Opportunities for targeted therapies in hepatocellular carcinoma

Somatostatin and Somatostatin Receptors in Tumour Biology

Somatostatin (SST), a growth hormone inhibitory peptide, is expressed in endocrine and non-endocrine tissues, immune cells and the central nervous system (CNS). Post-release from secretory or immune cells, the first most appreciated role that SST exhibits is the antiproliferative effect in target tissue that served as a potential therapeutic intervention in various tumours of different origins. The SST-mediated in vivo and/or in vitro antiproliferative effect in the tumour is considered direct via activation of five different somatostatin receptor subtypes (SSTR1-5), which are well expressed in most tumours and often more than one receptor in a single cell. Second, the indirect effect is associated with the regulation of growth factors. SSTR subtypes are crucial in tumour diagnosis and prognosis. In this review, with the recent development of new SST analogues and receptor-specific agonists with emerging functional consequences of signaling pathways are promising therapeutic avenues in tumours of different origins that are discussed.

Integrating network pharmacology and experimental models to examine the mechanisms of corosolic acid in preventing hepatocellular carcinoma progression through activation PERK-eIF2a-ATF4 signaling

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, with a high recurrence rate and heterogeneity. We aimed to examine the effect of corosolic acid (CRA) on HCC. We employed transcriptomics to validate the target molecules in CRA-treated HCC cells and conducted enrichment analyses that revealed their involvement in the regulation of endoplasmic reticulum (ER) stress and apoptosis. Our experimental data indicated that CRA markedly induced apoptosis in human HCC cell lines through the mitochondrial apoptosis pathway. We also revealed that the pro-apoptotic effects of CRA depended on ER stress, as pretreatment with selective ERS inhibitor salubrinal effectively reversed CRA-induced cell apoptosis. Furthermore, the knockdown of the unfolded protein response (UPR) protein CHOP remarkably abrogated CRA-induced expression of ER stress-associated proteins. Collectively, our results suggest that CRA triggers ER stress-mediated apoptosis in HCC cells via activation of the PERK-eIF2a-ATF4 pathway. Our findings provide novel insights into the potential therapeutic strategies for HCC.

The emerging role of MicroRNA-182 in tumorigenesis; a promising therapeutic target

A wide range of studies have indicated that microRNAs (miRNAs), a type of small single-stranded regulatory RNAs, are dysregulated in a different variety of human cancers. Therefore, they are expected to play important roles in tumorigenesis by functioning as oncogenic (oncomiRs) or tumor-suppressive miRNAs. Subsequently, their potential as diagnostic and therapeutic targets for malignancies has attracted attention in recent years. In particular, studies have revealed the aberrant expression of miR-182 through tumorigenesis and its important roles in various aspects of malignancies, including proliferation, metastasis, and chemoresistance. Accumulating reports have illustrated that miR-182, as a dual-role regulator, directly or indirectly regulates the expression of a wide range of genes and modulates the activity of various signaling pathways involved in tumor progression, such as JAK / STAT3, Wnt / β-catenin, TGF-β, and P13K / AKT. Therefore, considering the high therapeutic and diagnostic potential of miR-182, this review aims to point out the effects of miR-182 dysregulation on the signaling pathways involved in tumorigenesis.

Wnt/β-catenin targeting in liver carcinoma through nanotechnology-based drug repurposing: A review

Liver cancer is the fifth most widespread in the world, with a high fatality rate and poor prognosis.However,surgicalresction,thermal/radiofrequencyablation,chemo/radioembolization and pathway targeting to the cancer cells are all possible options for treating Liver Carcinoma. Unfortunately, once the tumour has developed and spread, diagnosis often occurs too late. The targeted therapy has demonstrated notable, albeit modest, efficacy in some patients with advanced HCC. This demonstrates the necessity of creating additional focused treatments and, in pursuit of this end, the need to find ever-more pathways as prospective targets. Despite the critical need, there are currently no Wnt signalling directed therapy on the research field, only a few methods have progressed beyond the early stage of clinical studies. In the present study, we report that repurposing of drug previously licensed for other diseases is one possible strategy inhibit malignant cell proliferation and renewal by removing individuals protein expression in the Wnt/β-catenin pathway. Particularly β-catenin complex is present in Liver cancer, where tumour necrosis factor is indispensable for the complex formation and β-catenin interactions are disrupted upon drug in nano-carrier through nanotechnology. This study findings not only highlight that repurposing drug could improve liver cancer treatment outcomes but also focused to character traits and functions of the Wnt signalling cascade's molecular targets and how they could be used to get anti-tumour results method to targeting Wnt/β-catenin in liver carcinoma.

Signaling Pathways Tuning Innate Lymphoid Cell Response to Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide and its incidence continues to rise globally. Various causes can lead to its development such as chronic viral infections causing hepatitis, cirrhosis or nonalcoholic steatohepatitis (NASH). The contribution of immune cells to HCC development and progression has been extensively studied when it comes to adaptive lymphocytes or myeloid populations. However, the role of the innate lymphoid cells (ILCs) is still not well defined. ILCs are a family of lymphocytes comprising five subsets including circulating Natural Killer (NK) cells, ILC1s, ILC2s, ILC3s and lymphocytes tissue-inducer cells (LTi). Mostly located at epithelial surfaces, tissue-resident ILCs and NK cells can rapidly react to environmental changes to mount appropriate immune responses. Here, we provide an overview of their roles and actions in HCC with an emphasis on the importance of diverse signaling pathways (Notch, TGF-β, Wnt/β-catenin…) in the tuning of their response to HCC.

Restoring NK cells functionality via cytokine activation enhances cetuximab-mediated NK-cell ADCC: A promising therapeutic tool for HCC patients

Natural Killer (NK) cells are considered the first line of defense against viral infections and tumors. Several factors affect NK cytotoxic activity rendering it dysfunctional and thereby impeding the ability to scavenge abnormal cells as a part of immune escaping mechanisms induced by different types of cancers. NK cells play a crucial role augmenting the activity of various types of anticancer mAb since dysfunctional NK cells are the main reason for the low response to these therapies. To this light, we examined the phenotypic characters of the circulating NK cells isolated from HCC patients compared to healthy controls. Then, dysfunctional NK cells, from HCC patients, were reactivated with cytokines cocktail and their cytotoxic activity with the anti-EGFR mAb "cetuximab" was investigated. This showed a downregulation of patients NK cells activating receptors (NKP30, NKP46, NKG2D and CD16) as well as CD56 and up-regulation of NKG2A inhibitory receptor. We also reported an increase in aberrant CD56^- NK cells subset in peripheral blood of HCC patients compared to healthy controls. Thus, confirming the dysfunctionality of peripheral NK cells isolated from HCC patients. Cytokines re-activation of those NK cells lead to upregulation of NK activating receptors and downregulation of inhibitory receptor. Moreover, the percentage of aberrant CD56^- NK cells subset was reduced. Here, we proved that advanced HCC patients have an increased percentage of more immature and noncytotoxic NK cell subsets in their peripheral blood, which might account for the low cytotoxicity noticed in those patients. A significant improvement in the cytotoxicity against HCC was noticed upon using reactivated NK cells combined with cetuximab. Therefore, this study highlights the potential recruitment of NK immune cells along with cetuximab to enhance cytotoxicity against HCC.

Recent Advances in Asialoglycoprotein Receptor and Glycyrrhetinic Acid Receptor-Mediated and/or pH-Responsive Hepatocellular Carcinoma- Targeted Drug Delivery

BACKGROUND

Hepatocellular carcinoma (HCC) seriously affects human health, especially, it easily develops multi-drug resistance (MDR) which results in treatment failure. There is an urgent need to develop highly effective and low-toxicity therapeutic agents to treat HCC and to overcome its MDR. Targeted drug delivery systems (DDS) for cancer therapy, including nanoparticles, lipids, micelles and liposomes, have been studied for decades. Recently, more attention has been paid to multifunctional DDS containing various ligands such as polymer moieties, targeting moieties, and acid-labile linkages. The polymer moieties such as poly(ethylene glycol) (PEG), chitosan (CTS), hyaluronic acid, pullulan, poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) protect DDS from degradation. Asialoglycoprotein receptor (ASGPR) and glycyrrhetinic acid receptor (GAR) are most often used as the targeting moieties, which are overexpressed on hepatocytes. Acid-labile linkage, catering for the pH difference between tumor cells and normal tissue, has been utilized to release drugs at tumor tissue.

OBJECTIVES

This review provides a summary of the recent progress in ASGPR and GAR-mediated and/or pH-responsive HCC-targeted drug delivery.

CONCLUSION

The multifunctional DDS may prolong systemic circulation, continuously release drugs, increase the accumulation of drugs at the targeted site, enhance the anticancer effect, and reduce side effects both in vitro and in vivo. But it is rarely used to investigate MDR of HCC; therefore, it needs to be further studied before going into clinical trials.

Improved survival following transarterial radioembolization of infiltrative-appearance hepatocellular carcinoma

PURPOSE

Infiltrative-appearance hepatocellular carcinoma presents a challenge to clinicians as diagnostic criteria continue to evolve and evidence-based treatment guidelines have yet to be established. While transarterial radioembolization has shown efficacy in hepatocellular carcinoma, many studies exclude infiltrative-appearance HCC in their analysis. The purpose of this study was to describe imaging features of infiltrative-appearance hepatocellular carcinoma and evaluate effects of radioembolization on survival.

METHODS

In a retrospective review, infiltrative HCC patients treated from 2008 to 2017 were identified. Patients were divided into two groups: TARE versus systemic therapy/palliative care. Demographics, dates of diagnosis/expiry, albumin, international normalized ratio (INR), sodium, alpha-fetoprotein (AFP), creatinine, Child-Pugh class, model for end-stage liver disease (MELD) score, bilirubin, radiation dose and volume were collected. Patients with bilirubin > 3 were excluded. Mann-Whitney U test and Fisher's exact test assessed differences between groups. Kaplan-Meier survival and Cox proportional hazard analyses were performed.

RESULTS

Fifty-three patients were identified, 15 underwent TARE while 38 served as control. Mean age was 60, 43 patients were male. The mean overall survival was 16.2 months for the TARE group and 5.3 months for the control group (Log-rank p < 0.0001). Cox proportional regression analysis revealed significant associations between survival and albumin (HR 0.210, 0.052-0.839, p = 0.027), Child-Pugh class B (HR 0.196, 0.055-0.696, p = 0.012), sorafenib (HR 0.106, 0.031-0.360, p < 0.001), and number of affected liver lobes (HR 1.864, 1.387-2.506, p < 0.001).

CONCLUSIONS

Transarterial radioembolization for infiltrative HCC improves life expectancy compared to treatment with comfort measures or systemic therapy.

Identification of immunological subtypes of hepatocellular carcinoma with expression profiling of immune-modulating genes

Recent studies demonstrate that immune checkpoint inhibitor (ICI) therapy has achieved success in many types of advanced cancers including advanced hepatocellular carcinoma (HCC). However, ICI therapy is beneficial in only some HCC patients, suggesting that immune-responses are highly variable in HCCs. Therefore, understanding the immune status in HCC microenvironment will facilitate ICI immunotherapy and guide patient selection for the therapy. In this study, we first analyzed the expression profile of immune-modulating genes and their relationship with survival of HCC patients using the data downloaded from The Cancer Genome Atlas - Liver Hepatocellular Carcinoma (TCGA-LIHC) database, and found that the higher expressions of CD276 (B7-H3) and CD47 were significantly associated with poor survival. Then we identified 4 immune subtypes of HCCs with different survivals by using the combination expression of B7-H3 (or CD47) and CD8. Patients with B7-H3^low/CD8^high or CD47^low/CD8^high have the best survival while ones with B7-H3^high/CD8^low or CD47^high/CD8^low have the worst survival. The 4 immune subtypes were validated in another 72 HCC patients obtained from South China. In conclusion, our findings suggest that HCC patient prognosis is associated with immunophenotypes by T cell infiltration (CD8 expression) and the expression of the adaptive immune resistance gene (B7-H3 or CD47), and this immune classification system will facilitate HCC patient selection for ICI immunotherapy.

Molecular Signaling Pathways and Therapeutic Targets in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a complex biological process and is often diagnosed at advanced stages with no effective treatment options. With advances in tumor biology and molecular genetic profiling, several different signaling pathways and molecular mechanisms have been identified as responsible for initiating and promoting HCC. Targeting these critical pathways, which include the receptor tyrosine kinase pathways, the Ras mitogen-activated protein kinase (Ras/Raf/MAPK), the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR), the Wnt/β-catenin signaling pathway, the ubiquitin/proteasome degradation and the hedgehog signaling pathway has led to the identification of novel therapeutics for HCC treatment. In this review, we elaborated on our current understanding of the signaling pathways involved in the development and initiation of HCC and anticipate the potential targets for therapeutic drug development.

NF90 stabilizes cyclin E1 mRNA through phosphorylation of NF90-Ser382 by CDK2

Nuclear factor 90 (NF90), an RNA-binding protein, has been implicated in regulating interleukin-2 (IL-2) and the immune response. It was recently reported that NF90 is upregulated in hepatocellular carcinoma (HCC) tissues and promotes HCC proliferation through upregulating cyclin E1 at the posttranscription level. However, the regulation of NF90 in HCC remains unclear. We demonstrate here that cyclin-dependent kinase (CDK) 2 interacts with NF90 and phosphorylated it at serine382. Mechanistically, phosphorylation of NF90-Ser382 determines the nuclear export of NF90 and stabilization of cyclin E1 mRNA. We also demonstrate that the phosphorylation deficient mutant NF90-S382A inhibits cell growth and induces cell cycle arrest at the G1 phase in HCC cells. Moreover, an NF90-S382A xenograft tumor had a decreased size and weight compared with the wildtype NF90. The NF90-S382A xenograft contained a significantly lower level of the proliferation marker Ki-67. Additionally, in HCC patients, NF90-Ser382 phosphorylation was stronger in tumor than in non-tumor tissues. Clinically, phosphorylation of NF90-Ser382 is significantly associated with larger tumor sizes, higher AFP levels, and shorter overall survival rates. These results suggest NF90-Ser382 phosphorylation serves as a potential diagnosis and prognostic marker and a promising pharmacological target for HCC.

F127 poloxamer effect on cytotoxicity induction of tumour cell cultures treated with doxorubicin

INTRODUCTION

Hepatocellular carcinoma is the most common liver malignancy and the third leading cause of cancer death worldwide. One crucial limitation in the pharmacotherapy for this tumour is its chemotherapy-resistant nature produced by the overexpression of several members of the ATP-binding cassette protein family that efflux drugs out of cells, as observed with the breast cancer resistant protein (BCRP).

OBJECTIVES

This study aimed to assess the ability of Pluronic^® F127 to reverse the multidrug resistance phenotype in two human hepatocellular cell lines.

METHODS

PLC/PRF/5 and SKHep1 cells were exposed to Pluronic^® F127 at several concentrations. The effect of F127 on BCRP expression (mRNA and protein), mitochondrial transmembrane potential and cell hypodiploidy was assessed. Finally, the effect of this copolymer on cytotoxicity of doxorubicin in both hepatoma cell lines was investigated, as expressed by its reverse resistance index.

KEY FINDINGS

It was demonstrated that F127 in both cell lines contributes to chemosensitization, as shown by BCRP down-regulation, an altered mitochondrial transmembrane potential and hypodiploidy and reverse resistance index values. A remarkable dependence of these effects significantly correlated with the copolymer concentration.

CONCLUSIONS

These findings further uncover the potential usefulness of this copolymer as multidrug resistance reversal agent, increasing the efficacy of cancer therapies.

Therapeutic Effects of Amino Acids in Liver Diseases: Current Studies and Future Perspectives

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver and the third most common cause of cancer-related death worldwide. HCC is caused by infection of hepatitis B/C virus and liver dysfunctions, such as alcoholic liver disease, nonalcoholic fatty liver disease, and cirrhosis. Amino acids are organic substances containing amine and carboxylic acid functional groups. There are over 700 kinds of amino acids in nature, but only about 20 of them are used to synthesize proteins in cells. Liver is an important organ for protein synthesis, degradation and detoxification as well as amino acid metabolism. In the liver, there are abundant non-essential amino acids, such as alanine, aspartate, glutamate, glycine, and serine and essential amino acids, such as histidine and threonine. These amino acids are involved in various cellular metabolisms, the synthesis of lipids and nucleotides as well as detoxification reactions. Understanding the role of amino acids in the pathogenesis of liver and the effects of amino acid intake on liver disease can be a promising strategy for the prevention and treatment of liver disease. In this review, we describe the biochemical properties and functions of amino acids and to review how they have been applied to treatment of liver diseases.

Targeted and Immune-Based Therapies for Hepatocellular Carcinoma

Treatment options for patients with hepatocellular carcinoma are rapidly changing based on positive results from phase 3 trials of targeted and immune-based therapies. More agents designed to target specific pathways and immune checkpoints are in clinical development. Some agents have already been shown to improve outcomes of patients with hepatocellular carcinoma, as first- and second-line therapies, and are awaiting approval by the Food and Drug Administration or have been recently approved. We summarize the targeted and immune-based agents in trials of patients with advanced hepatocellular carcinoma and discuss the future of these strategies for liver cancer.

MicroRNA-206 prevents the pathogenesis of hepatocellular carcinoma by modulating expression of met proto-oncogene and cyclin-dependent kinase 6 in mice

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide, and therapeutic agents for this malignancy are lacking. MicroRNAs play critical roles in carcinogenesis and present tremendous therapeutic potential. Here, we report that microRNA-206 is a robust tumor suppressor that plays important roles in the development of HCC by regulating cell-cycle progression and the cMet signaling pathway. MicroRNA-206 was underexpressed in livers of two HCC mouse models, human individuals bearing HCC, and human HCC cell lines. Combining bioinformatic prediction and molecular and cellular approaches, we identified cMET (Met proto-oncogene), cyclin D1 (CCND1), and cyclin-dependent kinase 6 (CDK6) as functional targets of microRNA-206. By inhibiting expression of cMET, CCND1, and CDK6, microRNA-206 delayed cell-cycle progression, induced apoptosis, and impaired proliferation of three distinct human HCC cell lines. Systemic administration of microRNA-206 completely prevented HCC development in both cMyc and V-Akt murine thymoma viral oncogene homolog 1/neuroblastoma RAS viral oncogene homolog (AKT/Ras) HCC mice, whereas 100% of control mice died from lethal tumor burdens. Conversely, reintroduction of cMet or Cdk6 into livers of cMyc and AKT/Ras HCC mice recovered growth of HCC inhibited by microRNA-206. These results strongly suggested that cMet and Cdk6 were two functional targets that mediated the inhibitory effect of microRNA-206 on the development of HCC. MicroRNA-206 overexpression demonstrated a profound therapeutic effect on HCC in xenograft and cMyc HCC mice.

CONCLUSION

In summary, this study defines a potentially critical role of microRNA-206 in preventing the growth of HCC and suggests its use as a potential therapeutic strategy for this malignancy. (Hepatology 2017;66:1952-1967).

Oncolytic Virus-Based Immunotherapies for Hepatocellular Carcinoma

Hepatocellular carcinoma is highly refractory cancer which is resistant to conventional chemotherapy and radiotherapy, carrying a dismal prognosis. Although many anticancer drugs have been developed for treating HCC, sorafenib is the only effective treatment, but it only prolongs survival duration for about 3 months. Recently, oncolytic virotherapy has shown promising results in treating HCCs and the effects can be more enhanced by adopting immune modulatory molecules. This review discusses the current status of treating HCC and the effective strategy of oncolytic virus-based immunotherapy for the treatment of HCCs.

Metabolic Pathway Inhibition in Liver Cancer

Liver cancer is fundamentally physiologically different from the surrounding liver tissue. Despite multiple efforts to target the altered signaling pathways created by oncogenic mutations, not many have focused on targeting the altered metabolism that allows liver cancer to develop and grow. Still to be resolved is the question of whether the altered metabolic pathways in this cancer differ enough from the surrounding noncancerous cells to allow for the development of potent and specific compounds. Clinical studies of metabolic modulators would provide some more information with regard to the feasibility of this approach. Furthermore, as it appears that oncogenic signaling is essential to this cancer's altered metabolism, it stands to reason that targeting this altered signaling may allow the exploitation of specific metabolic vulnerabilities in combination with other drugs for enhanced efficacy. The identification of biomarkers of metabolic sensitivity will also be essential to determine whether these drugs will have the desired effect.

Combined treatment with zingerone and its novel derivative synergistically inhibits TGF-β1 induced epithelial-mesenchymal transition, migration and invasion of human hepatocellular carcinoma cells

The epithelial-mesenchymal transition (EMT) is an important cellular process during which polarized epithelial cells become motile mesenchymal cells, which promote cancer metastasis. Ginger, the rhizome of Zingiber officinale, is extensively used in cooking worldwide and also as a traditional medicinal herb with antioxidant, anti-inflammatory and anticancer properties. Several pungent compounds have been identified in ginger, including zingerone, which has anticancer potential. However, the role of zingerone in EMT is unclear. We investigated the synergistic effect of zingerone and its derivative on EMT. Transforming growth factor-beta 1 (TGF-β1) induces the EMT to promote hepatocellular carcinoma metastasis, including migration and invasion. To understand the repressive role of the combination of zingerone and its derivative (ZD 2) in hepatocellular carcinoma metastasis, we investigated the potential use of each compound of ginger, such as zingerone, ZD 2 and 6-shogaol, or the mixture of zingerone and ZD 2 (ZD 2-1) as inhibitors of TGF-β1 induced EMT development in SNU182 hepatocellular carcinoma cells in vitro. We show that ZD 2-1, but not zingerone, ZD 2 and 6-shogaol significantly increased expression of the epithelial marker E-cadherin and repressed Snail upregulation and expression of the mesenchymal marker N-cadherin during initiation of the TGF-β1 induced EMT. In addition, ZD 2-1 inhibited the TGF-β1 induced increase in cell migration and invasion of SNU182 hepatocellular carcinoma cells. Furthermore, ZD 2-1 significantly inhibited TGF-β1 regulated matrix metalloproteinase-2/9 and activation of Smad2/3. We also found that ZD 2-1 inhibited nuclear translocation of NF-κB, activation of p42/44 MAPK/AP1 signaling pathway in the TGF-β1 induced EMT. Our findings provide new evidence that combined treatment with ZD 2, novel zingerone derivative, and zingerone synergistically suppresses hepatocellular carcinoma metastasis in vitro by inhibiting the TGF-β1 induced EMT.

OTX1 Contributes to Hepatocellular Carcinoma Progression by Regulation of ERK/MAPK Pathway

Orthodenticlehomeobox 1 (OTX1) overexpression had previously been associated with the progression of several tumors. The present study aimed to determine the expression and role of OTX1 in human hepatocellular carcinoma (HCC). The expression level of OTX1 was examined by quantitative real-time PCR (qRT-PCR) in 10 samples of HCC and paired adjacent non-cancerous tissues, and by immunohistochemistry (IHC) analysis in 128 HCC samples and matched controls. The relationship between OTX1 expression and the clinicopathological features werealso analyzed. Furthermore, the effects of OTX1 knockdown on cell proliferation and migration were determined in HCC cell lines. Axenograft mouse model was also established to investigate the role of OTX1 in HCC tumor growth. TheqRT-PCR and IHC analyses revealed that OTX1 was significantly elevated in HCC tissues compared with the paired non-cancerous controls. Expression of OTX1 was positively correlated with nodal metastasis status (P = 0.009) and TNM staging (P = 0.001) in HCC tissues. In addition, knockdown of OTX1 by shRNA significantly inhibited the proliferation and migration, and induced cell cycle arrest in S phase in vitro. Tumor growth was markedly inhibited by OTX1 silencing in the xenograft. Moreover, OTX1 silencing was causable for the decreased phosphorylation level of ERK/MAPK signaling. In conclusion, OTX1 contributes to HCC progression possibly by regulation of ERK/MAPK pathway. OTX1 may be a novel target for molecular therapy towards HCC.

Hepatocellular carcinoma: Will novel targeted drugs really impact the next future?

Cancer treatment has been revolutionized by the advent of new molecular targeted and immunotherapeutic agents. Identification of the role of tumor angiogenesis changed the understanding of many tumors. After the unsuccessful results with chemotherapy, sorafenib, by interfering with angiogenic pathways, has become pivotal in the treatment of hepatocellular carcinoma. Sorafenib is the only systemic treatment to show a modest but statistically significant survival benefit. All novel drugs and strategies for treatment of advanced hepatocellular carcinoma must be compared with the results obtained with sorafenib, but no new drug or drug combination has yet achieved better results. In our opinion, the efforts to impact the natural history of the disease will be directed not only to drug development but also to understanding the underlying liver disease (usually hepatitis B virus- or hepatitis C virus-related) and to interrupting the progression of cirrhosis. It will be important to define the role and amount of mutations in the complex pathogenesis of hepatocellular carcinoma and to better integrate locoregional and systemic therapies. It will be important also to optimize the therapeutic strategies with existing chemotherapeutic drugs and new targeted agents.

Huaier polysaccharide induces apoptosis in hepatocellular carcinoma cells through p38 MAPK

The underlying mechanism of the antitumor activity of Huaier polysaccharide (HP) remains to be explored. The present study aimed to investigate the inhibitory effect of HP on hepatocellular carcinoma (HCC) cells, and to explore the possible mechanisms of its anticancer effect. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while apoptotic nuclear changes were observed using Hoechst 33258 staining. The distribution of cell cycle and apoptosis were analyzed by flow cytometry, and western blotting was used to test the apoptotic pathways. Apoptosis and mitogen-activated protein kinase (MAPK) inhibitors were used to investigate the mechanism of apoptosis. HP triggered cell cycle arrest and apoptosis in HepG2 and Huh7 cells. Both the extrinsic and intrinsic apoptotic pathways were activated after HP treatment. Furthermore, HP enhanced the three major MAPK pathways (extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 MAPK) and inhibited the AKT/mechanistic target of rapamycin signaling pathway in HCC cells. Notably, the inactivation of p38 MAPK impaired the HP-induced cell death. HP exerted its antitumor effect on HCC cells through the regulation of the expression of the apoptosis-related proteins B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein and survivin. The present study provides evidence that HP induces apoptosis in HCC cells and demonstrated the role of p38 MAPK in HP-triggered cancer cell death.

Evaluation of antiangiogenic efficacy in advanced hepatocellular carcinoma: Biomarkers and functional imaging

Many years after therapeutic wilderness, sorafenib finally showed a clinical benefit in patients with advanced hepatocellular carcinoma. After the primary general enthusiasm worldwide, some disappointments emerged particularly since no new treatment could exceed or at least match sorafenib in this setting. Without these new drugs, research focused on optimizing care of patients treated with sorafenib. One challenging research approach deals with identifying prognostic and predictive biomarkers of sorafenib in this population. The task still seems difficult; however appropriate investigations could resolve this dilemma, as observed for some malignancies where other drugs were used.

Metastasis-associated in colon cancer 1 is an independent prognostic biomarker for survival in Klatskin tumor patients

Curative treatment of intrahepatic cholangiocarcinoma (ICC) and hilar cholangiocarcinoma (Klatskin tumors) is limited to surgical resection or orthotopic liver transplantation. However, not all patients benefit from a surgical approach and suffer from early tumor recurrence. Response to chemotherapy is generally poor and, until today, no targeted therapy could be established. Metastasis-associated in colon cancer 1 (MACC1) is a recently discovered regulator of the hepatocyte growth factor (HGF)/Met/mitogen-activated protein kinase pathway, which induces proliferation, migration, and invasion in cell culture, as well as metastasis in mice. MACC1 expression shows a significant correlation with Met expression in colon cancer tissue and is highly prognostic for occurrence of distant metastasis and survival in colon cancer patients. Thus, we aimed to measure the expression of MACC1, Met, and HGF messenger RNA in microdissected tumor tissue and corresponding normal liver tissue of 156 patients with Klatskin tumors (n = 76) and ICC (n = 80) using real-time quantitative reverse-transcriptase polymerase chain reaction. We used immunohistochemical staining to validate the results. MACC1 expression in tumor tissue of both tumor entities was significantly higher than in corresponding normal liver tissue (P < 0.001). Klatskin tumor patients with a history of tumor recurrence had significantly higher MACC1 expression than those without tumor recurrence (P = 0.005). Uni- und multivariate survival analysis showed that Klatskin tumor patients with high MACC1 had a significantly shorter overall (OS) and disease-free survival (DFS; P = 0.001 and P < 0.001, respectively). The multivariate analysis confirmed MACC1 to be an independent factor for overall survival in Klatskin tumor patients (hazard ratio: 2.777; 95% confidence interval: 1.389-5.555; P = 0.004).

CONCLUSION

Our study identified MACC1 as a highly prognostic biomarker for OS and DFS in Klatskin tumor patients. MACC1 expression could become an important diagnostic tool and might be a candidate for targeted therapy.

Optimal combination of antiangiogenic therapy for hepatocellular carcinoma

The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma (HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide.

Dendritic cells transfected with heat-shock protein 70 messenger RNA for patients with hepatitis C virus-related hepatocellular carcinoma: a phase 1 dose escalation clinical trial

BACKGROUND

We previously reported overexpression of heat-shock protein (HSP) 70 in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) using proteomic profiling and immunohistochemical staining (IHS). This suggested that HSP70 could be a molecular target for treatment of HCC.

METHODS

Twelve patients with HCV-related HCC were enrolled in a phase 1 clinical trial. Dendritic cells (DCs) transfected with HSP70 mRNA (HSP70-DCs) induced by electroporation were injected intradermally. Patients were treated three times every 3 weeks. The number of HSP70-DCs injected was 1 × 10(7) as the lowest dose, then 2 × 10(7) as the medium dose, and then 3 × 10(7) as the highest dose. Immunological analyses were performed.

FINDINGS

No adverse effects of grade III/IV, except one grade III liver abscess at the 3 × 10(7) dose, were observed. Thus, we added three more patients to confirm whether 3 × 10(7) is an appropriate dose. Eventually, we chose 3 × 10(7) as the recommended dose of DCs. Complete response (CR) without any recurrence occurred in two patients, stable disease in five, and progression of disease in five. The two patients with CR have had no recurrence for 44 and 33 months, respectively. IHS in one patient who underwent partial hepatectomy showed infiltration of CD8+ T cells and granzyme B in tumors, indicating that the dominant immune effector cells were cytotoxic T lymphocytes with tumor-killing activity.

INTERPRETATION

This study demonstrated that HSP70-DCs therapy is both safe and feasible in patients with HCV-related HCC. Further clinical trials should be considered.

Krüppel-like factor 4 modulates the migration and invasion of hepatoma cells by suppressing TIMP-1 and TIMP-2

Krüppel-like factor 4 (KLF4) plays important roles in development, stemness and tumorigenesis; however limited information is available on the detailed function of KLF4 in hepatocellular carcinoma (HCC). The objective of the present study was to examine the functional roles of KLF4 in the metastasis of HCC cells. KLF4 was overexpressed and knocked down by lentiviral transduction method in highly metastatic HCC cells. KLF4 overexpression in HCC cells led to inhibition of cell migration and invasion. These inhibitory effects were associated with the upregulation of tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 by KLF4. Treatment with recombinant TIMP-1 decreased the migratory ability of HCC cells. Moreover, myeloperoxidase (MPO)-TIMP-1/TIMP-2 inactivator counteracted the KLF4-induced inhibition of cell migration/invasion. Consistently, KLF4 knockdown in HCC cells downregulated TIMP-1 and TIMP-2 expression, consequently promoting cell migration and invasion. Furthermore, we found that KLF4 regulated E-cadherin and epithelial-mesenchymal transition (EMT)-related proteins such as snail, vimentin and Bmi1 to modulate the cell migration ability. These results together demonstrated for the first time that KLF4 plays an important role in inhibiting the aggressiveness of HCC cells via upregulation of TIMP-1 and TIMP-2.

Restoration of epigenetically silenced SULF1 expression by 5-aza-2-deoxycytidine sensitizes hepatocellular carcinoma cells to chemotherapy-induced apoptosis

Background

Hepatocellular carcinoma (HCC) is the second most frequent cause of cancer death worldwide. Sulfatase 1 (SULF1) functions as a tumor suppressor in HCC cell lines in vitro but also has an oncogenic effect in some HCCs in vivo.

Aim

The purpose of this study was to examine the mechanisms regulating SULF1 and its function in HCC.

Methods

First, SULF1 mRNA and protein expression were examined. Second, we examined SULF1 gene copy numbers in HCC cells. Third, we assessed whether DNA methylation or methylation and/or acetylation of histone marks on the promoter regulate SULF1 expression. Finally, we examined the effect of 5-aza-2′-deoxycytidine (5-Aza-dC) on sulfatase activity and drug-induced apoptosis.

Results

SULF1 mRNA was downregulated in nine of eleven HCC cell lines, but only in six of ten primary tumors. SULF1 mRNA correlated with protein expression. Gene copy number assessment by fluorescence in situ hybridization showed intact SULF1 alleles in low-SULF1-expressing cell lines. CpG island methylation in the SULF1 promoter and two downstream CpG islands did not show an inverse correlation between DNA methylation and SULF1 expression. However, chromatin immunoprecipitation showed that the SULF1 promoter acquires a silenced chromatin state in low-SULF1-expressing cells through an increase in di/trimethyl-K9H3 and trimethyl-K27H3 and a concomitant loss of activating acetyl K9, K14H3 marks. 5-Aza-dC restored SULF1 mRNA expression in SULF1-negative cell lines, with an associated increase in sulfatase activity and sensitization of HCC cells to cisplatin-induced apoptosis.

Conclusion

SULF1 gene silencing in HCC occurs through histone modifications on the SULF1 promoter. Restoration of SULF1 mRNA expression by 5-Aza-dC sensitized HCC cells to drug-induced apoptosis.

Farmer to pharmacist: curcumin as an anti-invasive and antimetastatic agent for the treatment of cancer

A huge number of compounds are widely distributed in nature and many of these possess medicinal/biological/pharmacological activity. Curcumin, a polyphenol derived from the rhizomes (underground stems) of Curcuma longa Linn (a member of the ginger family, commonly known as turmeric) is a culinary spice and therapeutic used in India for thousands of years to induce color and flavor in food as well as to treat a wide array of diseases. The origin of turmeric as spice and folklore medicine is so old that it is lost in legend. Curcumin has many beneficial pharmacological effects which includes, but are not limited with, antimicrobial, anti-inflammatory, antioxidant, antiviral, antiangiogenic, neurodegenerative diseases such as Alzheimer disease, and antidiabetic activities. Most importantly curcumin possesses immense antitumorigenic effect. It prevents tumor invasion and metastasis in a number of animal models, including models of lung, liver, stomach, colon, breast, esophageal cancer etc. Invasion and metastasis are considered as one of the hallmarks in cancer biology. The pertinent recent applications of curcumin as anti-invasive and antimetastatic agent in in vitro and in vivo and ex vivo studies as well as associated molecular mechanisms have been discussed in this review. Curcumin has also demonstrated the ability to improve patient outcomes in clinical trials.

Role of the ERK1/2 pathway in tumor chemoresistance and tumor therapy

Chemotherapy is one of the important methods for treatment in tumors. However, many tumor patients may experience tumor recurrence because of treatment failure due to chemoresistance. Although many signaling pathways could influence chemoresistance of tumor cells, the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway has gained significant attention because of its implications in signaling and which has crosstalk with other signaling pathways. Extensive studies conclude that ERK1/2 pathway is responding to chemoresistance in many kinds of malignant tumors. The aim of this review is to discuss on the role of ERK1/2 pathway in chemoresistance and therapy of tumors. A comprehensive understanding of ERK1/2 pathway in chemoresistance of tumors could provide novel avenues for treatment strategies of tumors.

Targeting the insulin-like growth factor pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Only 30%-40% of the patients with HCC are eligible for curative treatments, which include surgical resection as the first option, liver transplantation and percutaneous ablation. Unfortunately, there is a high frequency of tumor recurrence after surgical resection and most HCC seem resistant to conventional chemotherapy and radiotherapy. Sorafenib, a multi-tyrosine kinase inhibitor, is the only chemotherapeutic option for patients with advanced hepatocellular carcinoma. Patients treated with Sorafenib have a significant increase in overall survival of about three months. Therefore, there is an urgent need to develop alternative treatments. Due to its role in cell growth and development, the insulin-like growth factor system is commonly deregulated in many cancers. Indeed, the insulin-like growth factor (IGF) axis has recently emerged as a potential target for hepatocellular carcinoma treatment. To this aim, several inhibitors of the pathway have been developed such as monoclonal antibodies, small molecules, antisense oligonucleotides or small interfering RNAs. However recent studies suggest that, unlike most tumors, HCC development requires increased signaling through insulin growth factor II rather than insulin growth factor I. This may have great implications in the future treatment of HCC. This review summarizes the role of the IGF axis in liver carcinogenesis and the current status of the strategies designed to target the IGF-I signaling pathway for hepatocellular carcinoma treatment.

A phase II trial of bevacizumab plus temsirolimus in patients with advanced hepatocellular carcinoma

BACKGROUND

There is strong rationale to combine temsirolimus (TEM) with Bevacizumab (BEV) for patients with advanced HCC.

METHODS

A modified two-stage Simon phase II trial was performed with plans to advance to stage 2 if more than 2 patients had confirmed PR or >18 patients were progression free at 6 months out of 25 in stage 1. Toxicity, PFS and overall survival were secondary endpoints. Eligible pts had advanced HCC, Child Pugh A liver status and no prior systemic therapy involving the VEGF or m-TOR targeted agents. Patients were treated with temsirolimus 25 mg IV on Days 1, 8, 15, and 22 of a 28 day cycle and bevacizumab 10 mg/kg IV on Days 1 and 15 of the cycle.

RESULTS

Twenty-eight eligible patients were enrolled, 26 evaluable receiving a median of 6.5 cycles (range 1-18). Drug related toxicities were common including cytopenias, fatigue, mucositis, diarrhea and mild bleeds. Dose reductions or discontinuation of TEM were common. Accrual closed for presumed futility after interim analysis of the first 25 evaluable patients showed only one PR and 16/25 were progression-free at 6 months. However, the final data update in March 2013 demonstrated 4 confirmed PRs, a 5th unconfirmed PR and 16 /26 progression-free at 6 months. Median PFS and OS were 7 and 14 months respectively.

CONCLUSION

This first-line HCC trial evaluating the BEV/TEM doublet reports an ORR of 19 % and OS of 14 months which is favorable but requires further study at a more optimized dose and schedule.

Methylsulfonylmethane suppresses hepatic tumor development through activation of apoptosis

AIM: To investigate the effect of methylsulfonylmethane (MSM), recently reported to have anti-cancer effects, in liver cancer cells and transgenic mice.

METHODS: Three liver cancer cell lines, HepG2, Huh7-Mock and Huh7-H-ras^G12V, were used. Cell growth was measured by Cell Counting Kit-8 and soft agar assay. Western blot analysis was used to detect caspases, poly (ADP-ribose) polymerase (PARP), and B-cell lymphoma 2 (Bcl-2) expressions. For in vivo study, we administered MSM to H-ras^12V transgenic mice for 3 mo.

RESULTS: MSM decreased the growth of HepG2, Huh7-Mock and Huh7-H-ras^G12V cells in a dose-dependent manner. That was correlated with significantly increased apoptosis and reduced cell numbers in MSM treated cells. Cleaved caspase-8, cleaved caspase-3 and cleaved PARP were remarkably increased in the liver cancer cells treated with 500 mmol/L of MSM; however, Bcl-2 was slightly decreased in 500 mmol/L. Liver tumor development was greatly inhibited in the H-ras^12V transgenic mice treated with MSM, compared to control, by showing reduced tumor size and number. Cleaved PARP was significantly increased in non-tumor treated with MSM compared to control.

CONCLUSION: Liver injury was also significantly attenuated in the mice treated with MSM. Taken together, all the results suggest that MSM has anti-cancer effects through inducing apoptosis in liver cancer.

Signal transduction disturbance related to hepatocarcinogenesis in mouse by prolonged exposure to Nanjing drinking water

Toxicogenomic approaches were used to investigate the potential hepatocarcinogenic effects on mice by oral exposure to Nanjing drinking water (NJDW). Changes in the hepatic transcriptome of 3 weeks male mice (Mus musculus) were monitored and dissected after oral exposure to NJDW for 90 days. No preneoplastic and neoplastic lesions were observed in the hepatic tissue by the end of NJDW exposure. However, total of 746 genes were changed transcriptionally. Thirty-one percent of differentially expressed genes (DEGs) were associated with the functional categories of cell cycle regulation, adhesion, growth, apoptosis, and signal transduction, which are closely implicated in tumorigenesis and progression. Interrogation of Kyoto Encyclopedia of Genes and Genomes revealed that 43 DEGs were mapped to several crucial signaling pathways implicated in the pathogenesis of hepatocellular carcinoma (HCC). In signal transduction network constructed via Genes2Networks software, Egfr, Akt1, Atf2, Ctnnb1, Hras, Mapk1, Smad2, and Ccnd1 were hubs. Direct gene-disease relationships obtained from Comparative Toxicogenomics Database and scientific literatures revealed that the hubs have direct mechanism or biomarker relationships with hepatocellular preneoplastic lesions or hepatocarcinogenesis. Therefore, prolonged intake of NJDW without employing any indoor water treatment strategy might predispose mouse to HCC. Furthermore, Egfr, Akt1, Ctnnb1, Hras, Mapk1, Smad2, and Ccnd1 were identified as promising biomarkers of the potential combined hepatocarcinogenicity.

Recombinant human acid sphingomyelinase as an adjuvant to sorafenib treatment of experimental liver cancer

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the third leading cause of cancer death worldwide. The only approved systemic treatment for unresectable HCC is the oral kinase inhibitor, sorafenib. Recombinant human acid sphingomyelinase (rhASM), which hydrolyzes sphingomyelin to ceramide, is an orphan drug under development for the treatment of Type B Niemann-Pick disease (NPD). Due to the hepatotropic nature of rhASM and its ability to generate pro-apoptotic ceramide, this study evaluated the use of rhASM as an adjuvant treatment with sorafenib in experimental models of HCC.

METHODOLOGY/PRINCIPAL FINDINGS

In vitro, rhASM/sorafenib treatment reduced the viability of Huh7 liver cancer cells more than sorafenib. In vivo, using a subcutaneous Huh7 tumor model, mouse survival was increased and proliferation in the tumors decreased to a similar extent in both sorafenib and rhASM/sorafenib treatment groups. However, combined rhASM/sorafenib treatment significantly lowered tumor volume, increased tumor necrosis, and decreased tumor blood vessel density compared to sorafenib. These results were obtained despite poor delivery of rhASM to the tumors. A second (orthotopic) model of Huh7 tumors also was established, but modest ASM activity was similarly detected in these tumors compared to healthy mouse livers. Importantly, no chronic liver toxicity or weight loss was observed from rhASM therapy in either model.

CONCLUSIONS/SIGNIFICANCE

The rhASM/sorafenib combination exhibited a synergistic effect on reducing the tumor volume and blood vessel density in Huh7 xenografts, despite modest activity of rhASM in these tumors. No significant increases in survival were observed from the rhASM/sorafenib treatment. The poor delivery of rhASM to Huh7 tumors may be due, at least in part, to low expression of mannose receptors. The safety and efficacy of this approach, together with the novel findings regarding enzyme targeting, merits further investigation.

Design, synthesis, molecular modeling, and biological evaluation of sulfanilamide-imines derivatives as potential anticancer agents

A series of sulfanilamide Schiff base derivatives (1 to 15) have been designed as potential antitubulin agents depending on the chemical structures of combretastatine A-4 and isoquinoline sulfamate (antimitotic agents under investigation). The designed compounds were synthesized by microwave chemical synthesis, their purity was confirmed by melting point and HPLC and chemical structures were determined by FT-IR, UV, and ¹H and ¹³C-NMR spectroscopic techniques. The synthesized compounds have been docked in the colchicine binding site of β-tubulin using molecular modeling programs and the antitumor activities were screened on human breast and lung cancer cells by cell counting assay. Some tested compounds showed potent and selective activity against breast cancer (MCF-7) with IC₅₀ range of 90 to 166 μM. With regarding broad-spectrum activity, compounds 4, 8, and 13 have shown potent antitumor activity against human breast and human lung cells with IC₅₀ range of 96 to 140 μM. The obtained results suggest that the sulfanilamide Schiff base derivatives might potentially constitute an interesting novel class of anticancer agents, which deserve further studies.

The evolving landscape of therapeutic drug development for hepatocellular carcinoma

Currently, only one drug, sorafenib, is FDA approved for the treatment of advanced hepatocellular carcinoma (HCC), achieving modest objective response rates while still conferring an overall survival benefit. Unlike other solid tumors, no oncogenic addiction loops have been validated as clinically actionable targets in HCC. Outcomes of HCC could potentially be improved if critical molecular subclasses with distinct therapeutic vulnerabilities can be identified, biomarkers that predict recurrence or progression early can be determined and key epigenetic, genetic or microenvironment drivers that determine best response to a specific targeting treatment can be uncovered. Our group and others have examined the molecular heterogeneity of hepatocellular carcinoma. We have developed a panel of patient derived xenograft models to enable focused pre-clinical drug development of rationally designed therapies in specific molecular subgroups. We observed unique patterns, including synergies, of drug activity across our molecularly diverse HCC xenografts, pointing to specific therapeutic vulnerabilities for individual tumors. These efforts inform clinical trial designs and catalyze therapeutic development. It also argues for efficient strategic allocation of patients into appropriate enriched clinical trials. Here, we will discuss some of the recent important therapeutic studies in advanced HCC and also some of the potential strategies to optimize clinical therapeutic development moving forward.

Sorafenib suppresses growth and survival of hepatoma cells by accelerating degradation of enhancer of zeste homolog 2

Enhancer of zeste homolog 2 (EZH2) is a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes that regulate cancer cell growth and survival. It is overexpressed in hepatocellular carcinoma (HCC) with a clinical significance that remains obscure. Sorafenib, a multikinase inhibitor, has been used as a first-line therapeutic drug and shown clinical efficiency for advanced-stage HCC patients. In the present study, we found that sorafenib lowered the protein level of EZH2 through accelerating proteasome-mediated EZH2 degradation in hepatoma cells. Overexpression of EZH2 reversed sorafenib-induced cell growth arrest, cell cycle arrest, and cell apoptosis dependent on histone methyltransferase activity in hepatoma cells. More importantly, shRNA-mediated EZH2 knockdown or EZH2 inhibition with 3-deazaneplanocin A treatment promoted sorafenib-induced hepatoma cell growth arrest and apoptosis. Sorafenib altered the hepatoma epigenome by reducing EZH2 and H3K27 trimethylation. These results revealed a novel therapeutic mechanism underlying sorafenib treatment in suppressing hepatoma growth and survival by accelerating EZH2 degradation. Genetic deletion or pharmacological ablation of EZH2 made hepatoma cells more sensitive to sorafenib, which helps provide a strong framework for exploring innovative combined therapies for advanced-stage HCC patients.

Curcumin induces FasL-related apoptosis through p38 activation in human hepatocellular carcinoma Huh7 cells

AIM

The aim of this study is to explore the underlying molecular mechanism of curcumin-induced apoptosis in human hepatocellular carcinoma (HCC) Huh7 cells.

MAIN METHODS

Fas and FasL mRNA expression was analyzed by reverse transcription PCR. Western blot was applied to detect the protein expression of Bcl-2 family members, MAPK family members, c-Jun, c-Fos, ATF-2, caspase-3, PARP, TNF receptor family members and the respective ligands. Apoptotic cells were assayed with annexin V/PI double staining and flow cytometry.

KEY FINDINGS

Curcumin treatment resulted in a fast and significant increase of Fas and Fas ligand (FasL) along with activation of caspase-3 and cleavage of PARP in Huh7 cells. Inhibition of caspase-3 activity by the specific inhibitor Z-DEVD-FMK rescued Huh7 cells from curcumin-induced apoptosis. Neutralization of FasL significantly protected the cells from curcumin-induced caspase-3 activation and apoptosis in a dose-dependent manner. Moreover, p38 was rapidly activated in response to curcumin, and inactivation of p38 by pharmacologic inhibitor SB203580 dramatically suppressed curcumin-induced FasL expression and apoptosis.

SIGNIFICANCE

Our results demonstrated that curcumin induces apoptosis through p38-denpendent up-regulation of FasL in Huh7 cells.

Upregulation of protein tyrosine phosphatase type IVA member 3 (PTP4A3/PRL-3) is associated with tumor differentiation and a poor prognosis in human hepatocellular carcinoma

Background

Protein tyrosine phosphatase type IVA member 3 (PTP4A3/PRL-3), a metastasis-associated phosphatase, plays multiple roles in cancer metastasis. We investigated PTP4A3/PRL-3 expression and its correlation with the clinicopathological features and prognosis in hepatocellular carcinoma (HCC).

Methods

Gene expression profiles of PTP4A3/PRL-3 were obtained in poorly differentiated HCC tissues. The results were validated independently by TaqMan gene expression assays and immunohistochemical analysis.

Results

According to the microarray profiles, PTP4A3/PRL-3 was upregulated in patients with poorly differentiated disease compared to patients with well-differentiated disease with hepatic backgrounds associated with hepatitis B or C. Validation analysis showed that the PTP4A3/PRL-3 mRNA and protein levels were significantly associated with poor differentiation (P < 0.0001), high serum α-fetoprotein (P < 0.01), high serum protein induced by vitamin K absence/antagonist-II (PIVKA-II), and hepatic vascular invasion (P < 0.05). The expression of PTP4A3/PRL-3 protein was also correlated with advanced cancer stages (P < 0.01); this resulted in a significantly poorer prognosis in both overall (P = 0.0024) and recurrence-free survival (P = 0.0227). According Cox regression univariate analysis, the positive expression of PTP4A3/PRL-3 was a poor risk prognostic factor (OS, P = 0.0031; recurrence-free survival, P = 0.0245). Cox regression multivariate analysis indicated that high PTP4A3/PRL-3 expression was an independent, unfavorable prognostic factor for overall survival (hazard ratio 0.542; P = 0.048).

Conclusions

PTP4A3/PRL-3 might be closely associated with HCC progression, invasion, and metastasis. Its high expression had a negative impact on the prognosis of HCC patients. This strongly suggests that PTP4A3/PRL-3 should be considered as a prognostic factor. Further analysis should be pursued to evaluate it as a novel prognostic target.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-012-2395-2) contains supplementary material, which is available to authorized users.

Potent antitumoral effects of targeted promoter-driven oncolytic adenovirus armed with Dm-dNK for breast cancer in vitro and in vivo

Currently, no curative treatments are available for late-stage metastatic or recurrent breast cancer, because the cancer tolerates both chemotherapy and endocrine therapy. In this study, we investigated the feasibility of a dual-regulated oncolytic adenoviral vector with a novel suicide gene to treat breast cancer. Following targeted gene virotherapy of conditionally replicating adenoviruses (CRAds), the novel suicide gene of multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster (Dm-DNK) was inserted into the double-regulated oncolytic adenovirus SG500 to ensure more safety and enhanced antitumor activity against breast cancer both in vitro and in vivo. Selective replication, cell-killing efficacy, and cytotoxicity, combined with chemotherapeutics were investigated in several breast cell lines (MDA-MB-231 and MCF-7), normal cells (WI-38 and MRC-5), and human (MDA-MB-231) tumor models in vivo. The double-regulated SG500-dNK had high cell-killing activity in breast cancer. Replication was similar to wild-type in breast cells and was attenuated in normal cells. SG500-dNK combined with the chemotherapeutics (E)-5-(2-bromovinyl)-2'-deoxyuridine (Bvdu) and 2',2'-difluoro-deoxycytidine (dFdC) resulted in synergistically enhanced cell killing and greatly improved antitumor efficacy in vitro or in breast xenografts in vivo. These data suggest that the novel oncolytic variant SG500-dNK is a promising candidate for targeting breast tumors specifically when combined with chemotherapeutics.

Phase 2 trial of linifanib (ABT-869) in patients with unresectable or metastatic hepatocellular carcinoma

BACKGROUND

The efficacy and safety of linifanib (ABT-869), a selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor tyrosine kinases, were assessed in this phase 2, single-arm, open-label, multicenter trial.

METHODS

Eligible patients had unresectable or metastatic hepatocellular carcinoma and had received ≤ 1 prior systemic therapy. Patients received oral linifanib at a fasting dose of 0.25 mg/kg,. The primary endpoint was the progression-free rate at 16 weeks. Tumor response was assessed every 8 weeks. Secondary endpoints included the time to disease progression, overall survival, and objective response rate. Safety was also assessed.

RESULTS

Of the 44 patients enrolled, the majority were Asian (89%), had received no prior systemic therapy (82%), had Child-Pugh class A hepatic function (86%), and had hepatitis B virus infection (61%). The estimated progression-free rate at 16 weeks was 31.8% (34.2% for patients with Child-Pugh class A hepatic function), the estimated objective response rate was 9.1% (10.5% for patients with Child-Pugh class A hepatic function), the median time to disease progression was 3.7 months (3.7 months for patients with Child-Pugh class A hepatic function), and the median overall survival was 9.7 months (10.4 months for patients with Child-Pugh class A hepatic function). The most common linifanib-related adverse events were diarrhea (55%) and fatigue (52%). The most common linifanib-related grade 3/4 adverse events were hypertension (25%) and fatigue (14%). Serum levels of biomarkers cancer antigen (CA) 125, cytokeratin fragment (CYFRA)21.1, and protein induced by vitamin K absence or antagonist II (PIVKA) demonstrated potential as prognostic indicators of patient response or outcome.

CONCLUSIONS

Single-agent linifanib was found to be clinically active in patients with advanced hepatocellular carcinoma, with an acceptable safety profile.

Clinical course of sorafenib treatment in patients with hepatocellular carcinoma

OBJECTIVE

Sorafenib has been shown to improve survival of patients with advanced hepatocellular carcinoma (HCC). However, its tolerance in clinical practice has not been well evaluated, and whether sorafenib should be continued in cases of tumor progression or intolerance has not been established. The authors retrospectively assessed sorafenib tolerability, and evaluated the clinical course in patients who showed progression during sorafenib treatment.

MATERIAL AND METHODS

Between March 2008 and July 2010, 80 patients with advanced HCC were treated with sorafenib.

RESULTS

With a median of 78.5 days of treatment, 15% discontinued sorafenib due to adverse events. The duration was significantly longer in patients with Child-Pugh class A liver function (233 ± 240 days) than in those with Child-Pugh class B (100 ± 136 days; p = 0.006). The overall progression rate was 53% (43/80), with a median time to progression of 105 days (95% confidence interval, 59-150 days). After progression, 14 patients received conservative care only (group 1), 14 continued sorafenib monotherapy (group 2), 6 changed to treatment without sorafenib (group 3) and 9 underwent additional treatment with concomitant sorafenib (group 4). Survival after progression was significantly better in groups 2, 3 and 4 than in group 1 (p = 0.001).

CONCLUSIONS

Sorafenib was tolerable for most patients in clinical practice and may be continued in patients who show progression during sorafenib therapy. However, it was less well tolerated in patients with Child-Pugh class B liver function and should be used with caution in these patients.

Molecular mechanism inhibiting human hepatocarcinoma cell invasion by 6-shogaol and 6-gingerol

SCOPE

We previously demonstrated that 6-shogaol and 6-gingerol, two active compounds in ginger (Zingiber officinale), possess antiinvasive activity against highly metastatic hepatoma cells. The aims of this study were to evaluate the inhibitory effect and molecular mechanism underlying the transcription and translation of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (uPA) in Hep3B cells as well as the antiangiogenic activity of 6-gingerol and 6-shogaol.

METHODS AND RESULTS

By gelatin zymography and luciferase reporter gene assays, we found that 6-gingerol and 6-shogaol regulate MMP-2/-9 transcription. Moreover, 6-gingerol directly decreased expression of uPA, but the 6-shogaol-mediated decrease in uPA was accompanied by up-regulation of plasminogen activator inhibitor (PAI)-1. 6-Gingerol and 6-shogaol concentrations of ≥ 10 μM and ≥ 2.5 μM, respectively, significantly inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) and PI3K/Akt signaling, the activation of NF-κB, and the translocation of NF-κB and STAT3. Incubation of 6-gingerol or 6-shogaol with human umbilical vein endothelial cells or rat aortas significantly attenuated tube formation.

CONCLUSION

6-Shogaol and 6-gingerol effectively inhibit invasion and metastasis of hepatocellular carcinoma through diverse molecular mechanisms, including inhibition of the MAPK and PI3k/Akt pathways and NF-κB and STAT3 activities to suppress expression of MMP-2/-9 and uPA and block angiogenesis.

Aberrant methylation and downregulation of sall3 in human hepatocellular carcinoma

AIM: To investigated whether sall3 transcription was regulated by promoter CpG island hypermethylation in hepatocellular carcinoma (HCC).

METHODS: The cell lines Huh7, HepG2, SK-HEP1, SMMC7721, Bel7402, QGY7703 and a cohort of 38 HCC tissue specimens and corresponding nontumorous tissues were subjected to analysis for sall3 promoter CpG island methylation and mRNA transcription. sall3 promoter CpG island methylation levels were determined using the MassARRAY platform and mRNA transcription levels of the gene were detected by quantitative real-time polymerase chain reaction.

RESULTS: The levels of sall3 mRNA were decreased by more than twofold in 33 of 38 tumor tissues compared to adjacent noncancerous tissues. Among these 33 tumor tissues with lower levels of sall3 mRNA, 24 showed higher levels of methylation. Based on these results, we hypothesized that the decrease in sall3 mRNA transcription level was likely due to promoter CpG island hypermethylation. Changes in sall3 mRNA transcription and promoter CpG island methylation were determined in the above six cell lines after treatment with 0, 0.1, 0.5 and 2.5 μmol 5-aza-2-deoxycytidine, a demethylating agent. Promoter CpG island methylation levels decreased in a dose-dependent manner in all six cell lines, while the mRNA transcription level increased dose-dependently in Huh7, HepG2, SK-HEP1 and SMMC7721 cells and irregularly in Bel7402 and QGY7703 cells.

CONCLUSION: These results indicated that promoter CpG island hypermethylation contributes to the downregulation of sall3 mRNA transcription in HCC.

The Nedd8-activating enzyme inhibitor MLN4924 induces autophagy and apoptosis to suppress liver cancer cell growth

Posttranslational neddylation of cullins in the Cullin-Ring E3 ligase (CRL) complexes is needed for proteolytic degradation of CRL substrates, whose accumulation induces cell-cycle arrest, apoptosis, and senescence. The Nedd8-activating enzyme (NAE) is critical for neddylation of CRL complexes and their growth-promoting function. Recently, the anticancer small molecule MLN4924 currently in phase I trials was determined to be an inhibitor of NAE that blocks cullin neddylation and inactivates CRL, triggering an accumulation of CRL substrates that trigger cell-cycle arrest, apoptosis, and senescence in cancer cells. Here, we report that MLN4924 also triggers autophagy in response to CRL inactivation and that this effect is important for the ability of MLN4924 to suppress the outgrowth of liver cancer cells in vitro and in vivo. MLN4924-induced autophagy was attributed partially to inhibition of mTOR activity, due to accumulation of the mTOR inhibitory protein Deptor, as well as to induction of reactive oxygen species stress. Inhibiting autophagy enhanced MLN4924-induced apoptosis, suggesting that autophagy is a survival signal triggered in response to CRL inactivation. In a xenograft model of human liver cancer, MLN4924 was well-tolerated and displayed a significant antitumor effect characterized by CRL inactivation and induction of autophagy and apoptosis in liver cancer cells. Together, our findings support the clinical investigation of MLN4924 for liver cancer treatment and provide a preclinical proof-of-concept for combination therapy with an autophagy inhibitor to enhance therapeutic efficacy.

Resistance to paclitaxel in hepatoma cells is related to static JNK activation and prohibition into entry of mitosis

Hepatocellular carcinoma (HCC) generally shows chemoresistant features to anticancer agents. Paclitaxel has been clinically used in the treatment of various cancers. However, effect of paclitaxel on HCC has not been adequately addressed. Here, we found two categories of hepatoma cells in response to paclitaxel. Paclitaxel effectively decreased the cell viability of SNU475, Hep3B, and SNU387 HCC cells and Chang liver cells (death prone). In contrast, the other five hepatoma cell lines (SNU449, SNU398, SUN368, SNU354, and HepG2 cells) were resistant to paclitaxel (death reluctant). In response to paclitaxel, Bcl-2 was highly phosphorylated in death-prone cells, whereas much less Bcl-2 was phosphorylated in death-reluctant cells. Cotreatment with SP600125, an inhibitor JNK, significantly reduced the phosphorylated Bcl-2 in death-prone cells and caused a significant reduction in cell death. The reduced cell death was due to prohibition into mitotic entry as evidenced by low cyclin B(1)/Cdk1 kinase activity. In death-reluctant cells, inbuild-phospho-JNK levels were high but no longer activated in response to paclitaxel. We found that paclitaxel combined with caffeine or UCN-01, inhibitors of G(2) DNA damage checkpoint, was able to partially overcome resistance to paclitaxel in these cells. Thus our data provide the molecular basis of paclitaxel resistance in hepatoma cells, and appropriate combination therapy may increase treatment efficacy.