Targeting Autophagy Augments BBR-Mediated Cell Death in Human Hepatoma Cells Harboring Hepatitis C Virus RNA.

Chen-Jei Tai,Christopher D Richardson,Shu Hui Wong,Cheng-Jeng Tai,Liang-Tzung Lin,Ching-Hsuan Liu,Alagie Jassey

doi:10.3390/cells9040908

Abstract

Hepatocellular carcinoma (HCC), including hepatitis C virus (HCV)-induced HCC, is a deadly disease highly refractory to chemotherapy, thus requiring the continuous identification of novel treatment strategies. Berberine (BBR) has been previously reported to inhibit hepatoma cell growth, but the main type of cell death elicited by BBR, and whether the alkaloid can inhibit hepatoma cells carrying HCV genomes, is unclear. Herein, we show that BBR treatment induced a biphasic cell death irrespective of the presence of HCV subgenomic replicon RNA, first triggering apoptosis that then progressed to necrosis between 24 and 48 h post-treatment. Furthermore, BBR treatment potentiated the HCV replicon-induced reactive oxygen species (ROS) production, inhibition of which with an antioxidant attenuated the cell death that was elicited by BBR in these cells. Moreover, BBR dampened the autophagic response in HCV RNA-positive or negative hepatoma cells, and pharmacological inhibition of autophagy conversely augmented the BBR-induced cell death. Finally, BBR inhibited the growth of Huh-7 cells that were persistently infected with the full-length genome HCV particles, and concomitant pharmacological inhibition of autophagy potentiated the killing of these cells by BBR. Our findings suggest that combining BBR with the inhibition of autophagy could be an attractive treatment strategy against HCC, irrespective of the presence of the HCV genome.

Highlights

The incidence of hepatocellular carcinoma (HCC), which is the most common cause of primary liver cancer, is on the rise
Unlike the above study, we saw a switch in the form of cell death from apoptosis to predominantly necrosis at 48 h post-treatment (Figure 2d)
In support of the induction of necrotic cell death at 48 h post-treatment, the lactose dehydrogenase (LDH) assay, which is a well-known indicator for necrotic cell death [21], showed a negligible difference between the mock control groups (Huh-7 and Huh-7.HCVrep cells only) and the BBR-treated groups at 24 h post-treatment (Figure 2e), whereas BBR treatment for 48 h significantly increased LDH release (Figure 2f)

Summary

Introduction

The incidence of hepatocellular carcinoma (HCC), which is the most common cause of primary liver cancer, is on the rise. The current treatment strategies, including orthotropic liver transplantation, surgical resection, and ablations, are effective against HCC at early stages, most cases detected at the advanced stages are unsuitable for such therapies [3]. HCC at the advanced stage displays poor prognosis with a survival time of fewer than six months in the untreated patients [6]. The advent of the direct-acting antivirals (DAAs) has phenomenally improved the treatment of HCV infection, which is a leading cause of HCC, these drugs do not reduce the development of HCV-associated HCC in all patients [7,8]. Given that no effective vaccine still exists for the prevention of HCV infection, identifying/validating effective treatment strategies against HCC, HCV-induced HCC, is urgently needed

Methods

Results

Conclusion