Hsa_circ_0119412 is a tumor promoter in hepatocellular carcinoma by inhibiting miR-526b-5p to upregulate STMN1

Hepatocellular carcinoma (HCC) is always deemed a deadly malignancy worldwide. Non-coding RNAs, including circRNAs, are becoming more widely recognized as essential regulators of the malignant development of HCC. Thus, we elaborated the regulating role of hsa_circ_0119412 in HCC advancement. The qRT-PCR was done to estimate the expressions of hsa_circ_0119412, miR-526b-5p, and Stathmin 1 (STMN1) in HCC (clinical samples and cell lines), and immunoblotting was used to detect STMN1 protein level in HCC cell lines. The stability of the circRNA was checked by processing with ribonuclease R. The proliferative potential of HCC cells was examined via the CCK-8 assay and the migratory potential by the wound healing assay. Immunoblotting was done to examine Bax and Bcl-2 (apoptosis-related proteins). Luciferase and RIP assays were employed to establish the direct interactions among miR-526b-5p and hsa_circ 0119412/STMN1. In vivo tumor growth was measured by doing a xenograft tumor experiment. In the tissues of HCC patients and cell lines derived from HCC cells, hsa_circ_0119412 was distinctly over-expressed. Knocking down hsa_circ_0119412 impeded proliferation and migration while inducing apoptosis in HCC cells. Moreover, silencing hsa_circ_0119412 diminished tumor weight and volume in vivo. Interestingly, miR-526b-5p inhibition partially restored the anti-tumor effects of silencing hsa_circ_0119412. STMN1 expression was also abundant in HCC, suggesting that it play a tumor-promoting role. Mechanistically, hsa_circ_0119412 sponged miR-526b-5p, resulting in STMN1 upregulation and thus facilitating the progression of HCC. In conclusion, this study reveals that hsa_circ_0119412 knockdown attenuates the progression of HCC by targeting miR-526b-5p/STMN1 axis.