Experimental and clinical evidence suggests that GRPEL2 plays an oncogenic role in HCC development

Hepatocellular carcinoma (HCC) continues to cause severe burden worldwide. The limited options especially toward HCC with metastasis prompts us to identify novel molecules for either diagnostic/prognostic or therapeutic purposes. GRPEL2 is well defined in maintaining mitochondrial homeostasis, which is critical to multiple biological processes for cancer survival. However, its role in HCC progression was not investigated before. In our analysis using data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA LIHC) dataset and tissue microarray, higher expression levels of GRPEL2 were obseved in HCC tissues compared to in normal liver tissues, and indicated higher tumor grade, higher tumor stage, and shorter overall survival (OS). Consistent with the results of above analyses, the functional experiments validated that GRPEL2 acted as a tumor-promoting factor in HCC progression. GRPEL2 knockdown suppressed cell growth, migration, and invasion in vitro, as well as inhibited tumor growth in vivo. Moreover, GRPEL2 deficiency also accelerated reactive oxygen species (ROS) production and increased mitochondrial membrane potential (MMP), leading to cell apoptosis. In addition, we found that the cell cycle and NF-κB signaling pathways were responsible for GRPEL2-induced HCC progression, based on the results of Gene Set Enrichment Analysis (GSEA) and subsequent experimental validation. Our study, for the first time, identified the role of GRPEL2 in HCC development and provided a compelling biomarker for targted therapy in HCC treatment.