Objective To explore the expression of ubiquitin-specific protease 30(USP30)in hepatocellular carcinoma (HCC), and investigate its role in HCC cell proliferation, invasion, and migration.

Methods The expression differential of USP30 was analyzed in HCC tissues and adjacent tissues from The Cancer Genome Atlas (TCGA) database. Following that, we looked at the correlations of USP30 expression with the clinicopathological characteristics of HCC patients, including TNM and clinical stages. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression of USP30 in 5 HCC cell lines. We assessed the effects of USP30 over-expression and knockdown on proliferation, migration, and invasion of HCC cells with cell counting kit-8 (CCK-8) assay, transwell assay, and wound healing assay. The subcellular localization of USP30 in 293T cells was determined using an immunofluorescence assay.

Results The expression level of USP30 in HCC tissues was significantly higher than in adjacent tissues and significantly correlated with TNM and clinical stages in HCC. The mRNA and protein expression levels of USP30 were significantly higher in the 5 HCC cell lines than in normal liver cells. Overexpression of USP30 promoted the proliferation, invasion, and migration of HCC cells, while USP30 knockdown produced the opposite effects. Immunofluorescence assay identified subcellular localization of USP30 in the cytoplasm of 293T cells.

Conclusions USP30 is highly expressed in HCC tissues and cells to promote proliferation and metastasis in HCC cells and may serve as a potential molecular target for diagnosing and treating HCC.