Pathogenesis of hepatocellular carcinoma and molecular therapies

Prognostic value of ultra-low-pass whole-genome sequencing of circulating tumor DNA in hepatocellular carcinoma under systemic treatment

BACKGROUND/AIMS

New prognostic markers are needed to identify patients with hepatocellular carcinoma (HCC) who carry a worse prognosis. Ultra-low-pass whole-genome sequencing (ULP-WGS) (≤0.5× coverage) of cell-free DNA (cfDNA) has emerged as a low-cost promising tool to assess both circulating tumor DNA (ctDNA) fraction and large structural genomic alterations. Here, we studied the performance of ULP-WGS of plasma cfDNA to infer prognosis in patients with HCC.

METHODS

Plasma samples were obtained from patients with HCC prior to surgery, locoregional or systemic therapy, and were analyzed by ULP-WGS of cfDNA to an average genome-wide fold coverage of 0.3x. ctDNA and copy number alterations (CNA) were estimated using the software package ichorCNA.

RESULTS

Samples were obtained from 73 HCC patients at different BCLC stages (BCLC 0/A: n=37, 50.7%; BCLC B/C: n=36, 49.3%). ctDNA was detected in 18 out of 31 patients who received systemic treatment. Patients with detectable ctDNA showed significantly worse overall survival (median, 13.96 months vs not reached). ctDNA remained an independent predictor of prognosis after adjustment by clinical-pathologic features and type of systemic treatment (hazard ratio 7.69; 95%, CI 2.09-28.27). Among ctDNA-positive patients under systemic treatments, the loss of large genomic regions in 5q and 16q arms was associated with worse prognosis after multivariate analysis.

CONCLUSION

ULP-WGS of cfDNA provides clinically relevant information about the tumor biology. The presence of ctDNA and the loss of 5q and 16q arms in ctDNA-positive patients are independent predictors of worse prognosis in patients with advanced HCC receiving systemic therapy.

Potential role of human umbilical cord stem cells-derived exosomes as novel molecular inhibitors of hepatocellular carcinoma growth

Hepatocellular carcinoma (HCC) is one of the most critical cancers; thus, novel therapeutical regimens are of great need. In this study, we investigated the effects of umbilical cord mesenchymal stem cells (UC-MSCs) derived exosomes on HepG2 cell line, and the underlying mechanism to control HCC proliferation, to identify the potential clinical role of exosomes as a novel molecular therapeutic target. Proliferation, apoptosis, and angiogenesis effects were assessed together with the cell viability evaluation by MTT assay in HepG2 cells at 24/48 h. with or without UC-MSCs-derived exosomes. Gene expressions of TNF-α, caspase-3, VEGF, stromal cell-derived factor-1 (SDF-1), and CX chemokine receptor-4 (CXCR-4) were measured by quantitative real-time PCR technique. Expression of sirtuin-1 (SIRT-1) protein was detected by western blot. Treatment of HepG2 cells with UC-MSCs-derived exosomes for 24 and 48 h. demonstrated a significant reduction of cells survival compared to the control group (p < 0.05). The SIRT-1 protein, and VEGF, SDF-1, CXCR-4 expression levels were significantly lower, TNF-α and caspase-3 expression levels were significantly higher in exosomal-treated HepG2 cells for 24 and 48 h. than those in the control group. Moreover, our findings documented that the anti-proliferative, apoptotic, and anti-angiogenic effects were achieved in a time-dependent manner in which more effects were determined after 48 h supplementation compared to 24 h (p < 0.05). UC-MSCs-derived exosomes exert anticarcinogenic molecular effects on HepG2 cells through the involvement of SIRT-1, SDF-1, and CXCR-4. Hence, exosomes would be a potential novel therapy regimen against HCC. Large-scale studies are recommended to verify this conclusion.

A mixed blessing for liver transplantation patients - Rapamycin

BACKGROUND

Liver transplantation (LT) is an effective treatment option for end-stage liver disease. Mammalian target of rapamycin (mTOR) inhibitors, such as rapamycin, are widely used post LT.

DATA SOURCES

In this review, we focused on the anti-cancer activities and metabolic side effects of rapamycin after LT. The literature available on PubMed for the period of January 1999-September 2022 was reviewed. The key words were rapamycin, sirolimus, liver transplantation, hepatocellular carcinoma, diabetes, and lipid metabolism disorder.

RESULTS

Rapamycin has shown excellent effects and is safer than other immunosuppressive regimens. It has exhibited excellent anti-cancer activity and has the potential in preventing hepatocellular carcinoma (HCC) recurrence post LT. Rapamycin is closely related to two long-term complications after LT, diabetes and lipid metabolism disorders.

CONCLUSIONS

Rapamycin prevents HCC recurrence post LT in some patients, but it also induces metabolic disorders. Reasonable use of rapamycin benefits the liver recipients.

Down-regulation of hepatic expression of GHR/STAT5/IGF-1 signaling pathway fosters development and aggressiveness of HCV-related hepatocellular carcinoma: Crosstalk with Snail-1 and type 2 transforming growth factor-beta receptor

Background and aims

So far, few clinical trials are available concerning the role of growth hormone receptor (GHR)/signal transducer and activator of transcription 5 (STAT5)/insulin like growth factor-1 (IGF-1) axis in hepatocarcinogenesis. The aim of this study was to evaluate the hepatic expression of GHR/STAT5/IGF-1 signaling pathway in hepatocellular carcinoma (HCC) patients and to correlate the results with the clinico-pathological features and disease outcome. The interaction between this signaling pathway and some inducers of epithelial-mesenchymal transition (EMT), namely Snail-1 and type 2 transforming growth factor-beta receptor (TGFBR2) was studied too.

Material and methods

A total of 40 patients with HCV-associated HCC were included in this study. They were compared to 40 patients with HCV-related cirrhosis without HCC, and 20 healthy controls. The hepatic expression of GHR, STAT5, IGF-1, Snail-1 and TGFBR2 proteins were assessed by immunohistochemistry.

Results

Compared with cirrhotic patients without HCC and healthy controls, cirrhotic patients with HCC had significantly lower hepatic expression of GHR, STAT5, and IGF-1proteins. They also displayed significantly lower hepatic expression of TGFBR2, but higher expression of Snail-1 versus the non-HCC cirrhotic patients and controls. Serum levels of alpha-fetoprotein (AFP) showed significant negative correlations with hepatic expression of GHR (r = -0.31; p = 0.029) and STAT5 (r = -0.29; p = 0.04). Hepatic expression of Snail-1 also showed negative correlations with GHR, STAT5, and IGF-1 expression (r = -0.55, p = 0.02; r = -0.472, p = 0.035, and r = -0.51, p = 0.009, respectively), whereas, hepatic expression of TGFBR2 was correlated positively with the expression of all these proteins (r = 0.47, p = 0.034; 0.49, p = 0.023, and r = 0.57, p<0.001, respectively). Moreover, we reported that decreased expression of GHR was significantly associated with serum AFP level>100 ng/ml (p = 0.048), increased tumor size (p = 0.02), vascular invasion (p = 0.002), and advanced pathological stage (p = 0.01). Similar significant associations were found between down-regulation of STAT5 expression and AFP level > 100 ng/ml (p = 0.006), vascular invasion (p = 0.009), and advanced tumor stage (p = 0.007). Also, attenuated expression of IGF-1 showed a significant association with vascular invasion (p < 0.001). Intriguingly, we detected that lower expression of GHR, STAT5 and IGF-1 were considered independent predictors for worse outcome in HCC.

Conclusion

Decreased expression of GHR/STAT5/IGF-1 signaling pathway may have a role in development, aggressiveness, and worse outcome of HCV-associated HCC irrespective of the liver functional status. Snail-1 and TGFBR2 as inducers of EMT may be key players. However, large prospective multicenter studies are needed to validate these results.

Molecular classification of hepatocellular carcinoma: prognostic importance and clinical applications

Hepatocellular carcinoma (HCC) is a lethal human malignancy with a very low overall and long-term survival rate. Poor prognostic outcomes are predominantly associated with HCC due to a huge landscape of heterogeneity found in the deadliest disease. However, molecular subtyping of HCC has significantly improved the knowledge of the underlying mechanisms that contribute towards the heterogeneity and progression of the disease. In this review, we have extensively summarized the current information available about molecular classification of HCC. This review can be of great significance for providing the insight information needed for development of novel, efficient and personalized therapeutic options for the treatment of HCC patients globally.

NEAT1/hsa-miR-372-3p axis participates in rapamycin-induced lipid metabolic disorder

Rapamycin is a crucial immunosuppressive regimen for patients that have undergone liver transplantation (LT). However, one of the major side effects of rapamycin include metabolic disorders such as dyslipidemia, and the mechanism remains unknown. This study aims to explore the biomolecules that are responsible for rapamycin-induced dyslipidemia and the control strategies that can reverse the lipid metabolism disorder. In this study, data collected from LT patients, cell and mouse models treated with rapamycin were analyzed. Results showed an increase of triglycerides (TGs) induced by rapamycin. MicroRNAs (miRNAs) play important roles in many vital biological processes including TG metabolism. hsa-miR-372-3p was filtered using RNA sequencing and identified as a key regulator in rapamycin-induced TGs accumulation. Using bioinformatics and experimental analyses, target genes of hsa-miR-372-3p were predicted. These genes were alkylglycerone phosphate synthase (AGPS) and apolipoprotein C4 (APOC4), which are reported to be involved in TG metabolism. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was also identified as an upstream regulatory factor of hsa-miR-372-3p. From the results of this study, NEAT1/hsa-miR-372-3p/AGPS/APOC4 axis plays a vital role in rapamycin-disruption of lipid homeostasis. Therefore, targeting this axis is a potential therapeutic target combating rapamycin-induced dyslipidemia after LT.

Transgenic zebrafish for modeling hepatocellular carcinoma

Liver cancer is the third leading cause of cancer‐related deaths throughout the world, and more than 0.6 million people die from liver cancer annually. Therefore, novel therapeutic strategies to eliminate malignant cells from liver cancer patients are urgently needed. Recent advances in high‐throughput genomic technologies have identified de novo candidates for oncogenes and pharmacological targets. However, testing and understanding the mechanism of oncogenic transformation as well as probing the kinetics and therapeutic responses of spontaneous tumors in an intact microenvironment require in vivo examination using genetically modified animal models. The zebrafish (Danio rerio) has attracted increasing attention as a new model for studying cancer biology since the organs in the model are strikingly similar to human organs and the model can be genetically modified in a short time and at a low cost. This review summarizes the current knowledge of epidemiological data and genetic alterations in hepatocellular carcinoma (HCC), zebrafish models of HCC, and potential therapeutic strategies for targeting HCC based on knowledge from the models.

The combination of Biochanin A and SB590885 potentiates the inhibition of tumour progression in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most aggressive and frequently diagnosed malignancy of the liver. Despite aggressive therapy, life expectancy of many patients in these cases is extended by only a few months. Hepatocellular carcinoma (HCC) has a particularly poor prognosis and would greatly benefit from more effective therapies.

Methods

The CCK-8 assay and colony formation assays were used to test the cell proliferation and viability. The effects of combination Biochanin A and SB590885 on apoptosis and cell cycle arrest of HCC cells were analysed by flow cytometry. The expression of ERK MAPK and PI3K/AKT/mTOR signalling as well as apoptosis and cell cycle-related proteins in HCC cells were tested by western blotting. The HCC cell xenograft model was established to test the tumor proliferation. Serum and plasma were tested for liver and kidney safety markers (ALP, ALT, AST, total bilirubin, creatinine, urea nitrogen) by using SpectraMax i3X.

Results

The combination of natural product Biochanin A with the BRAF inhibitor SB590885 synergistically suppressed proliferation, and promoted cell cycle arrest and apoptosis in vitro. Furthermore, we demonstrated that the combination of Biochanin A and SB590885 led to increased impairment of proliferation and HCC tumour inhibition through disrupting of the ERK MAPK and the PI3K/AKT pathways in vitro. The volumes tumors and the weights of tumours were significantly reduced by the combination treatment compared to the control or single treatments in vivo. In addition, we found that there was no significant hepatorenal toxicity with the drug combination, as indicated by the hepatorenal toxicity test.

Conclusion

The results identify an effective combination therapy for the most aggressive form of HCC and provide the possibility of therapeutic improvement for patients with advanced HCC.

Treatment with a New Barbituric Acid Derivative Exerts Antiproliferative and Antimigratory Effects against Sorafenib Resistance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common cause of cancer death worldwide. Sorafenib, a multikinase inhibitor, is the first-line drug approved by the Food and Drug Administration (FDA) for the treatment of patients with advanced HCC. However, most patients who continuously receive sorafenib may acquire resistance to this drug. Therefore, it is important to develop a new compound to treat liver cancer and sorafenib-resistant liver cancer. Barbituric acid derivatives have been used as antiasthmatic drugs in the clinic. We previously reported that a novel barbituric acid derivative inhibited carbon tetrachloride-induced liver fibrosis in mice, but its effects on liver cancer remain unknown. Thus, the purpose of this study was to investigate the antitumor effect of barbituric acid derivatives on HCC cells and sorafenib-resistant HCC cells (HCC-SRs). Our findings reveal that one of the barbituric acid derivatives, BA-5, significantly inhibited HCC and HCC-SR cell viability in a dose- and time-dependent manner. Therefore, compound BA-5 was selected for further experiments. Western blot data revealed that BA-5 treatment decreased the phosphorylation of AKT/p70s6k without affecting the MAPK pathway and increased cleaved PARP and cleaved caspase-7 in both HCC and HCC-SR cells. Since epithelial-mesenchymal transition plays a significant role in regulating cancer invasion and migration, we used the wound healing assay to evaluate the antimigratory effect of compound BA-5. The results showed that BA-5 treatment inhibited HCC and HCC-SR cell migration and reduced Vimentin protein expression. These results were confirmed by microarray analysis showing that BA-5 treatment influenced cancer cell motility and growth-related pathways. In the xenograft mouse model experiment, BA-5 administration significantly inhibited HCC cancer cell growth in mice. Furthermore, the combination of BA-5 with a low dose of regorafenib synergistically inhibited HCC-SR cell proliferation. In conclusion, our study showed that the barbituric acid derivative BA-5 is a new candidate for HCC and sorafenib-resistant HCC therapy.

Is the era of sorafenib over? A review of the literature

Hepatocellular carcinoma (HCC) is one of the most severe diseases worldwide. For the different stages of HCC, there are different clinical treatment strategies, such as surgical therapy for the early stage, and transarterial chemoembolization (TACE) and selective internal radiation therapy (SIRT) for intermediate-stage disease. Systemic treatment, which uses mainly targeted drugs, is the standard therapy against advanced HCC. Sorafenib is an important first-line therapy for advanced HCC. As a classically effective drug, sorafenib can increase overall survival markedly. However, it still has room for improvement because of the heterogeneity of HCC and acquired resistance. Scientists have reported the acquired sorafenib resistance is associated with the anomalous expression of certain genes, most of which are also related with HCC onset and development. Combining sorafenib with inhibitors targeting these genes may be an effective treatment. Combined treatment may not only overcome drug resistance, but also inhibit the expression of carcinoma-related genes. This review focuses on the current status of sorafenib in advanced HCC, summarizes the inhibitors that can combine with sorafenib in the treatment against HCC, and provides the rationale for clinical trials of sorafenib in combination with other inhibitors in HCC. The era of sorafenib in the treatment of HCC is far from over, as long as we find better methods of medication.

Fine needle biopsy of malignant tumors of the liver: a retrospective study of 624 cases from a single institution experience

BACKGROUND

Liver is one of the most common organs involved by metastatic neoplasms. In addition, a number of primary tumors can arise in the liver. Fine needle biopsy (FNB) is the most commonly used method for diagnosis of liver masses. Not much literature is available during the past 10 years about FNB of liver tumors. All large studies were performed more than 15 years ago. With the introduction of new disease entities, new tumor classification systems, and new diagnostic methods, updated documentation of FNB of liver neoplasms is much needed.

METHODS

Liver FNB cases that were diagnosed as "Positive for Malignancy" between 2010 and 2018 were retrieved from the cytopathology database in our institution. Patient medical records, cytopathology and surgical pathology reports, and slides from selected cases were retrieved and reviewed.

RESULTS

Over 30 different types of malignant tumors were identified in 624 malignant FNB cases, with the most common tumors being metastatic colorectal and pancreatic adenocarcinomas. Rare tumors include EBV-positive leiomyosarcoma, mesothelioma, and paraganglioma, among others. A subset of patients presented with widespread metastases involving liver with no known history. Identifying the primary sites in those cases can be challenging. We also found that in our practice, a significant number of hepatocellular carcinoma were diagnosed by FNB in recent years.

CONCLUSIONS

A tremendous variety of neoplasms can occur in liver. Accurate diagnosis is essential for proper patient management. Familiarization with morphological features and judicious usage of ancillary studies are essential for accurate diagnosis.

Dandelion Polysaccharide Exerts Anti-Angiogenesis Effect on Hepatocellular Carcinoma by Regulating VEGF/HIF-1α Expression

Recent studies have revealed that natural plants-derived polysaccharides exhibit potent anti-tumor activity. Our earlier studies suggest that dandelion polysaccharide (DP) inhibits hepatocellular carcinoma (HCC) cell proliferation in vitro and in vivo. Here, we investigated the effects of DP on the angiogenesis of HCC and the potential molecular mechanisms by which DP regulates angiogenesis. Wound-healing and transwell invasion assays revealed that DP inhibited HUVECs migration and invasion in vitro, respectively. Tube formation assay, chick chorioallantoic membrane (CAM) assay, and immunohistochemistry (IHC) demonstrated that DP suppressed vasculogenesis in vitro and in vivo. Moreover, Western blot and immunofluorescence staining verified that DP treatment decreased the protein levels of some key factors involved in angiogenesis of HCC, such as hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF), p-PI3K, and p-AKT. However, activation of PI3K/AKT pathway with insulin-like growth factor 1 (IGF-1) treatment attenuated the effect of DP on angiogenesis via lowering the expression of HIF-1α and VEGF. In summary, we found that DP treatment inhibited angiogenesis in vivo and in vitro through suppressing expression of VEGF and HIF-1a. Furthermore, we showed that the expression of VEGF and HIF1-α was modulated by PI3K/AKT signaling. Collectively, our study suggests that DP is a promising anti-cancer drug candidate for treating HCC.

CPSF7 regulates liver cancer growth and metastasis by facilitating WWP2-FL and targeting the WWP2/PTEN/AKT signaling pathway

Alternative splicing within a gene can create different versions of an mRNA, called isoforms. CFIm, composed of a small subunit CFIm25 and two large subunits CFIm68 and CFIm59 (also known as CPSF7), has been proposed as an enhancer-dependent activator of mRNA 3' processing. In this study, we investigated the role of CPSF7 in hepatocellular carcinoma. Experimental evidence suggests that the expression level of CPSF7 is higher in liver cancer cells and tissues than in non-tumor hepatic cells and tissues. Furthermore, knockdown of CPSF7 effectively suppressed cell proliferation, migration and colony formation in liver cancer cells by inhibiting PTEN/AKT signaling. CPSF7 promoted WWP2-FL due to the presence of PTEN ubiquitination sites in this longer transcript. Taken together, we identified that CPSF7 regulates liver cancer growth by targeting WWP2-FL that in turn regulates AKT activation in a PTEN-dependent manner.

Apoptotic Effects of Xanthium strumarium via PI3K/AKT/mTOR Pathway in Hepatocellular Carcinoma

Xanthium strumarium (XS) has been traditionally used as a medicinal herb for treating inflammatory diseases, such as appendicitis, chronic bronchitis, rheumatism, and rhinitis. In this study, we yielded ethanol extracts from XS and investigated whether they could inhibit the progression of hepatocellular carcinoma (HCC) and its underlying mechanism. The XS-5 and XS-6 extracts dose-dependently inhibited the growth and proliferation in HCC cell lines. The apoptotic effects of them were observed via increased levels of cleaved caspase-3 and cleaved PARP, as well as elevated numbers of terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling- (TUNEL-) positive apoptotic cells. They also decreased XIAP and Mcl-1 expression via loss of mitochondrial membrane potential. Additionally, they inhibited the invasion and migration of HCC cells. In an ex vivo model, the extracts significantly inhibited tumor cell growth and induced apoptosis by increasing the expression of the cleaved caspase-3. A mechanistic study revealed that they effectively suppressed PI3K/AKT/mTOR signaling pathways in HCC cells. Taken together, our findings demonstrate that they could efficiently not only induce apoptosis but also inhibit cell growth, migration, and invasion of human HCC cells by blocking the PI3K/AKT/mTOR pathway. We suggest XS-5 and XS-6 as novel natural anti-HCC agents.

Preclinical efficacy of a novel dual PI3K/mTOR inhibitor, CMG002, alone and in combination with sorafenib in hepatocellular carcinoma

PURPOSE

Sorafenib has been the only first systemic drug that improves survival of patients with advanced hepatocellular carcinoma (HCC). However, because the response rate of sorafenib is relatively low, novel therapeutic strategies are needed to improve survival in patients with HCC. This study investigated the effect of CMG002 alone and in combination with sorafenib on HCC in vitro and vivo.

METHODS

The effect of a newly developed dual PI3K/mTOR inhibitor, CMG002, on the proliferation of Huh-7 and HepG2 HCC cells was investigated using the MTT assay. Western blotting was performed to assess phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. HepG2 cells were inoculated into mice, which were treated with vehicle, sorafenib, CMG002, and their combinations. Tumor cell proliferation and tumor angiogenesis were evaluated by immunohistochemical analysis of Ki-67 and CD31, respectively. Tumor cell apoptosis was detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Levels of key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways were evaluated by western blot analysis.

RESULTS

The combination of sorafenib and CMG002 additively inhibited Huh-7 and HepG2 cell proliferation compared to single-agent treatment. Sorafenib and CMG002 as single agents differentially inhibited or activated key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. The combination of sorafenib and CMG002 inhibited all key enzymes in the two pathways. Treatment with CMG002 for 4 weeks alone and in combination with sorafenib strongly inhibited tumor growth. CMG002 inhibited HCC cell proliferation, induced apoptosis, and decreased tumor angiogenesis. Furthermore, these effects were enhanced when CMG002 was combined with sorafenib.

CONCLUSIONS

The combination of CMG002 and sorafenib significantly inhibited HCC cell proliferation and tumorigenesis by inhibiting the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. These findings suggest that CMG002 to be a potential novel candidate treatment for HCC.

L-Dopa decarboxylase interaction with the major signaling regulator ΡΙ3Κ in tissues and cells of neural and peripheral origin

L-Dopa decarboxylase (DDC) catalyzes the decarboxylation of L-Dopa to dopamine and 5-hydroxytryptophan (5-HTP) to serotonin. Although DDC has been purified from a variety of peripheral organs, including the liver, kidney and pancreas, the physiological significance of the peripherally expressed enzyme is not yet fully understood. DDC has been considered as a potential novel biomarker for various types of cancer, however, the role of DDC in the development of hepatocellular carcinoma (HCC) remains to be evaluated. Phosphatidylinositol 3-kinase (PI3K), on the other hand, has been shown to play a key role in the tumorigenesis, proliferation, metastasis, apoptosis, and angiogenesis of HCC by regulating gene expression. We initially identified the interaction of DDC with PI3K by means of the phage display methodology. This association was further confirmed in human hepatocellular carcinoma cell lines, human embryonic kidney cells, human neuroblastoma cells, as well as mouse brain, by the use of specific antibodies raised against DDC and PI3K. Functional aspects of the above interaction were studied upon treatment with the DDC inhibitor carbidopa and the PI3K inhibitor LY294002. Interestingly, our data demonstrate the expression of the neuronal type DDC mRNA in HCC cells. The present investigation provides new evidence on the possible link of DDC with the PI3K pathway, underlining the biological significance of this complex enzyme.

Hepatic growth hormone - JAK2 - STAT5 signalling: Metabolic function, non-alcoholic fatty liver disease and hepatocellular carcinoma progression

The rising prevalence of obesity came along with an increase in associated metabolic disorders in Western countries. Non-alcoholic fatty liver disease (NAFLD) represents the hepatic manifestation of the metabolic syndrome and is linked to primary stages of liver cancer development. Growth hormone (GH) regulates various vital processes such as energy supply and cellular regeneration. In addition, GH regulates various aspects of liver physiology through activating the Janus kinase (JAK) 2- signal transducer and activator of transcription (STAT) 5 pathway. Consequently, disrupted GH - JAK2 - STAT5 signaling in the liver alters hepatic lipid metabolism and is associated with NAFLD development in humans and mouse models. Interestingly, while STAT5 as well as JAK2 deficiency correlates with hepatic lipid accumulation, recent studies suggest that these proteins have unique ambivalent functions in chronic liver disease progression and tumorigenesis. In this review, we focus on the consequences of altered GH - JAK2 - STAT5 signaling for hepatic lipid metabolism and liver cancer development with an emphasis on lessons learned from genetic knockout models.

Multiscale systems pharmacological analysis of everolimus action in hepatocellular carcinoma

Dysregulation of mTOR pathway is common in hepatocellular carcinoma (HCC). A translational quantitative systems pharmacology (QSP), pharmacokinetic (PK), and pharmacodynamic (PD) model dissecting the circuitry of this pathway was developed to predict HCC patients' response to everolimus, an mTOR inhibitor. The time course of key signaling proteins in the mTOR pathway, HCC cells viability, tumor volume (TV) and everolimus plasma and tumor concentrations in xenograft mice, clinical PK of everolimus and progression free survival (PFS) in placebo and everolimus-treated patients were extracted from literature. A comprehensive and multiscale QSP/PK/PD model was developed, qualified, and translated to clinical settings. Model fittings and simulations were performed using Monolix software. The S6-kinase protein was identified as critical in the mTOR signaling pathway for describing everolimus lack of efficacy in HCC patients. The net growth rate constant (kg) of HCC cells was estimated at 0.02 h^-1 (2.88%RSE). The partition coefficient of everolimus into the tumor (kp) was determined at 0.06 (12.98%RSE). The kg in patients was calculated from the doubling time of TV in naturally progressing HCC patients, and was determined at 0.004 day^-1. Model-predicted and observed PFS were in good agreement for placebo and everolimus-treated patients. In conclusion, a multiscale QSP/PK/PD model elucidating everolimus lack of efficacy in HCC patients was successfully developed and predicted PFS reasonably well compared to observed clinical findings. This model may provide insights into clinical response to everolimus-based therapy and serve as a valuable tool for the clinical translation of efficacy for novel mTOR inhibitors.

EGFR-PI3K-PDK1 pathway regulates YAP signaling in hepatocellular carcinoma: the mechanism and its implications in targeted therapy

The epidermal growth factor receptor (EGFR) pathway and Hippo signaling play an important role in the carcinogenesis of hepatocellular carcinoma (HCC). However, the crosstalk between these two pathways and its implications in targeted therapy remains unclear. We found that the activated EGFR signaling could bypass RhoA to promote the expression of YAP(Yes-associated protein), the core effector of the Hippo signaling, and its downstream target Cyr61. Further studies indicated that EGFR signaling mainly acted through the PI3K-PDK1 (Phosphoinositide 3-kinase-Phosphoinositide-dependent kinase-1) pathway to activate YAP, but not the AKT and MAPK pathways. While YAP knockdown hardly affected the EGFR signaling. In addition, EGF could promote the proliferation of HCC cells in a YAP-independent manner. Combined targeting of YAP and EGFR signaling by simvastatin and the EGFR signaling inhibitors, including the EGFR tyrosine kinase inhibitor (TKI) gefitinib, the RAF inhibitor sorafenib and the MEK inhibitor trametinib, presented strong synergistic cytotoxicities in HCC cells. Therefore, the EGFR-PI3K-PDK1 pathway could activate the YAP signaling, and the activated EGFR signaling could promote the HCC cell growth in a YAP-independent manner. Combined use of FDA-approved inhibitors to simultaneously target YAP and EGFR signaling presented several promising therapeutic approaches for HCC treatment.

Glutamine synthetase mediates sorafenib sensitivity in β-catenin-active hepatocellular carcinoma cells

The gene encoding β-catenin is frequently mutated in hepatocellular carcinoma cells. While the oncogenicity of β-catenin has been extensively studied, β-catenin’s role in hepatocellular carcinoma tumor metabolism is currently less well understood. In this study, we found that β-catenin regulates the expression of glutamine synthetase and triggers a series of metabolic changes leading to induction of autophagy in hepatocellular carcinoma cells. β-Catenin-active Hep3B and HepG2 cells exhibited higher basal levels of autophagic activity than did β-catenin wild-type cells. We also found that autophagy in β-catenin-active cells was mediated by glutamine synthetase, as silencing of glutamine synthetase significantly reduced autophagic activity. We also showed that β-catenin-active hepatocellular carcinoma cells were more sensitive to sorafenib than were β-catenin wild-type cells. Our results demonstrated that glutamine synthetase-mediated autophagy explains the high sensitivity of β-catenin-active hepatocellular carcinoma cells to sorafenib. Our results highlight the importance of glutamine metabolism in the regulation of autophagy in hepatocellular carcinoma cells. More importantly, our study unravels the molecular mechanisms leading to sorafenib sensitivity in hepatocellular carcinoma.

Loss of Pten synergizes with c-Met to promote hepatocellular carcinoma development via mTORC2 pathway

Hepatocellular carcinoma (HCC) is a deadly malignancy with limited treatment options. Activation of the AKT/mTOR cascade is one of the most frequent events along hepatocarcinogenesis. mTOR is a serine/threonine kinase and presents in two distinct complexes: mTORC1 and mTORC2. While mTORC1 has been extensively studied in HCC, the functional contribution of mTORC2 during hepatocarcinogenesis has not been well characterized, especially in vivo. Pten expression is one of the major mechanisms leading to the aberrant activation of the AKT/mTOR signaling. Here, we show that concomitant downregulation of Pten and upregulation of c-Met occurs in a subset of human HCC, mainly characterized by poor prognosis. Using CRISPR-based gene editing in combination with hydrodynamic injection, Pten was deleted in a subset of mouse hepatocytes (sgPten). We found that loss of Pten synergizes with overexpression of c-Met to promote HCC development in mice (sgPten/c-Met). At the molecular level, sgPten/c-Met liver tumor tissues display increased AKT and mTOR signaling. Using Rictor conditional knockout mice, we demonstrate that sgPten/c-Met-driven HCC development strictly depends on an intact mTORC2 complex. Our findings therefore support the critical role of mTORC2 in hepatocarcinogenesis. sgPten/c-Met mouse model represents a novel valuable system that can be used for the development of targeted therapy against this deadly malignancy.

Ganetespib radiosensitization for liver cancer therapy

Therapies for liver cancer particularly those including radiation are still inadequate. Inhibiting the stress response machinery is an appealing anti-cancer and radiosensitizing therapeutic strategy. Heat-shock-protein-90 (HSP90) is a molecular chaperone that is a prominent effector of the stress response machinery and is overexpressed in liver cancer cells. HSP90 client proteins include critical components of pathways implicated in liver cancer cell survival and radioresistance. The effects of a novel non-geldanamycin HSP90 inhibitor, ganetespib, combined with radiation were examined on 3 liver cancer cell lines, Hep3b, HepG2 and HUH7, using in vitro assays for clonogenic survival, apoptosis, cell cycle distribution, γH2AX foci kinetics and client protein expression in pathways important for liver cancer survival and radioresistance. We then evaluated tumor growth delay and effects of the combined ganetespib-radiation treatment on tumor cell proliferation in a HepG2 hind-flank tumor graft model. Nanomolar levels of ganetespib alone exhibited liver cancer cell anti-cancer activity in vitro as shown by decreased clonogenic survival that was associated with increased apoptotic cell death, prominent G2-M arrest and marked changes in PI3K/AKT/mTOR and RAS/MAPK client protein activity. Ganetespib caused a supra-additive radiosensitization in all liver cancer cell lines at low nanomolar doses with enhancement ratios between 1.33–1.78. These results were confirmed in vivo, where the ganetespib-radiation combination therapy produced supra-additive tumor growth delay compared with either therapy by itself in HepG2 tumor grafts. Our data suggest that combined ganetespib-radiation therapy exhibits promising activity against liver cancer cells, which should be investigated in clinical studies.

A validated, transitional and translational porcine model of hepatocellular carcinoma

Difficult questions are confronting clinicians attempting to improve hepatocellular carcinoma (HCC) outcomes. A large animal model with genetic, anatomical, and physiological similarities to humans is required to transition from mouse models to human clinical trials to address unmet clinical needs. To validate our previously reported inducible porcine cancer model (Oncopig) as a transitional HCC model, Oncopig hepatocyte cultures were transformed using Cre recombinase. The resulting porcine HCC cells (pHCC) expressed oncogenic TP53R167H and KRASG12D, and displayed nuclear pleomorphisms with pale to granular cytoplasm arranged in expanded plates similar to human HCC histopathology. Human HCC transcriptional hallmarks were detected in pHCC cells using RNA-seq, including TERT reactivation, apoptosis evasion, angiogenesis activation, and Wnt signaling activation. Master regulators of gene expression were conserved across Oncopig and 18 human HCC cell lines. pHCC injection into SCID mice resulted in tumors recapitulating human HCC characteristics, including thick trabeculae formation, pseudoacini patterning, and sheets of well-vascularized stroma. Finally, autologous injection of pHCC cells subcutaneously yielded a tumor histologically characterized as Edmondson Steiner (HCC nuclear grade assessment system) grade 2 HCC with trabecular patterning and T-lymphocyte infiltration. These data demonstrate the Oncopig HCC model's utility for improving detection, treatment, and biomarker discovery relevant to human HCC.

Oxidative stress plays a key role in butyrate-mediated autophagy via Akt/mTOR pathway in hepatoma cells

Hepatocellular Carcinoma (HCC) is one of the most aggressive forms of cancer, responsible for a number of deaths in humans. Butyrate, one of the short chain fatty acids produced by the gut microbiota during anaerobic fermentation, was shown to be beneficial for inhibiting cancer growth. In this study, we showed that sodium butyrate induced autophagy via reactive oxygen species (ROS) in hepatoma cells. Butyrate (0-6 mM) incubation significantly increased intracellular ROS levels (45.2% compared to control), which in turn inhibited phosphorylation of akt and mTOR, leading to the upregulation of autophagic proteins, such as beclin 1, ATG 5, LC3-II, followed by the increased autophagosome formation (34.4% compared to control cells). Addition of a known antioxidant, N-acetyl cysteine (NAC), reversed these butyrate-induced ROS and autophagy. It was also found that butyrate-induced ROS enhanced MAPK activation, which was inhibited by NAC. In conclusion, our data showed that butyrate induced ROS, which in turn induced autophagy via inhibition of akt/mTOR pathway. Hence, butyrate could be considered as a potential candidate for HCC treatment.

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in hepatocellular carcinoma

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha plays a crucial role in regulating the biosynthesis of mitochondria, which is closely linked to the energy metabolism in various tumors. This study investigated the regulatory role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha in the pathogenesis of hepatocellular carcinoma. In this study, the changes of peroxisome proliferator-activated receptor gamma coactivator-1 alpha messenger RNA levels between normal human liver and hepatocellular carcinoma tissue were examined by quantitative reverse transcription polymerase chain reaction. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by RNA interference in the human liver cell line L02, while overexpression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha complementary DNA in the human hepatocarcinoma cell line HepG2. Cellular morphological changes were observed via optical and electron microscopy. Cellular apoptosis was determined by Hoechst 33258 staining. In addition, the expression levels of 21,400 genes in tissues and cells were detected by microarray. It was shown that peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression was significantly downregulated in hepatocellular carcinoma compared with normal liver tissues. After knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression in L02 cells, cells reverted to immature and dedifferentiated morphology exhibiting cancerous tendency. Apoptosis occurred in the HepG2 cells after transfection by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha. Microarray analysis showed consistent results. The results suggest that peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in the formation and development of hepatocellular carcinoma and that peroxisome proliferator-activated receptor gamma coactivator-1 alpha may be a potential therapeutic target for hepatocellular carcinoma.

Tumor Microenvironment, a Paradigm in Hepatocellular Carcinoma Progression and Therapy

Hepatocellular carcinoma (HCC) is among the most lethal and prevalent cancers in the human population. Different etiological factors such as hepatitis B and C virus, alcohol and diabetes cause liver injury followed by inflammation, necrosis and hepatocytes proliferation. Continuous cycles of this destructive-regenerative process culminates in liver cirrhosis which is characterized by regenerating nodules that progress to dysplastic nodules and ultimately HCC. Despite its significance, there is only an elemental understanding of the pathogenetic mechanisms, and there are only limited therapeutic options. Therefore, the study of the involved molecular mechanisms can open a new insight to define more effective treatment strategies. A variety of alterations have been reported in HCC patients, particularly the cancer-associated microenvironment components including immune cells, fibroblast cells, endothelial cells and extracellular matrix can support the neoplastic cells to proliferate, growth and invade. This review summarizes the current state of knowledge and highlights the principal challenges that are relevant to controlling this milieu.

Tumor Microenvironment, a Paradigm in Hepatocellular Carcinoma Progression and Therapy

Hepatocellular carcinoma (HCC) is among the most lethal and prevalent cancers in the human population. Different etiological factors such as hepatitis B and C virus, alcohol and diabetes cause liver injury followed by inflammation, necrosis and hepatocytes proliferation. Continuous cycles of this destructive–regenerative process culminates in liver cirrhosis which is characterized by regenerating nodules that progress to dysplastic nodules and ultimately HCC. Despite its significance, there is only an elemental understanding of the pathogenetic mechanisms, and there are only limited therapeutic options. Therefore, the study of the involved molecular mechanisms can open a new insight to define more effective treatment strategies. A variety of alterations have been reported in HCC patients, particularly the cancer-associated microenvironment components including immune cells, fibroblast cells, endothelial cells and extracellular matrix can support the neoplastic cells to proliferate, growth and invade. This review summarizes the current state of knowledge and highlights the principal challenges that are relevant to controlling this milieu.

Genetic alterations in hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this cancer is still associated with a poor survival rate mainly due to late diagnosis. Therefore, a diagnosis must be made sufficiently early to perform curative and effective treatments. There is a need for a deeper understanding of the molecular mechanisms underlying the initiation and progression of HCC because these mechanisms are critical for making early diagnoses and developing novel therapeutic strategies. Over the past decade, much progress has been made in elucidating the molecular mechanisms underlying hepatocarcinogenesis. In particular, recent advances in next-generation sequencing technologies have revealed numerous genetic alterations, including recurrently mutated genes and dysregulated signaling pathways in HCC. A better understanding of the genetic alterations in HCC could contribute to identifying potential driver mutations and discovering novel therapeutic targets in the future. In this article, we summarize the current advances in research on the genetic alterations, including genomic instability, single-nucleotide polymorphisms, somatic mutations and deregulated signaling pathways, implicated in the initiation and progression of HCC. We also attempt to elucidate some of the genetic mechanisms that contribute to making early diagnoses of and developing molecularly targeted therapies for HCC.

The chimeric multi-domain proteins mediating specific DNA transfer for hepatocellular carcinoma treatment

AIM

This study was aimed to evaluate the therapeutic efficiency of a non-virus based specific chimeric multi-domain DNA transferred with apoptin in human hepatocellular carcinoma (HCC) HepG-2 cells in vitro and in mice H22 cells in vivo.

METHODS

We firstly constructed the multi-domain recombinant chimeric proteins based on recombinant proteins [G (yeast GAL4), NG (none GAL4), TG (GAL4 + Tat protein) and TNG (Tat protein)] and pUAS-Apoptin plasmid, and transfected them into human HepG-2 cells. The antitumor effect of this multi-domain recombinant chimeric proteins to HCC cells were detected by MTT assay, AO/EB staining, DAPI staining and Annexin V assay. In order to find the pathway of cell apoptosis, the Caspase (1, 3, 6 and 8) activity was detected. We then constructed the H22 liver cancer mice model and analyzed the anti-tumor rate and mice survival rate after treated with G/pUAS-Apoptin NG/pUAS-Apoptin TG/pUAS-Apoptin, and TNG/pUAS-Apoptin.

RESULTS

MTT results showed that the Tat protein (TG and TNG) significantly induced cell death in a time dependent manner. AO/EB, DAPI, Annexin V and Caspases assay results indicated that the Caspase 1, 3, 6 and 8 were highly expressed in TG/pUAS-Apoptin, and TNG/pUAS-Apoptin treated mouse groups. The antitumor rate and survival rate in TG/pUAS-Apoptin, and TNG/pUAS-Apoptin treated mouse groups were higher than in the other groups.

CONCLUSION

The Tat-apoptin is a potential anti-tumor agent for HCC treatment with remarkable anti-tumor efficacy and high safety based on non-virus gene transfer system. The anti-tumor function may be associated with high expression of Caspase 1, 3, 6 and 8.

Single Agent and Synergistic Activity of the "First-in-Class" Dual PI3K/BRD4 Inhibitor SF1126 with Sorafenib in Hepatocellular Carcinoma

Deregulated PI3K/AKT/mTOR, Ras/Raf/MAPK, and c-Myc signaling pathways are of prognostic significance in hepatocellular carcinoma (HCC). Sorafenib, the only drug clinically approved for patients with advanced HCC, blocks the Ras/Raf/MAPK pathway but it does not inhibit the PI3K/AKT/mTOR pathway or c-Myc activation. Hence, there is an unmet medical need to identify potent PI3K/BRD4 inhibitors, which can be used either alone or in combination with sorafenib to treat patients with advanced HCC. Herein, we show that SF1126 (pan PI3K/BRD4 inhibitor) as single agent or in combination with sorafenib inhibited proliferation, cell cycle, apoptosis, and multiple key enzymes in PI3K/AKT/mTOR and Ras/Raf/MAPK pathway in Hep3B, HepG2, SK-Hep1, and Huh7 HCC cell lines. We demonstrate that the active moiety of the SF1126 prodrug LY294002 binds to and blocks BRD4 interaction with the acetylated histone-H4 chromatin mark protein and displaced BRD4 coactivator protein from the transcriptional start site of MYC in Huh7 and SK-Hep1 HCC cell lines. Moreover, SF1126 blocked expression levels of c-Myc in HCC cells. Treatment of SF1126 either alone or in combination with sorafenib showed significant antitumor activity in vivo Our results establish that SF1126 is a dual PI3K/BRD4 inhibitor. This agent has completed a phase I clinical trial in humans with good safety profile. Our data support the potential future consideration of a phase II clinical trial of SF1126, a clinically relevant dual "first-in-class" PI3K/BRD4 inhibitor in advanced HCC, and a potential combination with sorafenib. Mol Cancer Ther; 15(11); 2553-62. ©2016 AACR.

Hepatocellular carcinoma: Review of disease and tumor biomarkers

Hepatocellular carcinoma (HCC) is a common malignancy and now the second commonest global cause of cancer death. HCC tumorigenesis is relatively silent and patients experience late symptomatic presentation. As the option for curative treatments is limited to early stage cancers, diagnosis in non-symptomatic individuals is crucial. International guidelines advise regular surveillance of high-risk populations but the current tools lack sufficient sensitivity for early stage tumors on the background of a cirrhotic nodular liver. A number of novel biomarkers have now been suggested in the literature, which may reinforce the current surveillance methods. In addition, recent metabonomic and proteomic discoveries have established specific metabolite expressions in HCC, according to Warburg’s phenomenon of altered energy metabolism. With clinical validation, a simple and non-invasive test from the serum or urine may be performed to diagnose HCC, particularly benefiting low resource regions where the burden of HCC is highest.

miR-663 overexpression induced by endoplasmic reticulum stress modulates hepatocellular carcinoma cell apoptosis via transforming growth factor beta 1

microRNAs are commonly dysregulated in a number of human cancers, for example, hepatocellular carcinoma (HCC), but the precise mechanism of dysregulation has not been extensively studied. Although previous studies have indicated that HCC cells are resistant to endoplasmic reticulum (ER) stress-induced apoptosis, little is known about the relationship between microRNAs and ER stress-mediated apoptosis resistance. In this study, we have demonstrated for the first time that the expression level of miR-663 was significantly upregulated in HCC cells co-incubated with tunicamycin, an ER stress inducer, as measured by a microRNA-chromatin immunoprecipitation microarray and quantitative real-time polymerase chain reaction; however, the effect of miR-663 on HCC cell apoptosis remains unknown. To investigate the potential involvement of miR-663 in HCC, HepG2 cells were transfected with mimics or inhibitors of miR-663. Consequently, we identified that downregulation of miR-663 suppressed HCC cell proliferation and promoted apoptosis under ER stress. Target gene analysis further predicted that the effects of miR-663 on HCC cells were mediated by directly targeting transforming growth factor beta 1 (TGFB1). Interestingly, the expression levels of TGFB1 changed inversely after downregulation or upregulation of miR-663 by inhibitors or mimics of miR-663 in HepG2 cells. Additionally, TGFB1 knockdown inhibited apoptosis in HepG2 cells. In sum, our study identifies a role for miR-663 as a critical regulator of ER stress-mediated apoptosis resistance in HCC cells via TGFB1. Accordingly, therapies aimed at the miR-663/TGFB1 axis might represent a hopeful strategy to overcome apoptosis resistance in HCC.

Discovery of benzenesulfonamide derivatives as potent PI3K/mTOR dual inhibitors with in vivo efficacies against hepatocellular carcinoma

The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is related to cellular activities. Abnormalities of this signaling pathway were discovered in various cancers, including hepatocellular carcinoma (HCC). The PI3K/mTOR dual inhibitors were proposed to have enhanced antitumor efficacies by targeting multiple points of the signaling pathway. We synthesized a series of propynyl-substituted benzenesulfonamide derivatives as PI3K/mTOR dual inhibitors. Compound 7k (NSC781406) was identified as a highly potent dual inhibitor, which exhibited potent tumor growth inhibition in the hepatocellular carcinoma BEL-7404 xenograft model. Compound 7k may be a potential therapeutic drug candidate for HCC.

Ion Channels and Oxidative Stress as a Potential Link for the Diagnosis or Treatment of Liver Diseases

Oxidative stress results from a disturbed balance between oxidation and antioxidant systems. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) may be either harmful or beneficial to the cells. Ion channels are transmembrane proteins that participate in a large variety of cellular functions and have been implicated in the development of a variety of diseases. A significant amount of the available drugs in the market targets ion channels. These proteins have sulfhydryl groups of cysteine and methionine residues in their structure that can be targeted by ROS and RNS altering channel function including gating and conducting properties, as well as the corresponding signaling pathways associated. The regulation of ion channels by ROS has been suggested to be associated with some pathological conditions including liver diseases. This review focuses on understanding the role and the potential association of ion channels and oxidative stress in liver diseases including fibrosis, alcoholic liver disease, and cancer. The potential association between ion channels and oxidative stress conditions could be used to develop new treatments for major liver diseases.

Safety and efficacy of sorafenib in Japanese patients with hepatocellular carcinoma in clinical practice: a subgroup analysis of GIDEON

BACKGROUND

GIDEON was a prospective, global, non-interventional study evaluating the safety of sorafenib in patients with unresectable hepatocellular carcinoma in real-world practice. The aim of this subgroup analysis was to assess the safety and efficacy of sorafenib as used by Japanese patients.

METHODS

In Japan, 508 patients were valid for safety analysis. Efficacy and safety were evaluated by the Child-Pugh score.

RESULTS

The number of patients with Child-Pugh A and B was 432 (85.0 %) and 58 (11.4 %), respectively. The median overall survival time and time to progression in patients with Child-Pugh A and Child-Pugh B were 17.4 and 4.9 months, 3.7 and 2.3 months, respectively. The most common drug-related adverse events (AEs) included hand-foot skin reaction (47.8 %), diarrhea (35.8 %) and hypertension (24.2 %). The incidences of all or drug-related AEs were similar between patients with Child-Pugh A and B. However, all or drug-related serious AEs, AEs resulting in permanent discontinuation of sorafenib and deaths were observed more frequently in patients with Child-Pugh B compared with Child-Pugh A. Duration of treatment tended to be shorter as the Child-Pugh score worsened.

CONCLUSIONS

Sorafenib was well tolerated by Japanese HCC patients in clinical settings. Patients with Child-Pugh B had shorter duration of treatment and higher incidence of SAEs. It is important to carefully evaluate patients' conditions and assess the benefit and risk before making a decision to treat patients with sorafenib.

Current and future treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents a unique challenge for physicians and patients. There is no definitively curative treatment. Rather, many treatment and management modalities exist with differing advantages and disadvantages. Both current guidelines and individual patient concerns must be taken into account in order to properly manage HCC. In addition, quality of life issues are particularly complex in patients with HCC and these concerns must also be factored into treatment strategies. Thus, considering all the options and their various pros and cons can quickly become complex for both clinicians and patients. In this review, we systematically discuss the current treatment modalities available for HCC, detailing relevant clinical data, risks and rewards and overall outcomes for each approach. Surgical options discussed include resection, transplantation and ablation. We also discuss the radiation modalities: conformal radiotherapy, yttrium 90 microspheres and proton and heavy ion radiotherapy. The biologic agent Sorafenib is discussed as a promising new approach, and recent clinical trials are reviewed. We then detail currently described molecular pathways implicated in the initiation and progression of HCC, and we explore the potential of each pathway as an avenue for drug exploitation. We hope this comprehensive and forward-looking review enables both clinicians and patients to understand various options and thereby make more informed decisions regarding this disease.

Identification of Chemical Inhibitors of β-Catenin-Driven Liver Tumorigenesis in Zebrafish

Hepatocellular carcinoma (HCC) is one of the most lethal human cancers. The search for targeted treatments has been hampered by the lack of relevant animal models for the genetically diverse subsets of HCC, including the 20-40% of HCCs that are defined by activating mutations in the gene encoding β-catenin. To address this chemotherapeutic challenge, we created and characterized transgenic zebrafish expressing hepatocyte-specific activated β-catenin. By 2 months post fertilization (mpf), 33% of transgenic zebrafish developed HCC in their livers, and 78% and 80% of transgenic zebrafish showed HCC at 6 and 12 mpf, respectively. As expected for a malignant process, transgenic zebrafish showed significantly decreased mean adult survival compared to non-transgenic control siblings. Using this novel transgenic model, we screened for druggable pathways that mediate β-catenin-induced liver growth and identified two c-Jun N-terminal kinase (JNK) inhibitors and two antidepressants (one tricyclic antidepressant, amitriptyline, and one selective serotonin reuptake inhibitor) that suppressed this phenotype. We further found that activated β-catenin was associated with JNK pathway hyperactivation in zebrafish and in human HCC. In zebrafish larvae, JNK inhibition decreased liver size specifically in the presence of activated β-catenin. The β-catenin-specific growth-inhibitory effect of targeting JNK was conserved in human liver cancer cells. Our other class of hits, antidepressants, has been used in patient treatment for decades, raising the exciting possibility that these drugs could potentially be repurposed for cancer treatment. In support of this proposal, we found that amitriptyline decreased tumor burden in a mouse HCC model. Our studies implicate JNK inhibitors and antidepressants as potential therapeutics for β-catenin-induced liver tumors.

Liver cancer is a leading cause of cancer-related death. Genetic analysis of liver cancer has enabled classification of these tumors into subsets with unique genetic, clinical, and prognostic features. The search for targeted liver cancer treatments has been hampered by the lack of relevant animal models for these genetically diverse subsets, including liver cancers that are defined by activating mutations in the gene encoding β-catenin, an integral component of the Wnt signaling pathway. Here we describe the generation and characterization of genetically modified zebrafish expressing hepatocyte-specific activated β-catenin. We used this new zebrafish model to screen for drugs that suppress β-catenin-induced liver growth, and identified two classes of hits, c-Jun N-terminal kinase (JNK) inhibitors and antidepressants, that suppressed this phenotype. Our findings provide insights into the mechanisms by which β-catenin promotes liver tumor formation and implicate JNK inhibitors and antidepressants as potential treatments for a subset of human liver cancers.

Molecular characterization of hepatocarcinogenesis using mouse models

Hepatocellular carcinoma (HCC) is a deadly disease, often unnoticed until the late stages, when treatment options become limited. Thus, there is a crucial need to identify biomarkers for early detection of developing HCC, as well as molecular pathways that would be amenable to therapeutic intervention. Although analysis of human HCC tissues and serum components may serve these purposes, inability of early detection also precludes possibilities of identification of biomarkers or pathways that are sequentially perturbed at earlier phases of disease progression. We have therefore explored the option of utilizing mouse models to understand in a systematic and longitudinal manner the molecular pathways that are progressively deregulated by various etiological factors in contributing to HCC formation, and we report the initial findings in characterizing their validity. Hepatitis B surface antigen transgenic mice, which had been exposed to aflatoxin B1 at various stages in life, were used as a hepatitis model. Our findings confirm a synergistic effect of both these etiological factors, with a gender bias towards males for HCC predisposition. Time-based aflatoxin B1 treatment also demonstrated the requirement of non-quiescent liver for effective transformation. Tumors from these models with various etiologies resemble human HCCs histologically and at the molecular level. Extensive molecular characterization revealed the presence of an 11-gene HCC-expression signature that was able to discern transformed human hepatocytes from primary cells, regardless of etiology, and from other cancer types. Moreover, distinct molecular pathways appear to be deregulated by various etiological agents en route to formation of HCCs, in which common pathways converge, highlighting the existence of etiology-specific as well as common HCC-specific molecular perturbations. This study therefore highlights the utility of these mouse models, which provide a rich resource for the longitudinal analysis of molecular changes and biomarkers associated with HCC that could be exploited further for therapeutic targeting.

The hop constituent xanthohumol exhibits hepatoprotective effects and inhibits the activation of hepatic stellate cells at different levels

Xanthohumol is the principal prenylated flavonoid of the female inflorescences of the hop plant. In recent years, various beneficial xanthohumol effects including anti-inflammatory, antioxidant, hypoglycemic activities, and anticancer effects have been revealed. This review summarizes present studies indicating that xanthohumol also inhibits several critical pathophysiological steps during the development and course of chronic liver disease, including the activation and pro-fibrogenic genotype of hepatic stellate cells. Also the various mechanism of action and molecular targets of the beneficial xanthohumol effects will be described. Furthermore, the potential use of xanthohumol or a xanthohumol-enriched hop extract as therapeutic agent to combat the progression of chronic liver disease will be discussed. It is notable that in addition to its hepatoprotective effects, xanthohumol also holds promise as a therapeutic agent for treating obesity, dysregulation of glucose metabolism and other components of the metabolic syndrome including hepatic steatosis. Thus, therapeutic xanthohumol application appears as a promising strategy, particularly in obese patients, to inhibit the development as well as the progression of non-alcoholic fatty liver disease.

HIF-2α attenuates lymphangiogenesis by up-regulating IGFBP1 in hepatocellular carcinoma

BACKGROUND INFORMATION

Tumour-associated lymphangiogenesis was identified as an important clinical determinant for the prognosis of hepatocellular carcinoma (HCC) and significantly influences patient survival. However, in this context, little is known about regulation of lymphangiogenesis by hypoxia-inducible factors (HIF). In HCC, mainly HIF-1α was positively correlated with lymphatic invasion and metastasis, whereas a defined role of HIF-2α is missing.

RESULTS

We created a stable knockdown (k/d) of HIF-1α and HIF-2α in HepG2 cells and generated co-cultures of HepG2 spheroids with embryonic bodies. This constitutes an in vitro tumour model mimicking the cancer microenvironment and allows addressing the role of distinct HIF isoforms in regulating HCC lymphangiogenesis. In co-cultures with a HIF-2α k/d, lymphangiogenesis was significantly increased, whereas the k/d of HIF-1α showed no effect. The HIF-2α-dependent lymphangiogenic phenotype was confirmed in vivo using matrigel plug assays with supernatants of HIF-2α k/d HepG2 cells. We identified and verified insulin-like growth factor binding protein 1 (IGFBP1) as a HIF-2α target gene. The potential of HepG2 cells to induce lymphangiogenesis in two independent functional assays was significantly enhanced either by a k/d of HIF-2α or by silencing IGFBP1. Moreover, we confirmed IGF as a potent pro-lymphatic growth factor with IGFBP1 being its negative modulator.

CONCLUSIONS

We propose that HIF-2α acts as an important negative regulator of hepatic lymphangiogenesis in vitro and in vivo by inducing IGFBP1 and thus, interfering with IGF signalling. Therefore, HIF-2α may constitute a critical target in HCC therapy.

Oleuropein induces apoptosis via activation of caspases and suppression of phosphatidylinositol 3-kinase/protein kinase B pathway in HepG2 human hepatoma cell line

Oleuropein is a polyphenol, that is found in extra‑virgin olive oil. Previous studies have shown that oleuropein inhibits cell proliferation and induces apoptosis in breast cancer, colorectal cancer and thyroid cancer. The aim of the present study was to investigate the effects of oleuropein in hepatocellular carcinoma (HCC) cells. The results of Cell Counting Kit 8 and flow cytometric analysis indicated that oleuropein effectively inhibited cell viability and induced apoptosis in HepG2 human hepatoma cells in a dose‑dependent manner, through activation of the caspase pathway. Proapoptotic Bcl‑2 family members, BAX and Bcl‑2, were involved in oleuropein‑induced apoptosis. The phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) signaling pathway was also shown to be involved in this process. Oleuropein was demonstrated to suppress the expression of activated AKT. In addition, AKT overexpression promoted cell survival following treatment with oleuropein, while inhibition of AKT promoted cell death. Furthermore, the data demonstrated that oleuropein induces the production of reactive oxygen species (ROS) and that the function of oleuropein is, at least partially, ROS‑dependent. These results suggest that oleuropein may be a promising novel chemotherapeutic agent in hepatocellular carcinoma.

Acquisition of an immunosuppressive protumorigenic macrophage phenotype depending on c-Jun phosphorylation

The inflamed tumor microenvironment plays a critical role in tumorigenesis. However, the mechanisms through which immune cells, particularly macrophages, promote tumorigenesis have only been partially elucidated, and the full scope of signaling pathways supplying macrophages with protumorigenic phenotypes still remain largely unknown. Here we report that germ-line absence of c-Jun N-terminal phosphorylation at serines 63 and 73 impedes inflammation-associated hepatocarcinogenesis, yet deleting c-Jun only in hepatocytes does not inhibit hepatocellular carcinoma (HCC) formation. Moreover, in human HCC-bearing livers, c-Jun phosphorylation is found in inflammatory cells, whereas it is mostly absent from malignant hepatocytes. Interestingly, macrophages in livers of mice with chronic hepatitis gradually switch their phenotype along the course of disease. Macrophage phenotype and density are dictated by c-Jun phosphorylation, in vitro and in vivo. Transition of macrophage phenotype, from antitumorigenic to protumorigenic, occurs before tumorigenesis, resulting in the production of various chemokines, including chemokine (C-C motif) ligand 17 (CCL17) and CCL22. Such signals, emanating from the liver microenvironment, direct the recruitment of regulatory T cells, which are known to facilitate HCC growth. Our findings identify c-Jun phosphorylation as a key mediator of macrophage education and point to the recruitment of immunosuppressive regulatory T cells as a possible protumorigenic mechanism.