Interferon-alpha2b (IFN-alpha2b)-induced apoptosis is mediated by p38 MAPK in hepatocytes from rat preneoplastic liver via activation of NADPH oxidase

Delta-tocotrienol enhances the antitumor effects of interferon alpha through ROS and Erk/MAPK signaling pathways in hepatocellular carcinoma cells

The complexity of hepatocellular carcinoma (HCC) signaling and the failure of pharmacological therapeutics reveal the significance of establishing new anti-cancer strategies. Interferon alpha (IFN α) has been used as adjuvant therapy for reducing HCC recurrence and improving survival. Delta-tocotrienol (δ-tocotrienol), a natural unsaturated isoform of vitamin E, is a promising candidate for cancer treatment. In this study, we evaluated whether the combination of δ-tocotrienol with IFN α displays significant advantages in the treatment of HCC cells. Results showed that the combination significantly decreased cell viability, migration and invasion of HCC cells compared to single therapies. Combining δ-tocotrienol and IFN α enhanced the decrease in proliferating cell nuclear antigen (PCNA) and matrix metalloproteinases MMP-7 and MMP-9. The combination also produced an enhancement of apoptosis together with increased Bax/Bcl-xL ratio and ROS generation. δ-tocotrienol induced Notch1 activation and changes in Erk and p38 MAPK signaling status. Blocking experiments confirmed that ROS and Erk are involved, at least in part, in the anticancer effects of the combined treatment. In conclusion, the combination of δ-tocotrienol with IFN α therapy showed promising results for HCC cells treatment, which makes the combination of cytokine-based immunotherapy with natural products a potential strategy against liver cancer.

Complete cure of a patient with HBV-associated hepatocellular carcinoma with lung metastasis using interferon and survival up to 108 months: A case report and literature review

Hepatocellular carcinoma (HCC) has a poor prognosis due to its asymptomatic onset and susceptibility to metastasis. The survival of patients with advanced HCC is 6-12 months. As a first-line medicine for the control of hepatitis B virus, interferon (IFN) is also capable of inhibiting tumor growth and modulating immunity. However, treatment of HCC with lung metastasis using IFN has been rarely reported. The present study reports the case of one patient with HCC having lung metastasis who underwent a one-time treatment with transcatheter arterial chemoembolization (TACE) and was subsequently completely cured by single peginterferon α 2a (PEG-IFNα2a); and has survived up to 108 months. A 53-year-old male patient diagnosed with HBV-related HCC with lung metastasis underwent TACE using floxuridine (FUDR) 500 mg, cisdiamine dichloroplatinum (CDDP) 20 mg, mitomycin 10 mg, and ultrafluid lipiodol 10 ml, together with local thoracic aorta chemotherapy using FUDR 250 mg and CDDP 20 mg. His metastatic lung cancer aggravated. However, after 9 months of treatment with subcutaneous injections of PEG-IFNα 2a once per week, the metastatic lung foci gradually shrunk until disappearance and the HCC lesion stabilized without progression. According to the World Health Organization criteria for the efficacy of solid tumors, this was a case of complete response. Upon follow-up up to 108 months his metastatic lung cancer had disappeared and HCC did not recur. Therefore, IFN intervention may be an appropriate novel adjuvant therapy for patients with HCC with lung metastasis and requires further attention and study.

FoxO3a nuclear localization and its association with β-catenin and Smads in IFN-α-treated hepatocellular carcinoma cell lines

Interferon-α2b (IFN-α2b) reduces proliferation and increases apoptosis in hepatocellular carcinoma cells by decreasing β-catenin/TCF4/Smads interaction. Forkhead box O-class 3a (FoxO3a) participates in proliferation and apoptosis and interacts with β-catenin and Smads. FoxO3a is inhibited by Akt, IκB kinase β (IKKβ), and extracellular-signal-regulated kinase (Erk), which promote FoxO3a sequestration in the cytosol, and accumulates in the nucleus upon phosphorylation by c-Jun N-terminal kinase (JNK) and p38 mitogen-activated kinase (p38 MAPK). We analyzed FoxO3a subcellular localization, the participating kinases, FoxO3a/β-catenin/Smads association, and FoxO3a target gene expression in IFN-α2b-stimulated HepG2/C3A and Huh7 cells. Total FoxO3a and Akt-phosphorylated FoxO3a levels decreased in the cytosol, whereas total FoxO3a levels increased in the nucleus upon IFN-α2b stimulus. IFN-α2b reduced Akt, IKKβ, and Erk activation, and increased JNK and p38 MAPK activation. p38 MAPK inhibition blocked IFN-α2b-induced FoxO3a nuclear localization. IFN-α2b enhanced FoxO3a association with β-catenin and Smad2/3/7. Two-step coimmunoprecipitation experiments suggest that these proteins coexist in the same complex. The expression of several FoxO3a target genes increased with IFN-α2b. FoxO3a knockdown prevented the induction of these genes, suggesting that FoxO3a acts as mediator of IFN-α2b action. Results suggest a β-catenin/Smads switch from TCF4 to FoxO3a. Such events would contribute to the IFN-α2b-mediated effects on cellular proliferation and apoptosis. These results demonstrate new mechanisms for IFN-α action, showing the importance of its application in antitumorigenic therapies.

Negative regulation of hepatitis C virus specific immunity is highly heterogeneous and modulated by pegylated interferon-alpha/ribavirin therapy

Specific inhibitory mechanisms suppress the T-cell response against the hepatitis C virus (HCV) in chronically infected patients. However, the relative importance of suppression by IL-10, TGF-β and regulatory T-cells and the impact of pegylated interferon-alpha and ribavirin (PegIFN-α/ribavirin) therapy on these inhibitory mechanisms are still unclear. We revealed that coregulation of the HCV-specific T-cell responses in blood of 43 chronic HCV patients showed a highly heterogeneous pattern before, during and after PegIFN-α/ribavirin. Prior to treatment, IL-10 mediated suppression of HCV-specific IFN-γ production in therapy-naive chronic HCV patients was associated with higher HCV-RNA loads, which suggests that protective antiviral immunity is controlled by IL-10. In addition, as a consequence of PegIFN-α/ribavirin therapy, negative regulation of especially HCV-specific IFN-γ production by TGF-β and IL-10 changed dramatically. Our findings emphasize the importance of negative regulation for the dysfunctional HCV-specific immunity, which should be considered in the design of future immunomodulatory therapies.

Control of JNK for an activation of NADPH oxidase in LPS-stimulated BV2 microglia

NADPH oxidase is a main regulator for H(2)O(2) productivity in neuroinflammatory cells, including microglia, under various CNS diseases and its activity is controlled by mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase (JNK). However, little is known about the link between NADPH oxidase-driven H(2)O(2) productivity and JNK in microglia. The purpose of this study is to uncover the link using lipopolysaccharide (LPS)-stimulated BV2 microglia. LPS-stimulated BV2 microglia produced H(2)O(2) that was decreased by NADPH oxidase inhibitors, including 4-(2-aminoethyl)benzenesulfonylfluoride and diphenyleneiodonium chloride. In addition, NADPH oxidase was activated in LPS-stimulated BV2 cells. These results suggest that NAPDH oxidase is a main factor for H(2)O(2) productivity in LPS-stimulated BV2 microglia. Based on a semi-quantitative PCR analysis, two of NADPH oxidase components, p47(phox) and gp91(phox), were involved in the activation of NADPH oxidase because transcriptional levels of both components were upregulated by LPS. Role of JNK in NADPH oxidase-regulated H(2)O(2) productivity was pursued using specific inhibitors, including SP600125 and JNK inhibitory peptide (JIP). Inhibition of the JNK pathways significantly reduced H(2)O(2) productivity, which was closely related to the attenuation of NADPH oxidase activation and the upregulation of components. We conclude that JNK pathways are involved in NADPH oxidase-mediated H(2)O(2) productivity in BV2 microglia.

Microarray approach reveals the relevance of interferon signaling pathways with rat liver restoration post 2/3 hepatectomy at cellular level

The immunomodulator interferons are assumed not only to fight tumor progress but also to inhibit liver regeneration by inactivating Kupffer cells. The potential mechanism is still poorly characterized. In particular, the relevance of interferon signaling to liver regeneration at cellular level still remains unknown. In this study, 8 types of rat liver cells from the regenerating liver at 10 recovery time points were separately isolated by percoll density gradient centrifugation and immunomagnetic bead. Transcription profiles of interferon-signaling pathway genes in each cell type along the time course of liver restoration were detected using Rat Genome 230 2.0 Array covering about 12,727 known genes. The chip data demonstrated that hepatocyte mainly up-regulated the IFN-alpha1-mediated JAK/STAT pathway genes; biliary epithelial cell mostly expressed the IFN-beta1-mediated p38 MAPK pathway genes; while the IFN-gamma-activated JAK/STAT pathway genes were down-regulated particularly in HSC, KC, and DC during liver regeneration. It is inferred that STAT3, in contrast to STAT1, seemingly takes a more active role in IFN-alpha1-mediated JAK/STAT pathway in hepatocyte; IFN-beta1-mediated p38 MAPK pathway possibly to some extent affects inflammation and apoptosis of biliary epithelial cell during liver regeneration; IFN-gamma-induced JAK/STAT pathway may be associated with the attenuated apoptosis induction in HSC, KC, and DC. Our data suggested that a better understanding about how interferon signals at liver cell level might be helpful in developing an effective approach to protecting against the inhibition of regeneration.

Attenuation of the Wnt/beta-catenin/TCF pathway by in vivo interferon-alpha2b (IFN-alpha2b) treatment in preneoplastic rat livers

Wnt/beta-catenin/T cell factor (TCF) pathway is activated in several types of human cancers, promoting cell growth and proliferation. Forkhead box containing protein class O (FOXO) transcription factors compete with TCF for beta-catenin binding, particularly under cellular oxidative stress conditions. Contrary to beta-catenin/TCF, beta-catenin/FOXO promotes the transcription of genes involved in cell cycle arrest and apoptosis. We have previously demonstrated that in vivo interferon-alpha2b (IFN-alpha2b) administration induces apoptosis in preneoplastic livers, a mechanism mediated by reactive oxygen species (ROS) and transforming growth factor-beta(1) (TGF-beta(1)). This study was aimed to assess the status of the Wnt/beta-catenin/TCF pathway in a very early stage of rat hepatocarcinogenesis and to further evaluate the effects of in vivo IFN-alpha2b treatment on it. We demonstrated that the Wnt/beta-catenin/TCF pathway is activated in preneoplastic rat livers. More important, in vivo IFN-alpha2b treatment inhibits Wnt/beta-catenin/TCF pathway and promotes programed cell death possibly providing a link with FOXO pathway.