CircCBFB is a mediator of hepatocellular carcinoma cell autophagy and proliferation through miR-424-5p/ATG14 axis

This study aims to investigate the role of circCBFB in hepatocellular carcinoma (HCC) cell proliferation and autophagy. qRT-PCR and Western blotting analyses quantified the expression levels of circCBFB, miR-424-5p, and ATG14 in HCC tissues and/or HCC cell lines. After transfection with pcDNA3.1-CircCBFB, sh-CircCBFB, miR-424-5p mimic, miR-424-5p inhibitor, pcDNA3.1-ATG14, sh-ATG14, sh-CircCBFB + miR-424-5p inhibitor, pcDNA3.1-CircCBFB + miR-424-5p mimic, sh-CircCBFB + pcDNA3.1-ATG14, or pcDNA3.1-CircCBFB + sh-ATG14, the proliferation, cell cycle, and apoptosis of Huh-7 and HCCLM3 cells were detected, respectively, through MTT assay and flow cytometry. Western blotting measured the expression levels of ATG14 and autophagy-related proteins (LC3-Iota Iota/LC3-Iota, Beclin1, and p62). The interactions among circCBFB, miR-424-5p, and ATG14 were identified through RNA fluorescence in situ hybridization and RNA immunoprecipitation. In HCC tissues, circCBFB and ATG14 were highly expressed, and miR-424-5p expression was downregulated. Transfection of pcDNA3.1-CircCBFB, miR-424-5p inhibitor, or pcDNA3.1-ATG14 into HCC cells facilitated HCC cell proliferation and autophagy, while suppressing cell apoptosis, evidenced by elevated cell viability, increased protein levels of autophagosome markers (LC3-Iota Iota/LC3-Iota and Beclin1), repressed apoptosis rate, and suppressed protein level of autophagy receptor p62. miR-424-5p was a target gene of circCBFB, and miR-424-5p negatively mediated ATG14. CircCBFB inhibits miR-424-5p and upregulates ATG14, thus promoting HCC cell proliferation and autophagy.

Automated summary

This study investigated the role of circCBFB in hepatocellular carcinoma (HCC) cell proliferation and autophagy. The results showed that circCBFB inhibits miR-424-5p and upregulates ATG14, thus promoting HCC cell proliferation and autophagy.