Circular RNA hsa_circ_000984 promotes colon cancer growth and metastasis by sponging miR-106b

Circular RNAs (circRNAs) as a novel type of noncoding RNAs (ncRNAs) are widely studied in the development of human various diseases, including cancer. Here, we found circular RNA hsa_circ_000984 encoded by the CDK6 gene was remarkably upregulated in the tissues of colorectal cancer (CRC) patients and in the CRC cell lines. Moreover, high expression level of hsa_circ_000984 was significantly associated with advanced colorectal cancer. Further analysis revealed that hsa_circ_000984 knockdown could inhibit cell proliferation, migration, invasion in vitro and tumor formation in vivo in CRC cell lines. Mechanically, we found that hsa_circ_000984 may act as a competing endogenous RNA (ceRNA) by competitively binding miR-106b and effectively upregulate the expression of CDK6, thereby inducing a series of malignant phenotypes of tumor cells. Taken together, these observations suggest that the hsa_circ_000984 could mediate the expression of gene CDK6 by acting as a ceRNA, which may contribute to a better understanding of between the regulatory miRNA network and CRC pathogenesis.