SNGH16 regulates cell autophagy to promote Sorafenib Resistance through suppressing miR-23b-3p via sponging EGR1 in hepatocellular carcinoma

Objective: Tumor cells could acquire drug resistance through cell Autophagy. This study aimed to explore the role of SNHG16 in sorafenib-resistant HCC cells and its mechanism with miR-23b-3p.

Methods: The sorafenib-resistant Hep3B cell model was established. The SNHG16 and miR-23b-3p gene expressions were determined in normal HCC and sorafenib-resistant HCC tissues. Detection of the expression of SNHG16 and miR-23b-3p and its respective correlation with survival rate were performed. Target genes to SNHG16 and miR-23b-3p were predicted, and verified by dual-fluorescent reporter assay. The effects of SNHG16 and miR-23b-3p on SNHG16, miR-23b-3p, EGR1 expression, viability, Apoptosis as well as LC3II/LC3 expression in Hep3B and Hep3B/So cells were detected by qRT-PCR, CCK-8, flow cytometry, and western blot. In in vivo studies, the NOD/SCID mice model was established to explore the effects of Hep3B and Hep3B/So cells with inhibited SNHG16 or miR-23b-3p on tumor size, EGR1 expression, and Autophagy.

Results: High SNHG16 expression in HCC-resistant tissues and low miR-23b-3p expression in all HCC tissues were detected, and the two were negatively correlated. Low SNHG16 and high miR-23b-3p were related to a high survival rate of HCC patients. Moreover, SNHG16 overexpression promoted Hep3B/So cell viability and Autophagy, suppressed Apoptosis by inhibiting miR-23b-3p expression through up-regulating EGR1, however, the effect of si-SNHG16 was opposite. In in vivo studies, miR-23b-3p inhibitor suppressed the high sorafenib sensitivity in Hep3B/So cells caused by SNHG16 silencing through promoting viability, Autophagy, and suppressing Apoptosis.

Conclusion: SNHG16 promotes Hep3B/So cell viability, Autophagy, and inhibits Apoptosis to maintain its resistance to sorafenib through regulating the expression of miR-23b-3p via sponging EGR1.