex mechanisms of metastatic CRC limit available therapeutic choice. Thus, identifying new CRC therapeutic targets is essential. Moesin (MSN), a member of the ezrin–radixin–moesin family, connects the cell membrane to the actin-based cytoskeleton and regulates cell morphology. We investigated the role of MSN in the progression of CRC. GENT2 and oncomine were used to study MSN expression and CRC patient outcomes. MSN-specific shRNAs or MSN-overexpressed plasmid were used to establish MSN-KD and MSN overexpressed cell lines, respectively. SRB, migration, wound healing, and flow cytometry were used to test cell survival and migration. Propidium iodide and annexin V stain were used to analyze the cell cycle and apoptosis. MSN expression was found to be higher in CRC tissues than in normal tissues. Higher MSN expression is associated with poor overall survival, disease-free survival, and relapse-free survival rates in CRC patients. MSN silencing inhibits cell proliferation, adhesion, migration, and invasion in vitro, whereas MSN overexpression accelerates cell proliferation, adhesion, migration, and invasion. RNA sequencing was used to investigate differentially expressed genes, and RUNX2 was discovered as a possible downstream target for MSN. In CRC patients, RUNX2 expression was significantly correlated with MSN expression. We also found that MSN silencing decreased cytoplasmic and nuclear β-catenin levels. Additionally, pharmacological inhibition of β-catenin in MSN-overexpressed cells led to a reduction of RUNX2, and activating β-catenin signaling by inhibiting GSK3β rescued the RUNX2 downregulation in MSN-KD cells. This confirms that MSN regulates RUNX2 expression via activation of β-catenin signaling. Finally, our result further determined that RUNX2 silencing reduced the ability of MSN overexpression cells to proliferate and migrate. MSN accelerated CRC progression via the β-catenin-RUNX2 axis. As a result, MSN holds the potential to become a new target for CRC treatment.