miR-17-5p Accelerates the Proliferation and Invasion of Colorectal Cancer via Regulating E2F1

miR-17-5p and E2F1 have been shown to have potential oncogenic effects in Colorectal Cancer (CRC) by bioinformatic approaches in our previous study. Building on these findings, we performed experimental validation and functional analysis of this miRNA and gene, which is critically important to CRC as diagnostics. This study considered the possible function of miR-17-5p and E2F1 in SW480 and SW620 cells. miR-17-5p mimic/inhibitor was transfected to SW620 cells to analyze epithelial-mesenchymal transition (EMT), cell proliferation, colony formation, and invasion for functional analysis. Furthermore, blood samples were gathered from CRC patients and healthy controls to compare miR-17-5p and E2F1 levels. Relative mRNA and protein levels were detected using RT-qPCR and ELISA, respectively. miR-17-5p was consistently upregulated in patients and cells compared to healthy controls and control cells. miR-17-5p stimulated the proliferation, colony formation, invasion, and EMT of SW620 cells. miR-17-5p also significantly induced the expression of E2F1; besides, miR-17-5p overexpression induced EMT with upregulation of ZEB-1, and downregulation of E-cadherin. E2F1 expression was also upregulated in CRC patients and cells and positively correlated with miR-17-5p expression level despite being a target gene. These results determined that miR-17-5p in CRC functions as an oncogenic miRNA, at least in part, by regulating E2F1 expression. They also may be able to act as novel noninvasive biomarkers for CRC detection.