Ring Finger Protein 141 (RNF141) Mediates Resistance to Sorafenib in Hepatocellular Carcinoma and Its Mechanisms

Abstract OBJECTIVE: This study aims to investigate the expression of ring finger protein 141 (RNF141) in hepatocellular carcinoma, its role in sorafenib resistance, and its possible mechanism. MATERIALS AND METHODS: The expression of RNF141 in the cancer and corresponding para-cancerous liver tissues of patients with hepatocellular carcinoma was detected using Immunohistochemistry (IHC) staining and Western blot. The liver cancer cell line (SMMC7721) and the sorafenib-resistant liver cancer cell line (SMMC7721-S) were transfected with lentivirus to overexpress or silence RNF141, and the IC50 of sorafenib was then measured. Flow cytometry and TUNEL staining were used to detect changes in cell apoptosis before and after overexpression and silencing of RNF141. The levels of the proliferation marker protein, proliferating cell nuclear antigen (PCNA), and the apoptosis marker protein, Cleaved PARP, were detected using Western blot. Additionally, a tumor xenograft model was constructed by subcutaneously injecting RNF141-knockdown SMMC7721 and SMMC7721-S stable transfected strains into nude mice. The study observed and recorded the shape, size, and weight of tumors in each group. Hematoxylin and Eosin (HE) staining and immunohistochemistry (IHC) staining of PCNA were used to verify the effect of RNF141 on the efficacy of sorafenib in vivo. Finally, digital gene expression profiling (DGE) was used to further screen the signaling pathways involved in RNF141-mediated HCC resistance to sorafenib. RESULTS: The study found that the expression of RNF141 was significantly higher in hepatocellular carcinoma tissues compared to corresponding paracancerous tissues (P<0.01), as shown by IHC staining results and Western blot analysis. Hepatocellular carcinoma cell lines that overexpress and silence RNF141, as well as sorafenib-resistant hepatocellular carcinoma cell lines, were successfully constructed. Overexpression of RNF141 resulted in an increase in the IC50 value of sorafenib in hepatocellular carcinoma cells, as well as the ability to resist sorafenib-induced proliferation inhibition and apoptosis. Conversely, silencing RNF141 resulted in a decrease in the IC50 value of sorafenib, and further enhanced sorafenib-induced proliferation inhibition and apoptosis. The digital gene expression profiling results were analysed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) signalling pathway enrichment analysis, which revealed a significant enrichment of the proteasome signalling pathway. CONCLUSION: RNF141 may contribute to sorafenib resistance in hepatocellular carcinoma through the proteasome signaling pathway.