Hsa_circ_0101050 Accelerates the Progression of Colon Cancer by Targeting the Mir-140–3 P/melk Axis

Background: Circular RNAs (circRNAs) are involved in the progression of colon cancer (CC). This study aimed to examine the role of a new circRNA circ_0101050 in CC. Methods: Dual-luciferase reporter and RNA immunoprecipitation analyses were performed to validate the target relationships among maternal embryonic leucine zipper kinase (MELK), microRNA (miR)-140-3 p, and circ_0101050. Expression levels were calculated using western blotting and/or quantitative reverse transcriptionpolymerase chain reaction (qRT-PCR). Western blotting was performed to evaluate the relative expression of Bcl2 and Bax proteins to determine cell death. Cell Counting Kit-8 (CCK-8) and colony formation assays were performed to determine the proliferative potential of CC cells. The migration rate of CC cells was evaluated using wound healing assays. Tumor formation tests were performed to determine the effect of circ_0101050 on tumor development in vivo. Results: Elevated levels of circ_0101050 and MELK were observed in CC. By inhibiting circ 0,101,050 or MELK, CC cell proliferation and migration were inhibited, but CC cell apoptosis was promoted. Silencing circ_0101050 also inhibited CC growth in vivo. We also found that miR-140-3 p was downregulated, which alleviated the repressive effects of circ_0101050 knockdown on proliferating and migrating CC cells, as well as the stimulating effect on apoptosis. In addition, the absence of MELK alleviated the effects of miR-140-3 p downregulation, which enhanced CC cell malignancy. Conclusions: Circ_0101050 exacerbates malignant phenotypes in CC by targeting the miR-140-3 p/MELK axis. These findings suggested that the circ_0101050/miR-140-3 p/MELK network may be a prospective target for CC treatment.