CircRIP2 aggravates the deterioration of colorectal carcinoma by negatively regulating CBFB.

OBJECTIVE: This study aims to detect expression pattern and clinical significance of circRIP2 in colorectal carcinoma (CRC). In the meantime, the regulatory effect of circRIP2 on CRC cell functions is clarified. PATIENTS AND METHODS: Relative levels of circRIP2 in 45 cases of CRC tissues and paracancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Its clinical significance in predicting pathological manifestations of CRC was analyzed. In vitro regulation of circRIP2 on proliferative and migratory abilities of Sw620 and HCT-116 cells was assessed by cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) and transwell assay, respectively. Dual-Luciferase reporter assay and rescue experiments were conducted to reveal the interaction between circRIP2 and its target gene CBFB, as well as their co-regulation on CRC cell functions. At last, in vivo regulation of circRIP2 on CRC growth in nude mice implanted with HCT-116 cells was explored. RESULTS: CircRIP2 was upregulated in these samples of CRC tissues and cell lines. High level of circRIP2 predicted advanced staging, and high risk of distant metastasis of CRC. In vitro knockdown of circRIP2 weakened proliferative and migratory abilities in Sw620 and HCT-116 cells. CBFB was downregulated in CRC tissues, which was negatively regulated by circRIP2 as its target gene. The attenuated proliferative and migratory abilities in Sw620 and HCT-116 cells with circRIP2 knockdown were abolished by co-silence of circRIP2 and CBFB. Moreover, in vivo knockdown of circRIP2 slowed down CRC growth in nude mice, and upregulated positive expression of CBFB in xenografted CRC tissues. CONCLUSIONS: CircRIP2 is a potential indicator for predicting tumor staging and distant metastasis of CRC. It aggravates the deterioration of CRC through negatively regulating CBFB.