The evaluation of loaded exosomes by microRNA-365 on NRF2/Keap1 signaling pathway in hepatocellular carcinoma By: Armita Ghotaslou Supervisors: Dr. & Dr. Advisors: Dr. Reza Rahbarghazi & Dr. Nosratollah Zarghami

Abstract

Introduction: Inhibition of cellular cytoprotection can be regarded as a hopeful therapeutic strategy against cancer. Alterations of miRNA levels may affect the mentioned defense in carcinoma cells. Exosome is a biological carrier with acknowledged success in gene delivery. This study was designed to determineif the restoring ofmiR-365a-3p levels, loaded in exosome (HEK293 derived),would have tumor fighting function against hepatocellular carcinoma (HepG2) and its effect on NRF2/Keap1 pathway . Main methods: After isolation of exosomes from HEK293, their characterization was performed using DLS, SEM, TEM, and western blot. The miR-365a-3p was loaded on to exosomes and transfected into the HepG2 cells. Next, the effect of this treatment on intracellular ROS, NRF2, SOD, HO-1 protein, and Bcl2 mRNA levels was investigated. Moreover, the impact of ExomiR-365a-3p on apoptosis, cell cycle, and migration of HepG2 cells was studied by Annexin V kit, PI staining, scratch wound healing, and ADAM-10 protein detection, respectively. Results: HEK293 exosomes were morphologically spherical and had a size of 50-80 nmandan average yield of 1.8 mg/ml. The efficiency of miR-365a encapsulation in exosomes was 81.3%. The efficiency of ExomiR transfection into HepG2 cells was around 80%. Reduction of NRF2 protein level with inverse augmentation of ROS levels was also detected In addition, the expression of other proteins of the NRF2/Keap1 pathway, including SOD, HO-1, was decreased. A significant population of exomiR-treated cells showed the intense decrease of Bcl2 transcript coupled with massive apoptosis and cell cycle interruption (p<0.05). Furthermore, the migration/scratch healing diminished along with ADAM-10 protein downregulation (p<0.05) Conclusion: Transfection of exosome-mediated miR-365a-3p amendment might cause the risk of oxidative damage with subsequent toxicity and death in HepG2 cells.