BackgroundThe overarching goal of this research was to identify the effect of miR-509-3-5p on colon cancer (CC) and its interaction with potential target gene GTSE1 in CC. MethodsThe miR-509-3-5p expression was ascertained after performing qRT-PCR analyses, and the ability of GTSE1 to influence this microRNA was detected after carrying out RNA pull-down assay. CCK-8 assay kit was first employed to determine the proliferation of the cells. To examine the migration and invasion level of HCT116 and SW480 cells, cell wound healing and transwell assay were later performed. After constructing luciferase reporter plasmids, luciferase reporter assay was used to confirm the impacts of miR-509-3-5p on GTSE1 in HCT116 and SW480 cells. ResultsWe found that miR-509-3-5p expression reduced in CC, and its overexpression inhibited the proliferation, migration and invasion of CC cells. We later discovered that miR-509-3-5p could target GTSE1 that was then proved to be an oncogene in CC. ConclusionOur study uncovered that miR-509-3-5p regulated CC malignancy by suppressing target gene GTSE1.