ICAT Promotes Cervical Cancer Cell Proliferation, Invasion, Migration and Epithelial‑to‑mesenchymal Transition Through HPV16 E6, E7/ miR-23b-3p/ ICAT Axis

Background: Human papillomavirus (HPV) 16 plays a crucial role in cervical cancer (CC) development. Previous study reported that inhibitor of β-catenin and TCF (ICAT) is upregulated in CC and promotes cervical tumor progression. Herein, we aimed to investigate the underlying molecular mechanism that HPV16 regulates the expression of ICAT and promotes the CC development. Methods: The expressions of HPV 16 E6, E7 and ICAT were modulated by small interfering RNA and recombinant adenovirus, respectively. qRT-PCR was conducted to detect the mRNA expression of HPV 16 E6, E7, ICAT and miR-23b-3p in SiHa and CasKi cells. Bioinformatics analysis was utilized to predict the potential miRNAs that could bind to the ICAT 3′ untranslated region. Then, the dual luciferase reporter assay was used to confirm that. Cell proliferation ability was detected by CCK-8 assay. Wound healing and Transwell assays were used to observe migration and invasion abilities. Protein expressions were measured with western blot. Results: Results revealed that after knocking down of HPV16 E6, E7, the expression of ICAT decreased, but the expression of miR-23b-3p increased. Besides, miR-23b-3p negatively modulated ICAT expression in HPV16 positive CC cells. Dual luciferase assays confirmed that ICAT was a target gene of miR-23b-3p. Functional experiments showed that the overexpression of miR-23b-3p suppressed malignant behaviors of SiHa and CasKi cells, such as migration, invasion and EMT. Importantly, the overexpression of ICAT counteracted the suppressive effect of miR-23b-3p on HPV16 positive cervical cancer cell. Furthermore, after the knockdown of HPV16 E6 and E7, the inhibition of miR-23b-3p could increase the ICAT expression and rescue the siRNA HPV16 E6, E7-mediated suppressive impact on the aggressiveness of SiHa and CasKi cells.Conclusions: Our study demonstrates that HPV 16 E6, E7/miR-23b-3p/ ICAT axis plays an important role in HPV16 positive CC pathogenesis, which may serve as a promising therapy target for HPV 16-associated cervical cancer.