Abstract
Colorectal cancer (CRC) is a lethal and common malignancy worldwide. Non‑coding (nc)RNAs have been shown to modulate tumor progression in several types of cancer. The present study aimed to investigate the role of hsa_circ_0000212 in CRC, as a sponge of microRNA (miR)‑491. The expression levels of miR‑491 and forkhead box P4 (FOXP4) were analyzed using data from The Cancer Genome Atlas. The association between miR‑491 and FOXP4 and the clinicopathological characteristics were also analyzed. A novel circular (circ)RNA, hsa_circ_0000212, was found to sponge miR‑491 based on bioinformatics analysis. The potential binding site between miR‑491 and FOXP4 or circ‑0000212 was validated using luciferase and RNA immunoprecipitation assays. The expression levels and distribution of circ‑0000212 was also determined. Cell Counting Kit‑8 and colony formation assays were performed to determine the role of miR‑491 or circ‑0000212 on the proliferation of the CRC cells. Decreased miR‑491 or increased FOXP4 expression levels were associated with the pathological stage in patients with CRC. In addition, miR‑491 inhibited cell proliferation by targeting FOXP4. circ‑0000212 was increased in CRC tissues and was predominantly localized in the cytoplasm. Furthermore, circ‑0000212 augmented viability of the CRC cells by sponging miR‑491 and modulating FOXP4. In conclusion, circ‑0000212 may serve as a novel tumor‑promoter and drug target in CRC.