MicroRNA-377 Counteracts With Cancer Stem Cell Phenotypes and Epithelial Mesenchymal Transformation by Targeting ZEB2 in Colon Cancer

Dysregulated microRNAs (miRNAs) have been implicated in the pathogenic processes of colon cancer. Epithelial mesenchymal transition (EMT) promotes metastatic progression and cancer stem cells are closely involved in colon cancer proliferation and metastasis. Functional effects of miR-377 on colon cancer stem cell phenotypes and EMT were then determined in the present study. Firstly, reduced miR-377 was found in colon cancer tissues and cell lines. Results from flow cytometry, sphere formation and western blot assays showed that miR-377 knockdown increased number of ALDH+ cells and promoted sphere formation ability. Moreover, cell migration/invasion and EMT of colon cancer cells were suppressed by miR-377 over-expression. On the contrary, miR-377 mimics caused the reversed results. ZEB2 (zinc finger E box-binding homeobox 2) was then validated as a binding target of miR-377. ZEB2 over-expression reversed the inhibitory abilities of miR-377 on cancer stem cell phenotypes, EMT, migration and invasion. In conclusion, miR-377 regulates cancer stem cell phenotypes and EMT in colon cancer cells via regulation of ZEB2, suggesting a new therapeutic strategy for colon cancer treatment.