SKA3 Promotes tumor growth by regulating CDK2/P53 phosphorylation in hepatocellular carcinoma

Abstract

Spindle and kinetochore-related complex subunit 3 (SKA3) is a component of the spindle and kinetochore-related complexes and is essential for accurate timing of late mitosis. However, the relationship between SKA3 and hepatocellular carcinoma (HCC) has not yet been fully elucidated. Gene expression omnibus (GEO) (GSE62232, GSE45436, GSE6764, and GSE36376) and The Cancer Atlas (TCGA) datasets were analyzed to identify differential expression genes. Cell proliferation ability was analyzed using Cell Counting Kit-8 (CCK8) assay and plate clone formation assay, while scratch wound healing assay and transwell assay were used to analyze cell invasion. The role of SKA3 in vivo was explored using subcutaneous xenotransplantation model and lung metastasis model. Bioinformatics analysis found that hepatocellular carcinoma patients with high levels of expression of SKA3 have a poor prognosis. Similarly, immunohistochemical staining of 236 samples of tumors also found higher SKA3 expression in them, than in adjacent normal liver tissues. Significant levels of inhibition of in vivo and in vitro tumor proliferation and invasion result from the downregulation of SKA3. Mechanistically, SKA3 was found to affect tumor progression through the cell cycle and P53 signaling pathway as shown by the gene enrichment analysis (GSEA). G2/M phase arrest and severe apoptosis was also found to result from SKA3 knockdown, as shown by the inhibition of CDK2/p53 phosphorylation together with downregulation of BAX/Bcl-2 expression in HCC cells. Overall, these findings uncover the role of SKA3 in regulating the apoptosis and proliferation of hepatocellular carcinoma cells. This study was able to uncover new information on the tumorigenesis mechanism in hepatocellular carcinoma.