Autophagy in the "inflammation-carcinogenesis" pathway of liver and HCC immunotherapy

New insight in treating autoimmune diseases by targeting autophagy

Autophagy is a highly conserved biological process in eukaryotes, which degrades cellular misfolded proteins, damaged organelles and invasive pathogens in the lysosome-dependent manner. Autoimmune diseases caused by genetic elements, environments and aberrant immune responses severely impact patients' living quality and even threaten life. Recently, numerous studies have reported autophagy can regulate immune responses, and play an important role in autoimmune diseases. In this review, we summarised the features of autophagy and autophagy-related genes, enumerated some autophagy-related genes involved in autoimmune diseases, and further overviewed how to treat autoimmune diseases through targeting autophagy. Finally, we outlooked the prospect of relieving and curing autoimmune diseases by targeting autophagy pathway.

Biological impact and therapeutic implication of tumor-associated macrophages in hepatocellular carcinoma

The tumor microenvironment is a complex space comprised of normal, cancer and immune cells. The macrophages are considered as the most abundant immune cells in tumor microenvironment and their function in tumorigenesis is interesting. Macrophages can be present as M1 and M2 polarization that show anti-cancer and oncogenic activities, respectively. Tumor-associated macrophages (TAMs) mainly have M2 polarization and they increase tumorigenesis due to secretion of factors, cytokines and affecting molecular pathways. Hepatocellular carcinoma (HCC) is among predominant tumors of liver that in spite of understanding its pathogenesis, the role of tumor microenvironment in its progression still requires more attention. The presence of TAMs in HCC causes an increase in growth and invasion of HCC cells and one of the reasons is induction of glycolysis that such metabolic reprogramming makes HCC distinct from normal cells and promotes its malignancy. Since M2 polarization of TAMs stimulates tumorigenesis in HCC, molecular networks regulating M2 to M1 conversion have been highlighted and moreover, drugs and compounds with the ability of targeting TAMs and suppressing their M2 phenotypes or at least their tumorigenesis activity have been utilized. TAMs increase aggressive behavior and biological functions of HCC cells that can result in development of therapy resistance. Macrophages can provide cell-cell communication in HCC by secreting exosomes having various types of biomolecules that transfer among cells and change their activity. Finally, non-coding RNA transcripts can mainly affect polarization of TAMs in HCC.

NPC1 promotes autophagy with tumor promotion and acts as a prognostic model for hepatocellular carcinoma

BACKGROUND

more and more studies have indicated that autophagy plays a crucial role in hepatocellular carcinoma (HCC) in recent years. Hence, our study aimed to establish a prognostic signature for HCC based on autophagy-related genes (ARGs) in order to predict the prognosis of HCC.

METHODS

All original gene-expression data and clinical information were downloaded from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO). ARGs were obtained from the Human Autophagy Database (HADb). Univariate Cox regression analysis, Least absolute shrinkage and selection operator (LASSO) and Principal Component Analysis (PCA) analysis were performed to identify and validate the validity and reliability of our eight-gene signature, Gene Set Enrichment Analysis (GSEA) was used to perform enrichment analysis by comparing high-risk and low-risk groups in KEGG (Kyoto Encyclopedia of Genes and Genomes) and GO (Gene Ontology) gene sets. Finally, we verified the gene (NPC1) by functional experiments in vitro and in vivo.

RESULTS

8 ARGs were identified for establishing an eight-gene signature. Then, we validated our eight-gene signature in training, internal, external, and entire testing cohorts. Besides, we also explored the relationships between the eight-gene signature and immune infiltration or immune checkpoints. We also identified NPC1 was closely related to Activated CD4 T cell and Type I IFN Response, and higher expressed level of HCC patients was more sensitive to CTLA4 and TNFRSF9 immune checkpoint inhibitors. NPC1 is highly expressed in HCC cells and tumor tissues, which promotes the proliferation, migration, and invasion of tumor cells by activating autophagy..

CONCLUSION

8 ARGs were used to establish a gene signature to predict the prognosis of HCC. we inferred that NPC1 can promote late autophagy, it could be a future novel therapeutic target of HCC.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Cell Death Pathway Regulation by Functional Nanomedicines for Robust Antitumor Immunity

Cancer immunotherapy has become a mainstream cancer treatment over traditional therapeutic modes. Cancer cells can undergo programmed cell death including ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis which are find to have intrinsic relationships with host antitumor immune response. However, direct use of cell death inducers or regulators may bring about severe side effects that can also be rapidly excreted and degraded with low therapeutic efficacy. Nanomaterials are able to carry them for long circulation time, high tumor accumulation and controlled release to achieve satisfactory therapeutic effect. Nowadays, a large number of studies have focused on nanomedicines-based strategies through modulating cell death modalities to potentiate antitumor immunity. Herein, immune cell types and their function are first summarized, and state-of-the-art research progresses in nanomedicines mediated cell death pathways (e.g., ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis) with immune response provocation are highlighted. Subsequently, the conclusion and outlook of potential research focus are discussed.

The current status and future of PD-L1 in liver cancer

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

Histomolecular characterisation of hepatitis B virus induced liver cancer

Hepatitis B virus (HBV)-associated liver cancer is the third most prevalent cancer-related cause of death worldwide. Different studies have been done on the histomolecular analysis of HBV induced-liver cancer including epigenetics which are dynamic molecular mechanisms to control gene expression without altering the host deoxyribonucleic acid, genomics characterise the integration of the viral genome with host genome, proteomics characterise how gene modifies and results overexpression of proteins, glycoproteomics discover different glyco-biomarker candidates and show glycosylation in malignant hepatocytes, metabolomics characterise how HBV impairs a variety of metabolic functions during hepatocyte immortalisation, exosomes characterise immortalised liver cells in terms of their differentiation and proliferation, and autophagy plays a role in the development of hepatocarcinogenesis linked to HBV infection.

Metabolic reprogramming, autophagy, and ferroptosis: Novel arsenals to overcome immunotherapy resistance in gastrointestinal cancer

BACKGROUND

Gastrointestinal cancer poses a serious health threat owing to its high morbidity and mortality. Although immune checkpoint blockade (ICB) therapies have achieved meaningful success in most solid tumors, the improvement in survival in gastrointestinal cancers is modest, owing to sparse immune response and widespread resistance. Metabolic reprogramming, autophagy, and ferroptosis are key regulators of tumor progression.

METHODS

A literature review was conducted to investigate the role of the metabolic reprogramming, autophagy, and ferroptosis in immunotherapy resistance of gastrointestinal cancer.

RESULTS

Metabolic reprogramming, autophagy, and ferroptosis play pivotal roles in regulating the survival, differentiation, and function of immune cells within the tumor microenvironment. These processes redefine the nutrient allocation blueprint between cancer cells and immune cells, facilitating tumor immune evasion, which critically impacts the therapeutic efficacy of immunotherapy for gastrointestinal cancers. Additionally, there exists profound crosstalk among metabolic reprogramming, autophagy, and ferroptosis. These interactions are paramount in anti-tumor immunity, further promoting the formation of an immunosuppressive microenvironment and resistance to immunotherapy.

CONCLUSIONS

Consequently, it is imperative to conduct comprehensive research on the roles of metabolic reprogramming, autophagy, and ferroptosis in the resistance of gastrointestinal tumor immunotherapy. This understanding will illuminate the clinical potential of targeting these pathways and their regulatory mechanisms to overcome immunotherapy resistance in gastrointestinal cancers.

HMMR alleviates endoplasmic reticulum stress by promoting autophagolysosomal activity during endoplasmic reticulum stress-driven hepatocellular carcinoma progression

BACKGROUND

The mechanism of hepatitis B virus (HBV)-induced carcinogenesis remains an area of interest. The accumulation of hepatitis B surface antigen in the endoplasmic reticulum (ER) of hepatocytes stimulates persistent ER stress. Activity of the unfolded protein response (UPR) pathway of ER stress may play an important role in inflammatory cancer transformation. How the protective UPR pathway is hijacked by cells as a tool for malignant transformation in HBV-related hepatocellular carcinoma (HCC) is still unclear. Here, we aimed to define the key molecule hyaluronan-mediated motility receptor (HMMR) in this process and explore its role under ER stress in HCC development.

METHODS

An HBV-transgenic mouse model was used to characterize the pathological changes during the tumor progression. Proteomics and transcriptomics analyses were performed to identify the potential key molecule, screen the E3 ligase, and define the activation pathway. Quantitative real-time PCR and Western blotting were conducted to detect the expression of genes in tissues and cell lines. Luciferase reporter assay, chromatin immunoprecipitation, coimmunoprecipitation, immunoprecipitation, and immunofluorescence were employed to investigate the molecular mechanisms of HMMR under ER stress. Immunohistochemistry was used to clarify the expression patterns of HMMR and related molecules in human tissues.

RESULTS

We found sustained activation of ER stress in the HBV-transgenic mouse model of hepatitis-fibrosis-HCC. HMMR was transcribed by c/EBP homologous protein (CHOP) and degraded by tripartite motif containing 29 (TRIM29) after ubiquitination under ER stress, which caused the inconsistent expression of mRNA and protein. Dynamic expression of TRIM29 in the HCC progression regulated the dynamic expression of HMMR. HMMR could alleviate ER stress by increasing autophagic lysosome activity. The negative correlation between HMMR and ER stress, positive correlation between HMMR and autophagy, and negative correlation between ER stress and autophagy were verified in human tissues.

CONCLUSIONS

This study identified the complicated role of HMMR in autophagy and ER stress, that HMMR controls the intensity of ER stress by regulating autophagy in HCC progression, which could be a novel explanation for HBV-related carcinogenesis.

Bioinformatics analysis and experimental validation of a novel autophagy-related signature relevant to immune infiltration for recurrence prediction after curative hepatectomy

Hepatocellular carcinoma (HCC) remains imposing an enormous economic and healthcare burden worldwide. In this present study, we constructed and validated a novel autophagy-related gene signature to predict the recurrence of HCC patients. A total of 29 autophagy-related differentially expressed genes were identified. A five-gene signature (CLN3, HGF, TRIM22, SNRPD1, and SNRPE) was constructed for HCC recurrence prediction. Patients in high-risk groups exhibited a significantly poor prognosis compared with low-risk patients both in the training set (GSE14520 dataset) and the validation set (TCGA and GSE76427 dataset). Multivariate cox regression analysis demonstrated that the 5-gene signature was an independent risk factor for recurrence-free survival (RFS) in HCC patients. The nomograms incorporating 5-gene signature and clinical prognostic risk factors were able to effectively predict RFS. KEGG and GSEA analysis revealed that the high-risk group was enriched with multiple oncology characteristics and invasive-related pathways. Besides, the high-risk group had a higher level of immune cells and higher levels of immune checkpoint-related gene expression in the tumor microenvironment, suggesting that they might be more likely to benefit from immunotherapy. Finally, the immunohistochemistry and cell experiments confirmed the role of SNRPE, the most significant gene in the gene signature. SNRPE was significantly overexpressed in HCC. After SNRPE knockdown, the proliferation, migration and invasion ability of the HepG2 cell line were significantly inhibited. Our study established a novel five-gene signature and nomogram to predict RFS of HCC, which may help in clinical decision-making for individual treatment.

An inflammation-related gene landscape predicts prognosis and response to immunotherapy in virus-associated hepatocellular carcinoma

Background

Due to the viral infection, chronic inflammation significantly increases the likelihood of hepatocellular carcinoma (HCC) development. Nevertheless, an inflammation-based signature aimed to predict the prognosis and therapeutic effect in virus-related HCC has rarely been established.

Method

Based on the integrated analysis, inflammation-associated genes (IRGs) were systematically assessed. We comprehensively investigated the correlation between inflammation and transcriptional profiles, prognosis, and immune cell infiltration. Then, an inflammation-related risk model (IRM) to predict the overall survival (OS) and response to treatment for virus-related HCC patients was constructed and verified. Also, the potential association between IRGs and tumor microenvironment (TME) was investigated. Ultimately, hub genes were validated in plasma samples and cell lines via qRT-PCR. After transfection with shCCL20 combined with overSLC7A2, morphological change of SMMC7721 and huh7 cells was observed. Tumorigenicity model in nude mouse was established.

Results

An inflammatory response-related gene signature model, containing MEP1A, CCL20, ADORA2B, TNFSF9, ICAM4, and SLC7A2, was constructed by conjoint analysis of least absolute shrinkage and selection operator (LASSO) Cox regression and gaussian finite mixture model (GMM). Besides, survival analysis attested that higher IRG scores were positively relevant to worse survival outcomes in virus-related HCC patients, which was testified by external validation cohorts (the ICGC cohort and GSE84337 dataset). Univariate and multivariate Cox regression analyses commonly proved that the IRG was an independent prognostic factor for virus-related HCC patients. Thus, a nomogram with clinical factors and IRG was also constructed to superiorly predict the prognosis of patients. Featured with microsatellite instability-high, mutation burden, and immune activation, lower IRG score verified a superior OS for sufferers. Additionally, IRG score was remarkedly correlated with the cancer stem cell index and drug susceptibility. The measurement of plasma samples further validated that CCL20 upexpression and SLC7A2 downexpression were positively related with virus-related HCC patients, which was in accord with the results in cell lines. Furthermore, CCL20 knockdown combined with SLC7A2 overexpression availably weakened the tumor growth in vivo.

Conclusions

Collectively, IRG score, serving as a potential candidate, accurately and stably predicted the prognosis and response to immunotherapy in virus-related HCC patients, which could guide individualized treatment decision-making for the sufferers.

YAP1 suppression inhibits autophagy and improves the efficacy of anti-PD-1 immunotherapy in hepatocellular carcinoma

Anti-PD-1 immunotherapy is a promising treatment for hepatocellular carcinoma (HCC), but some patients with HCC do not experience clinical benefits. Autophagy promotes tumor progression and participates in drug resistance. Previous studies have revealed that suppressing the expression level of Yes-associated protein 1 (YAP1) improves anti-PD-1 therapy efficacy. Therefore, the relationship between YAP1 expression and autophagy activity during anti-PD-1 treatment was investigated in this study. A positive correlation was found between the expression level of YAP1 and LC3B by analyzing The Cancer Genome Atlas (TCGA), UALCAN databases, and HCC tissue microarray. Meanwhile, YAP1 expression and autophagy constituted positive feedback, in which YAP1 inhibition decreased the autophagy activity in liver tumor cells by hepatocyte-specific Yap1 knockout mice. Further, anti-PD-1 treatment increased autophagy and YAP1 expression levels in the cancer tissues from DEN/TCPOBOP-induced liver cancer mice. Finally, Yap1 knockout suppressed autophagy and improved anti-PD-1 therapy efficacy in hepatocyte-specific Yap1 knockout mice with liver tumors. These results suggested that YAP1 suppression was sensitized to anti-PD-1 treatment and inhibited autophagy activity in liver tumor cells. YAP1 is a promising target for improving the efficacy of anti-PD-1 immunotherapy in HCC.

High p62 expression suppresses the NLRP1 inflammasome and increases stress resistance in cutaneous SCC cells

NLRP1 is the primary inflammasome sensor in human keratinocytes. Sensing of UVB radiation by NLRP1 is believed to underlie the induction of sunburn. Although constitutive NLRP1 activation causes skin inflammation and predisposes patients to the development of cutaneous SCCs, the NLRP1 pathway is suppressed in established SCCs. Here, we identified high levels of the autophagy receptor p62 in SCC cells lines and SCC tumors. Increased NF-κB activity in SCC cells causes p62 up-regulation. Suppression of p62 expression rescues UVB-induced NLRP1 inflammasome activation in early-stage SCC cells. p62 expression protects SCC cells from cytotoxic drugs, whereas NLRP1 sensitizes them. In summary, we identify p62 as a novel negative regulator of the NLRP1 inflammasome in human cutaneous SCC cells, in which suppression of NLRP1 by increased levels of p62 supports stress resistance of skin cancer cells.

The E3 ubiquitin ligase SOCS-7 reverses immunosuppression via Shc1 signaling in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common primary liver malignancies and is the third leading cause of tumor-related mortality worldwide. Despite advances in HCC treatment, diagnosis at the later stages, and the complex mechanisms relating to the cause and pathogenesis, results in less than 40% of HCC patients being eligible for potential therapy. Prolonged inflammation and resulting immunosuppression are major hallmarks of HCC; however, the mechanisms responsible for these processes have not been clearly elucidated. In this study, we identified SOCS-7, an inhibitor of cytokine signaling, as a novel regulator of immunosuppression in HCC. We found that SOCS-7 mediated E3 ubiquitin ligase activity on a signaling adaptor molecule, Shc1, in Huh-7 cells. Overexpression of SOCS-7 reduced the induction of immunosuppressive factors, TGF-β, Versican, and Arginase-1, and further reduced STAT3 activation. Furthermore, using an in vivo tumor model, we confirmed that SOCS-7 negatively regulates immunosuppression and inhibits tumor growth by targeting Shc1 degradation. Together, our study identified SOCS-7 as a possible therapeutic target to reverse immunosuppression in HCC.

Non-Apoptotic Programmed Cell Death-Related Gene Signature Correlates With Stemness and Immune Status and Predicts the Responsiveness of Transarterial Chemoembolization in Hepatocellular Carcinoma

Background: Non-apoptotic programmed cell death, including autophagy, ferroptosis, and pyroptosis, newly discovered in recent years, plays an important role in hepatocellular carcinoma (HCC). So, this study attempted to explore the relationship between non-apoptotic programmed cell death-related genes and the molecular characteristics, tumor microenvironment, and prognosis in HCC patients.

Methods: The transcriptomic and clinical data of HCC samples were downloaded from various public datasets, followed by acquiring non-apoptotic programmed cell death-related genes from the database. A gene signature model was then constructed using univariate and multivariate Cox regression analyses and validated in other cohorts as well as our institution sequencing data. Kaplan–Meier survival curves and time-dependent receiver operating characteristic curves were generated to evaluate the model’s predictive capability. Furthermore, the relationships among the gene signature, TP53 mutation, stemness, immune status, and responsiveness of transarterial chemoembolization (TACE) were analyzed.

Results: The gene signature model was constructed based on five autophagy-, three ferroptosis-, and two pyroptosis-related differentially expressed genes. The model accurately predicted that patients classified as low risk would have better overall survival than high-risk patients, which was robustly consistent with data from other cohorts as well as our institution sequencing data. The comprehensive results indicated that a high-risk index was correlated with a high TP53 mutation rate, high cancer cell stemness, high infiltration of immunosuppressive cells and low immunophenoscore, and low TACE responsiveness of HCC patients.

Conclusion: Collectively, the established non-apoptotic programmed cell death-related gene signature was shown to accurately predict prognosis, associated with the TP53 mutation and liver cancer cell stemness, reflect the tumor immune microenvironment, and predict TACE responsiveness in HCC patients.

An immune subtype-related prognostic signature of hepatocellular carcinoma based on single-cell sequencing analysis

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world and is often associated with a poor prognosis. The main reason for this poor prognosis is that inconspicuous early symptoms lead to delayed diagnosis. Treatment options for advanced HCC remain limited and ineffective. In this context, the exploration of the immune microenvironment in HCC becomes attractive. In this study, we divided HCC into immune cell and non-immune cell subtypes, by single-cell sequencing analysis of GEO dataset GSE146115. We found differentially expressed genes in the two subtypes, which we used to construct a prognostic model for HCC through Cox and Lasso regressions. Our prognostic model can accurately evaluate the prognosis of HCC patients, and provide a reference for the design of immunotherapy for HCC.

Oxygen-sensitive methylation of ULK1 is required for hypoxia-induced autophagy

Hypoxia is a physiological stress that frequently occurs in solid tissues. Autophagy, a ubiquitous degradation/recycling system in eukaryotic cells, renders cells tolerant to multiple stressors. However, the mechanisms underlying autophagy initiation upon hypoxia remains unclear. Here we show that protein arginine methyltransferase 5 (PRMT5) catalyzes symmetrical dimethylation of the autophagy initiation protein ULK1 at arginine 170 (R170me2s), a modification removed by lysine demethylase 5C (KDM5C). Despite unchanged PRMT5-mediated methylation, low oxygen levels decrease KDM5C activity and cause accumulation of ULK1 R170me2s. Dimethylation of ULK1 promotes autophosphorylation at T180, a prerequisite for ULK1 activation, subsequently causing phosphorylation of Atg13 and Beclin 1, autophagosome formation, mitochondrial clearance and reduced oxygen consumption. Further, expression of a ULK1 R170K mutant impaired cell proliferation under hypoxia. This study identifies an oxygen-sensitive methylation of ULK1 with an important role in hypoxic stress adaptation by promoting autophagy induction.

The Role of Macroautophagy and Chaperone-Mediated Autophagy in the Pathogenesis and Management of Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is a major health problem with the second highest mortality among all cancers and a continuous increase worldwide. HCC is highly resistant to available chemotherapeutic agents, leaving patients with no effective therapeutic option and a poor prognosis. Although an increasing number of studies have elucidated the potential role of autophagy underlying HCC, the complete regulation is far from understood. The different forms of autophagy constitute important cell survival mechanisms that could prevent hepatocarcinogenesis by limiting hepatocyte death and the associated hepatitis and fibrosis at early stages of chronic liver diseases. On the other hand, at late stages of hepatocarcinogenesis, they could support the malignant transformation of (pre)neoplastic cells by facilitating their survival.

Abstract

Hepatocarcinogenesis is a long process with a complex pathophysiology. The current therapeutic options for HCC management, during the advanced stage, provide short-term survival ranging from 10–14 months. Autophagy acts as a double-edged sword during this process. Recently, two main autophagic pathways have emerged to play critical roles during hepatic oncogenesis, macroautophagy and chaperone-mediated autophagy. Mounting evidence suggests that upregulation of macroautophagy plays a crucial role during the early stages of carcinogenesis as a tumor suppressor mechanism; however, it has been also implicated in later stages promoting survival of cancer cells. Nonetheless, chaperone-mediated autophagy has been elucidated as a tumor-promoting mechanism contributing to cancer cell survival. Moreover, the autophagy pathway seems to have a complex role during the metastatic stage, while induction of autophagy has been implicated as a potential mechanism of chemoresistance of HCC cells. The present review provides an update on the role of autophagy pathways in the development of HCC and data on how the modulation of the autophagic pathway could contribute to the most effective management of HCC.

Potential Anticancer Activity of the Furanocoumarin Derivative Xanthotoxin Isolated from Ammi majus L. Fruits: In Vitro and In Silico Studies

Ammi majus L., an indigenous plant in Egypt, is widely used in traditional medicine due to its various pharmacological properties. We aimed to evaluate the anticancer properties of Ammi majus fruit methanol extract (AME) against liver cancer and to elucidate the active compound(s) and their mechanisms of action. Three fractions from AME (Hexane, CH₂Cl₂, and EtOAc) were tested for their anticancer activities against HepG2 cell line in vitro (cytotoxicity assay, cell cycle analysis, annexin V-FITC apoptosis assay, and autophagy efflux assay) and in silico (molecular docking). Among the AME fractions, CH₂Cl₂ fraction revealed the most potent cytotoxic activity. The structures of compounds isolated from the CH₂Cl₂ fraction were elucidated using ¹H- and ¹³C-NMR and found that Compound 1 (xanthotoxin) has the strongest cytotoxic activity against HepG2 cells (IC₅₀ 6.9 ± 1.07 µg/mL). Treating HepG2 cells with 6.9 µg/mL of xanthotoxin induced significant changes in the DNA-cell cycle (increases in apoptotic pre-G1 and G2/M phases and a decrease in the S-phase). Xanthotoxin induced significant increase in Annexin-V-positive HepG2 cells both at the early and late stages of apoptosis, as well as a significant decrease in autophagic flux in cancer compared with control cells. In silico analysis of xanthotoxin against the DNA-relaxing enzyme topoisomease II (PDB code: 3QX3) revealed strong interaction with the key amino acid Asp479 in a similar fashion to that of the co-crystallized inhibitor (etoposide), implying that xanthotoxin has a potential of a broad-spectrum anticancer activity. Our results indicate that xanthotoxin exhibits anticancer effects with good biocompatibility toward normal human cells. Further studies are needed to optimize its antitumor efficacy, toxicity, solubility, and pharmacokinetics.

Pharmacokinetic/Pharmacodynamic Determinations of Iron-tannic Molecular Nanoparticles with its Implication in MR Imaging and Enhancement of Liver Clearance

Assessment and enhancement of liver clearance are promising strategies for protection of liver from various liver diseases. Iron-tannic nanoparticles (FTs) were previously considered as imageable autophagic enhancers with biodegradation potential. Herein, we present a new approach for utilizing Iron-tannic nanoparticles (FTs) as a tool for imaging and increasing liver clearance. Pharmacokinetic profiling suggested that FTs were initially found in blood circulation and thereafter were distributed to the liver. By using MR imaging (T1 weighted), maximum MRI signal enhancement was found to occur after 30 minutes post-injection (i.v.) and gradually decreased afterward. Decreasing MRI signal may be due to FTs metabolism by the liver. By assessing imaging-derived pharmacokinetics, we can simply determine the rate constant of liver degradation of FTs. Potentially, we might use this parameter to monitor liver function, where its clearance is of concern. Once functional implication of FTs in liver clearance was investigated, FTs were found to induce hepatocyte autophagy along with activation of lysosomes. Consequently, the hepatocytes were capable of efficiently clearing cellular debris. From these results, it is clear that FTs should be considered as a molecular tool for quantitative MRI-derived liver function assessment, and for enhancing clearance function in liver parenchyma. Hopefully, our findings will pave the way to develop new strategies for non-invasive assessment and enhancement of liver clearance.

Loss of SPTBN1 Suppresses Autophagy Via SETD7-mediated YAP Methylation in Hepatocellular Carcinoma Initiation and Development

BACKGROUND & AIMS

Loss of Spectrin beta, non-erythrocytic 1 (SPTBN1) plays an important role in the carcinogenesis of hepatocellular carcinoma (HCC); however, the mechanisms underlying its involvement remain poorly understood. Defects in autophagy contribute to hepatic tumor formation. Hence, in this study, we explored the role and mechanism of SPTBN1 in the autophagy of hepatic stem cells (HSCs) and HCC cells.

METHODS

Expansion, autophagy, and malignant transformation of HSCs were detected in the injured liver of Sptbn1^+/- mice induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine treatment. Hippo pathway and Yes-associated protein (YAP) stabilization were examined in isolated HSCs, Huh-7, and PLC/PRF/5 HCC cells and hepatocytes with or without loss of SPTBN1.

RESULTS

We found that heterozygous SPTBN1 knockout accelerated liver tumor development with 3,5-diethoxycarbonyl-1,4-dihydrocollidine induction. Rapamycin promoted autophagy in murine HSCs and reversed the increased malignant transformation induced by heterozygous SPTBN1 deletion. Loss of SPTBN1 also decreased autophagy and increased YAP stability and nuclear localization in human HCC cells and tissues, whereas YAP inhibition attenuated the effects of SPTBN1 deficiency on autophagy. Finally, we found that SPTBN1 positively regulated the expression of suppressor of variegation 3-9-enhancer of zeste-trithorax domain containing lysine methyltransferase 7 to promote YAP methylation, which may lead to YAP degradation and inactivation.

CONCLUSIONS

Our findings provide the first demonstration that loss of SPTBN1 impairs autophagy of HSCs to promote expansion and malignant transformation during hepatocarcinogenesis. SPTBN1 also cooperates with suppressor of variegation 3-9-enhancer of zeste-trithorax domain containing lysine methyltransferase 7 to inactive YAP, resulting in enhanced autophagy of HCC cells. These results may open new avenues targeting SPTBN1 for the prevention and treatment of HCC.

An Autophagy-Related Gene-Based Prognostic Risk Signature for Hepatocellular Carcinoma: Construction and Validation

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer. Treatment is dramatically difficult due to its high complexity and poor prognosis. Due to the disclosed dual functions of autophagy in cancer development, understanding autophagy-related genes devotes into novel biomarkers for HCC.

METHODS

Differential expression of genes in normal and tumor groups was analyzed to acquire autophagy-related genes in HCC. These genes were subjected to GO and KEGG pathway analyses. Genes were then screened by univariate regression analysis. The screened genes were subjected to multivariate Cox regression analysis to build a prognostic model. The model was validated by the ICGC validation set.

RESULTS

To sum up, 42 differential genes relevant to autophagy were screened by differential expression analysis. Enrichment analysis showed that they were mainly enriched in pathways including regulation of autophagy and cell apoptosis. Genes were screened by univariate analysis and multivariate Cox regression analysis to build a prognostic model. The model constituted 6 feature genes: EIF2S1, BIRC5, SQSTM1, ATG7, HDAC1, and FKBP1A. Validation confirmed the accuracy and independence of this model in predicting the HCC patient's prognosis.

CONCLUSION

A total of 6 feature genes were identified to build a prognostic risk model. This model is conducive to investigating interplay between autophagy-related genes and HCC prognosis.

Construction of a Prognostic Model for Hepatocellular Carcinoma Based on Immunoautophagy-Related Genes and Tumor Microenvironment

Background

The aim of this study was to screen and identify immunoautophagy-related genes (IARGs) in HCC patients and clarify their potential prognostic value in HCC patients.

Methods

Immune-related genes and autophagy-related gene were downloaded from public databases. Cox regression analysis was used to selected several immunoautophagy-related genes to establish a prognostic model, and patients were divided into high- and low-risk groups based on median risk score. We analyzed the overall survival and clinicopathological characteristics between two groups. Meanwhile, internal validation dataset and external ICGC dataset were used to verify robustness of the model. Associations between six immune cells infiltrates and risk score were analyzed.

Results

A prognostic model was established based on CANX and HDAC1. The prognoses of the high-risk group were worse than low-risk group in both TCGA and ICGC datasets. Multivariate Cox regression analysis showed that risk score was an independent prognostic factor for HCC patients. Results showed that the risk score in young group was higher than elderly group. Patients with poorly differentiated tumor may have high risk score and poor survival. The score was positively correlated with immune cells.

Conclusion

Our study shows that immunoautophagy-related genes have potential prognostic value for patients with HCC and may provide new information and direction for targeted therapy.

Mechanism of miR-204-5p in exosomes derived from bronchoalveolar lavage fluid on the progression of pulmonary fibrosis via AP1S2

Background

Exosomes are nanoscale vesicles secreted by various types of cells that are responsible for intracellular communication. Despite that bronchoalveolar lavage fluid (BALF) has been proven to involve in tumor development, more efforts are required to investigate the impact of BALF on pulmonary fibrosis (PF). This study aimed to investigate the mechanism of how exosomal miR-204-5p from BALF facilitates PF progression in rats.

Methods

PF rat model was established by intratracheal injection of bleomycin. BALF-derived exosomes (Exo) were extracted from normal and PF rats. PF-Exo (BALF-derived Exo from PF rats) and miR-204-5p antagomir were injected into rats to investigate the effect of exosomal miR-204-5p on PF. Collagen content in lung tissues of rats was assessed by Masson staining, hydroxyproline (HYP) content assay and immunohistochemistry (IHC). Primary lung fibroblasts were isolated, and treated by TGF-β1. After co-transfection of PF-Exo, miR-204-5p inhibitor and sh-AP1S2, cell proliferation, levels of miR-204-5p, fibrotic markers α-SMA and collagen 1 (Col 1), and proteins of autophagy markers LC3II, LC3I and P62 were measured. The interaction between miR-204-5p and AP1S2 was determined by bioinformatics online software TargetScan and dual-luciferase reporter assay.

Results

miR-204-5p was abundantly expressed in the PF-Exo group. PF-Exo injection potentiated PF progression and proliferation ability of lung fibroblasts in vivo and in vitro. Injection with PF-Exo and miR-204-5p antagomir significantly increased the LC3II/I ratio and decreased the HYP content, proteins of α-SMA, Col 1 and P62, collagen content in rat lung tissues of PF rats. TGF-β1 induction elevated the LC3II/LC3I ratio, suppressed the cell proliferation rate, and decreased the levels of α-SMA, Col 1 and P62. Additionally, AP1S2 was a direct target of miR-204-5p. miR-204-5p inhibitor can counteract the effect of PF-Exo in proliferation of lung fibroblasts, while sh-AP1S2 eliminated the effect of miR-204-5p inhibitor.

Conclusions

Exosomal miR-204-5p from BALF inhibits autophagy to promote the progression of PF rats by targeting AP1S2.

Enhanced anticancer activity by the combination of vinpocetine and sorafenib via PI3K/AKT/GSK-3β signaling axis in hepatocellular carcinoma cells

Vinpocetine is widely used to treat cerebrovascular diseases. However, the effect of vinpocetine to treat hepatocellular carcinoma (HCC) has not been investigated. In this study, we revealed that vinpocetine was associated with antiproliferative activity in HCC cells, but induced cytoprotective autophagy, which restricted its antitumor activity. Autophagy inhibitors improved the antiproliferative activity of vinpocetine in HCC cells. Sorafenib is effective to treat advanced HCC, but the effect of autophagy induced by sorafenib is indistinct. We demonstrated vinpocetine plus sorafenib suppressed the cytoprotective autophagy activated by vinpocetine in HCC cells and significantly induced apoptosis and suppressed cell proliferation in HCC cells. In addition, vinpocetine plus sorafenib activates glycogen synthase kinase 3β (GSK-3β) and subsequently inhibits cytoprotective autophagy induced by vinpocetine in HCC cells. Meanwhile, overexpression of GSK-3β was efficient to increase the apoptosis induced by vinpocetine plus sorafenib in HCC cells. Our study revealed that vinpocetine plus sorafenib could suppress the cytoprotective autophagy induced by vinpocetine and subsequently show synergistically anti-HCC activity via activating GSK-3β and the combination of vinpocetine and sorafenib might reverse sorafenib resistance via the PI3K/protein kinase B/GSK-3β signaling axis. Thus, vinpocetine may be a potential candidate for sorafenib sensitization and HCC treatment, and our results may help to elucidate more effective therapeutic options for HCC patients with sorafenib resistance.

Tumor-Associated Macrophages in Hepatocellular Carcinoma: Friend or Foe?

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, and it has diverse etiologies with multiple mechanisms. The diagnosis of HCC typically occurs at advanced stages when there are limited therapeutic options. Hepatocarcinogenesis is considered a multistep process, and hepatic macrophages play a critical role in the inflammatory process leading to HCC. Emerging evidence has shown that tumor-associated macrophages (TAMs) are crucial components defining the HCC immune microenvironment and represent an appealing option for disrupting the formation and development of HCC. In this review, we summarize the current knowledge of the polarization and function of TAMs in the pathogenesis of HCC, as well as the mechanisms underlying TAM-related anti-HCC therapies. Eventually, novel insights into these important aspects of TAMs and their roles in the HCC microenvironment might lead to promising TAM-focused therapeutic strategies for HCC.

The Pathways Underlying the Multiple Roles of p62 in Inflammation and Cancer

p62 is a highly conserved, multi-domain, and multi-functional adaptor protein critically involved in several important cellular processes. Via its pronounced domain architecture, p62 binds to numerous interaction partners, thereby influencing key pathways that regulate tissue homeostasis, inflammation, and several common diseases including cancer. Via binding of ubiquitin chains, p62 acts in an anti-inflammatory manner as an adaptor for the auto-, xeno-, and mitophagy-dependent degradation of proteins, pathogens, and mitochondria. Furthermore, p62 is a negative regulator of inflammasome complexes. The transcription factor Nrf2 regulates expression of a bundle of ROS detoxifying genes. p62 activates Nrf2 by interaction with and autophagosomal degradation of the Nrf2 inhibitor Keap1. Moreover, p62 activates mTOR, the central kinase of the mTORC1 sensor complex that controls cell proliferation and differentiation. Through different mechanisms, p62 acts as a positive regulator of the transcription factor NF-κB, a central player in inflammation and cancer development. Therefore, p62 represents not only a cargo receptor for autophagy, but also a central signaling hub, linking several important pro- and anti-inflammatory pathways. This review aims to summarize knowledge about the molecular mechanisms underlying the roles of p62 in health and disease. In particular, different types of tumors are characterized by deregulated levels of p62. The elucidation of how p62 contributes to inflammation and cancer progression at the molecular level might promote the development of novel therapeutic strategies.

RNA N 6-Methyladenosine in Cancer Metastasis: Roles, Mechanisms, and Applications

Cancer metastasis is a symptom of adverse prognosis, a prime origin of therapy failure, and a lethal challenge for cancer patients. N⁶-methyladenosine (m⁶A), the most prevailing modification in messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs) of higher eukaryotes, has attracted increasing attention. Growing studies have verified the pivotal roles of m⁶A methylation in controlling mRNAs and ncRNAs in diverse physiological processes. Remarkably, recent findings have showed that aberrant methylation of m⁶A-related RNAs could influence cancer metastasis. In this review, we illuminate how m⁶A modifiers act on mRNAs and ncRNAs and modulate metastasis in several cancers, and put forward the clinical application prospects of m⁶A methylation.

BACH1 is transcriptionally inhibited by TET1 in hepatocellular carcinoma in a microRNA-34a-dependent manner to regulate autophagy and inflammation

Hepatocellular carcinoma (HCC), one of the main contributors to cancer-associated deaths globally, is characterized by high invasiveness. Herein, we studied the molecular mechanisms underlying ten-eleven translocation 1 (TET1)-mediated autophagy in HCC. Following data mining using GSE101728, GSE14520 and GSE138178, TET1 was screened out, and the differential expression of TET1 was verified by bioinformatics analysis. TET1, one of the prognostic markers in HCC, was poorly expressed in HCC. Through functional experiments, we determined that upregulation of TET1 inhibited the proliferation, migration, invasion, tumorigenesis, metastasis and inflammatory factors of HCC cells, and promoted cell autophagy and apoptosis. Mechanistically, TET1 activated miR-34a by demethylating miR-34a. BTB domain and CNC homology 1 (BACH1) was identified as the target gene of miR-34a. Notably, Downregulation of miR-34a increased cellular inflammatory factors and decreased autophagy in the presence of TET1, while declines in BACH1 suppressed cellular inflammatory factors and enhanced autophagy in the presence of miR-34a inhibitor. BACH1 negatively regulated the p53 pathway. In conclusion, TET1 is a tumor suppressor in the progression of HCC by regulating the miR-34a/BACH1/p53 axis, and may contribute to the improvement of HCC prognosis and therapy.

Autophagy, an accomplice or antagonist of drug resistance in HCC?

Hepatocellular carcinoma (HCC) is a highly lethal malignancy characterized by poor prognosis and a low 5-year survival rate. Drug treatment is proving to be effective in anti-HCC. However, only a small number of HCC patients exhibit sensitive responses, and drug resistance occurs frequently in advanced patients. Autophagy, an evolutionary process responsible for the degradation of cellular substances, is closely associated with the acquisition and maintenance of drug resistance for HCC. This review focuses on autophagic proteins and explores the intricate relationship between autophagy and cancer stem cells, tumor-derived exosomes, and noncoding RNA. Clinical trials involved in autophagy inhibition combined with anticancer drugs are also concerned.

Identification and Validation of a Prognostic Model Based on Three Autophagy-Related Genes in Hepatocellular Carcinoma

Background

Accumulating studies have demonstrated that autophagy plays an important role in hepatocellular carcinoma (HCC). We aimed to construct a prognostic model based on autophagy-related genes (ARGs) to predict the survival of HCC patients.

Methods

Differentially expressed ARGs were identified based on the expression data from The Cancer Genome Atlas and ARGs of the Human Autophagy Database. Univariate Cox regression analysis was used to identify the prognosis-related ARGs. Multivariate Cox regression analysis was performed to construct the prognostic model. Receiver operating characteristic (ROC), Kaplan-Meier curve, and multivariate Cox regression analyses were performed to test the prognostic value of the model. The prognostic value of the model was further confirmed by an independent data cohort obtained from the International Cancer Genome Consortium (ICGC) database.

Results

A total of 34 prognosis-related ARGs were selected from 62 differentially expressed ARGs identified in HCC compared with noncancer tissues. After analysis, a novel prognostic model based on ARGs (PRKCD, BIRC5, and ATIC) was constructed. The risk score divided patients into high- or low-risk groups, which had significantly different survival rates. Multivariate Cox analysis indicated that the risk score was an independent risk factor for survival of HCC after adjusting for other conventional clinical parameters. ROC analysis showed that the predictive value of this model was better than that of other conventional clinical parameters. Moreover, the prognostic value of the model was further confirmed in an independent cohort from ICGC patients.

Conclusion

The prognosis-related ARGs could provide new perspectives on HCC, and the model should be helpful for predicting the prognosis of HCC patients.

Are Markers of Systemic Inflammatory Response Useful in the Management of Patients With Neuroendocrine Neoplasms?

Given the increasing incidence of neuroendocrine neoplasms (NENs) over the past few decades, a more comprehensive knowledge of their pathophysiological bases and the identification of innovative NEN biomarkers represents an urgent unmet need. There is still little advance in the early diagnosis and management of these tumors, due to the lack of sensible and specific markers with prognostic value and ability to early detect the response to treatment. Chronic systemic inflammation is a predisposing factor for multiple cancer hallmarks, as cancer proliferation, progression and immune-evading. Therefore, the relevance of inflammatory biomarkers has been identified as critical in several types of tumours, including NENs. A bidirectional relationship between chronic inflammation and development of NENs has been reported. Neuroendocrine cells can be over-stimulated by chronic inflammation, leading to hyperplasia and neoplastic transformation. As the modulation of inflammatory response represents a therapeutic target, inflammatory markers could represent a promising new key tool to be applied in the diagnosis, the prediction of response to treatment and also as prognostic biomarkers in NENs field. The present review provides an overview of the pre-clinical and clinical data relating the potentially usefulness of circulating inflammatory markers: neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), cytokines and tissue inflammatory markers (PD-1/PD-L1), in the management of NENs. (1) NLR and PLR have both demonstrated to be promising and simple to acquire biomarkers in patients with advanced cancer, including NEN. To date, in the context of NENs, the prognostic role of NLR and PLR has been confirmed in 15 and 4 studies, respectively. However, the threshold value, both for NLR and PLR, still remains not defined. (2) Cytokines seem to play a central role in NENs tumorigenesis. In particular, IL-8 levels seems to be a good predictive marker of response to anti-angiogenic treatments. (3) PD-1 and PD-L1 expression on tumour cells and on TILs, have demonstrated to be promising predictive and prognostic biomarkers in NENs. Unfortunately, these two markers have not been validated so far and further studies are needed to establish their indications and utility.

Inhibition of B7-H4 promotes hepatocellular carcinoma cell apoptosis and autophagy through the PI3K signaling pathway

B7-H4 and autophagy can regulate or be induced by the PI3K signaling pathway. However, the association between B7-H4 and autophagy in hepatocellular carcinoma (HCC)remains unclear. The aim of this work was to investigate whether B7-H4 regulates autophagy via the PI3K signaling pathway in HCC cells. Here, western blotting was used to measure the expression of the related proteins involved in changes in of autophagy and apoptosis, such as LC3, P62, cleaved caspase 3, cleaved PARP, BCL-2, and BAX in Huh7 and Hep3B cells. Additionally, PI3K/AKT/mTOR signaling pathway proteins were measured. Cell counting kit-8 and flow cytometry were used to analyze the effects of B7-H4 siRNA interference on cell proliferation with the interference of B7-H4 siRNA. We found that B7-H4 siRNA increased HCC cell apoptosis and autophagy, and reduced cell proliferation. Moreover, the apoptosis-related proteins cleaved caspase 3, cleaved PARP and BAX were increased and Bcl-2 was decreased after B7-H4 siRNA interference. The expression level of the autophagy-related protein LC3Ⅱ was upregulated, while expression of the autophagy adaptor P62 expression was decreased in B7-H4 siRNA-pretreated cells. Furthermore, our data revealed that B7-H4 regulated apoptosis and autophagy through the PI3K signaling pathway in HCC cells. Therefore, these results suggested that B7-H4 plays an important role in HCC progression by affecting cell apoptosis and autophagy.

MicroRNA200a enhances antitumor effects in combination with doxorubicin in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is often treated with doxorubicin. MicroRNAs have been shown to have important regulatory roles in cancer and serve as a target in chemoresistance. In this study, we investigated the effects of specific microRNA-200a (miR-200a) on HCC tumor cell growth and effect of doxorubicin-mediated cytotoxicity. Our results show miR-200a is downregulated in human HCC and HCC tumor cell lines. Increasing miR-200a expression inhibited HCC growth and synergized with the antitumor effects of doxorubicin. Inhibiting endogenous miR-200a promoted tumor growth and chemotherapeutic resistance. Increasing miR-200a expression inhibited tumor metabolism (ATP production, mitochondrial respiration, glycolysis), while inhibition of endogenous miR-200a reversed these effects. MiR-200a expression also increased autophagy and synergized with doxorubicin-mediated cytotoxicity. This study identifies a novel role of miR-200a in potentiating doxorubicin-mediated therapeutic effects in HCC.

A four-methylated mRNA signature-based risk score system predicts survival in patients with hepatocellular carcinoma

Evidence suggests that altered DNA methylation plays a causative role in the pathogenesis of various cancers, including hepatocellular carcinoma (HCC). Thus, methylated differently expressed genes (MDEGs) could potentially serve as biomarkers and therapeutic targets in HCC. In the present study, screening four genomics profiling datasets (GSE62232, GSE84402, GSE73003 and GSE57956) enabled us to identify a total of 148 MDEGs. A signature was then established based on the top four MDEGs (BRCA1, CAD, CDC20 and RBM8A). Taking clinical variables into consideration, we constructed a risk score system consisting of the four-MDEG signature and the patients' clinical features, which was predictive of prognosis in HCC. The prognostic value of the HCC risk score system was confirmed using TCGA HCC samples. The scores were then used to construct a nomogram, performance of which was evaluated using Harrel's concordance index (C-index) and a calibration curve. The signature-based nomogram for prediction of overall survival in HCC patients exhibited good performance and was superior to traditional staging systems (C-index: 0.676 vs 0.629, P< 0.05). We have thus established a novel risk score system that is predictive of prognosis and is a potentially useful guide for personalized treatment of HCC patients.

NOD2 inhibits tumorigenesis and increases chemosensitivity of hepatocellular carcinoma by targeting AMPK pathway

Nucleotide binding oligomerization domain 2 (NOD2) is a recognized innate immune sensor which can initiate potent immune response against pathogens. Many innate immune sensors have been reported to be of great importance in carcinogenesis. However, the role of NOD2 in cancer is not well understood. Here we investigated the role of NOD2 in the development of hepatocellular carcinoma (HCC). We demonstrated that NOD2 deficiency promoted hepatocarcinogenesis in N-nitrosodiethylamine (DEN)/carbon tetrachloride (CCl₄) induced HCC mice model and xenograft tumor model. In vitro investigation showed that NOD2 acted as a tumor suppressor and inhibited proliferation, colony formation and invasion of HCC cells. Clinical investigation showed that NOD2 expression was completely lost or significantly downregulated in clinical HCC tissues, and loss of NOD2 expression was significantly correlated with advanced disease stages. Further investigation showed that NOD2 exerted its anti-tumor effect through activating adenosine 5'-monophosphate (AMP) -activated protein kinase (AMPK) signaling pathway, and NOD2 significantly enhanced the sensitivity of HCC cells to sorafenib, lenvatinib and 5-FU treatment through activating AMPK pathway induced apoptosis. Moreover, we demonstrated that NOD2 activated AMPK pathway by directly binding with AMPKα-LKB1 complex, which led to autophagy-mediated apoptosis of HCC cells. Altogether, this study showed that NOD2 acted as a tumor suppressor as well as a chemotherapeutic regulator in HCC cells by directly activating AMPK pathway, which indicated a potential therapeutic strategy for HCC treatment by upregulating NOD2-AMPK signaling axis.

Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) in autophagy-induced hepatocellular carcinoma

Autophagy, an evolutionarily conserved catabolic process, is the most important pathogenic events in the development and progression of liver diseases. Deregulation of Nrf2 is proposed to play a key pathogenic role in hepatocellular carcinoma (HCC). Under certain pathophysiological conditions, such as oxidative stress, impaired autophagy is accompanied by the Nrf2 activation that leads to the detrimental effects favoring the proliferation and survival of HCC. Elucidating its role and potential mechanism is essential for understanding tumorigenesis and the development of effective clinical application. Nrf2 is participated in HCC proliferation, migration and invasion through autophagy pathways. These includes the negatively regulated-Nrf2 by Keap1 that participates in HCC tumorigenesis via regulating ROS production, in which autophagy may contribute to oxidant metabolic reprogramming of HCC cells. Post-transcriptional modifications, such as phosphorylation and ubiquitination of Nrf2, can be positively or negatively induced by multiple transcription factors. Nrf2 exhibits chemoresistance through its binding sites in the promoter region of the target genes. Nrf2 may be a valuable potential biomarker and therapeutic strategy for diagnostics, prognostics and treatment of HCC.

Circular RNA ABCB10 promotes hepatocellular carcinoma progression by increasing HMG20A expression by sponging miR-670-3p

Background/aims

The dysregulation of circABCB10 may play an critical role in tumor progression. However, its function in liver cancer (HCC) is still unclear. Therefore, this experimental design is based on circABCB10 to explore the pathogenesis of HCC.

Methods

The expression of circABCB10 and miR-670-3p in HCC tissues was detected by RT-qPCR. CCK-8, Brdu incorporation, colony formation and transwell assays were used to determine the effect of circABCB10 on HCC cell proliferation and migration. Target gene prediction and screening, luciferase reporter assays were used to validate downstream target genes of circABCB10 and miR-670-3p. HMG20A expression was detected by RT-qPCR and Western blotting. The tumor changes in mice were detected by in nude mice.

Results

CircABCB10 was significantly increased in HCC tissues and cell lines, and high CircABCB10 expression was directly associated with low survival in HCC patients. Silencing of circABCB10 inhibited proliferation and invasion of hepatocellular carcinoma. In addition, circABCB10 acted as a sponge of miR-670-3p to upregulate HMG20A expression. In addition, overexpression of miR-670-3p or knockdown of HMG20A reversed the carcinogenic effects of circABCB10 in HCC. There was a negative correlation between the expression of circABCB10 and miR-670-3p, and a positive correlation between the expression of circABCB10 and HMG20A in HCC tissues.

Conclusion

circABCB10 promoted HCC progression by modulating the miR-670-3p/HMG20A axis, and circABCB10 may be a potential therapeutic target for HCC.

Trail registration JL1H384739, registered at Sep 09, 2014.

The ATG16L1 gene variant rs2241880 (p.T300A) is associated with susceptibility to HCC in patients with cirrhosis

BACKGROUND AND AIMS

Protein and organelle turnover by autophagy is a key component to maintain cellular homeostasis. Loss of the autophagy protein ATG16L1 is associated with reduced bacterial killing and aberrant interleukin-1β production, perpetuating inflammation and carcinogenesis. Here we hypothesized that the functional p.T300A gene variant in ATG16L1 is associated with an increased risk for hepatocellular carcinoma (HCC) in cirrhosis.

METHODS

A case-control study was performed using a prospective derivation cohort (107 patients with HCC and 101 controls) and an independent validation cohort (124 patients with HCC and 108 controls) of patients with cirrhosis of any aetiology. ATG16L1 p.T300A (rs2241880) and PNPLA3 p.I148M (rs738409) variants were determined by real-time PCR.

RESULTS

The G allele of the ATG16L1 p.T300A variant was more frequent in patients with HCC compared to controls without HCC in the derivation cohort (0.62 vs. 0.51, P = .022) and in the validation cohort (0.59 vs. 0.50, P = .045). In combined analysis, the odds ratios (OR) were 1.76 (95% CI: 1.07-2.88) for G allele positivity and 2.43 (95% CI: 1.37-4.31) for p.T300A G allele homozygosity. This association was independent from the presence of a PNPLA3 variant, which was also associated with HCC (OR 2.10; 95% CI: 1.20-3.66), and it remained significant after adjustment for male sex, age and aetiology in multivariate analysis.

CONCLUSION

The common germ-line ATG16L1 gene variant is a risk factor for HCC in patients with cirrhosis. Personalized strategies employing the genetic risk conferred by ATG16L1 and PNPLA3 may be used for risk-based surveillance in cirrhosis.

Cordycepin suppresses the migration and invasion of human liver cancer cells by downregulating the expression of CXCR4

Liver cancer is a worldwide threat to human health. High expression levels of C-X-C chemokine receptor type 4 (CXCR4) have been reported to promote the migration and invasion capacities of liver cancer cells. Cordycepin, extracted from Cordyceps militaris, has anti-inflammatory, antioxidant and anticancerous properties. Therefore, in the present study, migration assays, western blotting, reverse transcription-quantitative PCR and immunofluorescence analyses were conducted to determine whether cordycepin was able to suppress the migration and invasion abilities of liver cancer cells by inhibiting CXCR4 expression. The results suggested that cordycepin notably inhibited migration and invasion, and decreased the expression of CXCR4 in a dose-dependent manner. Activation of phosphorylated (p-) NF-κB inhibitor α (IκBα) and p-P65, the principal components of the NF-κB signaling pathway, was also downregulated. In addition, cordycepin markedly suppressed the nuclear translocation of P65, but had no effect on the expression of total IκBα (t-IκBα) and total P65 (t-P65). JSH-23, an inhibitor of the NF-κB pathway, impaired the migration of liver cancer cells, and was found to act synergistically with cordycepin. Furthermore, cordycepin treatment reduced the chemotactic migration ability of liver cancer cells to stromal cell-derived factor 1 (SDF1), which was significantly enhanced following treatment with JSH-23. Collectively, the present results indicated that cordycepin inhibited the nuclear translocation of P65 by preventing p-IκBα activation; this resulted in the downregulation of CXCR4 expression, and subsequently, in the impaired migration and invasion abilities of liver cancer cells and attenuated reactivity to SDF1. The current study revealed a novel mechanism for the antimetastatic activity of cordycepin and its potential to exert positive synergistic effects with other compounds for the treatment of liver cancer.

Association of CTLA-4, TNF alpha and IL 10 polymorphisms with susceptibility to hepatocellular carcinoma

Our aim was to evaluate the association of genetic polymorphisms of immunoregulatory molecules with susceptibility to hepatocellular carcinoma (HCC). The polymorphisms in CTLA-4 (-318 T/C, CT60 G/A), TNF (-238 G/A, -308 G/A) and IL10 (-592 C/A, -819 C/T) were genotyped by PCR and DNA sequencing. The functional relevance of the polymorphisms was examined by ELISAs, in vitro lymphocyte proliferation assay and cytotoxic assay. The CTLA-4 -318 TC/TT, CTLA-4 CT60 GG, IL10 -592 CA and -819 CT/TT variants, CTLA-4 -318 T and IL 10 -819 T alleles were positively associated with HCC risk (P < .05). While TNF -238 AA variant, TNF -238 A allele were associated with decreased risk of HCC (P < .05). Furthermore, combinations of CTLA-4 -318 TC/TT and TNF -238 GG/GA; CTLA-4 -318 TC/TT and IL 10 -819 CC; CTLA-4 -318 CC and IL 10 -819 CT/TT in patients with HCC were statistically significant (P < .05). Peripheral blood mononuclear cells (PBMCs) carrying -318 TC/TT genotypes exhibited significantly lower proliferation rates, decreased IL-2, IL-4 levels, fewer cytolytic activities and elevated TGF-β levels. For IL 10 -819 C/T, the CC genotype was significantly associated with higher proliferation rate, decreased TGF-β, IL-10 levels and higher cytolytic activities (P < .05). For TNF -238 G/A, the AA genotype only had association with serum IL-2, IL-4 (P < .05). In addition, we also found that CTLA-4 -318 T/C, IL-10 -819 T/C variants, combinations of CTLA-4 -318 CC with IL 10 -819 CT or TT, CTLA-4 -318 TC or TT with IL 10 -819 CT or TT were associated with the severity of HCC. These findings suggest that CTLA-4 -318 TC/TT and IL 10 -819 CT/TT could promote the pathogenesis of HCC, which might be related with down-regulation of Th1/Th2-type cytokines and/or up-regulation of Th3-type cytokines.

The peculiar aging of human liver: A geroscience perspective within transplant context

An appraisal of recent data highlighting aspects inspired by the new Geroscience perspective are here discussed. The main findings are summarized as follows: i) liver has to be considered an immunological organ, and new studies suggest a role for the recently described cells named telocytes; ii) the liver-gut axis represents a crucial connection with environment and life style habits and may influence liver diseases onset; iii) the physiological aging of liver shows relatively modest alterations. Nevertheless, several molecular changes appear to be relevant: a) an increase of microRNA-31-5p; -141-3p; -200c-3p expressions after 60 years of age; b) a remodeling of genome-wide DNA methylation profile evident until 60 years of age and then plateauing; c) changes in transcriptome including the metabolic zones of hepatocyte lobules; d) liver undergoes an accelerated aging in presence of chronic inflammation/liver diseases in a sort of continuum, largely as a consequence of unhealthy life styles and exposure to environmental noxious agents. We argue that chronic liver inflammation has all the major characteristics of "inflammaging" and likely sustains the onset and progression of liver diseases. Finally, we propose to use a combination of parameters, mostly obtained by omics such as transcriptomics and epigenomics, to evaluate in deep both the biological age of liver (in comparison with the chronological age) and the effects of donor-recipient age-mismatches in the context of liver transplant.

Autophagy in liver diseases: Time for translation?

Autophagy is a self-eating catabolic pathway that contributes to liver homeostasis through its role in energy balance and in the quality control of the cytoplasm, by removing misfolded proteins, damaged organelles and lipid droplets. Autophagy not only regulates hepatocyte functions but also impacts on non-parenchymal cells, such as endothelial cells, macrophages and hepatic stellate cells. Deregulation of autophagy has been linked to many liver diseases and its modulation is now recognized as a potential new therapeutic strategy. Indeed, enhancing autophagy may prevent the progression of a number of liver diseases, including storage disorders (alpha-1 antitrypsin deficiency, Wilson's disease), acute liver injury, non-alcoholic steatohepatitis and chronic alcohol-related liver disease. Nevertheless, in some situations such as fibrosis, targeting specific liver cells must be considered, as autophagy displays opposing functions depending on the cell type. In addition, an optimal therapeutic time-window should be identified, since autophagy might be beneficial in the initial stages of disease, but detrimental at more advanced stages, as in the case of hepatocellular carcinoma. Finally, identifying biomarkers of autophagy and methods to monitor autophagic flux in vivo are important steps for the future development of personalized autophagy-targeting strategies. In this review, we provide an update on the regulatory role of autophagy in various aspects of liver pathophysiology, describing the different strategies to manipulate autophagy and discussing the potential to modulate autophagy as a therapeutic strategy in the context of liver diseases.

E2-Induced Activation of the NLRP3 Inflammasome Triggers Pyroptosis and Inhibits Autophagy in HCC Cells

Emerging evidence suggests that 17β-estradiol (E2) and estrogen receptor (ER) signaling are protective against hepatocellular carcinoma (HCC). In our previous study, we showed that E2 suppressed the carcinogenesis and progression of HCC by targeting NLRP3 inflammasome activation, whereas the molecular mechanism by which the NLRP3 inflammasome initiated cancer cell death was not elucidated. The present study aimed to investigate the effect of NLRP3 inflammasome activation on cell death pathways and autophagy of HCC cells. First, we observed an increasing mortality in E2-treated HCC cells, and then apoptotic and pyroptotic cell death were both detected. The mortality of HCC cells was largely reversed by the caspase 1 antagonist, YVAD-cmk, suggesting that E2-induced cell death was associated with caspase 1-dependent pyroptosis. Second, the key role of the NLRP3 inflammasome in autophagy of HCC cells was assessed by E2-induced activation of the NLRP3 inflammasome, and we demonstrated that autophagy was inhibited by the NLRP3 inflammasome via the E2/ERβ/AMPK/mTOR pathway. Last, the interaction of pyroptosis and autophagy was confirmed by flow cytometry methods. We observed that E2-induced pyroptosis was dramatically increased by 3-methyladenine (3-MA) treatment, which was abolished by YVAD-cmk treatment, suggesting that caspase 1-dependent pyroptosis was negatively regulated by autophagy. In conclusion, E2-induced activation of the NLRP3 inflammasome may serve as a suppressor in HCC progression, as it triggers pyroptotic cell death and inhibits protective autophagy.

Potent effects of dioscin against hepatocellular carcinoma through regulating TP53-induced glycolysis and apoptosis regulator (TIGAR)-mediated apoptosis, autophagy, and DNA damage

BACKGROUND AND PURPOSE

Dioscin shows potent effects against cancers. We aimed to elucidate its pharmacological effects and mechanisms of action on hepatocellular carcinoma (HCC) in vivo and in vitro.

EXPERIMENTAL APPROACH

Effects of dioscin were investigated in SMMC7721 and HepG2 cells, diethylnitrosamine-induced primary liver cancer in rats, and cell xenografts in nude mice. Isobaric tags for relative and absolution quantitation (iTRAQ)-based proteomics was used to find dioscin's targets and investigate its mechanism.

KEY RESULTS

In SMMC7721 and HepG2 cells dioscin markedly inhibited cell proliferation and migration, induced apoptosis, autophagy, and DNA damage. It inhibited DEN-induced primary liver cancer in rats, markedly changed body weights and restored levels of α fetoprotein, alanine transaminase, aspartate transaminase, γ-glutamyltransferase, alkaline phosphatase, and Ki67. It also inhibited growth of xenografts in mice. In SMMC7721 cells, 191 differentially expressed proteins were found after dioscin, based on iTRAQ-based assay. TP53-inducible glycolysis and apoptosis regulator (TIGAR) was identified as being significantly down-regulated by dioscin. Dioscin induced cell apoptosis, autophagy, and DNA damage via increasing expression levels of p53, cleaved PARP, Bax, cleaved caspase-3/9, Beclin-1, and LC3 and suppressing those of Bcl-2, p-Akt, p-mammalian target of rapamycin (mTOR), CDK5, p-ataxia telangiectasia-mutated gene (ATM). The transfection of TIGAR siRNA into SMMC7721 cells and xenografts in nude mice further confirmed that the potent activity of dioscin against HCC is evoked by adjusting TIGAR-mediated inhibition of p53, Akt/mTOR, and CDK5/ATM pathways.

CONCLUSIONS AND IMPLICATIONS

The data suggest that dioscin has potential as a therapeutic, and TIGAR as a drug target for treating HCC.

Role of autophagy in tumorigenesis, metastasis, targeted therapy and drug resistance of hepatocellular carcinoma

Autophagy is a “self-degradative” process and is involved in the maintenance of cellular homeostasis and the control of cellular components by facilitating the clearance or turnover of long-lived or misfolded proteins, protein aggregates, and damaged organelles. Autophagy plays a dual role in cancer, including in tumor progression and tumor promotion, suggesting that autophagy acts as a double-edged sword in cancer cells. Liver cancer is one of the greatest leading causes of cancer death worldwide due to its high recurrence rate and poor prognosis. Especially in China, liver cancer has become one of the most common cancers due to the high infection rate of hepatitis virus. In primary liver cancer, hepatocellular carcinoma (HCC) is the most common type. Considering the perniciousness and complexity of HCC, it is essential to elucidate the function of autophagy in HCC. In this review, we summarize the physiological function of autophagy in cancer, analyze the role of autophagy in tumorigenesis and metastasis, discuss the therapeutic strategies targeting autophagy and the mechanisms of drug-resistance in HCC, and provide potential methods to circumvent resistance and combined anticancer strategies for HCC patients.