PLK1 Is Implicated in the Poor Prognosis of Hepatocellular Carcinoma

Abstract

We aimed to identify if PLK1 could be used as a new diagnostic and therapeutic biomarker in hepatocellular carcinoma (HCC) patient. Expression of PLK1 in HCC was analyzed by using GEPIA (Gene Expression Profiling Interactive Analysis) and UALCAN databases. GEPIA and CBioPortal tools were applied to determine patients’ survival and PLK1 mutations, respectively. PPI (Protein-Protein Interaction) networks were further built by STRING (Search Tool for the Retrieval of Interacting Genes) and Metascape Web portals. The data demonstrated that the expression of PLK1 in HCC was significantly enhanced when compared to normal liver tissues (P < 0.001). A higher PLK1 expression resulted in a remarkably shorter disease-free survival as well as overall survival. Moreover, the expression of PLK1 in HCC was related to HCC patients’ grade and race, but not gender. The data also suggested that expression of PLK1 elevated gradually from stage 1 to 3 but decreased in stage 4. Three specific gene mutations K146R, S335Afs*120 and D429H of PLK1 occurred in HCC and these unique mutations were not seen in any other tumor tissues. Finally, PPI networks and GO enrichment analysis suggested that PLK1 might be associated with cell cycle and p53 signaling pathway etc. Taken together, our novel findings suggest that PLK1 is implicated in the poor prognosis of hepatocellular carcinoma.