Karyopherin subunit-α 2 expression accelerates cell cycle progression by upregulating CCNB2 and CDK1 in hepatocellular carcinoma

Different types of cancer exhibit distinct gene expression profiles. The present study aimed to identify a specific gene dysregulated in hepatocellular carcinoma (HCC) that was essential for cancer progression. The whole transcriptomes of primary HCC tissue samples were analyzed with microarrays. The most significantly differentially expressed gene was identified, specifically karyopherin subunit-alpha 2 (KPNA2), and an analysis using the Oncomine online tool was performed with data from The Cancer Genome Atlas to predict associated genes in HCC. Reverse transcription-quantitative polymerase chain reaction was performed to confirm the gene expression levels of KPNA2, and the RNA interference knockdown of KPNA2 was performed to identify the effect on putative downstream target genes. A proliferation assay and flow cytometry analysis was used to assess the function of KPNA2 in the regulation of the cell cycle. The results demonstrated that KPNA2 expression was significantly upregulated in HCC tumor tissues compared with liver tissues and was associated with cyclin B2 (CCNB2) and cyclin-dependent kinase 1 (CDK1) expression. KPNA2 expression was identified a novel marker to predict the outcome of patients. In addition, KPNA2 knockdown downregulated CCNB2 and CDK1, inhibited cell proliferation and induced cell cycle arrest in the G2/M phase. In conclusion, it was demonstrated that KPNA2 may promote tumor cell proliferation by increasing the expression of CCNB2/CDK1. KPNA2 could be a target for therapeutic intervention in HCC.