Objective To investigate the expression of miR-92a in breast cancer tissues and whether it can influence the migration and invasion ability of breast cancer cells through kruppel-like factor 4 (KLF4). Methods ① The expressions of miR-92a and KLF4 mRNA in cancer tissues and adjacent tissues were detected by qRT-PCR in 122 breast cancer patients who were operated in our hospital from May 2017 to October 2019. ② The expression of miR-92a in MCF-7 breast cancer cells was up-regulated or knocked out. Cell survival rate was detected by MTT assay, cell migration ability was detected by scratch assay, cell invasion ability was detected by Transwell assay, and the relative expression levels of KLF4, E-cadherin (E-cad), and N-cadherin (N-cad) proteins were detected by Western blotting. ③ The targeting relationship between miR-92a and KLF4 was detected by dual luciferase reporter gene assay. Results ① The relative expression levels of miR-92a and KLF4 mRNA in cancer tissues were higher than those in adjacent tissues (P<0.05). ② The up-regulation of miR-92a expression had no effect on the survival rate of MCF-7 breast cancer cells, but the migration and invasion ability of cells were enhanced (P<0.05). The knockdown of miR-92a expression decreased the survival rate of MCF-7 breast cancer cells and the ability of cell migration and invasion (P<0.05). ③ The miR-92a and KLF4 had a direct targeting relationship, up-regulation of miR-92a expression increased the relative expression levels of KLF4 and N-cad proteins, while decreased the relative expression level of E-cad protein (P<0.05). After knockout of miR-92a expression, the relative expression levels of KLF4 and N-cad proteins were decreased, while the relative expression level of E-cad protein was increased (P<0.05). Conclusion The miR-92a is highly expressed in breast cancer cells, and knockout of miR-92a expression can inhibit KLF4 signaling pathway and reduce the migration and invasion ability of breast cancer cells.
MicroRNA-92a (miR-92a) is an evolutionarily highly conserved pathogenic microRNA that is a member of the microRNA-17-92 gene cluster and is involved in the regulation of biological activities such as cell proliferation, apoptosis and differentiation. Recent studies have revealed that disorders of miR-92a expression are associated with disease development and exert pathogenic effects mainly through the regulation of target genes or target proteins. The current research related to miR-92a is mainly focused on malignant tumors, and its high expression has been found to be associated with cancer cell malignancy and reduced sensitivity of tumors to radiotherapy. miR-92a targeting target genes or target proteins to cause disease and its relationship with radiotherapy has been a hot research topic in recent years. Based on this, This article reviews the latest research on miR-92a target gene or target protein pathogenesis and its impact on chemotherapy in order to provide targets for clinical disease treatment.