Inhibition of pMAPK14 Overcomes Resistance to Sorafenib in Hepatoma Cells with Hepatitis B Virus

Review of Related Factors for Persistent Risk of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Chronic hepatitis B virus (HBV) infection is the largest global cause of hepatocellular carcinoma (HCC). Current HBV treatment options include pegylated interferon-alpha and nucleos(t)ide analogues (NAs), which have been shown to be effective in reducing HBV DNA levels to become undetectable. However, the literature has shown that some patients have persistent risk of developing HCC. The mechanism in which this occurs has not been fully elucidated. However, it has been discovered that HBV's covalently closed circular DNA (cccDNA) integrates into the critical HCC driver genes in hepatocytes upon initial infection; additionally, these are not targets of current NA therapies. Some studies suggest that HBV undergoes compartmentalization in peripheral blood mononuclear cells that serve as a sanctuary for replication during antiviral therapy. The aim of this review is to expand on how patients with HBV may develop HCC despite years of HBV viral suppression and carry worse prognosis than treatment-naive HBV patients who develop HCC. Furthermore, HCC recurrence after initial surgical or locoregional treatment in this setting may cause carcinogenic cells to behave more aggressively during treatment. Curative novel therapies which target the life cycle of HBV, modulate host immune response, and inhibit HBV RNA translation are being investigated.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

Canonical WNT Signaling Activated by WNT7B Contributes to L-HBs-Mediated Sorafenib Resistance in Hepatocellular Carcinoma by Inhibiting Mitophagy

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally, with hepatitis B virus (HBV) infection accounting for over half of all cases. HBV leads to the development of HCC according to a body of literature. Our previous research and other studies also suggest that HBV causes chemotherapeutic treatment resistance, however, the mechanism is uncertain. The WNT family, which encodes secreted signaling molecules, has been linked to carcinogenesis in a variety of malignancies, including HCC. However, little is known regarding WNT7B, a WNT ligand, in the development of HCC and HBV-induced chemoresistance. In this study, the bioinformatics analysis and immunohistochemistry (IHC) staining of clinical samples revealed that WNT7B was overexpressed in HBV-associated HCC tissues versus nontumor liver tissues, which was related to HCC patient survival. Further study in vitro showed that WNT7B and its receptor frizzled-4 (FZD4) were upregulated in response to large hepatitis B surface antigens (L-HBs). L-HBs increased canonical WNT signaling in HCC cells through WNT7B/FZD4. According to functional experiments, WNT7B enhanced the cell proliferation and metastasis in HCC. In vivo and in vitro studies investigated whether L-HBs induced sorafenib resistance by WNT7B in HCC. Interestingly, L-HBs suppressed sorafenib-induced mitophagy by increasing WNT7B/CTNNB1 signaling, resulting in chemoresistance. The findings revealed that WNT7B could be a promising molecular therapeutic target as well as a predictor of sorafenib resistance in HBV-related HCC. The suppression of HBV structural proteins such as L-HBs may play a crucial role in systemic chemotherapy resistance in HBV-associated HCC.

HBx increases chromatin accessibility and ETV4 expression to regulate dishevelled-2 and promote HCC progression

Hepatitis B virus (HBV) infection is the predominant causes of hepatocellular carcinoma (HCC). HBV X protein (HBx), as the most frequently integrated viral gene sequence following HBV infection, plays a critical role in the pathogenesis of HCC. H3K27ac is a characteristic marker for identifying active enhancers and even indicates chromatin accessibility associated with super-enhancers (SEs). In this study, H3K27ac ChIP-seq was applied for high-quality SE annotation of HBx-induced SEs and chromatin accessibility evaluation. The results indicated that HBx preferentially affects enrichment of H3K27ac in transcription factor signaling pathway genes, including ETV4. RNA-seq indicated that ETV4 is upregulated by HBx and that upregulated ETV4 promotes HCC progression. Interestingly, ETV4 was also included in the 568 cancer driver gene pool obtained by the Integrative OncoGenomics pipeline. However, the biological function and mechanism of ETV4 remain incompletely understood. In vivo and in vitro, we found that increased ETV4 expression promotes HCC cell migration and invasion by upregulating DVL2 and activating Wnt/β-catenin. The mRNA and protein levels of ETV4 are higher in tumor tissues compared with adjacent tissues, and high expression of ETV4 is associated with poor prognosis in HCC patients. In summary, we first confirm that ETV4 is significantly upregulated by HBx and involved in SE-associated chromatin accessibility. Increased expression of ETV4 promotes HCC cell invasion and metastasis by upregulating DVL2. The present study provides insight into the ETV4-DVL2-β-catenin axis in HBV-related HCC, which will be helpful for treating patients with aggressive HCC.

Induced Mitochondrial Alteration and DNA Damage via IFNGR-JAK2-STAT1-PARP1 Pathway Facilitates Viral Hepatitis Associated Hepatocellular Carcinoma Aggressiveness and Stemness

Simple Summary

Hepatitis virus is a major risk factor for liver cancer. We analyzed possible synergism between momelotinib and sorafenib in hepatitis virus-associated liver cancer. The combined effect of momelotinib and sorafenib both at in vitro and in vivo synergistically sup-presses the proliferation of vHCC cells and effectively reduces the tumor burden. Our results showed that momelotinib effectively suppressed the expression of the IFNGR-JAK-STAT-PARP1 pathway, which results in the downregulation of cancer stem cell genes and enhances the antitumor efficacy of sorafenib by initiating the expression of apoptosis-related genes and inhibiting the DNA repair gene in vHCC cells, thus maximizing its therapeutic potential for patients with HCC.

Abstract

Background: Hepatitis virus is a major risk factor for liver cancer. The mitochondrial dysfunction IFN gamma-related pathways are activated after virus infection. Jak family-related protein is involved in the downstream of IFN gamma-related pathways. However, the effect of the IFNGR-JAK-STAT pathway acting as functional regulators of their related protein expression on virus infection and hepatocellular carcinoma (HCC) remains unclear. Interestingly, the role of the DNA repair gene (PARP1) in therapy resistant cancers also has not been studied and explored well. In this study, we hypothesized that momelotinib could suppress the progression of HCC by targeting Jak family related and PARP1 DNA repair protein. Based on this observation, we link the relevant targets of the JAK family and the potential applications of targeted therapy inhibitors. Methods: We analyzed possible synergism between momelotinib and sorafenib in hepatitis virus-associated liver cancer. Immunostaining, colony formation assay, cell invasion, migration, and tumorsphere-formation assay were used for drug cytotoxicity, cell viability, and possible molecular mechanism. Result: We first demonstrated that the expression of Jak1 and 2 is significantly upregulated in vHCC than in nvHCC/normal liver tissues. In addition, the gene expression of IFN gamma-related pathways is activated after virus infection. Additionally, we found that momelotinib significantly inhibited the growth of HCC cells and reduces the expression of Jak2, which showed the importance of momelotinib in targeting Jak2 and reducing tumorigenesis in HCC. Meanwhile, momelotinib effectively inhibited the IFNGR-JAK-STAT pathway and reduced the migratory/invasive ability of vHCC cells through down-regulating EMT biomarkers (E-cadherin and vimentin), transcription factor (Slug), and significantly inhibits the DNA damage repair enzyme PARP1. It also induced cell apoptosis of vHCC cells. Furthermore, the combined effect of momelotinib and sorafenib both at in vitro and in vivo synergistically suppresses the proliferation of vHCC cells and effectively reduces the tumor burden. Conclusions: Our results showed that momelotinib effectively suppressed the expression of the IFNGR-JAK-STAT-PARP1 pathway, which results in the downregulation of cancer stem cell genes and enhances the antitumor efficacy of sorafenib by initiating the expression of apoptosis-related genes and inhibiting the DNA repair gene in vHCC cells, thus maximizing its therapeutic potential for patients with HCC.

The Mechanisms of HBV-Induced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy, and the hepatitis B virus (HBV) is its major pathogenic factor. Over the past decades, it has been confirmed that HBV infection could promote disease progression through a variety of mechanisms, ultimately leading to the malignant transformation of liver cells. Many factors have been identified in the pathogenesis of HBV-associated HCC (HBV-HCC), including HBV gene integration, genomic instability caused by mutation, and activation of cancer-promoting signaling pathways. As research in the progression of HBV-HCC progresses, the role of many new mechanisms, such as epigenetics, exosomes, autophagy, metabolic regulation, and immune suppression, is also being continuously explored. The occurrence of HBV-HCC is a complex process caused by interactions across multiple genes and multiple steps, where the synergistic effects of various cancer-promoting mechanisms accelerate the process of disease evolution from inflammation to tumorigenesis. In this review, we aim to provide a brief overview of the mechanisms involved in the occurrence and development of HBV-HCC, which may contribute to a better understanding of the role of HBV in the occurrence and development of HCC.

Hepatitis B virus induces sorafenib resistance in liver cancer via upregulation of cIAP2 expression

BACKGROUND

HBV promotes cell survival by upregulating the expression of the cellular inhibitor of apoptosis protein 2 (cIAP2), however whether it is involved in HBV-induced sorafenib resistance in liver cancer remains unclear.

METHODS

cIAP2 overexpression and knockdown was adopted to assess the involvement of cIAP2 in HBV-induced sorafenib resistance. Anti-HBV drug lamivudine and Akt inhibitor were used to investigate the impact of HBV replication on cIAP2 expression and sorafenib resistance. Xenotransplantation mouse model was used to confirm the data on cell lines in vitro.

RESULTS

Liver cancer cell line HepG2.215 showed increased cIAP2 expression and enhanced resistance to sorafenib. Upon sorafenib treatment, overexpression of cIAP2 in HepG2 lead to decreased cleaved caspase 3 level and increased cell viability, while knockdown of cIAP2 in HepG2.215 resulted in increased level of cleaved caspase 3 and decreased cell viability, suggesting the involvement of cIAP2 in HBV-induced sorafenib resistance. Furthermore, anti-HBV treatment reduced cIAP2 expression and partially restored sorafenib sensitivity in HepG2.215 cells. Xenotransplantation mouse model further confirmed that co-treatment with lamivudine and sorafenib could reduce sorafenib-resistant HepG2.215 tumor cell growth.

CONCLUSION

cIAP2 is involved in HBV-induced sorafenib resistance in liver cancer and anti-HBV treatments reduce cIAP2 expression and partially restore sorafenib sensibility.

The Role of IGF/IGF-1R Signaling in Hepatocellular Carcinomas: Stemness-Related Properties and Drug Resistance

Insulin-like Growth Factor (IGF)/IGF-1 Receptor (IGF-1R) signaling is known to regulate stem cell pluripotency and differentiation to trigger cell proliferation, organ development, and tissue regeneration during embryonic development. Unbalanced IGF/IGF-1R signaling can promote cancer cell proliferation and activate cancer reprogramming in tumor tissues, especially in the liver. Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death, with a high incidence and mortality rate in Asia. Most patients with advanced HCC develop tyrosine kinase inhibitor (TKI)-refractoriness after receiving TKI treatment. Dysregulation of IGF/IGF-1R signaling in HCC may activate expression of cancer stemness that leads to TKI refractoriness and tumor recurrence. In this review, we summarize the evidence for dysregulated IGF/IGF-1R signaling especially in hepatitis B virus (HBV)-associated HCC. The regulation of cancer stemness expression and drug resistance will be highlighted. Current clinical treatments and potential therapies targeting IGF/IGF-1R signaling for the treatment of HCC will be discussed.

Current status and future prospects of p38α/MAPK14 kinase and its inhibitors

P38α (which is also named MAPK14) plays a pivotal role in initiating different disease states such as inflammatory disorders, neurodegenerative diseases, cardiovascular cases, and cancer. Inhibitors of p38α can be utilized for treatment of these diseases. In this article, we reviewed the structural and biological characteristics of p38α, its relationship to the fore-mentioned disease states, as well as the recently reported inhibitors and classified them according to their chemical structures. We focused on the articles published in the literature during the last decade (2011-2020).

Bufalin inhibits hepatitis B virus-associated hepatocellular carcinoma development through androgen receptor dephosphorylation and cell cycle-related kinase degradation

PURPOSE

Hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), which has a male predominance, lacks effective therapeutic options. Previously, the cardiac glycoside analogue bufalin has been found to inhibit HBV infection and HCC development. As yet, however, its molecular role in HBV-associated HCC has remained obscure.

METHODS

Colony formation and soft agar assays, xenograft and orthotopic mouse models and HBV X protein (HBx) transgenic mice with exposure to diethylnitrosamine were used to evaluate the effect of bufalin on HBV-associated HCC growth and tumorigenicity. HBx-induced oncogenic signaling regulated by bufalin was assessed using PCR array, chromatin immunoprecipitation, site-directed mutagenesis, luciferase reporter, transcription and protein expression assays. Synergistic HCC therapeutic effects were examined using combinations of bufalin and sorafenib.

RESULTS

We found that bufalin exerted a more profound effect on inhibiting the proliferation of HBV-associated HCC cells than of non HBV-associated HCC cells. Bufalin significantly inhibited HBx-induced malignant transfromation in vitro and tumorigenicity in vivo. Androgen receptor (AR) signaling was found to be a target of bufalin resistance to HBV-associated hepatocarcinogenesis. We also found that bufalin induced both AR dephosphorylation and cell cycle-related kinase (CCRK) degradation to inhibit β-catenin/TCF signaling, which subsequently led to cell cycle arrest via cyclin D1 down-regulation and p21 up-regulation, resulting in HCC regression. Furthermore, we found that bufalin reduced > 60% diethylnitrosamine-induced hepatocarcinogenesis in HBx transgenic mice, and improved the sensitivity of refractory HBV-associated HCC cells to sorafenib treatment.

CONCLUSION

Our results indicate that bufalin acts as a potential anti-HCC therapeutic candidate to block HBx-induced AR/CCRK/β-catenin signaling by targeting AR and CCRK, which may provide a novel strategy for the treatment of HBV-associated HCC.

MicroRNA-216a-3p promotes sorafenib sensitivity in hepatocellular carcinoma by downregulating MAPK14 expression

We investigated MAPK14-dependent resistance to sorafenib in hepatocellular carcinoma (HCC). Bioinformatics analysis and dual luciferase reporter assays in HCC cell lines showed that miR-216a-3p directly binds to the 3'UTR of MAPK14 mRNA and downregulates MAPK14 protein expression. Consequently, miR-216a-3p expression correlates inversely with MAPK14 protein levels in HCC patient tissues. miR-216a-3p overexpression significantly increases the sorafenib sensitivity of HCC cells by suppressing MAPK14 expression and reducing the subsequent activation of the MEK/ERK and ATF2 signaling pathways. The growth of xenograft tumors derived from miR-216a-3p-overexpression HCC cells was significantly diminished in sorafenib-treated Balb/c nude mice compared to controls. High miR-216a-3p levels in HCC tissue samples prior to treatment correlated with a better sorafenib response and favorable prognosis. Our findings thus demonstrate that miR-216a-3p enhances sorafenib sensitivity in HCC cells and tumor tissues by decreasing MAPK14 levels, thereby inhibiting the MAPK14-dependent MEK/ERK and ATF2 signaling.

Ataxia telangiectasia mutated pathway disruption affects hepatic DNA and tissue damage in nonalcoholic fatty liver disease

To overcome the rising burdens of nonalcoholic fatty liver disease, mechanistic linkages in mitochondrial dysfunction, inflammation and hepatic injury are critical. As ataxia telangiectasia mutated (ATM) gene oversees DNA integrity and mitochondrial homeostasis, we analyzed mRNAs and total proteins or phosphoproteins related to ATM gene by arrays in subjects with healthy liver, fatty liver or nonalcoholic steatohepatitis. Functional genomics approaches were used to query DNA damage or cell growth events. The effects of fatty acid-induced toxicity in mitochondrial health, DNA integrity and cell proliferation were validated in HuH-7 cells, including by inhibiting ATM kinase activity or knckdown of its mRNA. In fatty livers, DNA damage and ATM pathway activation was observed. During induced steatosis in HuH-7 cells, lowering of ATM activity produced mitochondrial dysregulation, DNA damage and cell growth inhibition. In livers undergoing steatohepatitis, ATM was depleted with increased hepatic DNA damage and growth-arrest due to cell cycle checkpoint activations. Moreover, molecular signatures of oncogenesis were associated with upstream mechanistic networks directing cell metabolism, inflammation or growth that were either activated (in fatty liver) or inactivated (in steatohepatitis). To compensate for hepatic growth arrest, preoncogenic oval cell populations expressing connexin-43 and/or albumin emerged. These oval cells avoided DNA damage and proliferated actively. We concluded that ATM is a major contributor to the onset and progression of nonalcoholic fatty liver disease. Therefore, specific markers for ATM pathway dysregulation will allow prospective segregation of cohorts for disease susceptibility and progression from steatosis to steatohepatitis. This will offer superior design and evaluation parameters for clinical trials. Restoration of ATM activity with targeted therapies should be appropriate for nonalcoholic fatty liver disease.