Objective To investigate the mechanism of hsa_circRNA_000596 (circ-596) in promoting invasion and metastasis of cervical cancer cells.

Methods The cervical squamous cell carcinoma (CSCC) tissue, normal cervical tissue adjacent to cancer and clinical data of 69 cases with CSCC were collected. RNA in situ hybridization (RISH) was used to detect the expression of circ-596 and analyze its association with clinical data of CSCC. The invasive ability of cervical cancer cells was detected by Transwell assay; the regulation of downstream target gene by circ-596 was detected by quantitative reverse transcriptase PCR (qRT-PCR). Dual luciferase reporting experiment was used to verify the regulation of miR-197-3p on the downstream target gene RNF146; the regulation of miR-197-3p/RNF146 by circ-596 and its effect on invasion ability were analyzed in rescue experiment.

Results Circ-596 was mainly positively expressed in CSCC tissues, and the positive expression rate was 63.77%(44/69), which was higher than 17.39% (12/69) in adjacent normal tissues (χ²=8.254, P=0.004). Circ-596 positive expression was closely correlated with tumor differentiation and lymph node metastasis (P < 0.05). The results of Transwell experiment showed that compared with the control cells, the number of cervical cancer cells with overexpression of circ-596 increased, and the number of cells with knockdown expression of circ-596 decreased (P < 0.05). Bioinformatics prediction results showed that miR-197-3p was the downstream target gene of circ-596, and RNF146 was the downstream target gene of miR-197-3p. The results of qRT-PCR showed that overexpression of circ-596 could down-regulate the expression of miR-197-3p, and down-expression of circ-596 could up-regulate the expression of miR-197-3p (P < 0.05). The results of dual luciferase reporter gene experiments showed that miR-197-3p bound to the 3'UTR of RNF146 gene, thereby inhibiting the relative activity of luciferase. Rescue experiment results showed that circ-596 could inhibit the expression of miR-197-3p, and thereby promoting the expression of RNF146, and enhancing the invasion ability of cervical cancer cells.

Conclusion Circ-596 is mainly positively expressed in CSCC tissues, and its positive expression is closely related to the degree of tumor differentiation and lymph node metastasis. Circ-596 promotes the expression of RNF146 by binding to miR-197-3p, thereby promoting the invasion and metastasis of cervical cancer cells.