ObjectiveThis paper attempts to investigate the expression level of protein arginine methyltransferase 3 (PRMT3) in hepatocellular carcinoma (HCC) tissues and analyze its relationship with oxaliplatin resistance and the prognosis of patients.MethodsFrom January 2019 to June 2022, tumor and adjacent normal tissues (>5 cm from tumor margin) were collected from 52 patients with hepatitis B-related HCC (set as the HCC group) hospitalized in Cangzhou People's Hospital. For comparison, liver tissue samples were obtained via ultrasound-guided puncture from 38 patients with chronic hepatitis B (set as the chronic hepatitis B group) and 38 patients with hepatitis B-related cirrhosis (set as the hepatitis B-related cirrhosis group), and from 38 patients undergoing surgical resection for liver hemangioma (set as the control group). PRMT3 expression levels in tissues were assessed via immunohistochemical staining. PRMT3 expression levels in tissues were assessed via immunohistochemical staining. All HCC patients received the FOLFOX4 chemotherapy regimen, with oxaliplatin as the primary agent, and the correlations between PRMT3 expression, chemotherapy efficacy, and patient prognosis were analyzed. SNU-398 cells in logarithmic growth phase were divided into the Lv-shNC group (transfected with negative control lentivirus) and the Lv-shPRMT3 group (transfected with PRMT3 interfering lentivirus). After treatment with different concentrations of oxaliplatin, the effect of PRMT3 on oxaliplatin cytotoxicity was observed. Cells were taken from the Lv-shNC group and the Lv-shPRMT3 group, and added to culture medium containing 20 μmol/L oxaliplatin (designated as the Lv-shNC+OXA group and the Lv-shPRMT3+OXA group, respectively). The proliferation, migration, invasion, and apoptosis abilities of each group of cells were analyzed.ResultsThe positive expression rate of PRMT3 in HCC tissue is significantly higher compared to adjacent tissues and to tissues from the chronic hepatitis B group, the hepatitis B-related cirrhosis group, and control group (P<0.05). ROC curve analysis show that the area under the curve (AUC), sensitivity, and specificity of PRMT3 for diagnosing HCC in HCC tissues are 0.831 (95%CI: 0.763 to 0.899), 75.00%, and 91.23%, respectively. Compared with the PRMT3 negative expression group, the total effective rate of treatment in the PRMT3 positive expression group is significantly reduced (χ²=4.392, P=0.036), and so is the 2-year survival rate (χ²=5.148, P=0.023). The relative expression level of PRMT3 in the Lv-shPRMT3 group cells is significantly lower than that in the Lv-shNC group (t=10.844, P<0.05). As the concentration of oxaliplatin added increases, the cell inhibition rates of both groups significantly increase. Compared with the Lv-shNC group, the number of monoclonal cells formed and the number of transmembrane cells in the Lv-shPRMT3 group and the Lv-shNC+OXA group are significantly reduced, the apoptosis rate is significantly increased, and the scratch healing rate is significantly decreased (P<0.05). Compared with the Lv-shPRMT3 group and the Lv-shNC+OXA group, the number of monoclonal cells formed and the number of transmembrane cells in the Lv-shPRMT3+OXA group are significantly reduced, the apoptosis rate is significantly increased, and the scratch healing rate is significantly decreased (P<0.05).ConclusionsPRMT3 is highly expressed in HCC tissues, and downregulation of PRMT3 expression can inhibit cell proliferation, migration, and invasion, and can promote cell apoptosis, thereby increasing the sensitivity of HCC cells to oxaliplatin and reducing the rate of drug resistance. PRMT3 is expected to become a diagnostic biomarker and therapeutic target for HCC.