PSME4 Activates mTOR Signaling and Promotes the Malignant Progression of Hepatocellular Carcinoma

Background: As hepatocellular carcinoma (HCC) having the second-highest mortality rate globally, the early diagnosis and prognosis of HCC have always been the focus of various studies. Although PSME4 has been reported to be closely related to several malignancies, its role in HCC remains unclear. Materials and Methods: The TCGA-LIHC database and HCC tissues were used to explore the expression of PSME4 in HCC. Gene set enrichment analysis (GSEA) was used to forecast the biological behavior of HCC cells that PSME4 might be involved in regulation. In addition, CCK-8, colony formation and flow cytometry assays were used to explore the effect of PSME4 on HCC cells. Furthermore, the underlying PSME4-related signaling pathways in HCC were further confirmed using GSEA. Results: We found that the expression of PSME4 in HCC tissues was significantly higher than that in adjacent normal tissues, and patients with high PSME4 expression have a poor prognosis. CCK-8, colony formation and flow cytometry assays shown that knockdown of PSME4 inhibits HCC cell proliferation of HCC cells, promotes cell apoptosis and moves the cell cycle away from the S phase. Mechanistically, PSME4 may promote the development of HCC through mTOR signaling pathway. Conclusion: The high expression of PSME4 in HCC promotes the proliferation of HCC cells via the mTOR signalling pathway. Therefore, PSME4 is an emerging tumour marker for the early diagnosis and prognosis of HCC.