Hepatocyte IKKbeta/NF-kappaB inhibits tumor promotion and progression by preventing oxidative stress-driven STAT3 activation

Cooperative defenses during enteropathogenic infection

During their co-evolution with pathogens, hosts acquired defensive health strategies that allow them to maintain their health or promote recovery when challenged with infections. The cooperative defense system is a largely unexplored branch of these evolved defense strategies. Cooperative defenses limit physiological damage and promote health without having a negative impact on a pathogen's ability to survive and replicate within the host. Here, we review recent discoveries in the new field of cooperative defenses using the model pathogens Citrobacter rodentium and Salmonella enterica. We discuss not only host-encoded but also pathogen-encoded mechanisms of cooperative defenses. Cooperative defenses remain an untapped resource in clinical medicine. With a global pandemic exacerbated by a lack of vaccine access and a worldwide rise in antibiotic resistance, the study of cooperative defenses offers an opportunity to safeguard health in the face of pathogenic infection.

Anticancer Applications and Pharmacological Properties of Piperidine and Piperine: A Comprehensive Review on Molecular Mechanisms and Therapeutic Perspectives

Piperine and piperidine are the two major alkaloids extracted from black pepper (Piper nigrum); piperidine is a heterocyclic moiety that has the molecular formula (CH₂)₅NH. Over the years, many therapeutic properties including anticancer potential of these two compounds have been observed. Piperine has therapeutic potential against cancers such as breast cancer, ovarian cancer, gastric cancer, gliomal cancer, lung cancer, oral squamous, chronic pancreatitis, prostate cancer, rectal cancer, cervical cancer, and leukemia. Whereas, piperidine acts as a potential clinical agent against cancers, such as breast cancer, prostate cancer, colon cancer, lung cancer, and ovarian cancer, when treated alone or in combination with some novel drugs. Several crucial signalling pathways essential for the establishment of cancers such as STAT-3, NF-κB, PI3k/Aκt, JNK/p38-MAPK, TGF-ß/SMAD, Smac/DIABLO, p-IκB etc., are regulated by these two phytochemicals. Both of these phytochemicals lead to inhibition of cell migration and help in cell cycle arrest to inhibit survivability of cancer cells. The current review highlights the pharmaceutical relevance of both piperine and piperidine against different types of cancers.

SHC4 promotes tumor proliferation and metastasis by activating STAT3 signaling in hepatocellular carcinoma

Background

The Src homology and collagen 4 (SHC4) is an important intracellular adaptor protein that has been shown to play a pro-cancer role in melanoma and glioma. However, the biological function and detailed mechanisms of SHC4 in hepatocellular carcinoma progression are unclear. This study aimed to evaluate the potential prognostic and treatment value of SHC4 in patients with HCC.

Methods

The expression status of SHC4 in HCC tissues were investigated by immunohistochemistry and western blotting. Clinical significance of SHC4 was evaluated in a large cohort of HCC patients. The effects of SHC4 repression or overexpression on migration, invasion, and tumor growth were detected by colony formation assay, wound healing, transwell assays, and xenograft assay. Cell cycle and EMT-related proteins were detected by western blotting and immunofluorescence. In addition, the molecular regulation between SHC4 and STAT3 signaling in HCC were discovered by western blotting, immunofluorescence and xenograft assay.

Results

SHC4 was overexpressed in HCC compared to adjacent normal liver tissues and increased SHC4 expression was associated with high AFP level, incomplete tumor encapsulation, poor tumor differentiation and poor prognosis. SHC4 was shown to enhance cell proliferation, colony formation, cells migration and invasion in vitro, and promotes cell cycle progression and EMT process in HCC cells. Tumor xenograft model assay confirmed the oncogenic role of SHC4 in tumorigenicity in nude mice. Moreover, activation of STAT3 signaling was found in the SHC4 overexpressed HCC cells and HCC tissues. Further intervention of STAT3 confirmed STAT3 as an important signaling pathway for the oncogenic role of SHC4 in HCC.

Conclusions

Together, our results reveal that SHC4 activates STAT3 signaling to promote HCC progression, which may provide new clinical ideas for the treatment of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02446-9.

Changes in immune profile affect disease progression in hepatocellular carcinoma

Objective: Hepatocellular carcinoma (HCC) as a chronic liver condition is largely associated with immune responses. Previous studies have revealed that different subsets of lymphocytes play fundamental roles in controlling or improving the development and outcome of solid tumors like HCC. Hence, this study aimed to investigate whether immune system changes were related to disease development in HCC patients. Methods: Peripheral blood mononuclear cells were isolated from 30 HCC patients and 30 healthy volunteers using Ficoll density centrifugation. The isolated cells were stained with different primary antibodies and percentages of different immune cells were determined by flow cytometry. Results: HCC patients indicated significant reductions in the numbers of CD4⁺ cells, Tbet+IFNγ+cells, and GATA+IL-4+cells in peripheral blood in comparison with healthy individuals (p < 0.05). There was no significant change in IL-17+RORγt+cells between patient and healthy groups. In contrast, Foxp3+CD127^lowcell frequency was significantly higher in patients than healthy subjects (p < 0.0001). The numbers of Th1, Th2, and Th17 cells were significantly lower in HCC patients than healthy control (p < 0.0001), although the reduction in Th2 cell numbers was not statistically significant. On the contrary, Treg percentage showed a significant increase in patients compared to healthy subjects (p < 0.0001). Other data revealed that Th1, Th2, and Th17 cell frequencies were significantly higher in healthy individuals than patients with different TNM stages of HCC, with the exception of Th2 in patients with stage II HCC (p < 0.01-0.05). Treg percentage was significantly increased in patients with different TNM stages (p < 0.0001). Among all CD4⁺ T cells, the frequency of Th2 cell was significantly associated with TNM stages of HCC (p < 0.05). Conclusion: Our data provide further evidence to show that immune changes may participate in determining HCC progression and disease outcome. However, it should be mentioned that more investigations are needed to clarify our results and explain possible impacts of other immune cells on the pathogenesis of HCC.

3-Formylchromone Counteracts STAT3 Signaling Pathway by Elevating SHP-2 Expression in Hepatocellular Carcinoma

Simple Summary

STAT3 acts as a potential tumor-promoting transcription factor that gets aberrantly activated in several types of human cancers and plays a crucial role in tumor progression and metastasis. STAT3 expression has been correlated with a dismal prognosis and poor survival. In this study, we have demonstrated that 3-formylchromone inhibits the STAT3 signaling in HCC cells by modulating SHP-2 expression. It also effectively diminished the tumor growth and subsequent reduction in metastasis in the HCC mouse model without exhibiting any major side effects.

Abstract

Hepatocellular carcinoma (HCC) is one of the leading cancers that contribute to a large number of deaths throughout the globe. The signal transducer and activator of transcription 3 (STAT3) is a tumorigenic protein that is overactivated in several human malignancies including HCC. In the present report, the effect of 3-formylchromone (3FC) on the STAT3 signaling pathway in the HCC model was investigated. 3FC downregulated the constitutive phosphorylation of STAT3 and non-receptor tyrosine kinases such as JAK1 and JAK2. It also suppressed the transportation of STAT3 to the nucleus and reduced its DNA-binding ability. Pervanadate treatment overrode the 3FC-triggered STAT3 inhibition, and the profiling of cellular phosphatase expression revealed an increase in SHP-2 levels upon 3FC treatment. The siRNA-driven deletion of SHP-2 led to reinstate STAT3 activation. 3FC downmodulated the levels of various oncogenic proteins and decreased CXCL12-driven cell migration and invasion. Interestingly, 3FC did not exhibit any substantial toxicity, whereas it significantly regressed tumor growth in an orthotopic HCC mouse model and abrogated lung metastasis. Overall, 3FC can function as a potent agent that can display antitumor activity by targeting STAT3 signaling in HCC models.

Pharmacologic Antagonization of Cannabinoid Receptor 1 Improves Cholestasis in Abcb4-/- Mice

BACKGROUND & AIMS

The endocannabinoid system is involved in the modulation of inflammatory, fibrotic, metabolic, and carcinogenesis-associated signaling pathways via cannabinoid receptor (CB)1 and CB2. We hypothesized that the pharmacologic antagonization of CB1 receptor improves cholestasis in Abcb4^-/- mice.

METHODS

After weaning, male Abcb4^-/- mice were treated orally with rimonabant (a specific antagonist of CB1) or ACEA (an agonist of CB1) until up to 16 weeks of age. Liver tissue and serum were isolated and examined by means of serum analysis, quantitative real time polymerase chain reaction, Western blot, immunohistochemistry, and enzyme function. Untreated Abcb4^-/- and Bagg Albino Mouse/c wild-type mice served as controls.

RESULTS

Cholestasis-induced symptoms such as liver damage, bile duct proliferation, and enhanced circulating bile acids were improved by CB1 antagonization. Rimonabant treatment also improved Phosphoenolpyruvat-Carboxykinase expression and reduced inflammation and the acute-phase response. The carcinogenesis-associated cellular-Jun N-terminal kinase/cellular-JUN and signal transducer and activator of transcription 3 signaling pathways activated in Abcb4^-/- mice were reduced to wild-type level by CB1 antagonization.

CONCLUSIONS

We showed a protective effect of oral CB1 antagonization in chronic cholestasis using the established Abcb4^-/- model. Our results suggest that pharmacologic antagonization of the CB1 receptor could have a therapeutic benefit in cholestasis-associated metabolic changes, liver damage, inflammation, and carcinogenesis.

TM4SF5-mediated liver malignancy involves NK cell exhaustion-like phenotypes

Aberrant extracellular matrix and immune cell alterations within the tumor microenvironment promote the pathological progression of liver carcinogenesis. Although transmembrane 4 L six family member 5 (TM4SF5) is involved in liver fibrosis and cancer, its mechanism avoiding immune surveillance during carcinogenesis remains unknown. We investigated how TM4SF5-mediated signaling caused immune evasion using in vitro primary cells and in vivo liver tissues from genetic or chemically induced mouse models. TM4SF5-transgenic and diethylnitrosamine (DEN)-induced liver cancer mouse models exhibited fibrotic and cancerous livers, respectively, with enhanced TM4SF5, pY⁷⁰⁵STAT3, collagen I, and laminin γ2 levels. These TM4SF5-mediated effects were abolished by TM4SF5 inhibitor, 4'-(p-toluenesulfonylamido)-4-hydroxychalcone (TSAHC). TM4SF5-dependent tumorigenesis involved natural killer (NK) cell exhaustion-like phenotypes including the reduction of NK cell number or function, which were blocked with TSAHC treatment. TM4SF5 expression in cancer cells downregulated stimulatory ligands and receptors for NK cell cytotoxicity, including SLAMF6, SLAMF7, MICA/B, and others. TM4SF5 suppression or inhibition reduced STAT3 signaling activity and recovered the receptor levels and NK cell surveillance, leading to reduced fibrotic and cancerous phenotypes, and longer survival. Altogether, these findings suggest that TM4SF5-mediated STAT3 activity for extracellular matrix modulation is involved in the progression of liver disease to HCC and that TM4SF5 appears to suppress NK cells during liver carcinogenesis.

Dark and bright side of targeting fibroblast growth factor receptor 4 in the liver

Fibroblast growth factor (FGF) receptor 4 (FGFR4) and its cognate ligand, FGF19, are implicated in a range of cellular processes, including differentiation, metabolism and proliferation. Indeed, their aberrant activation has been associated with the development of hepatic tumours. Despite great advances in early diagnosis and the development of new therapies, liver cancer is still associated with a high mortality rate, owing primarily to high molecular heterogeneity and unclear molecular targeting. The development of FGFR4 inhibitors is a promising tool in patients with concomitant supraphysiological levels of FGF19 and several clinical trials are testing these treatments for patients with advanced hepatocellular carcinoma (HCC). Conversely, using FGF19 analogues to activate FGFR4-KLOTHO β represents a novel therapeutic strategy in patients presenting with cholestatic liver disorders and non-alcoholic steatohepatitis, which could potentially prevent the development of metabolic HCC. Herein, we provide an overview of the currently available therapeutic options for targeting FGFR4 in HCC and other liver diseases, highlighting the need to carefully stratify patients and personalise therapeutic strategies.

PIAS3/SOCS1-STAT3 axis responses to oxidative stress in hepatocellular cancer cells

The participation of STAT3 and its upstream inhibitors, PIAS3 and SOCS1, in the oxidative response of hepatocellular carcinoma (HCC) cells was uncertain. Here, the expression of PIAS3 and SOCS1 in HCC tissues and cell lines was explored, and we sought to determine whether oxidative stress epigenetically regulated PIAS3 and SOCS1 expression and STAT3 activation in HCC cells. The expression of PIAS3 and SOCS1 was markedly decreased in HCC cell lines and tissues compared to normal hepatic cells and tissues. In HCC patients, low PIAS3 and SOCS1 expression were associated with poor survival. Oxidative stress induced by H₂O₂ in HepG2 cells was indicated by low antioxidant levels and high protein carbonyl content. Moreover, oxidative stress in HepG2 cells contributed to reduced proliferation but increased apoptosis, migration, and invasion capacity, which might be counteracted by antioxidants, such as tocopheryl acetate (TA). PIAS3 and SOCS1 expression was markedly decreased, while STAT3 was activated in HepG2 cells in response to H₂O₂ exposure. Co-treatment with antioxidant TA effectively increased the expression of PIAS3 and SOCS1, but it dephosphorylated STAT3 in H₂O₂-treated cells. PIAS1 or SOCS1 overexpression in HepG2 cells after H₂O₂ treatment restored cell viability and anti-oxidative responses and decreased apoptosis, migration, and invasion ability, and dephosphorylated STAT3 levels. Co-administration of the STAT3 activator, colivelin, partially abolished the effect of PIAS3 and SOCS1 overexpression in these processes. Therefore, oxidative stress in HCC cells may improve their migration and reduce proliferation through STAT3 activation through the repression of PIAS3 and SOCS1 expression.

Role of Hepatocyte-Derived Osteopontin in Liver Carcinogenesis

Osteopontin (OPN) expression correlates with tumor progression in many cancers, including hepatocellular carcinoma (HCC); however, its role in the onset of HCC remains unclear. We hypothesized that increased hepatocyte‐derived OPN is a driver of hepatocarcinogenesis. Analysis of a tissue microarray of 366 human samples revealed a continuous increase in OPN expression during hepatocarcinogenesis. In patients with cirrhosis, a transcriptome‐based OPN correlation network was associated with HCC incidence along 10 years of follow‐up, together with messenger RNA (mRNA) signatures of carcinogenesis. After diethylnitrosamine (DEN) injection, mice with conditional overexpression of Opn in hepatocytes (Opn^Hep transgenic [Tg]) showed increased tumor burden. Surprisingly, mice with conditional ablation of Opn in hepatocytes (Opn^ΔHep) expressed a similar phenotype. The acute response to DEN was reduced in Opn^ΔHep, which also showed more cancer stem/progenitor cells (CSCs, CD44⁺AFP⁺) at 5 months. CSCs from Opn^Hep Tg mice expressed several mRNA signatures known to promote carcinogenesis, and mRNA signatures from Opn^Hep Tg mice were associated with poor outcome in human HCC patients. Treatment with rOPN had little effect on CSCs, and their progression to HCC was similar in Opn^−/− compared with wild‐type mice. Finally, ablation of Cd44, an OPN receptor, did not reduce tumor burden in Cd44^−/−Opn^Hep Tg mice. Conclusions: Hepatocyte‐derived OPN acts as a tumor suppressor at physiological levels by controlling the acute response to DEN and the presence of CSCs, while induction of OPN is pro‐tumorigenic. This is primarily due to intracellular events rather that by the secretion of the protein and receptor activation.

Regression of Hepatic Fibrosis and Evolution of Cirrhosis: A Concise Review

Fibrosis is not a unidirectional, linear process, but a dynamic one resulting from an interplay of fibrogenesis and fibrolysis depending on the extent and severity of a biologic insult, or lack thereof. Regression of fibrosis has been documented best in patients treated with phlebotomies for hemochromatosis, and after successful suppression and eradication of chronic hepatitis B and C infections. This evidence mandates a reconsideration of the term "cirrhosis," which implies an inevitable progression towards liver failure. Furthermore, it also necessitates a staging system that acknowledges the bidirectional nature of evolution of fibrosis, and has the ability to predict if the disease process is progressing or regressing. The Beijing classification attempts to fill this gap in contemporary practice. It is based on microscopic features termed "the hepatic repair complex," defined originally by Wanless and colleagues. The elements of the hepatic repair complex represent the 3 processes of fragmentation and regression of scar, vascular remodeling (resolution), and parenchymal regeneration. However, regression of fibrosis does not imply resolution of cirrhosis, which is more than just a stage of fibrosis. So far, there is little to no evidence to suggest that large regions of parenchymal extinction can be repopulated by regenerating hepatocytes. Similarly, the vascular lesions of cirrhosis persist, and there is no evidence of complete return to normal microcirculation in cirrhotic livers. In addition, the risk of hepatocellular carcinoma is higher compared with the general population and these patients need continued screening and surveillance.

Antagonizing STK25 Signaling Suppresses the Development of Hepatocellular Carcinoma Through Targeting Metabolic, Inflammatory, and Pro-Oncogenic Pathways

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is one of the most fatal and fastest-growing cancers. Recently, nonalcoholic steatohepatitis (NASH) has been recognized as a major catalyst for HCC. Thus, additional research is critically needed to identify mechanisms involved in NASH-induced hepatocarcinogenesis, to advance the prevention and treatment of NASH-driven HCC. Because the sterile 20-type kinase serine/threonine kinase 25 (STK25) exacerbates NASH-related phenotypes, we investigated its role in HCC development and aggravation in this study.

METHODS

Hepatocarcinogenesis was induced in the context of NASH in Stk25 knockout and wild-type mice by combining chemical procarcinogens and a dietary challenge. In the first cohort, a single injection of diethylnitrosamine was combined with a high-fat diet-feeding. In the second cohort, chronic administration of carbon tetrachloride was combined with a choline-deficient L-amino-acid-defined diet. To study the cell-autonomous mode of action of STK25, we silenced this target in the human hepatocarcinoma cell line HepG2 by small interfering RNA.

RESULTS

In both mouse models of NASH-driven HCC, the livers from Stk25-/- mice showed a markedly lower tumor burden compared with wild-type controls. We also found that genetic depletion of STK25 in mice suppressed liver tumor growth through reduced hepatocellular apoptosis and decreased compensatory proliferation, by a mechanism that involves protection against hepatic lipotoxicity and inactivation of STAT3, ERK1/2, and p38 signaling. Consistently, silencing of STK25 suppressed proliferation, apoptosis, migration, and invasion in HepG2 cells, which was accompanied by lower expression of the markers of epithelial-mesenchymal transition and autophagic flux.

CONCLUSIONS

This study provides evidence that antagonizing STK25 signaling hinders the development of NASH-related HCC and provides an impetus for further analysis of STK25 as a therapeutic target for NASH-induced HCC treatment in human beings.

Progression on the Roles and Mechanisms of Tumor-Infiltrating T Lymphocytes in Patients With Hepatocellular Carcinoma

Primary liver cancer (PLC) is one of the most common malignancies in China, where it ranks second in mortality and fifth in morbidity. Currently, liver transplantation, hepatic tumor resection, radiofrequency ablation, and molecular-targeted agents are the major treatments for hepatocellular carcinoma (HCC). Overall, HCC has a poor survival rate and a high recurrence rate. Tumor-infiltrating lymphocytes (TILs) have been discovered to play essential roles in the development, prognosis, and immunotherapy treatment of HCC. As the major component cells of TILs, T cells are also proved to show antitumor and protumor effects in HCC. Foxp3+, CD8+, CD3+, and CD4+ T lymphocytes are the broadly studied subgroups of TILs. This article reviews the roles and mechanisms of different tumor-infiltrating T lymphocyte subtypes in HCC.

A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

circGLI3 Inhibits Oxidative Stress by Regulating the miR-339-5p/VEGFA Axis in IPEC-J2 Cells

As a new type of noncoding RNA, circular RNA (circRNA) is stable in cells and not easily degraded. This type of RNA can also competitively bind miRNAs to regulate the expression of their target genes. The role of circRNA in the mechanism of intestinal oxidative stress (OS) in weaned piglets is still unclear. In our research, diquat (DQ) was used to induce OS in small intestinal epithelial cells (IPEC-J2) to construct an OS cell model. Mechanistically, dual luciferase reporter assays, fluorescence in situ hybridization (FISH), and western blotting were performed to confirm that circGLI3 directly sponged miR-339-5p and regulated the expression of VEGFA. Overexpression of circGLI3 promoted IPEC-J2 cell proliferation, increased the proportion of S-phase cells (P < 0.01), and reduced reactive oxygen species (ROS) generation when IPEC-J2 cells were subjected to OS. circGLI3 can increase the activity of glutathione peroxidase (GSH-Px) and the total antioxidant capacity (T-AOC) in IPEC-J2 cells and reduce the malondialdehyde (MDA) content and levels of inflammatory factors. Therefore, overexpression of circGLI3 reduced oxidative damage, whereas miR-339-5p mimic counteracted these effects. We identified a regulatory network composed of circGLI3, miR-339-5p, and VEGFA and verified that circGLI3 regulates VEGFA by directly binding miR-339-5p. The expression of VEGFA affects IPEC-J2 cell proliferation, cell cycle progression, and ROS content and changes the levels of antioxidant enzymes and inflammatory factors. This study reveals the molecular mechanism by which circGLI3 inhibits OS in the intestine of piglets and provides a theoretical basis for further research on the effect of OS on intestinal function.

Does Schistosoma Mansoni Facilitate Carcinogenesis?

Schistosomiasis is one of the most prominent parasite-induced infectious diseases, causing tremendous medical and socioeconomic problems. Current studies have reported on the spread of endemic regions and the fear of development of resistance against praziquantel, the only effective drug available. Among the Schistosoma species, only S. haematobium is classified as a Group 1 carcinogen (definitely cancerogenic to humans), causing squamous cell carcinoma of the bladder, whereas infection with S. mansoni is included in Group 3 of carcinogenic hazards to humans by the International Agency for Research on Cancer (IARC), indicating insufficient evidence to determine its carcinogenicity. Nevertheless, although S. mansoni has not been discussed as an organic carcinogen, the multiplicity of case reports, together with recent data from animal models and cell culture experiments, suggests that this parasite can predispose patients to or promote hepatic and colorectal cancer. In this review, we discuss the current data, with a focus on new developments regarding the association of S. mansoni infection with human cancer and the recently discovered biomolecular mechanisms by which S. mansoni may predispose patients to cancer development and carcinogenesis.

Advances of Targeted Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the common and fatal malignancies, which is a significant global health problem. The clinical applicability of traditional surgery and other locoregional therapies is limited, and these therapeutic strategies are far from satisfactory in improving the outcomes of advanced HCC. In the past decade, targeted therapy had made a ground-breaking progress in advanced HCC. Those targeted therapies exert antitumor effects through specific signals, including anti-angiogenesis or cell cycle progression. As a standard systemic therapy option, it tremendously improves the survival of this devastating disease. Moreover, the combination of targeted therapy with immune checkpoint inhibitor (ICI) has demonstrated more potent anticancer effects and becomes the hot topic in clinical studies. The combining medications bring about a paradigm shift in the treatment of advanced HCC. In this review, we presented all approved targeted agents for advanced HCC with an emphasis on their clinical efficacy, summarized the advances of multi-target drugs in research for HCC and potential therapeutic targets for drug development. We also discussed the exciting results of the combination between targeted therapy and ICI.

The zinc finger protein Miz1 suppresses liver tumorigenesis by restricting hepatocyte-driven macrophage activation and inflammation

Chronic inflammation plays a central role in hepatocellular carcinoma (HCC), but the contribution of hepatocytes to tumor-associated inflammation is not clear. Here, we report that the zinc finger transcription factor Miz1 restricted hepatocyte-driven inflammation to suppress HCC, independently of its transcriptional activity. Miz1 was downregulated in HCC mouse models and a substantial fraction of HCC patients. Hepatocyte-specific Miz1 deletion in mice generated a distinct sub-group of hepatocytes that produced pro-inflammatory cytokines and chemokines, which skewed the polarization of the tumor-infiltrating macrophages toward pro-inflammatory phenotypes to promote HCC. Mechanistically, Miz1 sequestrated the oncoprotein metadherin (MTDH), preventing MTDH from promoting transcription factor nuclear factor κB (NF-κB) activation. A distinct sub-group of pro-inflammatory cytokine-producing hepatocytes was also seen in a subset of HCC patients. In addition, Miz1 expression inversely correated with disease recurrence and poor prognosis in HCC patients. Our findings identify Miz1 as a tumor suppressor that prevents hepatocytes from driving inflammation in HCC.

Hemistepsin a Induces Apoptosis of Hepatocellular Carcinoma Cells by Downregulating STAT3

Hemistepta lyrata (Bunge) Bunge is a biennial medicinal plant possessing beneficial effects including anti-inflammation, and hemistepsin A (HsA) isolated from H. lyrata has been known as a hepatoprotective sesquiterpene lactone. In this report, we explored the cytotoxic effects of H. lyrata on hepatocellular carcinoma (HCC) cells and investigated the associated bioactive compounds and their relevant mechanisms. From the viability results of HCC cells treated with various H. lyrata extracts, HsA was identified as the major compound contributing to the H. lyrata-mediated cytotoxicity. HsA increased expression of cleaved PARP and cells with Sub-G1 phase, Annexin V binding, and TUNEL staining, which imply HsA induces apoptosis. In addition, HsA provoked oxidative stress by decreasing the reduced glutathione/oxidized glutathione ratio and accumulating reactive oxygen species and glutathione-protein adducts. Moreover, HsA inhibited the transactivation of signal transducer and activator of transcription 3 (STAT3) by its dephosphorylation at Y705 and glutathione conjugation. Stable expression of a constitutive active mutant of STAT3 prevented the reduction of cell viability by HsA. Finally, HsA enhanced the sensitivity of sorafenib-mediated cytotoxicity by exaggerating oxidative stress and Y705 dephosphorylation of STAT3. Therefore, HsA will be a promising candidate to induce apoptosis of HCC cells via downregulating STAT3 and sensitizing conventional chemotherapeutic agents.

NAFLD-Associated HCC: Progress and Opportunities

Due to an increase in the obesity-associated metabolic syndrome of epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC) in western countries. This presents added challenges, as NAFLD-associated HCC tends to present at an advanced stage in older patients with co-morbidities. Their prognosis is generally poor with the benefits of standard therapies less certain. The pathogenesis of NAFLD-associated HCC is multifactorial and not well understood, although the risk of HCC developing undoubtedly increases as NAFLD progresses to steatohepatitis and cirrhosis. Recent advances in our understanding of the drivers of NAFLD and HCC will hopefully lead to the development of clinically relevant biomarkers, tools and strategies to aid the identification of high-risk patients, inform preventive measures, and introduction of better tolerated targeted therapies. Lifestyle modification and chemoprevention with drugs such as anti-platelets, statins and anti-diabetics are being evaluated for HCC prevention. The landmark IMBrave150 study introducing the combination of atezolizumab and bevacizumab has recently transformed the landscape of systemic therapies in HCC, with follow-up analyses and real-world data for patients with NAFLD-associated HCC eagerly anticipated. While responses may vary in ways not yet appreciated, the rate of discovery and progress suggests imminent change and opportunities.

Type I Interferon Signaling Accelerates Liver Regeneration by Metabolic Modulation in Noninfectious Conditions

Type I interferon (IFN-I) has a well-known function in controlling viral infections, but its contribution in hepatocyte proliferation and hepatocellular carcinoma (HCC) formation remains unclear. Mice deficient in IFN-α receptor expression in whole mice or only in hepatocytes (Ifnar^-/- and Ifnar^Δliver) were used to investigate the role of IFN-I signaling in cell proliferation and cancer formation in the liver. Ifnar^-/- mice were resistant to chemical-induced HCC formation in the absence of infection. The results show that low grade of IFN-I and interferon-stimulated gene were expressed substantially in naïve mouse liver. The low level of IFN-I activation is constantly present in mouse liver after weaning and negatively modulates forkhead box O hepatic expression. The IFN-I signaling can be partially blocked by the clearance of lipopolysaccharide. Mice lacking IFN-I signaling have lower basal proliferation activity and delayed liver regeneration processes after two-thirds partial hepatectomy. The activation of IFN-I signaling on hepatocyte controls glucose homeostasis and lipid metabolism to support proliferation potency and long-term tumorigenesis. Our results reveal a positive role of low-grade IFN-I singling to hepatocyte proliferation and HCC formation by modulating glucose homeostasis and lipid metabolism.

IL-6 promotes MYC-induced B cell lymphomagenesis independent of STAT3

The inflammatory cytokine IL-6 is known to play a causal role in the promotion of cancer, although the underlying mechanisms remain to be completely understood. Interplay between endogenous and environmental cues determines the fate of cancer development. The Eμ-myc transgenic mouse expresses elevated levels of c-Myc in the B cell lineage and develops B cell lymphomas with associated mutations in p53 or other genes linked to apoptosis. We generated Eμ-myc mice that either lacked the IL-6 gene, or lacked the STAT3 gene specifically in B cells to determine the role of the IL-6/JAK/STAT3 pathway in tumor development. Using the Eμ-myc lymphoma mouse model, we demonstrate that IL-6 is a critical tumor promoter during early stages of B cell lymphomagenesis. IL-6 is shown to inhibit the expression of tumor suppressors, notably BIM and PTEN, and this may contribute to advancing MYC-driven B cell tumorigenesis. Several miRNAs known to target BIM and PTEN are upregulated by IL-6 and likely lead to the stable suppression of pro-apoptotic pathways early during the tumorigenic process. STAT3, a classical downstream effector of IL-6, appears dispensable for Eμ-myc driven lymphomagenesis. We conclude that the growth-promoting and anti-apoptotic mechanisms activated by IL-6 are critically involved in Eμ-myc driven tumor initiation and progression, but the B cell intrinsic expression of STAT3 is not required.

A Positive Feedback Loop of AKR1C3-Mediated Activation of NF-κB and STAT3 Facilitates Proliferation and Metastasis in Hepatocellular Carcinoma

AKR1C3 is an enzyme belonging to the aldo-ketoreductase family, the members of which catalyze redox transformations involved in biosynthesis, intermediary metabolism, and detoxification. AKR1C3 plays an important role in tumor progression and metastasis, however, little is known about the function and the molecular mechanism underlying the role of AKR1C3 in hepatocellular carcinoma (HCC). In this study, we report that AKR1C3 is significantly upregulated in HCC and that increased AKR1C3 is associated with poor survival. AKR1C3 positively regulated HCC cell proliferation and metastasis in vitro and in vivo. AKR1C3 promoted tumor proliferation and metastasis by activating NF-κB signaling. Furthermore, AKR1C3 regulated NF-κB activity by modulating TRAF6 and inducing its autoubiquitination in HCC cells. Activation of NF-κB released proinflammatory factors that facilitated the phosphorylation of STAT3 and increased tumor cell proliferation and invasion. Gain- and loss-of-function experiments showed that AKR1C3 promoted tumor proliferation and invasion via the IL6/STAT3 pathway. STAT3 also directly bound the AKR1C3 promoter and increased transcription of AKR1C3, thereby establishing a positive regulatory feedback loop. Treatment with the AKR1C3 inhibitors indocin and medroxyprogesterone acetate inhibited tumor growth and invasion and promoted apoptosis in HCC cells. Collectively, these results indicate that a AKR1C3/NF-κB/STAT3 signaling loop results in HCC cell proliferation and metastasis and could be a promising therapeutic target in HCC. SIGNIFICANCE: These findings elucidate a novel AKR1C3-driven signaling loop that regulates proliferation and metastasis in HCC, providing potential prognostic and therapeutic targets in this disease.

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

Targeting EphA2 suppresses hepatocellular carcinoma initiation and progression by dual inhibition of JAK1/STAT3 and AKT signaling

Hepatocellular carcinoma (HCC) remains one of the deadliest malignancies worldwide. One major obstacle to treatment is a lack of effective molecular-targeted therapies. In this study, we find that EphA2 expression and signaling are enriched in human HCC and associated with poor prognosis. Loss of EphA2 suppresses the initiation and growth of HCC both in vitro and in vivo. Furthermore, CRISPR/CAS9-mediated EphA2 inhibition significantly delays tumor development in a genetically engineered murine model of HCC. Mechanistically, we discover that targeting EphA2 suppresses both AKT and JAK1/STAT3 signaling, two separate oncogenic pathways in HCC. We also identify a small molecule kinase inhibitor of EphA2 that suppresses tumor progression in a murine HCC model. Together, our results suggest EphA2 as a promising therapeutic target for HCC.

Role of necroptosis in chronic hepatic inflammation and fibrosis in a mouse model of increased oxidative stress

Mice deficient in the antioxidant enzyme Cu/Zn-superoxide dismutase (Sod1^-/- or Sod1KO mice) have increased oxidative stress, show accelerated aging and develop spontaneous hepatocellular carcinoma (HCC) with age. Similar to humans, HCC development in Sod1KO mice progresses from non-alcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH) with fibrosis, which eventually progresses to HCC. Oxidative stress plays a role in NAFLD to NASH progression, and liver inflammation is the main mechanism that drives the disease progression from NASH to fibrosis. Because necroptosis is a major source of inflammation, we tested the hypothesis that increased necroptosis in the liver plays a role in increased inflammation and fibrosis in Sod1KO mice. Phosphorylation of MLKL (P-MLKL), a well-accepted marker of necroptosis, and expression of MLKL protein were significantly increased in the livers of Sod1KO mice compared to wild type (WT) mice indicating increased necroptosis. Similarly, phosphorylation of RIPK3 and RIPK3 protein levels were also significantly increased. Markers of pro-inflammatory M1 macrophages, NLRP3 inflammasome, and transcript levels of pro-inflammatory cytokines and chemokines, e.g., TNFα, IL-6, IL-1β, and Ccl2 that are associated with human NASH, were significantly increased. Expression of antioxidant enzymes and heat shock proteins, and markers of fibrosis and oncogenic transcription factor STAT3 were also upregulated and autophagy was downregulated in the livers of Sod1KO mice. Short term treatment of Sod1KO mice with necrostatin-1s (Nec-1s), a necroptosis inhibitor, reversed these conditions. Our data show for the first time that necroptosis-mediated inflammation contributes to fibrosis in a mouse model of increased oxidative stress and accelerated aging, that also exhibits progressive HCC development.

Endoplasmic Reticulum Stress Signaling and the Pathogenesis of Hepatocarcinoma

Hepatocellular carcinoma (HCC), also known as hepatoma, is a primary malignancy of the liver and the third leading cause of cancer mortality globally. Although much attention has focused on HCC, its pathogenesis remains largely obscure. The endoplasmic reticulum (ER) is a cellular organelle important for regulating protein synthesis, folding, modification and trafficking, and lipid metabolism. ER stress occurs when ER homeostasis is disturbed by numerous environmental, physiological, and pathological challenges. In response to ER stress due to misfolded/unfolded protein accumulation, unfolded protein response (UPR) is activated to maintain ER function for cell survival or, in cases of excessively severe ER stress, initiation of apoptosis. The liver is especially susceptible to ER stress given its protein synthesis and detoxification functions. Experimental data suggest that ER stress and unfolded protein response are involved in HCC development, aggressiveness and response to treatment. Herein, we highlight recent findings and provide an overview of the evidence linking ER stress to the pathogenesis of HCC.

NF-κB in Cancer Immunity: Friend or Foe?

The emergence of immunotherapies has definitely proven the tight relationship between malignant and immune cells, its impact on cancer outcome and its therapeutic potential. In this context, it is undoubtedly critical to decipher the transcriptional regulation of these complex interactions. Following early observations demonstrating the roles of NF-κB in cancer initiation and progression, a series of studies converge to establish NF-κB as a master regulator of immune responses to cancer. Importantly, NF-κB is a family of transcriptional activators and repressors that can act at different stages of cancer immunity. In this review, we provide an overview of the selective cell-intrinsic contributions of NF-κB to the distinct cell types that compose the tumor immune environment. We also propose a new view of NF-κB targeting drugs as a new class of immunotherapies for cancer.

Synergistic antitumor activity of sorafenib and artesunate in hepatocellular carcinoma cells

Sorafenib is currently the standard chemotherapy drug for treatment of advanced hepatocellular carcinoma (HCC). But its efficacy requires improvement, it is imperative to seek therapeutic strategies that combine sorafenib with other anticancer agents. In this study we investigated the synergistic anticancer effect of combining sorafenib and artesunate, an anti-malaria drug derivative, against HCC in vitro and in vivo. We first showed that artesunate (1-100 μM) alone dose-dependently inhibited the proliferation of five HCC cell lines tested with IC50 values of around 100 μM. Artesunate treatment dose-dependently increased the ROS level in both HuH7 and Hep3B cells; addition of NAC significantly ameliorated the antiproliferation effect of artesunate against HuH7 and Hep3B cells. Then we demonstrated that combination of sorafenib and artesunate exerted synergistic antiproliferation effect and induced synergistic apoptosis in HCC cell lines. In nude mice bearing Hep3B xenografts, combined administration of sorafenib and artesunate significantly enhanced the suppression on tumor growth. We further revealed that sorafenib dose-dependently decreased the levels of p-ERK and p-STAT3, whereas artesunate markedly increased the levels of p-ERK and p-STAT3 in HuH7 and Hep3B cells. When used in combination, sorafenib abolished artesunate-elevated levels of p-STAT3 and p-ERK. Moreover, pharmacological inhibition of ERK by inhibitor PD0325901 or STAT3 by inhibitor Stattic markedly enhanced the anticancer activity of artesunate, suggesting that suppression of ERK and STAT3 signaling by sorafenib contributes to the synergistic anticancer activity against HCC caused by combination of sorafenib and artesunate. Taken together, our results provide an evidence for possible use of sorafenib plus artesunate or artemisinin analogs for treatment of HCC in the future.

Risk Factors, Pathogenesis, and Strategies for Hepatocellular Carcinoma Prevention: Emphasis on Secondary Prevention and Its Translational Challenges

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated mortality globally. Given the limited therapeutic efficacy in advanced HCC, prevention of HCC carcinogenesis could serve as an effective strategy. Patients with chronic fibrosis due to viral or metabolic etiologies are at a high risk of developing HCC. Primary prevention seeks to eliminate cancer predisposing risk factors while tertiary prevention aims to prevent HCC recurrence. Secondary prevention targets patients with baseline chronic liver disease. Various epidemiological and experimental studies have identified candidates for secondary prevention-both etiology-specific and generic prevention strategies-including statins, aspirin, and anti-diabetic drugs. The introduction of multi-cell based omics analysis along with better characterization of the hepatic microenvironment will further facilitate the identification of targets for prevention. In this review, we will summarize HCC risk factors, pathogenesis, and discuss strategies of HCC prevention. We will focus on secondary prevention and also discuss current challenges in translating experimental work into clinical practice.

Metabolic interaction between amino acid deprivation and cisplatin synergistically reduces phosphoribosyl-pyrophosphate and augments cisplatin cytotoxicity

Cisplatin is a mainstay of cancer chemotherapy. It forms DNA adducts, thereby activating poly(ADP-ribose) polymerases (PARPs) to initiate DNA repair. The PARP substrate NAD⁺ is synthesized from 5-phosphoribose-1-pyrophosphate (PRPP), and we found that treating cells for 6 h with cisplatin reduced intracellular PRPP availability. The decrease in PRPP was likely from (1) increased PRPP consumption, because cisplatin increased protein PARylation and PARP1 shRNA knock-down returned PRPP towards normal, and (2) decreased intracellular phosphate, which down-regulated PRPP synthetase activity. Depriving cells of a single essential amino acid decreased PRPP synthetase activity with a half-life of ~ 8 h, and combining cisplatin and amino acid deprivation synergistically reduced intracellular PRPP. PRPP is a rate-limiting substrate for purine nucleotide synthesis, and cisplatin inhibited de novo purine synthesis and DNA synthesis, with amino acid deprivation augmenting cisplatin’s effects. Amino acid deprivation enhanced cisplatin’s cytotoxicity, increasing cellular apoptosis and DNA strand breaks in vitro, and intermittent deprivation of lysine combined with a sub-therapeutic dose of cisplatin inhibited growth of ectopic hepatomas in mice. Augmentation of cisplatin’s biochemical and cytotoxic effects by amino acid deprivation suggest that intermittent deprivation of an essential amino acid could allow dose reduction of cisplatin; this could reduce the drug’s side effects, and allow its use in cisplatin-resistant tumors.

Evodiamine inhibits high-fat diet-induced colitis-associated cancer in mice through regulating the gut microbiota

OBJECTIVE

High-fat diet is one of the main risk factors that disrupt the balance of gut microbiota, which eventually will induce colorectal cancer (CRC). Evodiamine (EVO) is a wildly used multifunctional traditional Chinese medicine extract. In this study, we investigated the role of gut microbiota in high-fat diet-propelled CRC and the potential of EVO for CRC chemoprevention.

METHODS

Gut microbiota, serum d-lactic acid and endotoxin from 38 patients with colon cancer and 18 healthy subjects were detected by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). In addition, body mass index, phospho-signal transducer and activator of transcription 3 (p-STAT3) expression in cancer tissues and paracancerous tissues were detected by immunohistochemistry. A mouse intestinal inflammatory tumor model was established by azomethane/sodium dextran sulfate, followed by treatment with EVO and 5-aminosalicylic acid (ASA). Gut microbiota and inflammatory factors were detected by quantitative polymerase chain reaction, while serum d-lactic acid and endotoxin were detected by ELISA. Furthermore, cell proliferation, cell apoptosis, and interleukin (IL)-6/STAT3/P65 pathway were evaluated by 5-ethynyl-2'-deoxyuridine, terminal-deoxynucleotidyl transferase-mediated nick-end labeling, and Western blot assays.

RESULTS

In patients with colon cancer, the numbers of Enterococcus faecalis and Escherichia coli were increased, while those of Bifidobacterium, Campylobacter and Lactobacillus were decreased. Serum endotoxin and d-lactic acid levels and p-STAT3 levels were significantly increased. In the mouse model, both EVO and ASA inhibited tumor formation, decreased the proliferation of tumor cells, and induced apoptosis of tumor cells. Compared with the control group, the numbers of E. faecalis and E. coli were decreased, while Bifidobacterium, Campylobacter and Lactobacillus numbers were increased. In the EVO group, serum endotoxin and d-lactic acid levels and inflammatory factors were significantly decreased. Further, the IL6/STAT3/P65 signaling pathway was inhibited in the EVO group.

CONCLUSION

EVO may inhibit the occurrence of colon cancer by regulating gut microbiota and inhibiting intestinal inflammation. The potential mechanism involves inhibition of the IL6/STAT3/P65 signaling pathway, revealing its potential therapeutic significance in clinical applications.

Suppressor of cytokine signaling proteins 1 and 3 and hepatitis B virus infection

Suppressor of cytokine signaling proteins (SOCS) are cytokine pathway inhibitors that play an important role in regulating the antiviral effect of interferon (IFN). Current studies have shown that SOCS1 and SOCS3 are closely related to hepatitis B virus (HBV) infection. Inhibition or stimulation of SOCS1 and SOCS3 expression may affect the antiviral effect by regulating the production of IFN, and may also affect the pathogenicity of HBV together with other cytokines or transcription regulators. This paper mainly discusses the possible mechanisms of SOCS1 and SOCS3 in HBV infection.

STAT3 and AKT signaling pathways mediate oncogenic role of NRSF in hepatocellular carcinoma

Neuron-restrictive silencer factor (NRSF) is a zinc finger protein that acts as a negative transcriptional regulator by recruiting histone deacetylases and other co-factors. It plays a crucial role in nervous system development and is recently reported to be involved in tumorigenesis in a tumor type-dependent manner; however, the role of NRSF in hepatocellular carcinoma (HCC) tumorigenesis remains unclear. Here, we found that NRSF expression was up-regulated in 27 of 49 human HCC tissue samples examined. Additionally, mice with conditional NRSF-knockout in the liver exhibited a higher tolerance against diethylnitrosamine (DEN)-induced acute liver injury and were less sensitive to DEN-induced HCC initiation. Our results showed that silencing NRSF in HepG2 cells using RNAi technology significantly inhibited HepG2 cell proliferation and severely hindered their migration and invasion potentials. Our results demonstrated that NRSF plays a pivotal role in promoting DEN-induced HCC initiation via a mechanism related to the STAT3 and AKT signaling pathways. Thus, NRSF could be a potential therapeutic target for treating human HCC.

Hepatic Hippo signaling inhibits development of hepatocellular carcinoma

Primary liver cancer is one of the most common cancer worldwide. Hepatocellular carcinoma (HCC) in particular, is the second leading cause of cancer deaths in the world. The Hippo signaling pathway has emerged as a major oncosuppressive pathway that plays critical roles inhibiting hepatocyte proliferation, survival, and HCC formation. A key component of the Hippo pathway is the inhibition of yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) transcription factors by the Hippo kinase cascade. Aberrant activation of YAP or TAZ has been found in several human cancers including HCC. It is also well established that YAP/TAZ activation in hepatocytes causes HCC in mouse models, indicating that YAP/TAZ are potential therapeutic targets for human liver cancer. In this review, we summarize the recent findings regarding the multifarious roles of Hippo/YAP/TAZ in HCC development, and focus on their cell autonomous roles in controlling hepatocyte proliferation, differentiation, survival and metabolism as well as their non-cell autonomous in shaping the tumor microenvironment.

Dietary Restriction Suppresses Steatosis-Associated Hepatic Tumorigenesis in Hepatitis C Virus Core Gene Transgenic Mice

BACKGROUND AND AIMS

Dietary restriction (DR) is a preventive strategy for obesity, metabolic syndrome, cardiovascular disease, and diabetes. Although an interconnection between obesity, metabolic syndrome, fatty liver, and hepatocellular carcinoma has been documented, the mechanism and impact of DR on steatosis-derived hepatocarcinogenesis are not fully understood. This study aimed to evaluate whether DR can prevent hepatic tumorigenesis.

METHODS

Male hepatitis C virus core gene transgenic (HCVcpTg) mice that develop spontaneous age-dependent insulin resistance, hepatic steatosis, and ensuing liver tumor development without apparent hepatic fibrosis, were fed with either a control diet ad libitum (control group) or 70% of the same control diet (DR group) for 15 months, and liver phenotypes were investigated.

RESULTS

DR significantly reduced the number and volume of liver tumors. DR attenuated hepatic oxidative and endoplasmic reticulum stress and markedly suppressed nuclear factor-κB, signal transducer and activator of transcription 3 (STAT3) and STAT5, and phosphorylation of extracellular signal-regulated kinase, leading to downregulation of several pro-oncogenic mediators, such as cyclin D1. Serum insulin and insulin-like growth factor 1 levels, as well as hepatic expression of insulin receptor substrate 1/2, phosphatidylinositol-3 kinase, and serine/threonine-protein kinase AKT, were downregulated by DR. A transcriptome analysis revealed that STAT3 signaling and lipogenesis were the most suppressed hepatocarcinogenic pathways affected by DR. Additionally, DR stimulated autophagy and p62/sequestosome 1 degradation, enhanced phosphorylation of AMP-activated protein kinase α, increased fibroblast growth factor 21 expression, and attenuated expression of senescence-associated secretory phenotypes.

CONCLUSION

DR suppressed steatosis-associated hepatic tumorigenesis in HCVcpTg mice, mainly due to attenuation of pathways involved in inflammation, cellular stress, cell proliferation, insulin signaling, and senescence. These findings support the notion that persistent 30% reduction of daily food intake is beneficial for preventing steatosis-associated hepatocarcinogenesis caused by HCV core protein.

Complement factor H-deficient mice develop spontaneous hepatic tumors

Hepatocellular carcinoma (HCC) is difficult to detect, carries a poor prognosis, and is one of few cancers with an increasing yearly incidence. Molecular defects in complement factor H (CFH), a critical regulatory protein of the complement alternative pathway (AP), are typically associated with inflammatory diseases of the eye and kidney. Little is known regarding the role of CFH in controlling complement activation within the liver. While studying aging CFH-deficient (fH-/-) mice, we observed spontaneous hepatic tumor formation in more than 50% of aged fH-/- males. Examination of fH-/- livers (3-24 months) for evidence of complement-mediated inflammation revealed widespread deposition of complement-activation fragments throughout the sinusoids, elevated transaminase levels, increased hepatic CD8+ and F4/80+ cells, overexpression of hepatic mRNA associated with inflammatory signaling pathways, steatosis, and increased collagen deposition. Immunostaining of human HCC biopsies revealed extensive deposition of complement fragments within the tumors. Investigating the Cancer Genome Atlas also revealed that increased CFH mRNA expression is associated with improved survival in patients with HCC, whereas mutations are associated with worse survival. These results indicate that CFH is critical for controlling complement activation in the liver, and in its absence, AP activation leads to chronic inflammation and promotes hepatic carcinogenesis.

Schistosoma mansoni Egg-Secreted Antigens Activate Hepatocellular Carcinoma-Associated Transcription Factors c-Jun and STAT3 in Hamster and Human Hepatocytes

Clinical data have provided evidence that schistosomiasis can promote hepatocellular carcinogenesis. c-Jun and STAT3 are critical regulators of liver cancer development and progression. The aim of the present study was to investigate the hepatocellular activation of c-Jun and STAT3 by Schistosoma mansoni infection. Expression and function of c-Jun and STAT3 as well as proliferation and DNA repair were analyzed by western blotting, electrophoretic mobility-shift assay, and immunohistochemistry in liver of S. mansoni-infected hamsters, Huh7 cells, primary hepatocytes, and human liver biopsies. Hepatocellular activation of c-Jun was demonstrated by nuclear translocation of c-Jun, enhanced phosphorylation (Ser73), and AP-1/DNA-binding in response to S. mansoni infection. Nuclear c-Jun staining pattern around lodged eggs without ambient immune reaction, and directionally from granuloma to the central veins, suggested that substances released from schistosome eggs were responsible for the observed effects. In addition, hepatocytes with c-Jun activation show cell activation and DNA double-strand breaks. These findings from the hamster model were confirmed by analyses of human biopsies from patients with schistosomiasis. Cell culture experiments finally demonstrated that activation of c-Jun and STAT3 as well as DNA repair were induced by an extract from schistosome eggs (soluble egg antigens) and culture supernatants of live schistosome egg (egg-conditioned medium), and in particular by IPSE/alpha-1, the major component secreted by live schistosome eggs. The permanent activation of hepatocellular carcinoma-associated proto-oncogenes such as c-Jun and associated transcription factors including STAT3 by substances released from tissue-trapped schistosome eggs may be important factors contributing to the development of liver cancer in S. mansoni-infected patients. Therefore, identification and therapeutic targeting of the underlying pathways is a useful strategy to prevent schistosomiasis-associated carcinogenesis.

Emerging risk factors for nonalcoholic fatty liver disease associated hepatocellular carcinoma

Worldwide, nonalcoholic fatty liver disease (NAFLD) has reached epidemic proportions and in parallel, hepatocellular carcinoma (HCC) has become one of the fastest growing cancers. Epidemiological studies have not only shed light on the prevalence and incidence of the disease but have also unmasked important environmental risk factors, including the role of diabetes and dyslipidemia in disease pathogenesis. Genetic association studies have identified single nucleotide polymorphisms implicated in NAFLD-HCC, many of which are part of lipid metabolism pathways. Through these clinical studies and subsequently, translational and basic research, the role of statins as a chemoprotective agent has also emerged with ongoing clinical trials assessing their utility in HCC prevention and treatment. In this review, we summarize the recent epidemiological studies describing the burden of NAFLD-HCC in different patient populations and countries. We discuss the genetic and environmental risk factors for NAFLD-HCC and highlight the chemoprotective role of statins and aspirin. We also summarize what is known about NAFLD-HCC in the cirrhosis and non-cirrhosis populations and briefly address the role of surveillance in NAFLD-HCC patients.

Identification of integrin β6 gene promoter and analysis of its transcription regulation in colon cancer cells

BACKGROUND

The integrin β6 gene, which is expressed in epithelial cancer, plays a pivotal role in various aspects of cancer progression. The present research for integrin β6 regulation mainly focuses on the post-transcription and translation related regulation mechanism and its role in tumorigenesis. The mechanisms of how the integrin β6 gene is regulated transcriptionally, and the promoter and transcription factors responsible for basic transcription of integrin β6 gene remain unknown.

AIM

To clone and characterize the integrin β6 promoter.

METHODS

Software analysis was used to predict the region of integrin β6 promoter. Luciferase reporter plasmids, which contained the integrin β6 promoter, were constructed. Element deletion analysis was performed to identify the location of core promoter and binding sites for transcription factors.

RESULTS

The regulatory elements for the transcription of the integrin β6 gene were located between -286 and -85 and contained binding sites for transcription factors such as STAT3 and Ets-1.

CONCLUSION

For the first time, we found the region of β6 core promoter and demonstrated the binding sites for transcription factors such as Ets-1 and STAT3, which are important for integrin β6 promoter transcription activity. These findings are important for investigating the mechanism of integrin β6 activation in cancer progression.

Hepatitis delta virus interacts with splicing factor SF3B155 and alters pre-mRNA splicing of cell cycle control genes

Hepatitis delta virus (HDV) is the agent responsible for the most severe form of human viral hepatitis. The HDV genome consists of a single-stranded circular RNA molecule that encodes for one single protein, the delta antigen. Given its simplicity, HDV must make use of several host cellular proteins to accomplish its life cycle processes, including transcription, replication, post-transcriptional, and post-translational modifications. Consequently, identification of the interactions established between HDV components and host proteins assumes a pivotal interest in the search of novel therapeutic targets. Here, we used the yeast three-hybrid system to screen a human liver cDNA library to identify host proteins that interact with the HDV genomic RNA. One of the identified proteins corresponded to the splicing factor SF3B155, a component of the U2snRNP complex that is essential for the early recognition of 3' splice sites in the pre-mRNAs of human genes. We show that the interaction between the HDV genomic RNA and SF3B155 occurs in vivo and that the expression of HDV promotes changes in splicing of human genes whose alternative splicing is SF3B155-dependent. We further show that expression of HDV triggers alterations in several constitutive and alternative splicing events in the tumor suppressor RBM5 transcript, with consequent reduction of its protein levels. This is the first description that HDV expression promotes changes in the splicing of human genes, and we suggest that the HDV-induced alternative splicing changes, through SF3B155 sequester, may contribute for the early progression to hepatocellular carcinoma characteristic of HDV-infected patients.

Hepatitis C Virus and Hepatocellular Carcinoma: When the Host Loses Its Grip

Chronic infection with hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma (HCC). Novel treatments with direct-acting antivirals achieve high rates of sustained virologic response; however, the HCC risk remains elevated in cured patients, especially those with advanced liver disease. Long-term HCV infection causes a persistent and accumulating damage of the liver due to a combination of direct and indirect pro-oncogenic mechanisms. This review describes the processes involved in virus-induced disease progression by viral proteins, derailed signaling, immunity, and persistent epigenetic deregulation, which may be instrumental to develop urgently needed prognostic biomarkers and as targets for novel chemopreventive therapies.

Circulating Neutrophils Predict Poor Survival for HCC and Promote HCC Progression Through p53 and STAT3 Signaling Pathway

Background: Tumor-associated neutrophils (TANs) contribute to tumor progression, invasion, and angiogenesis. However, most studies focus on tumor infiltration neutrophils while the roles of circulating neutrophils in tumor progression remain unclear. This study was aimed to verify the pro-tumor effects of circulating neutrophils and its' mechanism in HCC.

Methods: We collected clinical data of 127 HCC patients underwent TACE. The prognostic factors for overall survival (OS) were analyzed by Kaplan-Meier curve and Cox models. Circulating neutrophils of HCC patients were sorted and co-cultured with human HCC cell lines MHCC-97H and SMMC-7721. Then we detected tumor cells' proliferation, migration, and invasion. Phosphokinase array was used to determine the kinase profile on MHCC-97H and SMMC-7721 cultured with or without circulating neutrophils.

Results: The result of multivariate analyses of 127 patients showed that increased circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. Circulating neutrophils promoted migration and invasion of HCC cell lines but had no impact on proliferation. The kinase profile on HCC cell lines showed that p-p53^S46 and p-STAT3^Y705 were up-regulated after co-cultured with circulating neutrophils. Repeated scratch tests and transwell tests showed a reversed impact on migration and invasion of circulating neutrophils after we treated HCC cell lines with inhibitors of p53 or STAT3.

Conclusion: Circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. It had pro-tumor effect on HCC through p53 and STAT3 signaling pathway.

Scinderin suppresses cell proliferation and predicts the poor prognosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains an intractable disease despite numerous advancements made in the available treatments over recent decades. Therefore, investigation of the underlying pathogenesis of HCC is urgently required. Our previous microarray result showed that SCIN was generally downregulated in 23 paired tumor/normal tissues. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were performed in the present study in order to detect the expression of scinderin (SCIN). Lentivirus-mediated gene delivery was used in order to produce SCIN-manipulated cell lines. MTT and crystal violet assays were performed in order to investigate cell growth, and fluorescence-activated cell sorting analysis was used in order to determine cell cycle distribution. SCIN was downregulated in HCC samples, and low SCIN expression predicted the poor prognosis of patients with HCC. Notably, SCIN may have the potential to serve as an independent risk factor for overall survival (3-year overall survival rate of 28.6 and 10.3% in high SCIN expression and low SCIN expression groups, respectively) and disease-free survival (3-year recurrence rate of 71.4 and 84.6% in high SCIN expression and low SCIN expression groups, respectively) in HCC. SCIN inhibited HCC cell proliferation both in vitro and in subcutaneous tumor formation assay. Furthermore, SCIN decreased the levels of phosphorylated STAT3, thereby downregulating cyclin A1 levels in HCC cells. The results of the present study demonstrate the tumor suppressive role of SCIN in HCC, providing a candidate strategy to treat this disease.

JAK/STAT signaling in hepatocellular carcinoma

Liver cancer is the second most lethal cancer in the world with limited treatment options. Hepatocellular carcinoma (HCC), which accounts for more than 80% of all liver cancers, has had increasing global incidence over the past few years. There is an urgent need for novel and better therapeutic intervention for HCC patients. The JAK/STAT signaling pathway plays a multitude of important biological functions in both normal and malignant cells. In a subset of HCC, JAK/STAT signaling is aberrantly activated, leading to dysregulation of downstream target genes that controls survival, angiogenesis, stemness, immune surveillance, invasion and metastasis. In this review, we will focus on the role of JAK/STAT signaling in HCC and discuss the current clinical status of several JAK/STAT inhibitors.

Wu Mei Wan attenuates CAC by regulating gut microbiota and the NF-kB/IL6-STAT3 signaling pathway

BACKGROUND

Colorectal cancer (CRC) has a high incidence and mortality rate worldwide. Colitis-associated CRC (CAC) is used for describing the relationship between inflammation and CRC. No chemopreventive agents have been found to be both effective and safe in CRC. Therefore, the prevention and treatment of CAC are extremely urgent. Wu Mei Wan (WMW) has been used for the clinical treatment of enteritis with a remarkable efficacy. Here, we aim to investigate the underlying mechanism of WMW in the prevention of CAC.

METHODS

The AOM/DSS-induced CAC mouse model was used, and the mice were divided into normal control (NC), AOM/DSS model control (MC), and AOM/DSS plus WMW (WMW). The weight of mice, the score of DAI, survival rate, number of tumors and sample collection were performed at the end of the 14^th week. Histopathological examination was performed using Hematoxylin-Eosin (HE) staining. Tumor cell proliferation was indicated by the expression of PCNA, and p65 and p-STAT3 were detected by immunohistochemistry. Serum IL-6 levels were detected by enzyme-linked immunosorbent assay (ELISA). The expression of p65, IL-6 and p-STAT3 in the colon was detected by Western Blot. Intestinal flora was analyzed by 16S rDNA sequencing.

RESULTS

WMW improved the survival rate of mice in the MC group and also attenuated CAC symptoms such as abnormal clinical colitis and pathological changes to intestinal tissue by reducing DAI score, tumor formation, tumor volume, and grade of tumorigenesis. WMW also reduced the proliferation of tumor cells in colon tissues. WMW decreased the expression of p65, IL-6, and p-STAT3 in colon tumors of CAC mice. WMW decreased Bacteroidetes and increased Firmicutes at the phylum level, while decreasing bacteroidales_s24-7_group and increasing the number of Lachnospiraceae at the family level.

CONCLUSION

WMW attenuates CAC by regulating the balance between "tumor-promoting bacteria" and "tumor-suppressing bacteria" and the NF-kB/IL-6/STAT3 pathway. WMW has the potential to be a safe and effective chemopreventive drug but further clinical evidence is necessary.

Bnip3 in mitophagy: Novel insights and potential therapeutic target for diseases of secondary mitochondrial dysfunction

The present review is a summary of the recent literature concerning Bnip3 expression, function, and regulation, along with its implications in mitochondrial dysfunction, disorders of mitophagy homeostasis, and development of diseases of secondary mitochondrial dysfunction. As a member of the Bcl-2 family of cell death-regulating factors, Bnip3 mediates mPTP opening, mitochondrial potential, oxidative stress, calcium overload, mitochondrial respiratory collapse, and ATP shortage of mitochondria from multiple cells. Recent studies have discovered that Bnip3 regulates mitochondrial dysfunction, mitochondrial fragmentation, mitophagy, cell apoptosis, and the development of lipid disorder diseases via numerous cellular signaling pathways. In addition, Bnip3 promotes the development of cardiac hypertrophy by mediating inflammatory response or the related signaling pathways of cardiomyocytes and is also responsible for raising abnormal mitophagy and apoptosis progression through multiple molecular signaling pathways, inducing the pathogenesis and progress of hepatocellular carcinoma (HCC). Different molecules regulate Bnip3 expression at both the transcriptional and post-transcriptional level, leading to mitochondrial dysfunction and unbalance of mitophagy in hepatocytes, which promotes the development of non-alcoholic fatty liver disease (NAFLD). Thus, Bnip3 plays an important role in mitochondrial dysfunction and mitophagy homeostasis and has emerged as a promising therapeutic target for diseases of secondary mitochondrial dysfunction.

Bifunctional Naphthoquinone Aromatic Amide-Oxime Derivatives Exert Combined Immunotherapeutic and Antitumor Effects through Simultaneous Targeting of Indoleamine-2,3-dioxygenase and Signal Transducer and Activator of Transcription 3

Indoleamine-2,3-dioxygenase 1 (IDO1) and signal transducer and activator of transcription 3 (STAT3) are important targets in the tumor microenvironment for cancer therapy. In the present study, a set of naphthoquinone aromatic amide-oxime derivatives were designed, which stimulated the immune response via IDO1 inhibition and simultaneously displayed powerful antitumor activity against three selected cancer cell lines through suppressing STAT3 signaling. The representative compound 8u bound effectively to IDO1, with greater inhibitory activity relative to the commercial IDO1 inhibitor 4-amino-N-(3-chloro-4-fluorophenyl)-N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide (IDO5L) in addition to the efficient suppression of nuclear translocation of STAT3. Consistently, in vivo assays demonstrated a higher antiproliferative activity of compound 8u in both wild-type B16-F10 isograft tumors and an athymic HepG2 xenograft model relative to 1-methyl-l-tryptophan (1-MT) and doxorubicin (DOX). This bifunctional compound with dual immunotherapeutic and anticancer efficacy may represent a new generation of highly efficacious drug candidates for cancer therapy.

Upregulated Seizure-Related 6 Homolog-Like 2 Is a Prognostic Predictor of Hepatocellular Carcinoma

Seizure-related 6 homolog-like 2 (SEZ6L2), which is localized on the cell surface, has been found to be associated with tumor angiogenesis and lung cancer progression. However, the role of SEZ6L2 in hepatocellular carcinoma (HCC) is still unclear. We obtained data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) to investigate SEZ6L2 expression and regulation in HCC. Then, HCC tissue samples were collected to verify SEZ6L2 by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining (IHC). Patient information was collected for survival and prognosis analysis. qRT-PCR, IHC, and bioinformatics analysis showed that the SEZ6L2 protein was highly expressed in HCC samples. Clinical data showed that high SEZ6L2 protein expression was correlated with tumor-node-metastasis (TNM) stages (P = 0.046), tumor number (P = 0.016), and tumor size (P = 0.029). Meanwhile, SEZ6L2 overexpression was closely associated with poor overall survival and disease-free survival in HCC patients. Moreover, SEZ6L2 is an independent prognostic predictor for the survival of HCC patients. This study suggests a significant correlation between SEZ6L2 and HCC, which means that SEZ6L2 may potentially serve as a useful prognostic biomarker for HCC patients.

Cruel to Be Kind: Epithelial, Microbial, and Immune Cell Interactions in Gastrointestinal Cancers

A plethora of experimental and epidemiological evidence supports a critical role for inflammation and adaptive immunity in the onset of cancer and in shaping its response to therapy. These data are particularly robust for gastrointestinal (GI) cancers, such as those affecting the GI tract, liver, and pancreas, on which this review is focused. We propose a unifying hypothesis according to which intestinal barrier disruption is the origin of tumor-promoting inflammation that acts in conjunction with tissue-specific cancer-initiating mutations. The gut microbiota and its products impact tissue-resident and recruited myeloid cells that promote tumorigenesis through secretion of growth- and survival-promoting cytokines that act on epithelial cells, as well as fibrogenic and immunosuppressive cytokines that interfere with the proper function of adaptive antitumor immunity. Understanding these relationships should improve our ability to prevent cancer development and stimulate the immune system to eliminate existing malignancies.