Involvement of androgen receptor and glucose-regulated protein 78 kDa in human hepatocarcinogenesis. Exp Cell Res. 2014;323:326-336. [PMID: 24583399 DOI: 10.1016/j.yexcr.2014.02.017]

Therapeutic prospects of sex hormone receptor signaling in hormone-responsive cancers

Globally, hormone-responsive cancers afflict millions of people contributing to cancer-related morbidity and mortality. While hormone-responsive cancers overburden patients, their close families, and even health budgets at the local levels, knowledge of these cancers particularly their biology and possible avenues for therapy remains poorly exploited. Herewith, this review highlights the role of sex hormones (estrogens and androgens) in the pathophysiology of hormone-responsive cancers and the exploration of therapeutic targets. Major scientific databases including but not limited to Scopus, PubMed, Science Direct, Web of Science core collections, and Google Scholar were perused using a string of search terms: Hormone-responsive cancers, androgens and cancers, estrogens and cancer, androgen receptor signalling, estrogen receptor signalling, etc.

YAP-TEAD inhibition is associated with upregulation of an androgen receptor mediated transcription program providing therapeutic escape

Cholangiocarcinoma (CCA) is a highly aggressive form of liver cancer and is an increasing cause of cancer-related death worldwide. Despite its increasing incidence globally and alarming mortality, treatment options for CCA have largely remained unchanged, stressing the importance of developing new effective therapies. YAP activation is common in CCA, and its major transcriptional signaling partners are the TEAD proteins. CA3 is a small-molecule YAP-TEAD disrupter discovered utilizing a TEAD reporter assay. Utilizing CCA, gastric cancer cell lines, and patient-derived xenograft models (PDX), we demonstrate that CA3 is effective in inducing cell death and delaying tumor growth in both FGFR2 fusion and wild-type models. CA3 was associated with on-target decreases in YAP-TEAD target gene expression, TEAD reporter activity, and overall TEAD levels. Hippo pathway signaling was not altered as there was no change in YAP phosphorylation status in the cells exposed to CA3. RNA sequencing of gastric cancer and CCA models demonstrated upregulation of an androgen receptor-mediated transcriptional program following exposure to CA3 in five unique models tested. Consistent with this upstream regulator analysis, CA3 exposure in CCA cells was associated with increased AR protein levels, and combinatorial therapy with CA3 and androgen receptor blockade was associated with increased cancer cell death. CA3 behaves functionally as a YAP-TEAD disrupter in the models tested and demonstrated therapeutic efficacy. Exposure to CA3 was associated with compensatory androgen receptor signaling and dual inhibition improved the therapeutic effect.

In silico and network pharmacology analysis of fucosterol: a potent anticancer bioactive compound against HCC

The Fucaceae family of marine brown algae includes Ascophyllum nodosum. Fucosterol (FSL) is a unique bioactive component that was identified through GC-MS analysis of the hydroalcoholic extract of A. nodosum. Fucosterol's mechanism of action towards hepatocellular cancer was clarified using network pharmacology and docking study techniques. The probable target gene of FSL has been predicted using the TargetNet and SwissTargetPred databases. GeneCards and the DisGNet database were used to check the targeted genes of FSL. By using the web programme Venny 2.1, the overlaps of FSL and HCC disease demonstrated that 18 genes (1.3%) were obtained as targeted genes Via the STRING database, a protein-protein interaction (PPI) network with 18 common target genes was constructed. With the aid of CytoNCA, hub genes were screened using the Cytoscape software, and the targets' hub genes were exported into the ShinyGo online tool for study of KEGG and gene ontology enrichment. Using the software AutoDock, a hub gene molecular docking study was performed. Ten genes, including AR, CYP19A1, ESR1, ESR2, TNF, PPARA, PPARG, HMGCR, SRC, and IGF1R, were obtained. The 10 targeted hubs docked with FSL successfully. The active components FSL of ASD, the FSL, are engaged in fatty liver disease, cancer pathways, and other signalling pathways, which could prove beneficial for the management of HCC.

Sex steroid axes in determining male predominance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death. The mechanisms for male propensity in HCC incidence, prognosis and treatment responses are complicated and remain inconclusive. Sex-biased molecular signatures in carcinogenesis, viral infections and immune responses have been studied predominantly within the context of sex hormones effects. This review integrates current knowledge on the mechanisms through which the hormones regulate HCC development in sexually dimorphic fashion. Firstly, the androgen/androgen receptor (AR) accelerate cell proliferation and virus infection, especially during the initial stage of HCC, while estrogen/estrogen receptor (ER) function in an opposite way to induce cell apoptosis and immune responses. Interestingly, the controversial effects of AR in late stage of HCC metastasis are summarized and the reasons are attributed to inconsistent cancer grading or experimental models between the studies. In addition, the new insights into these intricate cellular and molecular mechanisms underlying sexual dimorphism are fully discussed. A detailed understanding of sex hormones-associated regulation to male predominance in HCC may help to develop personalized therapeutic strategies in high-risk populations.

Sorafenib combined with STAT3 knockdown triggers ER stress-induced HCC apoptosis and cGAS-STING-mediated anti-tumor immunity

Sorafenib is the first-line treatment for advanced hepatocellular carcinoma (HCC). However, it is difficult to alleviate this disease process using single-agent chemotherapy. Using combination therapies for advanced HCC has become a major trend. Given that STAT3 overexpression is involved in chemotherapy resistance and the immune escape of HCC cells, it has become a potential therapeutic target for HCC in recent years. GEO database analysis showed that STAT3 levels in tumor tissues from non-responders were significantly higher than those in responders to sorafenib. Our studies demonstrated that STAT3 knockdown promoted sorafenib-induced ER stress-induced apoptosis. Importantly, the DNA released by dead HCC cells stimulated the cGAS-STING signaling pathway in CD103⁺ DCs and promoted type I interferon production, thus, enhancing the anti-tumor function of CD8⁺ T and NK cells. In conclusion, our results revealed that the combination strategy of sorafenib and STAT3 knockdown might be a potential treatment strategy for HCC, directly and efficiently disturbing the tumor features of HCC cells while improving the tumor microenvironment via the cGAS-STING-Type I IFNs axis of DCs, inducing anti-HCC immune responses.

PRNCR1: a long non-coding RNA with a pivotal oncogenic role in cancer

Long non-coding RNAs (lncRNAs) have been gaining importance in the field of cancer research in recent years. PRNCR1 (prostate cancer-associated non-coding RNA1) is a 12.7 kb, intron-less lncRNA found to play an oncogenic role in malignancy of diverse organs including prostate, breast, lung, oral cavity, colon and rectum. Single-nucleotide polymorphisms (SNPs) of PRNCR1 locus have been found to be associated with cancer susceptibility in different populations. In this review, an attempt has been made for the first time to summarize all sorts of available data on PRNCR1 to date from relevant databases (GeneCard, LncExpDB, Ensembl genome browser, and PubMed). As functional roles of PRNCR1, miRNA (microRNA) sponging was mostly highlighted in the pathogenesis of different cancer; in addition, an association of the lncRNA with chromatin-modifying complex to enhance androgen receptor-mediated gene transcription was reported in prostate cancer. Diagnostic and prognostic importance of PRNCR1 was found in some malignancies suggesting potency of the lncRNA to serve as a clinical biomarker. For PRNCR1 SNPs, although cancer susceptibility of the risk alleles/genotypes was reported in different populations, majorities of the findings were not replicated and underlying molecular mechanisms remained unexplored. Therapeutic implication of PRNCR1 was not studied well and future research may come up in this direction for intervening novel strategies to fight against cancer.

The androgen receptor expression and its activity have different relationships with prognosis in hepatocellular carcinoma

The role of the Androgen Receptor (AR) expression and its activity in the prognosis of hepatocellular carcinoma (HCC) remains inconclusive. The aim of this study is to analyze the role of the AR expression and its activity as prognostic biomarkers in HCC. Three-hundred and thirty-seven patients from The Cancer Genome Atlas (TCGA) (107 females; 59.42 years [SD = 13.0]) were included. To infer AR activity, the expression-profile of previously validated androgen responsive genes (ARGs) was included. AR activity was shown by the AR-Score-21 (21 ARGs) and AR-Score-13 (13 ARGs) that were computed based on the expression of the selected ARGs. Those ARGs whose expression was significantly different between histological grades were used for computing two new AR-Scores. HCC patients with higher AR expression showed a higher median overall survival (OS). AR-Score 21 and AR-Score-13 did not show any association with prognosis. Six of the 21 ARGs of the AR-Score-21 and 7 of the 13 ARGs of the AR-Score-13 showed a significant different expression profile among histological grades. Based on these differences, another two AR-Scores were computed (AR-Score-6 and AR-Score-7). They showed the relative increase of upregulated to downregulated ARGs in high-grade HCC. Higher AR activity inferred by these AR-Scores was associated with worse outcomes. The expression of AR is associated with a better prognosis in HCC. However, the activity of the AR seems to be qualitatively different among histological grades. The AR activity inferred by the shifted ARGs is associated with a worse prognosis in HCC patients.

Obesity, Diabetes and COVID-19: An Infectious Disease Spreading From the East Collides With the Consequences of an Unhealthy Western Lifestyle

The pandemic of COVID-19, caused by the coronavirus, SARS-CoV-2, has had a global impact not seen for an infectious disease for over a century. This acute pandemic has spread from the East and has been overlaid onto a slow pandemic of metabolic diseases of obesity and diabetes consequent from the increasing adoption of a Western-lifestyle characterized by excess calorie consumption with limited physical activity. It has become clear that these conditions predispose individuals to a more severe COVID-19 with increased morbidity and mortality. There are many features of diabetes and obesity that may accentuate the clinical response to SARS-CoV-2 infection: including an impaired immune response, an atherothrombotic state, accumulation of advanced glycation end products and a chronic inflammatory state. These could prime an exaggerated cytokine response to viral infection, predisposing to the cytokine storm that triggers progression to septic shock, acute respiratory distress syndrome, and multi-organ failure. Infection leads to an inflammatory response and tissue damage resulting in increased metabolic activity and an associated increase in the mechanisms by which cells ingest and degrade tissue debris and foreign materials. It is becoming clear that viruses have acquired an ability to exploit these mechanisms to invade cells and facilitate their own life-cycle. In obesity and diabetes these mechanisms are chronically activated due to the deteriorating metabolic state and this may provide an increased opportunity for a more profound and sustained viral infection.

A zinc finger family protein, ZNF263, promotes hepatocellular carcinoma resistance to apoptosis via activation of ER stress-dependent autophagy

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. Endoplasmic reticulum stress (ERS) is generally activated in HCC and is important for the sensitivity of HCC to anticancer drugs. ERS-dependent autophagy is a crucial mechanism affecting the sensitivity of HCC to anticancer drugs, but the mechanism by which ERS regulates autophagy is not well understood. Zinc finger protein 263 (ZNF263) is a transcription factor member of the zinc finger family. However, its functional role in HCC remains to be studied. In the current study, we investigated the role of ZNF263 in regulating ERS-induced chemoresistance in HCC and its possible mechanism. We found that ZNF263 was the most significant ERS-specific super-enhancer bounding transcriptional factor and was up-regulated in HCC patients and cell lines. Further, ZNF263 expression correlated with ERS, clinical stage and shorter survival in HCC patients. ZNF263 knockdown by RNA interference results in decreased proliferation, apoptosis resistance, and chemoresistance. Further study showed that ZNF263 increased chemoresistance by activating ERS-related autophagy. In conclusion, our study highlights ZNF263 as a functional ERS-related tumor activator and indicates it as a potential target for HCC therapy.

Emerging roles and the regulation of aerobic glycolysis in hepatocellular carcinoma

Liver cancer has become the sixth most diagnosed cancer and the fourth leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is responsible for up to 75–85% of primary liver cancers, and sorafenib is the first targeted drug for advanced HCC treatment. However, sorafenib resistance is common because of the resultant enhancement of aerobic glycolysis and other molecular mechanisms. Aerobic glycolysis was firstly found in HCC, acts as a hallmark of liver cancer and is responsible for the regulation of proliferation, immune evasion, invasion, metastasis, angiogenesis, and drug resistance in HCC. The three rate-limiting enzymes in the glycolytic pathway, including hexokinase 2 (HK2), phosphofructokinase 1 (PFK1), and pyruvate kinases type M2 (PKM2) play an important role in the regulation of aerobic glycolysis in HCC and can be regulated by many mechanisms, such as the AMPK, PI3K/Akt pathway, HIF-1α, c-Myc and noncoding RNAs. Because of the importance of aerobic glycolysis in the progression of HCC, targeting key factors in its pathway such as the inhibition of HK2, PFK or PKM2, represent potential new therapeutic approaches for the treatment of HCC.

Thapsigargin promotes colorectal cancer cell migration through upregulation of lncRNA MALAT1

Colorectal cancer (CRC) is the third most common tumor in the world; however, the role and mechanism of endoplasmic reticulum (ER) stress in CRC metastasis remains largely unclear. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA), which has previously been associated with CRC metastasis. It has been suggested that ER stress pathways regulate lncRNA expression; however, the effect of ER stress on MALAT1 expression in cancer is unknown. The present study aimed to investigate the relationship between ER stress pathways, MALAT1 expression and cell migration in CRC cells. ER stress was induced by thapsigargin (TG); low dose TG induced the migration of HT29 and HCT116 cells, but not SW1116 and SW620 cells. This effect was associated with increased expression levels of MALAT1, as the knockdown of MALAT1 prevented TG-induced cell migration. TG-induced MALAT1 expression was associated with inositol-requiring enzyme 1 (IRE1) expression and activation of the protein kinase R (PKR)-like ER kinase (PERK) signaling pathway. X-box-binding protein 1 (XBP1) and activating transcription factor 4 (ATF4) binding sites were predicted to be located in the MALAT1 gene promoter regions and the expression of MALAT1 was positively associated with XBP1 and ATF4 expression levels in CRC tissue samples. Thus, these findings indicated that ER stress may promote the migration of CRC cells and contribute to the progression of CRC through the activation of the IRE1/XBP1 and PERK/eIF2α/ATF4 signaling pathways. In conclusion, to the best of our knowledge, this study is the first report that lncRNA MALAT1 expression is regulated by the IRE1/XBP1 pathway in CRC.

Nandrolone induces a stem cell-like phenotype in human hepatocarcinoma-derived cell line inhibiting mitochondrial respiratory activity

Nandrolone is a testosterone analogue with anabolic properties commonly abused worldwide, recently utilized also as therapeutic agent in chronic diseases, cancer included. Here we investigated the impact of nandrolone on the metabolic phenotype in HepG2 cell line. The results attained show that pharmacological dosage of nandrolone, slowing cell growth, repressed mitochondrial respiration, inhibited the respiratory chain complexes I and III and enhanced mitochondrial reactive oxygen species (ROS) production. Intriguingly, nandrolone caused a significant increase of stemness-markers in both 2D and 3D cultures, which resulted to be CxIII-ROS dependent. Notably, nandrolone negatively affected differentiation both in healthy hematopoietic and mesenchymal stem cells. Finally, nandrolone administration in mice confirmed the up-regulation of stemness-markers in liver, spleen and kidney. Our observations show, for the first time, that chronic administration of nandrolone, favoring maintenance of stem cells in different tissues would represent a precondition that, in addition to multiple hits, might enhance risk of carcinogenesis raising warnings about its abuse and therapeutic utilization.

Androgen Receptor (AR)-TLR4 Crosstalk Mediates Gender Disparities in Hepatocellular Carcinoma Incidence and Progression

Background: Androgen receptor (AR) has a role in regulating malignancies and gender disparities in hepatocellular carcinoma (HCC). Recently, TLR4 activation is demonstrated to be required for HCC progression; however, whether and how TLR4 interacts with AR is largely unknown.

Methods: The tumorigenesis was detected in female and male mice induced by DEN/CCL_4, then TLR4 and AR signals were detected in liver tissues by qPCR and FACS. The proliferation, colony formation and migration of HCC cell treated with TLR4 agonist LPS, or/and androgen DHT were evaluated in vitro. Furthermore, the expression of TLR4 and AR was detected by IHC in tissue microarray of HCC, and correlation of AR and TLR4 was defined.

Results: Male mice are more susceptible to develop HCC than female mice. Meanwhile, we found baseline TLR4 levels were higher in male mice than in female mice. AR expression in male mice was increased by treatment with DEN/CCL₄. And, AR was constitutively expressed in human HCC cell lines. Dihydrotestosterone (DHT) stimulated TLR4 expression in both HepG2 and HepG2 2.15 cells, which could be blocked by silencing AR. On the other hand, treatment with LPS stimulated AR expression, but it was blocked by treatment with TLR4 antagonist and in cells deficient for TLR4. DHT treatment exacerbated TLR4-induced cellular proliferation, colony formation, migration, and invasion of HepG2 cells. The positive relationship between AR and TLR4 was confirmed in human HCC samples.

Conclusions: DHT-AR-TLR4 signaling enhances the development of HCC cells and facilitates their migration and invasion, demonstrating a mechanism underlying gender disparity in HCC.

GRP78-targeted ferritin nanocaged ultra-high dose of doxorubicin for hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer deaths, primarily due to its high incidence of recurrence and metastasis. Considerable efforts have therefore been undertaken to develop effective therapies; however, effective anti-HCC therapies rely on identification of suitable biomarkers, few of which are currently available for drug targeting.

Methods: GRP78 was identified as the membrane receptor of HCC-targeted peptide SP94 by immunoprecipitation and mass spectrum analysis. To develop an effective anti-HCC drug nanocarrier, we first displayed GRP78-targeted peptide SP94 onto the exterior surface of Pyrococcus furiosus ferritin Fn (HccFn) by genetic engineering approach, and then loaded doxorubicin (Dox) into the cavities of HccFn via urea-based disassembly/reassembly method, thereby constructing a drug nanocarrier called HccFn-Dox.

Results: We demonstrated that HccFn nanocage encapsulated ultra-high dose of Dox (up to 400 molecules Dox/protein nanocage). In vivo animal experiments showed that Dox encapsulated in HccFn-Dox was selectively delivered into HCC tumor cells, and effectively killed subcutaneous and lung metastatic HCC tumors. In addition, HccFn-Dox significantly reduced drug exposure to healthy organs and improved the maximum tolerated dose by six-fold compared with free Dox.

Conclusion: In conclusion, our findings clearly demonstrate that GRP78 is an effective biomarker for HCC therapy, and GRP78-targeted HccFn nanocage is effective in delivering anti-HCC drug without damage to healthy tissue.

Identification and characterisation of the epididymal proteins in the lizard, Eutropis carinata (Reptilia, Squamata) (Schneider, 1801)

Lizards are seasonal breeders. Cyclic reproductive nature makes lizard as a useful model for the study of the reproductively active protein secretions in the epididymis. During breeding season, the epididymides of the lizard secret proteins that mixes with the spermatozoa and create a favourable environment for sperm maturation. In this spectrum, the aim of this study is to identify and characterize proteins which are present in the lumen of the epididymis of the lizard, E. carinata during the active phase of reproduction. The identification and analysis of the proteins are done through the proteomic approaches. The epididymal luminal fluid sample was taken from the reproductively active and inactive phase and these are subjected to the size exclusion chromatography. Two major peaks (peak 1 and peak 2) were obtained in the epididymal luminal fluid sample taken during the reproductively active phase. On the other hand, the sample from the reproductively inactive phase showed one peak (peak 1) whereas, peak 2 is not present during this phase. The peak 2 belong to reproductively active phase was later subjected to the proteomic analysis. Appropriate gel electrophoresis separation and purification methods are combined with LC-MS/MS in order to identify and characterize the proteins that are presented during the reproductively active phase. Further, in this work, nine proteins are identified including three enzymes and three heat shock proteins. Among the identified proteins, bioinformatics analysis predicts that majority of them are localized in the cytoplasm. In addition to this, an observation is made in the endoplasmic reticulum where it is seen that a close protein-protein interaction network of three molecular chaperones are involved in protein processing. Overall, this paper opens up a new dimension search for epididymal markers for the first time in reptiles, particularly lizards.

Inhibitory effect of Japanese rice-koji miso extracts on hepatitis A virus replication in association with the elevation of glucose-regulated protein 78 expression

Hepatitis A virus (HAV) infection is one of the major causes of acute hepatitis and acute liver failure in developing and developed countries. Although effective vaccines for HAV infection are available, outbreaks of HAV infection still cause deaths, even in developed countries. One approach to control HAV infection is prevention through diet, which can inhibit HAV propagation and replication. Glucose-regulated protein 78 (GRP78) is a member of the heat shock protein 70 family of molecular chaperone required for endoplasmic reticulum stress and stress-induced autophagy. We previously showed that the elevation of GRP78 expression inhibits HAV replication. It has been reported that Japanese miso extracts, which was made from rice-koji, enhance GRP78 expression. In the present study, we used human hepatoma Huh7 cells and human hepatocyte PXB cells to examine the efficacy of Japanese miso extracts as antiviral agents against HAV. Japanese miso extracts enhanced GRP78 expression and inhibited HAV replication in human hepatocytes. Together, these results demonstrate that Japanese miso extracts may partly modulate GRP78 expression and additively or synergistically work as antivirals against HAV infection. Japanese miso extracts can be used as effective dietary supplements for severe hepatitis A.

The hepatocyte proteome in organotypic rat liver models and the influence of the local microenvironment

BACKGROUND

Liver models that closely mimic the in vivo microenvironment are useful for understanding liver functions, capabilities, and intercellular communication processes. Three-dimensional (3D) liver models assembled using hepatocytes and liver sinusoidal endothelial cells (LSECs) separated by a polyelectrolyte multilayer (PEM) provide a functional system while also permitting isolation of individual cell types for proteomic analyses.

METHODS

To better understand the mechanisms and processes that underlie liver model function, hepatocytes were maintained as monolayers and 3D PEM-based formats in the presence or absence of primary LSECs. The resulting hepatocyte proteomes, the proteins in the PEM, and extracellular levels of urea, albumin and glucose after three days of culture were compared.

RESULTS

All systems were ketogenic and found to release glucose. The presence of the PEM led to increases in proteins associated with both mitochondrial and peroxisomal-based β-oxidation. The PEMs also limited production of structural and migratory proteins associated with dedifferentiation. The presence of LSECs increased levels of Phase I and Phase II biotransformation enzymes as well as several proteins associated with the endoplasmic reticulum and extracellular matrix remodeling. The proteomic analysis of the PEMs indicated that there was no significant change after three days of culture. These results are discussed in relation to liver model function.

CONCLUSIONS

Heterotypic cell-cell and cell-ECM interactions exert different effects on hepatocyte functions and phenotypes.

Atg9b Deficiency Suppresses Autophagy and Potentiates Endoplasmic Reticulum Stress-Associated Hepatocyte Apoptosis in Hepatocarcinogenesis

The aim of this study was to investigate the mechanism underlying autophagy deficiency during hepatic carcinogenesis. For this purpose, we used choline-deficient, amino acid-defined (CDAA) hepatocarcinogenesis model in mice. miRNA microarrays combined with computational target predictions and GO analysis were used to identify molecular processes involved in carcinogenesis. PCR profiler array was employed to detect the dysregulated autophagy-related genes during carcinogenesis. We observed induction of hepatic tumours with increased inflammation, DNA damage, and cell death. These cellular processes were particularly detected upon oncogenic transformation of hepatocytes in which ER stress was excessively induced. Microarray combined with GO analysis showed that transformation of hepatocytes resulted in dysregulated events associated with cytoplasmic vesicle formation, which, in turn, was related to ER stress-induced autophagy. Defects of autophagy were observed in livers harbouring tumours and suffered a loss of expression of autophagy-related protein 9b (Atg9b). Hepatocytes lacking Atg9b were vulnerable to cell death induced by ER stress stimulus mainly caused by accumulation of ubiquitinated proteins. Loss of Atg9b also blocked recruitment of p62-associated ubiquitinated protein for autophagosome-lysosome degradation as Atg9b-driven phagophores may facilitate docking of both LC3 and p62 to initiate autophagy-associated degradation. miR-3091-3p from tumour-derived exosomes, which were internalised by hepatocytes, could suppress Atg9b expression. Observations from this study advance our knowledge about the regulation of autophagy during hepatocarcinogenesis.

Gender disparity in hepatocellular carcinoma (HCC): multiple underlying mechanisms

On the global scale, hepatitis B virus (HBV) infection is the main cause of hepatocellular carcinoma (HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However, the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.

Androgen Receptor Could Be a Potential Therapeutic Target in Patients with Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a male-dominant disease with poor prognosis. Sorafenib is the only approved systemic chemotherapeutic drug for patients with advanced HCC. Previous studies have shown that androgen and androgen receptor (AR) are involved in human hepatocarcinogenesis and the development of HCC. Here, we discuss the recent data on AR and HCC, and the combination of sorafenib and inhibitors of AR for advanced-HCC patients. Androgen-dependent and androgen-independent AR activation exist in human hepatocarcinogenesis. AR could directly control hepatocarcinogenesis and regulate the innate immune system to influence HCC progression. Combination of sorafenib with AR inhibitors might represent a potential treatment for patients with advanced HCC.

Glucose-regulated protein 78 is an antiviral against hepatitis A virus replication

Infection with hepatitis A virus (HAV) is a major cause of acute hepatitis globally and it is important to identify the mechanisms of HAV replication. Glucose-regulated protein 78 (GRP78) is an endoplasmic reticulum (ER) chaperone and serves a role in unfolded protein response pathways. Previous studies have demonstrated that GRP78 functions as an endogenous antiviral factor. In the present study, two loss-of-function studies using GRP78 were completed to elucidate the role of GRP78 in HAV infection. HAV replication was observed to be enhanced by deficient GRP78 although GRP78-deficiency also led to lower expression of ER stress molecules downstream of GRP78. Therefore, GRP78 appears to be a potential novel defensive molecule against HAV in hepatocytes.

Overexpression of the androgen receptor in human hepatoma cells and its effect on fatty acid metabolism

Hepatocellular carcinoma (HCC) is a predominantly male disease in which the androgen receptor (AR) serves an important pathogenic role in hepatocarcinogenesis. Fatty acid metabolism also contributes to hepatocarcinogenesis and is associated with the prognosis of cancer. The present study aimed to investigate the effects of the AR on fatty acid metabolism-associated gene expression in human hepatoma cell lines. AR-expression plasmids or control plasmids were transiently transfected into the human HCC cell lines Huh7 and HepG2. After 48 h, cellular protein and RNA were extracted and the expression of AR was confirmed by western blotting. Complementary DNA was synthesized and subjected to a quantitative polymerase chain reaction-based array to examine the expression of 84 fatty acid metabolism-associated genes. Overexpression of AR significantly downregulated the expression of 11 fatty acid metabolism-associated genes in Huh7 cells and 35 in HepG2 cells. The overexpression of AR also resulted in the upregulation of 6 fatty acid metabolism genes in HepG2 cells; however, it had no effect in Huh7 cells. Acyl-coenzyme A (CoA) thioesterase 7 and acyl-CoA oxidase 3 were downregulated in both cell lines. In conclusion, upregulation of AR via overexpression led to the disturbance of fatty acid metabolism-associated gene expression in human HCC cells. Therefore, the AR may serve a role in hepatocarcinogenesis via the regulation of hepatocellular fatty acid metabolism.

Overexpression of c-Jun contributes to sorafenib resistance in human hepatoma cell lines

Background

Despite recent advances in treatment strategies, it is still difficult to cure patients with hepatocellular carcinoma (HCC). Sorafenib is the only approved multiple kinase inhibitor for systemic chemotherapy in patients with advanced HCC. The majority of advanced HCC patients are resistant to sorafenib. The mechanisms of sorafenib resistance are still unknown.

Methods

The expression of molecules involved in the mitogen-activated protein kinase (MAPK) signaling pathway in human hepatoma cell lines was examined in the presence or absence of sorafenib. Apoptosis of human hepatoma cells treated with sorafenib was investigated, and the expression of Jun proto-oncogene (c-Jun) was measured.

Results

The expression and phosphorylation of c-Jun were enhanced in human hepatoma cell lines after treatment with sorafenib. Inhibiting c-Jun enhanced sorafenib-induced apoptosis. The overexpression of c-Jun impaired sorafenib-induced apoptosis. The expression of osteopontin, one of the established AP-1 target genes, was enhanced after treatment with sorafenib in human hepatoma cell lines.

Conclusions

The protein c-Jun plays a role in sorafenib resistance in human hepatoma cell lines. The modulation and phosphorylation of c-Jun could be a new therapeutic option for enhancing responsiveness to sorafenib. Modulating c-Jun may be useful for certain HCC patients with sorafenib resistance.

Nonalcoholic steatohepatitis-related hepatocellular carcinoma: is there a role for the androgen receptor pathway?

The epidemic of insulin resistance, obesity, and metabolic syndrome has led to the emergence of nonalcoholic steatohepatitis (NASH) as the most common cause of liver disease in the US. Patients with NASH are at an increased risk for hepatic disease-related morbidity and death, and chronic inflammation in NASH patients can lead to hepatocellular carcinoma (HCC). The prevalence of HCC is higher in males than in females, and genetic studies have identified androgen and androgen receptors (ARs) as partially responsible for the gender disparity in the development of liver disease and HCC. Although many factors are known to play important roles in the progression of inflammation in NASH patients, the role of androgen and AR in the progression of NASH to HCC has been understudied. This review summarizes the evidence for a potential role of androgen and the AR pathway in the development of NASH-related HCC and in the treatment of HCC. It has been proposed that AR plays a role in the progression of HCC: inhibitory roles in early stages of hepatocarcinogenesis and tumor-promoting roles in advanced stages. AR can be activated by several pathways, even in the absence of androgen. While AR has been explored as a potential therapeutic target in HCC, several clinical trials have failed to demonstrate a clinical benefit of antiandrogen drugs in HCC. This review discusses the potential reason for these observations and discuss the potential future trials design in this important setting.

Targeting endoplasmic reticulum stress in liver disease

INTRODUCTION

The accumulation of unfolded protein in the endoplasmic reticulum (ER) initiates an unfolded protein response (UPR) via three signal transduction cascades, which involve protein kinase RNA-like ER kinase (PERK), inositol requiring enzyme-1α (IRE1α) and activating transcription factor-6α (ATF6α). An ER stress response is observed in nearly all physiologies related to acute and chronic liver disease and therapeutic targeting of the mechanisms implicated in UPR signaling have attracted considerable attention.

AREAS COVERED

This review focuses on the correlation between ER stress and liver disease and the possible targets which may drive the potential for novel therapeutic intervention. Expert Commentary: We describe pathways which are involved in UPR signaling and their potential correlation with various liver diseases and underlying mechanisms which may present opportunities for novel therapeutic strategies are discussed.

Modulation of Autophagy by Sorafenib: Effects on Treatment Response

The multikinase inhibitor sorafenib is, at present, the only drug approved for the treatment of hepatocellular carcinoma (HCC), one of the most lethal types of cancer worldwide. However, the increase in the number of sorafenib tumor resistant cells reduces efficiency. A better knowledge of the intracellular mechanism of the drug leading to reduced cell survival could help to improve the benefits of sorafenib therapy. Autophagy is a bulk cellular degradation process activated in a broad range of stress situations, which allows cells to degrade misfolded proteins or dysfunctional organelles. This cellular route can induce survival or death, depending on cell status and media signals. Sorafenib, alone or in combination with other drugs is able to induce autophagy, but cell response to the drug depends on the complex integrative crosstalk of different intracellular signals. In cancerous cells, autophagy can be regulated by different cellular pathways (Akt-related mammalian target of rapamycin (mTOR) inhibition, 5′ AMP-activated protein kinase (AMPK) induction, dissociation of B-cell lymphoma 2 (Bcl-2) family proteins from Beclin-1), or effects of some miRNAs. Inhibition of mTOR signaling by sorafenib and diminished interaction between Beclin-1 and myeloid cell leukemia 1 (Mcl-1) have been related to induction of autophagy in HCC. Furthermore, changes in some miRNAs, such as miR-30α, are able to modulate autophagy and modify sensitivity in sorafenib-resistant cells. However, although AMPK phosphorylation by sorafenib seems to play a role in the antiproliferative action of the drug, it does not relate with modulation of autophagy. In this review, we present an updated overview of the effects of sorafenib on autophagy and its related activation pathways, analyzing in detail the involvement of autophagy on sorafenib sensitivity and resistance.

Dietary Cocoa Powder Improves Hyperlipidemia and Reduces Atherosclerosis in apoE Deficient Mice through the Inhibition of Hepatic Endoplasmic Reticulum Stress

Cocoa powder is rich in flavonoids, which have many beneficial effects on human health, including antioxidative and anti-inflammatory effects. The aim of our study was to investigate whether the intake of cocoa powder has any influence on hyperlipidemia and atherosclerosis and examine the underlying molecular mechanisms. We fed apoE knockout mice a Western diet supplemented with either 0.2% (low group) or 2% (high group) cocoa powder for 12 weeks. The groups fed dietary cocoa powder showed a significant reduction in both plasma cholesterol levels and aortic atherosclerosis compared to the control group. Analysis of mRNA profiling of aortic atherosclerotic lesions revealed that the expression of several genes related to apoptosis, lipid metabolism, and inflammation was significantly reduced, while the antiapoptotic gene Bcl2 was significantly increased in the cocoa powder group compared to the control. RT-PCR analysis along with Western blotting revealed that a diet containing cocoa powder inhibited the expression of hepatic endoplasmic reticulum stress. These data suggest that cocoa powder intake improves hyperlipidemia and atherosclerosis, and such beneficial effects are possibly mediated through the suppression of hepatic endoplasmic reticulum stress.

Low expression of B-cell-associated protein 31 in human primary hepatocellular carcinoma correlates with poor prognosis

AIMS

The aim of the present study was to investigate the prognostic value of B-cell associated protein 31 (BAP31) in human primary hepatocellular carcinoma (HCC).

METHODS AND RESULTS

BAP31 levels were evaluated by immunohistochemistry on tissue microarrays. The integral optical density, representing the expression level of BAP31 in each tissue sample, was calculated with image-pro plus. Immunohistochemical analysis of BAP31 levels in 74 paired HCC tissues and peritumoral non-cancerous tissues showed that BAP31 expression was significantly higher in HCC tumour tissues (P = 0.025). The prognostic value of BAP31 in HCC was evaluated in 234 cases in a training cohort and in 63 cases in a validation cohort. The expression level of BAP31 was significantly correlated with overall survival (OS) in both the training cohort and the validation cohort. The lower the level of BAP31 expression in HCC tissue, the poorer the prognosis. Univariate and multivariate analyses showed that the expression level of BAP31 in HCC was an independent prognostic factor for OS in both the training cohort and the validation cohort.

CONCLUSIONS

BAP31 expression is an independent prognostic factor for OS of patients with postoperative HCC, and low expression levels of BAP31 in HCC may indicate poor outcomes of HCC patient after surgical resection.

Current management of patients with hepatocellular carcinoma

The current management therapies for hepatocellular carcinoma (HCC) patients are discussed in this review. Despite the development of new therapies, HCC remains a “difficult to treat” cancer because HCC typically occurs in advanced liver disease or hepatic cirrhosis. The progression of multistep and multicentric HCC hampers the prevention of the recurrence of HCC. Many HCC patients are treated with surgical resection and radiofrequency ablation (RFA), although these modalities should be considered in only selected cases with a certain HCC number and size. Although there is a shortage of grafts, liver transplantation has the highest survival rates for HCC. Several modalities are salvage treatments; however, intensive care in combination with other modalities or in combination with surgical resection or RFA might offer a better prognosis. Sorafenib is useful for patients with advanced HCC. In the near future, HCC treatment will include stronger molecular targeted drugs, which will have greater potency and fewer adverse events. Further studies will be ongoing.

The androgen receptor as an emerging target in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the male-dominant liver diseases with poor prognosis, although treatments for HCC have been progressing in the past decades. Androgen receptor (AR) is a member of the nuclear receptor superfamily. Previous studies reported that AR was expressed in human HCC and non-HCC tissues. AR is activated both ligand-dependently and ligand-independently. The latter is associated with a mitogen-activated protein kinase–, v-akt murine thymoma viral oncogene homolog 1–, or signal-transducer and activator of transcription–signaling pathway, which has been implicated in the development of HCC. It has been reported that more than 200 RNA expression levels are altered by androgen treatment. In the liver, androgen-responsive genes are cytochrome P450s, transforming growth factor β, vascular endothelial growth factor, and glucose-regulated protein 78 kDa, which are also associated with human hepatocarcinogenesis. Recent studies also revealed that AR plays a role in cell migration and metastasis. It is possible that cross-talk among AR-signaling, endoplasmic reticulum stress, and innate immune response is important for human hepatocarcinogenesis and HCC development. This review shows that AR could play a potential role in human HCC and represent one of the important target molecules for the treatment of HCC.

Hepatitis C virus nonstructural protein 5A inhibits thapsigargin-induced apoptosis

Background

We previously reported that the hepatitis C virus (HCV) nonstructural protein 5A (NS5A) down-regulates TLR4 signaling and lipopolysaccharide-induced apoptosis of hepatocytes. There have been several reports regarding the association between HCV infection and endoplasmic reticulum (ER) stress. Here, we examined the regulation of HCV NS5A on the apoptosis of hepatocytes induced by thapsigargin, an inducer of ER stress.

Methods

The apoptotic response to thapsigargin and the expression of molecules involved in human hepatocyte apoptotic pathways were examined in the presence or absence of HCV NS5A expression.

Results

HCV JFH1 infection induced ER stress in the Huh7 cell line. HCV NS5A protected HepG2 cells against thapsigargin-induced apoptosis, the effect of which was linked to the enhanced expression of the 78-kDa glucose-regulated protein/immunoglobulin heavy-chain binding protein (GRP78). Consistent with a conferred pro-survival advantage, HCV NS5A reduced poly(adenosine diphosphate-ribose) polymerase cleavage and activation of caspases-3, -7 and -9, and Bax expression, while increasing the expressions of the anti-apoptotic molecules XIAP and c-FLIP. HCV NS5A weakly interacts with GRP78 and enhances GRP78 expression in hepatocytes.

Conclusion

HCV NS5A enhances GRP78 expression, resulting in the inhibition of apoptotic properties, and inhibits thapsigargin-induced apoptotic pathways in human hepatocytes, suggesting that disruption of ER stress-mediated apoptosis may have a role in the pathogenesis of HCV infection. Thus, HCV NS5A might engender the survival of HCV-infected hepatocytes contributing to the establishment of persistent infection.

Knockdown of glucose-regulated protein 78 enhances poly(ADP-ribose) polymerase cleavage in human pancreatic cancer cells exposed to endoplasmic reticulum stress

The present study examined the expression of glucose‑regulated protein 78 (GRP78/Bip) in human pancreatic cancer cell lines and the effect of knockdown of GRP78 on the cleavage of poly(ADP-ribose) polymerase (PARP). Human pancreatic cancer cell lines (KP-2, MIAPaCa-2, Panc-1 and SUIT-2), constitutively expressed GRP78. We also demonstrated that ER stress induced by thapsigargin upregulated protein levels of GRP78. In the presence of thapsigargin, knockdown of GRP78 enhanced the PARP cleavage in the human pancreatic cancer cells. These results provide evidence that GRP78 is a potential therapeutic target for 'difficult-to-treat' pancreatic cancer, in which ER stress signaling in part falls into disorder.

Androgen receptor signaling in hepatocellular carcinoma and pancreatic cancers

Hepatocellular carcinoma (HCC) and pancreatic cancer remain difficult to treat, and despite the ongoing development of new treatments, the overall survival rate has only modestly improved over the past decade. Liver and pancreatic progenitors commonly develop from endoderm cells in the embryonic foregut. A previous study showed that HCC and pancreatic cancer cell lines variably express androgen receptor (AR), and these cancers and the surrounding tissues also express AR. AR is a ligand-dependent transcription factor that belongs to the nuclear receptor superfamily. Androgen response element is present in regulatory elements on the AR-responsive target genes, such as transforming growth factor beta-1 (TGF beta-1) and vascular endothelial growth factor (VEGF). It is well known that the activation of AR is associated with human carcinogenesis in prostate cancer as well as HCC and pancreatic cancer and that GRP78, TGF beta, and VEGF all play important roles in carcinogenesis and cancer development in these cancers. HCC is a male-dominant cancer irrespective of its etiology. Previous work has reported that vertebrae forkhead box A 1/2 are involved in estrogen receptors and/or AR signaling pathways, which may contribute to the gender differences observed with HCC. Our recent work also showed that AR has a critical role in pancreatic cancer development, despite pancreatic cancer not being a male dominant cancer. Aryl hydrocarbon (or dioxin) receptor is also involved in both HCC and pancreatic cancer through the formation of complex with AR. It is possible that AR might be involved in their carcinogenesis through major histocompatibility complex class I chain-related gene A/B. This review article describes AR and its role in HCC and pancreatic cancer and suggests that more specific AR signaling-inhibitors may be useful in the treatment of these “difficult to treat” cancers.