Background and aims As a ferroptosis inducer, sorafenib, a first-line treatment for hepatocellular carcinoma (HCC), has a significant antitumor effect. Nonetheless, HCC patients frequently develop sorafenib resistance. Here, we investigated the impacts of progestagen-associated endometrial protein (PAEP), which controls sorafenib resistance and tumorigenesis in HCC. Furthermore, we investigated the function of PAEP and the underlying molecular mechanisms that cause HCC ferroptosis when sorafenib is applied. Methods Western blot analysis, cell proliferation, colony formation and animal experiments were performed to investigate the function of PAEP in sorafenib resistance and tumorigenesis in HCC. We detected the levels of reactive oxygen species, iron, and malondialdehyde and preformed transmission electron microscopy to investigate the relationship between PAEP and ferroptosis. Co-immunoprecipitation (co-IP) assay was performed to investigate the underlying molecular mechanisms of PAEP that cause HCC ferroptosis. Results PAEP was significantly overexpressed in HCC tissues, and this was associated with a poor clinical prognosis. PAEP silencing dramatically reduced HCC cells’ malignant phenotype. We found that sorafenib-induced ferroptosis was more sensitive to HCC cells with PAEP knockdown. Furthermore, the orthotopic cell line-derived xenograft mouse model results showed that sorafenib sensitivity can be effectively increased in vivo by PAEP knockdown. We determined that transferrin (TF) was a PAEP target using the String database, and we further supported this finding with Co-IP analysis. Additionally, on sorafenib-induced ferroptosis in HCC cells, TF partially reversed the effects of PAEP knockdown. Conclusions Our research indicates that PAEP may be a potential biomarker for predicting sorafenib resistance in HCC and disruption of PAEP expression may be a potential cancer-directed therapeutic option for HCC.

AIM: To observe the ability of dendritic cells (DC) vaccine transfected with human hepatocellular carcinoma (HCC) total RNA induce specific cytotoxic T lymphocyte(CTL) response in vitro. METHODS: DCs generated from HCC patient's peripheral blood mononuclear cells (PBMC) were incubated with recombinant human granulocyte macrophage colony-stimulationg factor (GM-CSF) and human interleukin (IL-4). Tumor total RNA was isolated from Hep G-2 cells and HCC cells. DCs transfected with tumor total RNA were used to induce specific CTL proliferation. Specific cytotoxicity was measured using MTT method. RESULTS: DC transfected with HepG-2 cell RNA and HCC RNA exhibited increased expression of CD83, CD86 and HLA-DR. The CTL from DCs transfected with HepG-2 cell RNA killed 5.84%, 14.26%, 25.19%, or 35.78% of HepG-2 cells, and 5.26%, 11.67%, 14.68%, or 23.24% of HCC cells, respectively, at an E/T ratio of 2.5, 5, 10, or 20. The CTL from DCs transfected with HCC cells RNA killed 4.65%, 12.23%, 15.61%, or 19.15% of HepG-2 cells, and 7.20%, 12.83%, 27.21%, or 31.15% of HCC cells,respectively, at an E/T ratio of 2.5, 5, 10, and 20. These CTL did not kill allogeneic malignant cells as human gastric carcinoma cells SGC-7901. CONCLUSION: DC transfected with tumor-derived total RNA could induce specific antitumor immune CTL response. These results suggest that CTL generation is applicable to adoptive immunotherapy of HCC.