In this study, we aimed to investigate the molecular mechanism of Krüppel-like factor 7 (KLF7) in colorectal cancer (CRC) cell invasion and migration. The expression pattern of KLF7 in CRC tissues and the correlation between KLF7 expression and clinical symptoms of CRC were analyzed. CRC cell lines were transfected with si-KLF7, followed by qRT-PCR or western blot detection of KLF7, miR-139-5p, and tumor protein D52 (TPD52) expression, cell counting kit-8 (CCK-8) assay to detect cell viability, and transwell detection of invasion and migration. Chromatin immunoprecipitation (ChIP) analyzed the enrichment KLF7 in the miR-139-5p promoter. The dual-luciferase reporter assay verified the binding relationship between KLF7 and miR-139-5p, and between miR-139-5p and TPD52. In the subcutaneous tumorigenesis experiment, tumor growth was observed and ki67-positive expression was detected. KLF7 is abundantly expressed in CRC cells KLF7 silencing inhibits CRC cell viability, invasion, and migration. KLF7 represses miR-139-5p expression by binding to the miR-139-5p promoter. miR-139-5p targets TPD52 expression. miR-13-5p inhibition or TPD52 overexpression partially counteracted the effect of KLF7 silencing in CRC cells. KLF7 silencing suppresses tumor growth in vivo. In conclusion, KLF7 suppresses miR-139-5p expression by binding to the miR-139-5p promoter, thereby upregulating TPD52 expression and enhancing CRC cell invasion and migration.
Keywords: Colorectal cancer; KLF7; invasion; miR-139-5p; migration.