circLETM1 upregulates KRT80 via adsorbing miR-143-3p and promotes the progression of colorectal cancer

Background Emerging evidence has indicated that circular RNAs (circRNAs) play vital roles in colorectal cancer (CRC). CircRNA leucine zipper and EF-hand containing transmembrane protein 1 (circLETM1) have been found to be ectopic in CRC, but their role in CRC has not been studied yet. Objective This study aims to explore the roles of circLETM1 in CRC and the possible molecular mechanism. Result The results showed that circLETM1 was highly expressed in CRC cells, and was localized at the cytoplasm. Functional assays verified that overexpression of circLETM1 could facilitate, but circLETM1 downregulation could hamper proliferation, migration and invasion abilities of CRC cells. In addition, mechanism assays found that circLETM1 absorbed and reduced microRNA (miR)-143-3p expression to promote keratin 80 (KRT80). Rescue experiments proved that circLETM1 mediated CRC proliferation, migration and invasion through KRT80. Conclusion Taken together, our results suggested that circLETM1 promotes proliferation, migration and invasion through the miR-143-3p/KRT80 axis in CRC. Therefore, targeting circLETM1 may provide a novel option for CRC treatment.