Introduction: Hepatocellular carcinoma (HCC), a deadly form of liver cancer, is influenced by miRNAs and imbalances in redox homeostasis. Cancer cells adapt themselves to high oxidative stress by increasing self-antioxidant levels. MicroRNA-365a-3p (miR-365a-3p) has emerged as a critical regulator of cellular processes, yet its specific role in oxidative stress within liver cells remains poorly understood. This study investigates the effects of miR-365a on antioxidant protein expression, reactive oxygen species (ROS) levels, and apoptosis in HepG2 cells.
Methods: The miR-365a mimic was delivered to HCC cells using Lipofectamine reagent. Next, the effect of the miR-365a-3p on intracellular ROS was detected using DCFDA method. The network of proteins involved in oxidative responses were extracted from String Database then two key proteins downstream to Nrf2 protein including superoxide dismutase1 (SOD1) and, Heme Oxygenase 1(HO-1) were selected. Finally, the effect of miR-365a-3p treatment on levels of HO-1, and SOD1 proteins were investigated using western blot. Apoptosis was detected by flowcytometry.
Results: We found that the increasing intracellular levels of miR-365a-3p led to a marked downregulation of key antioxidant proteins, including SOD1 and HO-1. Consequently, this downregulation resulted in a significant accumulation of ROS, indicating a failure of cancer cell antioxidant performance and accumulation of ROS. Such high levels of ROS massive programmed death in HepG2 cells.
Conclusion: Our results suggest that miR-365a-3p may play a pivotal role in modulating oxidative stress responses in HepG2 cells which results in triggering apoptosis. These findings pave the way for further investigations into the therapeutic applications of miR-365a-3p in oxidative stress-related liver diseases.