Interferon-α sensitizes HBx-expressing hepatocarcinoma cells to chemotherapeutic drugs through inhibition of HBx-mediated NF-κB activation
Yanning Liu 1
Email: [email protected]
Guohua Lou 1
Email: [email protected]
Wei Wu 1
Email: [email protected]
Yu Shi 1
Email: [email protected]
Min Zheng 1
Email: [email protected]
Zhi Chen 1*
*Corresponding author
Email: [email protected]
1 State Key Laboratory of Infectious Disease Diagnosis and Treatment, The
First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003,
China
Abstract
Background
Hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) is characterized by high
chemotherapy resistance; however, the underlying mechanism has not been fully clarified. In addition, HBx protein has been reported to play a key role in virus-mediated hepatocarcinogenesis. Therefore, the present study aims to investigate the role of HBx in the drug-resistance of HBV-related HCC and examine whether such drug-resistance can be
reversed by IFN-α treatment.
Methods
We established HBx-expressing cells by liposome-mediated transfection of HBx into the
Huh7 cell line. MTT, Annexin V/PI, and cell cycle assay were used for determining the
cellular growth inhibition, apoptosis, and growth arrest, respectively, after treatment with
chemical drug. We further used tumor-bearing mice model to compare the tumor growth
inhibition efficacy of ADM and 5-FU between the Huh7-HBx group and the control group, as
well as the ADM + IFN- α or ADM + IMD treated group and the ADM treated group. SQ-Real time-PCR was performed to analyze the expression of MDR-associated genes and anti-apoptotic genes. Moreover, immunofluorescence and Western blotting were used to determine the subcellular localization of p65 and the phosphorylation of IκBα.
Results
The IC50 values of Huh7-HBx cells against ADM and Amn were 2.317 and 1.828-folds higher than those of Huh7-3.1 cells, respectively. The apoptosis ratio a
nd growth arrest was significantly lower in Huh7-HBx cells after treatment with A
DM. The in vivo experiment also confirmed that the Huh7-HBx group was much more resistant to ADM or 5-FU than the control. Furthermore, the expression of MDR-associated genes, such as MDR1, MRP1,LRP1, and ABCG2, were significantly up-regulated in Huh7-HBx cells, and the NF-κB pathway was activated after HBx gene transfection in Huh7 cells. However, combined with IFN-α in ADM treatment, the HBx induced drug-resistance in Huh7-HBx cells can be partly abolished in in vitro and in vivo models. Moreover, we found that the NF-κB canonical pathway was affected by IFN-α treatment, and the expression of anti-apoptotic genes, such as Gadd45β, Survivin, and c-IAP-1 was down-regulated by IFN-α treatment in a dose-dependent manner.
Conclusions
HBx protein can induce MDR of HBV-related HCC by activating the NF-κB pathway, which can be partly abolished by IFN-α treatment 作者: StephenW 时间: 2013-5-30 20:40