Role of thioredoxin reductase 1 in multidrug resistance caused by reactive oxygen species-related cell apoptosis in hepatocellular carcinoma / 临床肝胆病杂志

ABSTRACT

Objective Drug resistance is the main cause of chemotherapy failure in hepatocellular carcinoma (HCC), and thioredoxin reductase 1 (TXNRD1), as a major influencing factor for reactive oxygen species (ROS) metabolism, has been proven to be associated with the poor prognosis of patients with HCC. This study aims to explore the role of TXNRD1 in the mechanism of multidrug resistance in HCC. Methods BEL/FU cells in BEL-7402 cell line were selected as the multidrug-resistant cell line. The siRNA was used for the intervention of TXNRD1 expression; quantitative real-time PCR and Western blotting were used to measure the expression of TXNRD1; CCK-8 assay and flow cytometry were used to evaluate the effect of TXNRD1 on hepatocyte ROS accumulation, resistance to 5-fluorouracil (5-Fu) and doxorubicin (DOX), and apoptosis in vitro; a xenograft tumor model was established to investigate the effect of auranofin (AUR) on drug resistance in vivo. The two-independent-samples t test was used for comparison of continuous data between two groups. Results As a multidrug-resistant HCC cell line, BEL/Fu showed high mRNA and protein expression levels of TXNRD1 (both P < 0.05). Compared with 5-Fu or DOX treatment alone, the TXNRD1 inhibitor AUR combined with 5-Fu or DOX had had a significant reduction in the number of colony formation ( P < 0.01) and a significant increase in apoptosis ratio ( P < 0.001). The ROS scavenger N-acetylcysteine (NAC) significantly weakened the effect of TXNRD1 knockdown by siRNA on the drug resistance of BEL/Fu cells, and the application of NAC effectively reduced the apoptosis ratio of cells after siRNA interference ( P < 0.001). Animal experiments also confirmed that compared with the nude mice treated with 5-Fu alone, the nude mice treated with 5-Fu and AUR had a significantly lower tumor mass ( P < 0.001) and a significantly smaller tumor volume ( P < 0.001). Conclusion TXNRD1 plays an important role in the drug resistance of HCC, and inhibition of its level in cells can effectively improve drug resistance. As a TXNRD1 inhibitor, AUR has great application prospects in the multimodality therapy for HCC.