Hsa_circ_0031288/hsa-miR-139-3p/Bcl-6 regulatory feedback circuit influences the invasion and migration of cervical cancer HeLa cells.

Circular RNA (circRNA) molecules contain microRNA (miRNA) response elements that are able to competitively bind miRNAs as well as function as miRNA sponges within cells, which can reduce miRNA inhibition of target genes, thereby increasing their expression. TargetScan and miRanda bioinformatic tools were used to analyze the binding sites between genes. The relative levels of gene expression in tissues and cells were verified using quantitative reverse transcription-polymerase chain reaction. Inhibition of cell proliferation was detected using a WST-8 method. Cell invasion ability and migration ability were assessed using a Transwell migration assay and a scratch assay, respectively. The binding of miRNA and circRNA was detected using an RNA pull-down assay. Bifluorescence reporter gene vectors were constructed to verify the binding of miRNA to messenger RNA. A tumor model of cervical cancer cell transplantation in mice was constructed to observe the effect of the genes on tumor growth. hsa_circ_0031288 and B-cell CLL/lymphoma 6 (Bcl-6) exhibited high expression in cervical cancer cells and tissue, while hsa-miR-139-3p exhibited low expression. Reducing hsa_circ_0031288 and Bcl-6 expression or increasing hsa-miR-139-3p expression significantly inhibited the migration, invasion, proliferation, and growth of xenograft and HeLa cells. hsa_circ_0031288 had a regulatory effect on hsa-miR-139-3p, and hsa-miR-139-3p targeted the 3' untranslated region of Bcl-6. Reducing hsa_circ_0031288 expression promoted hsa-miR-139-3p expression, while overexpressing miR-139-3p inhibited the transcription of Bcl-6. In the cervical cancer HeLa cell line, the hsa_circ_0031288/hsa-miR-139-3p/Bcl-6 regulatory axis affects cell migration and proliferation, and its mechanism may involve hsa_circ_0031288 acting as a sponge for hsa-miR-139-3p, thereby relieving the transcriptional inhibition of Bcl-6. This suggests an approach for elucidating the pathogenesis of cervical cancer while offering new intervention targets for cervical cancer treatment.