The management of hepatocellular carcinoma. Current expert opinion and recommendations derived from the 10th World Congress on Gastrointestinal Cancer, Barcelona, 2008

Dovitinib sensitizes hepatocellular carcinoma cells to TRAIL and tigatuzumab, a novel anti-DR5 antibody, through SHP-1-dependent inhibition of STAT3

Hepatocellular carcinoma (HCC) often displays resistance to recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Dovitinib, a multiple tyrosine kinase inhibitor, and tigatuzumab, a novel humanized anti-human death receptor 5 (DR5) agonistic antibody, are both under clinical investigations in HCC. Here, we report that dovitinib sensitizes resistant HCC cells to TRAIL- and tigatuzumab-induced apoptosis through inhibition of signal transducers and activators of transcription 3 (STAT3). Our data indicate that HCC cells showed significant resistance to TRAIL- and tigatuzumab-induced apoptosis. The combination of dovitinib and tigatuzumab restored the sensitivity of HCC cells to TRAIL- and tigatuzumab-induced apoptosis. Dovitinib down-regulated phospho-STAT3 (Tyr705) (p-STAT3) and subsequently reduced the protein levels of STAT3-regulated proteins, Mcl-1, survivin and cylcin D1, in TRAIL-treated HCC cells. Knockdown of STAT3 by RNA-interference overcame apoptotic resistance to TRAIL in HCC cells, and ectopic expression of STAT3 in HCC cells abolished the sensitizing effect of dovitinib on TRAIL-induced apoptosis. Importantly, silencing SHP-1 by RNA-interference reduced the effects of dovitinib and TRAIL on p-STAT3 and apoptosis, whereas co-treatment of TRAIL and dovitinib increased the activity of SHP-1. Moreover, in vivo the combination of tigatuzumab and dovitinib inhibited Huh-7 xenograft tumor growth. In conclusion, dovitinib sensitizes resistant HCC cells to TRAIL- and tigatuzumab-induced apoptosis through a novel machinery: SHP-1 dependent STAT3 inhibition.

Liver, gastrointestinal, and cardiac toxicity in intermediate hepatocellular carcinoma treated with PRECISION TACE with drug-eluting beads: results from the PRECISION V randomized trial

OBJECTIVE

The purpose of our study was to evaluate hepatic, gastrointestinal, and cardiac toxicity after PRECISION transarterial chemoembolization (TACE) with drug-eluting beads (DEB) versus conventional TACE with doxorubicin in the treatment of intermediate-stage hepatocellular carcinoma (HCC).

SUBJECTS AND METHODS

Two hundred twelve patients (185 men and 27 women; mean age, 67 years) were randomized to TACE with DEB or conventional TACE. The majority of patients (67% in both groups) presented in a more advanced stage. Safety was measured by rate of adverse events (Southwest Oncology Group criteria) and changes in laboratory parameters. Cardiotoxicity was assessed with left ventricular ejection fraction (LVEF) mainly on MRI or echocardiography.

RESULTS

The mean maximum postchemoembolization alanine transaminase increase in the DEB group was 50% less than in the conventional TACE group (p < 0.001) and 41% less in respect to aspartate transaminase (p < 0.001). End-of-study values returned to approximately baseline levels but with greater variability in conventional TACE patients. Treatment-emergent adverse events in the hepatobiliary system organ class occurred in 16.1% of DEB group patients compared with 25% of conventional TACE patients. There were fewer liver toxicity events in the DEB group. There was a small but statistically significant difference in mean change from baseline in LVEF between the two groups of 4 percentage points for the conventional TACE group (95% CI, 0.71-7.3; p = 0.018).

CONCLUSION

PRECISION TACE with DEB loaded with doxorubicin offers a safe therapy option for intermediate-stage HCC, even in patients with more advanced liver disease.

Hepatic arterial infusion of doxorubicin-loaded microsphere for treatment of hepatocellular cancer: a multi-institutional registry

BACKGROUND

Hepatic intra-arterial therapy for unresectable hepatocellular cancer (HCC) has been shown to improve overall survival, but can have significant toxicity. A recent prospective randomized controlled trial demonstrated superior response rates and significantly less morbidity and doxorubicin-related adverse events with drug-eluting beads with doxorubicin (DEBDOX) compared with conventional chemoembolization. The aim of this study was to confirm the efficacy of DEBDOX for the treatment of unresectable HCC.

STUDY DESIGN

This open-label, multicenter, multinational single-arm study included 118 intermediate-staged HCC patients who were not candidates for transplantation or resection. Patients received DEBDOX at each treatment. Complications and response rates to treatment were analyzed.

RESULTS

There were 118 patients who received a total of 186 DEBDOX treatments with a median total treatment dose of 75 mg (range 38 to 150 mg), and median overall total hepatic exposure of 150 mg (range 150 to 600 mg). Five lesions were targeted, with a median size of 5.3 cm (range 1.0 to 16.9 cm). Severe adverse events related to liver dysfunction were seen after 4% of treatments. Overall survival was a median of 14.2 months (range 5 to 30 months), with progression-free survival of 13 months and hepatic-specific progression-free survival of 16 months. Okuda class less than 1 at time of treatment, reduction of alpha-fetoprotein of 1,000 ng/mL at the first post-treatment evaluation, delivery of more than 200 mg doxorubicin, and less than 25% liver involvement were all predictors of favorable overall survival assessed by multivariable analyses.

CONCLUSIONS

Hepatic intra-arterial injection of DEBDOX is safe and effective in the treatment of HCC, as demonstrated by a minimal complication rate and robust and durable tumor response.

HS-116, a novel phosphatidylinositol 3-kinase inhibitor induces apoptosis and suppresses angiogenesis of hepatocellular carcinoma through inhibition of the PI3K/AKT/mTOR pathway

The phosphatidylinositol 3-kinase (PI3K) pathway plays a central role in cell proliferation and survival of human cancers. As PI3K is active in many cancer patients, resulting in cancer development and progression, we developed an azaindole derivative, HS-116 as a novel PI3K inhibitor. This study aimed to clarify the anticancer effect of HS-116 in human hepatocellular carcinoma (HCC). To identify the effect of HS-116 on HCC cells, a PI3K assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blotting were conducted. IC(50) of HS-116 for PI3Kα was 31nM, and it effectively suppressed the phosphorylation of PI3K downstream factors such as AKT, mTOR, p70S6K, and 4EBP1. Also, HS-116 induced apoptosis by increasing the proportion of sub-G1 apoptotic cells from 1.8% to 35% and increasing the expressions of Bax, cleaved-caspase-3, and cleaved-PARP as well as decreasing the expression of Bcl-2. In addition, chromatin condensation and apoptotic bodies were detected in HS-116-treated HCC cells. Furthermore, HS-116 decreased protein expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), and inhibited the tube formation and migration of human umbilical vein endothelial cells (HUVECs). In vivo, the ability of mice to vascularize subcutaneously implanted Matrigel plugs was diminished when the mice were treated with HS-116. These results show that HS-116 inhibits the PI3K/AKT/mTOR pathway via apoptosis and anti-angiogenesis in HCC cells. We suggest that HS-116 may be an effective novel therapeutic candidate against HCC.

Cluster analysis of indicators of liver functional and preoperative low branched-chain amino acid tyrosine ration indicate a high risk of early recurrence in analysis of 165 hepatocellular carcinoma patients after initial hepatectomy

BACKGROUND

Cluster analysis is used for dividing many prognostic indicators, including liver function, tumor progression, and operative variables, into specific clusters. The albumin (ALB), hepatocyte growth factor (HGF), and branched chain amino-acid to tyrosine ratio (BTR) may represent the severity of liver disease and function of the hepatic reserve. We developed the ALB-BTR and HGF-BTR classifications depending on each level to find specific unique subgroups. Our aim was to identify specific subgroups destined for favorable and poor prognoses after initial hepatectomy.

METHODS

Between 2002 and 2008, 165 patients were analyzed retrospectively. Liver function indicators, including BTR, tumor-related factors, and operative variables, were evaluated by cluster analysis with Ward's criterion. The ALB-BTR classification was divided into 4 groups depending on ALB (cutoff value, 4.0 g/dL) and BTR (cutoff value, 6.0). The HGF-BTR classification was also divided into 4 groups depending on HGF (cutoff value, 0.35 ng/mL) and BTR (cutoff value, 6.0). The prognoses of the subgroups were compared by the log-rank test.

RESULTS

Cluster analysis divided multiple indicators into 5 different clusters. In each cluster, we further analyzed subgroups using the ALB-BTR and HGF-BTR classification. Mean recurrence-free survival times in ALB-GI (19.1 ± 2.4 months) and HGF-GIII (29.4 ± 3.8 months) were less than their mean overall survival times.

CONCLUSION

Cluster analysis is useful to find similar and different indicators. Even though liver function was well preserved, low BTR could identify early recurrence in hepatocellular carcinoma patients after resection.

Secreted ERBB3 isoforms are serum markers for early hepatoma in patients with chronic hepatitis and cirrhosis

Most hepatocellular carcinoma (HCC) is generated from chronic hepatitis and cirrhosis. To discover new markers for early HCC in patients with chronic hepatitis and cirrhosis, we initiated our search in the interstitial fluid of tumor (TIF) via differential gel electrophoresis and antibody arrays and identified secreted ERBB3 isoforms (sERBB3). The performance of serum sERBB3 in diagnosis of HCC was analyzed using receiver operating characteristic curves (ROC). The serum sERBB3 level was significantly higher in HCC than in cirrhosis (p < 0.001) and chronic hepatitis (p < 0.001). The accuracy of serum sERBB3 in detection of HCC was further validated in two independent sets of patients. In discrimination of early HCC from chronic hepatitis or cirrhosis, serum sERBB3 had a better performance than alpha-fetoprotein (AFP) (areas under ROC [AUC]: sERBB3 vs AFP = 93.1 vs 81.0% from chronic hepatitis and 70.9 vs 62.7% from cirrhosis). Combination of sERBB3 and AFP further improved the accuracy in detection of early HCC from chronic hepatitis (AUC = 97.1%) or cirrhosis (AUC = 77.5%). Higher serum sERBB3 levels were associated with portal-vein invasion and extrahepatic metastasis of HCC (p = 0.017). Therefore, sERBB3 are serum markers for early HCC in patients with chronic hepatitis and cirrhosis.

Thermo-targeted drug delivery of geldanamycin to hyperthermic tumor margins with diblock elastin-based biopolymers

The tumor margins are the barrier to hepatocellular carcinoma (HCC) eradication for tumors>3 cm. Indeed, inadequately treated tumor margins commonly result in local and regional HCC recurrence with increased size and mass. Tumor recurrence is a common problem with chemotherapy, radiotherapy, thermal ablation, and/or surgical resection, by the inability to properly treat the tumor core and the tumor margins. Here we present novel thermosensitive biopolymer-drug conjugates for thermo-targeted chemotherapy at hyperthermic isotherms produced by focal, locoregional thermal ablation. The chemotherapeutic target is heat shock protein 90 (HSP90), a key molecular chaperone of several, and potent pro-oncogenic pathways including Akt, Raf-1, and mutated p53 that is upregulated in HCC. To inhibit HSP90, we have chosen geldanamycin (GA), a potent HSP90 inhibitor. GA has gained significant attention for its low IC50 ~ 1 nM and inhibition of Akt and Raf-1, amongst other critical pro-oncogenic pathways. Despite such evidence, clinical trials of GA have not shown promise due to off-target toxicity and poor formulation design. Here, we propose using diblock elastin-based biopolymers as a Ringsdorf macromolecular GA solubilizer--a new generation containing functional poly(Asp)/(Glu) blocks for facile drug conjugation and an ELP block for thermo-targeting of hyperthermic ablative margins. GA release is controlled by pH-sensitive, covalent hydrazone bonds with the biopolymer backbone to avoid systemic toxicity and off-target effects. The resultant biopolymer-conjugates form stable nanoconstructs and display tunable, acute phase transitions at high temperatures. Drug release kinetics are favorable with or without the presence of serum. Thermo-targeted chemotherapy and synchronous thermal ablation provide a unique opportunity for simultaneous destruction of the HCC ablative margins and tumor core for focal, locoregional control of HCC.

Bortezomib sensitizes HCC cells to CS-1008, an antihuman death receptor 5 antibody, through the inhibition of CIP2A

Previously, we have shown that bortezomib overcame TRAIL resistance in hepatocellular carcinoma (HCC) cells via the inhibition of Akt. Here, we report that bortezomib sensitizes these TRAIL-resistant cells, including Huh-7, Hep3B, and Sk-Hep1, to CS-1008, a humanized agonistic antihuman death receptor 5 antibody. Cancerous inhibitor of protein phosphatase 2A (CIP2A) mediated the sensitizing effect of bortezomib to CS-1008 through inhibiting protein phosphatase 2A (PP2A) activity. Combination treatment of bortezomib and CS-1008 downregulated CIP2A in a concentration- and time-dependent manner, and increased PP2A activity in HCC cells. Importantly, ectopic expression of CIP2A decreased Akt-related PP2A activity, indicating that CIP2A negatively regulates Akt-related PP2A activity in HCC cells. Moreover, silencing CIP2A by short interfering RNA enhanced CS-1008-induced apoptosis in HCC cells and ectopic expression of CIP2A in HCC cells abolished CS-1008-induced apoptosis, indicating that CIP2A plays an important role in the sensitizing effect of bortezomib to CS-1008. Finally, our in vivo data showed that CS-1008 and bortezomib combination treatment decreased tumor growth significantly. In conclusion, bortezomib sensitized HCC cells to CS-1008 through the inhibition of CIP2A.

Intraoperative ultrasound score to predict recurrent hepatocellular carcinoma after radical treatments

Despite the high complete necrosis rate of radio-frequency ablation (RFA) or the complete removal following curative hepatic resection (HR), recurrent hepatocellular carcinoma (HCC) remains a significant problem. The aim of the study is to identify some intraoperative ultrasound (IOUS) patterns, predicting intrahepatic recurrences. From January 1997 to July 2009, 410 patients with HCC were treated (162 HR and 248 RFA through a surgical access). All patients were submitted to IOUS examination: 148 IOUS were performed during the laparotomic access while 262 IOUS were performed during the laparoscopic access. Primary HCC was classified according to diameter, HCC pattern (nodular or infiltrative), echogenicity (hyper- or hypo-echoic), echotexture (homogeneous or inhomogeneous), capsular invasion, mosaic pattern, nodule in nodule aspect and infiltration of portal vessels. Number of HCC nodules was also considered. Multivariate analysis (Cox model) was performed to determine features associated with recurrent HCC using IOUS patterns that independently predicted recurrent HCC, a IOUS score was developed. The patients were followed for 3-127 months, (median follow-up: 21.5 months). In 220 patients (54%), intrahepatic recurrences occurred. In 155 patients (38%), distant intrahepatic recurrences arose in different segments at the primary tumor site. In 65 HCC cases (16%), local recurrences were found. At multivariate analysis, multiple nodules, HCC diameter (>20 mm), HCC pattern (infiltrative), hyperechoic nodule and portal infiltration were statistically significant for risk factor of intrahepatic recurrences. Therefore, a IOUS scoring system was calculated on the basis of multivariate analysis and identified three risk categories of patients: in group 1 recurrences occurred in 37%, group 2 in 46% and group 3 in 66% (p = 0.0001). IOUS is an accurate staging tool during "surgical" procedures. This study showed an added value of IOUS: it permitted to identify ultrasound patterns, which can predict the risk of HCC recurrences. The calculated IOUS score permits to intraoperatively evaluate the actual surgical choice and to program the best treatment strategies during the follow-up period.

Development and validation of a new prognostic score of death for patients with hepatocellular carcinoma in palliative setting

BACKGROUND & AIMS

Patients with hepatocellular carcinoma (HCC) in a palliative setting have a poor prognosis despite recent therapeutic progress. Several prognostic scores, such as the BCLC and the CLIP, have been shown to be useful in helping select treatment options ranging from transplantation to palliative care. However, the discriminatory ability of these scores is inadequate in palliative settings, which concern about 70% of HCC patients. In this paper, we propose and validate a new prognostic score for patients in the palliative setting.

METHODS

The prognostic score was developed on a set of 416 patients from a negative randomized clinical trial conducted by the Fédération Francophone de Cancers Digestifs. It was then subsequently validated on a second set of 271 patients from another negative trial. Backward selection was used to identify independent baseline characteristics. Measures of discrimination and predictive values were computed to assess the quality of the developed score. Comparisons with the BCLC and the CLIP - with and without the WHO performance status (PS) score - were performed.

RESULTS

Tumour morphology, portal vein obstruction, metastasis, ascites, jaundice, alpha-foetoprotein, and serum alkaline phosphatase were included in the final score. From the training dataset, three groups of increasing risk were defined, and these were associated with hazard ratios (HR) of 2.13 and HR = 5.72. Similar results were obtained on the validation dataset. This score provides a better discriminatory ability than BCLC and CLIP in this setting. Unfortunately, absolute performances for these scores remain poor.

CONCLUSIONS

The new prognostic score and CLIP + PS are recommended in palliative settings. However, new prognostic variables are necessary.

Acetaldehyde adducts in alcoholic liver disease

Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD), with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC). Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2-15%) versus cirrhosis (15-20%) is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular system and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.

Tumor initiation and progression in hepatocellular carcinoma: risk factors, classification, and therapeutic targets

Hepatocellular carcinoma (HCC) is a major health problem worldwide responsible for 500 000 deaths annually. A number of risk factors are associated with either the induction of the disease or its progression; these include infection with hepatitis B or C virus, alcohol consumption, non-alcoholic steatohepatitis and certain congenital disorders. In around 80% of the cases, HCC is associated with cirrhosis or advanced fibrosis and with inflammation and oxidative stress. In this review we focus firstly on the different risk factors for HCC and summarize the mechanisms by which each is considered to contribute to HCC. In the second part we look at the molecular processes involved in cancer progression. HCC development is recognized as a multistep process that normally develops over many years. Over this period several mutations accumulate in the cell and that stimulate malign transformation, growth, and metastatic behavior. Over the recent years it has become evident that not only the tumor cell itself but also the tumor microenviroment plays a major role in the development of a tumor. There is a direct link between the role of inflammation and cirrhosis with this microenviroment. Both in vitro and in vivo it has been shown that tumor formation and metastatic properties are linked to epithelial-mesenchymal transition (EMT), a process by which facillitates the tumor cell's attempts to migrate to a more favourable microenviroment. Several groups have analyzed the gene expression in HCC and its surrounding tissue by microarray and this has resulted in the molecular classification into a distinct number of classes. Here we also found a role for hypoxia induced gene expression leading to a clinically more aggressive gene expression in HCC. Molecular analysis also helped to identify important cellular pathways and possible therapeutic targets. The first molecule that in this way has shown clinical application for liver cancer is the multikinase inhibitor sorafenib, others are currently in different stages of clinical studies like the mTOR inhibitor everolimus.

Sorafenib overcomes TRAIL resistance of hepatocellular carcinoma cells through the inhibition of STAT3

PURPOSE

Recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising antitumor agent. However, many hepatocellular carcinoma (HCC) cells show resistance to TRAIL-induced apoptosis. Here, we report that sorafenib improves the antitumor effect of TRAIL-related agents in resistant HCC.

EXPERIMENTAL DESIGN

HCC cell lines (PLC5, Huh-7, Hep3B, and Sk-Hep1) were treated with sorafenib and/or TRAIL-related agents (TRAIL or LBY135) and analyzed in terms of apoptosis and signal transduction. In vivo efficacy was determined in nude mice with PLC5 xenografts.

RESULTS

Sorafenib, the only approved drug for HCC, sensitizes resistant HCC cells to an agonistic DR5 antibody (LBY135) and TRAIL-induced apoptosis in TRAIL-resistant HCC cells. We found that STAT3 played a significant role in mediating TRAIL sensitization. Our data showed that sorafenib downregulated phospho-STAT3 (pSTAT3) and subsequently reduced the expression levels of STAT3-related proteins (Mcl-1, survivin, and cyclin D1) in a dose- and time-dependent manner in TRAIL-treated HCC cells. Knockdown of STAT3 by RNA interference overcame apoptotic resistance to TRAIL in HCC cells, and ectopic expression of STAT3 in HCC cells abolished the TRAIL-sensitizing effect of sorafenib. Moreover, SHP-1 inhibitor reversed downregulation of pSTAT3 and apoptosis induced by sorafenib, and silencing of SHP-1 by RNA interference abolished the effects of sorafenib on pSTAT3. Notably, sorafenib increased SHP-1 activity in PLC5 cells. Finally, sorafenib plus LBY135 significantly suppressed PLC5 xenograft tumor growth.

CONCLUSIONS

Sorafenib sensitizes resistant HCC cells to TRAIL-induced apoptosis at clinical achievable concentrations, and this effect is mediated via the inhibition of STAT3.

Hepatic stellate cells in inflammation-fibrosis-carcinoma axis

Almost 80% of hepatocellular carcinoma (HCC) cases are associated with chronic hepatitis and cirrhosis resulting from inflammation and fibrosis. A three-step process of "inflammation-fibrosis-carcinoma" is believed to be involved in hepatocarcinogenesis. The activation of hepatic stellate cells (HSCs) may serve as an important mediator in the process of inflammation-fibrosis-carcinoma axis, even in tumor metastasis. A remarkable knowledge of activated HSCs in the pathology of HCC development is mostly focused on the liver fibrosis. The molecular links that connects inflammation and cancer in the activation of HSC are not completely known. This highlights urgent need to increase our understanding of the cellular and molecular mechanisms, by which activation of HSCs is involved in the hepatic inflammation, carcinogenesis, and metastasis.

Salirasib inhibits the growth of hepatocarcinoma cell lines in vitro and tumor growth in vivo through ras and mTOR inhibition

Background

Dysregulation of epidermal growth factor and insulin-like growth factor signaling play important roles in human hepatocellular carcinoma (HCC), leading to frequent activation of their downstream targets, the ras/raf/extracellular signal-regulated kinase (ERK) and the phosphoinositide 3-kinase (PI3K)/Akt/mammalian Target of Rapamycin (mTOR) pathways. Salirasib is an S-prenyl-cysteine analog that has been shown to block ras and/or mTOR activation in several non hepatic tumor cell lines. We investigated in vitro the effect of salirasib on cell growth as well as its mechanism of action in human hepatoma cell lines (HepG2, Huh7, and Hep3B) and its in vivo effect in a subcutaneous xenograft model with HepG2 cells.

Results

Salirasib induced a time and dose dependent growth inhibition in hepatocarcinoma cells through inhibition of proliferation and partially through induction of apoptosis. A 50 percent reduction in cell growth was obtained in all three cell lines at a dose of 150 μM when they were cultured with serum. By contrast, salirasib was more potent at reducing cell growth after stimulation with EGF or IGF2 under serum-free conditions, with an IC₅₀ ranging from 60 μM to 85 μM. The drug-induced anti-proliferative effect was associated with downregulation of cyclin A and to a lesser extent of cyclin D1, and upregulation of p21 and p27. Apoptosis induction was related to a global pro-apoptotic balance with caspase 3 activation, cytochrome c release, death receptor upregulation, and a reduced mRNA expression of the apoptosis inhibitors cFLIP and survivin. These effects were associated with ras downregulation and mTOR inhibition, without reduction of ERK and Akt activation. In vivo, salirasib reduced tumour growth from day 5 onwards. After 12 days of treatment, mean tumor weight was diminished by 56 percent in the treated animals.

Conclusions

Our results show for the first time that salirasib inhibits the growth of human hepatoma cell lines through inhibition of proliferation and induction of apoptosis, which is associated with ras and mTOR inhibition. The therapeutic potential of salirasib in human HCC was further confirmed in a subcutaneous xenograft model.

CIP2A mediates effects of bortezomib on phospho-Akt and apoptosis in hepatocellular carcinoma cells

Previously, we reported that Akt inactivation determines the sensitivity of hepatocellular carcinoma (HCC) cells to bortezomib. In this study, we report that cancerous inhibitor of protein phosphatase 2A (CIP2A), a cellular inhibitor of protein phosphatase 2A (PP2A), mediates the apoptotic effect of bortezomib in HCC. Silencing PP2A by small interference RNA (siRNA) abolishes bortezomib-induced down-regulation of phospho-Akt and apoptosis. Bortezomib increases PP2A activity in sensitive HCC cells, including Sk-Hep1, Hep3B and Huh-7, but not in resistant PLC5 cells. Bortezomib down-regulates CIP2A in a dose- and time-dependent manner in all sensitive HCC cells, whereas no alterations in CIP2A were found in resistant PLC5 cells. Knockdown of CIP2A by siRNA restored bortezomib's effects on apoptosis and PP2A activity in PLC5 cells. Moreover, over-expression of CIP2A up-regulated phospho-Akt and protected Sk-Hep1 cells from bortezomib-induced apoptosis. It is significant that, ectopic expression of CIP2A decreased Akt-related PP2A activity, whereas silencing CIP2A increased this activity, indicating that CIP2A negatively regulates Akt-related PP2A activity in HCC cells, furthermore, our in vivo data showed that bortezomib down-regulates CIP2A and up-regulates PP2A activity in Huh-7 tumors, but not in PLC5 tumors. In conclusion, inhibition of CIP2A determines the effects of bortezomib on apoptosis and PP2A-dependent Akt inactivation in HCC.

Sustained treatment response of metastatic hepatocellular carcinoma with bevacizumab and sorafenib

The overall survival for patients with advanced hepatocellular carcinoma (HCC) is still limited. Although the multi-kinase inhibitor sorafenib has recently been approved for this disease, response rates are still low and patients often face dose-limiting toxicities which lead to a reduction in prognosis and treatment success. We here report a patient with metastasized HCC who shows a sustained response for more than 30 mo to sorafenib therapy after failure of a first line therapy with gemcitabine, oxaliplatin and bevacizumab.

Safety studies on intrahepatic or intratumoral injection of oncolytic vesicular stomatitis virus expressing interferon-beta in rodents and nonhuman primates

Toxicology studies were performed in rats and rhesus macaques to establish a safe starting dose for intratumoral injection of an oncolytic vesicular stomatitis virus expressing human interferon-beta (VSV-hIFNbeta) in patients with hepatocellular carcinoma (HCC). No adverse events were observed after administration of 7.59 x 10(9) TCID(50) (50% tissue culture infective dose) of VSV-hIFNbeta into the left lateral hepatic lobe of Harlan Sprague Dawley rats. Plasma alanine aminotransferase and alkaline phosphatase levels increased and platelet counts decreased in the virus-treated animals on days 1 and 2 but returned to pretreatment levels by day 4. VSV-hIFNbeta was also injected into normal livers or an intrahepatic McA-RH7777 HCC xenograft established in Buffalo rats. Buffalo rats were more sensitive to neurotoxic effects of VSV; the no observable adverse event level (NOAEL) of VSV-hIFNbeta in Buffalo rats was 10(7) TCID(50). Higher doses were associated with fatal neurotoxicity and infectious virus was recovered from tumor and brain. Compared with VSV-hIFNbeta, toxicity of VSV-rIFNbeta (recombinant VSV expressing rat IFN-beta) was greatly diminished in Buffalo rats (NOAEL, >10(10) TCID(50)). Two groups of two adult male rhesus macaques received 10(9) or 10(10) TCID(50) of VSV-hIFNbeta injected directly into the left hepatic lobe under computed tomographic guidance. No neurological signs were observed at any time point. No abnormalities (hematology, clinical chemistry, body weights, behavior) were seen and all macaques developed neutralizing anti-VSV antibodies. Plasma interleukin-6, tumor necrosis factor-alpha, and hIFN-beta remained below detection levels by ELISA. On the basis of these studies, we will be proposing a cautious approach to dose escalation in a phase I clinical trial among patients with HCC.

Systematic review and meta-analysis of steatosis as a risk factor in major hepatic resection

Background

The risk of major hepatic resection in patients with hepatic steatosis remains controversial. A meta-analysis was performed to establish the best estimate of the impact of steatosis on patient outcome following major hepatic surgery.

Methods

A systematic search was performed following Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Risk ratios (RRs) for complication and mortality rates were calculated for patients with no, less than 30 per cent and at least 30 per cent steatosis, and a meta-analysis was carried out.

Results

Of six observational studies identified, four including a total of 1000 patients were subjected to meta-analysis; two others were tabulated separately. Compared with patients without steatosis, those with less than 30 per cent and at least 30 per cent steatosis had a significantly increased risk of postoperative complications, with a RR of 1·53 (95 per cent confidence interval (c.i.) 1·27 to 1·85) and 2·01 (1·66 to 2·44) respectively. Patients with at least 30 per cent steatosis had an increased risk of postoperative death (RR 2·79, 95 per cent c.i. 1·19 to 6·51).

Conclusion

Patients with steatosis had an up to twofold increased risk of postoperative complications, and those with excessive steatosis had an almost threefold increased risk of death.

Effects of HSP70 antisense oligonucleotide on the proliferation and apoptosis of human hepatocellular carcinoma cells

The study investigated the effects of heat shock protein 70 (HSP70) antisense oligonucleotide (ASODN) on the proliferation and apoptosis of a human hepatocellular carcinoma cell line (SMMC-7721 cells) in vitro. HSP70 oligonucleotide was transfected into SMMC-7721 cells by the mediation of Sofast transfection reagent. Inhibition rate of SMMC-7721 cells was determined by using MTT method. Apoptosis rate and cell cycle distribution were measured by flow cytometry. Immunocytochemistry staining was used to observe the expression of HSP70, Bcl-2 and Bax. The results showed that HSP70 ASODN at various concentrations could significantly inhibit the growth of SMMC-7721 cells, and the inhibition effect peaked 48 h after transfection with 400-nmol/L HSP70 ASODN. Cytometric analysis showed the apoptotic rate was increased in a dose- and time-dependent manner in the HSP70 ASODN-treated cells. The percentage of cells in the G2/M and S phases was significantly decreased and that in the G0/G1 phase increased as the HSP70 ASODN concentration was elevated and the exposure time prolonged. Immunocytochemistry showed that treatment of SMMC-7721 cells with HSP70 ASODN resulted in decreased expressions of HSP70 and Bcl-2 proteins, and an increased expression of Bax protein. It was concluded that the HSP70 ASODN can inhibit the growth of the SMMC-7721 cells and increase cell apoptosis by down-regulating the expression of HSP70. HSP70 ASODN holds promise for the treatment of hepatocellular carcinoma.

Roles of hypoxia-inducible factor-1alpha (HIF-1alpha) versus HIF-2alpha in the survival of hepatocellular tumor spheroids

Hypoxia-inducible factors (HIFs) provoke adaptation to hypoxic stress occurring in rapidly growing tumor tissues. Therefore, overexpression of HIF-1 or HIF-2 is a common feature in hepatocellular carcinoma but their specific function is still controversially discussed. To analyze HIF function in hypoxia-induced cell death we created a stable knockdown of HIF-1alpha and HIF-2alpha in HepG2 cells and generated tumor spheroids as an in vitro hepatocellular carcinoma model. Knockdown of HIF-1alpha enhanced expression of HIF-2alpha and vice versa. Unexpectedly, knockdown of HIF-1alpha or HIF-2alpha increased cell viability as well as spheroid size and decreased caspase-3 activity. Antiapoptotic Bcl-X(L) expression increased in both knockdown spheroids, whereas proapoptotic Bax was only reduced in HIF-1alpha-knockdown cells. Furthermore, an HIF-2alpha-knockdown significantly increased Bcl-2/adenovirus E1B 19 kDa-interacting protein 3 (BNIP3) expression in an HIF-1alpha-dependent manner. Concomitantly, electron microscopy revealed a substantial increase in autophagosomal structures in HIF-2alpha-knockdown spheroids and mito-/lysotracker costaining confirmed lysosomal activity of these autophagosomes. Blocking autophagosome maturation using 3-methyladenine restored cell death in HIF-2alpha-knockdown clones comparable to wildtype cells.

CONCLUSION

An HIF-1alpha-knockdown increases HIF-2alpha expression and shifts the balance of Bcl-2 family members toward survival. The knockdown of HIF-2alpha raises autophagic activity and attenuates apoptosis by enhancing HIF-1alpha expression. Our data indicate that enhanced expression of one HIF-isoform causes a survival advantage in hepatocellular carcinoma development.

Hepatocellular carcinoma in thalassemia: A critical review

Due to blood transfusions, thalassemics are often infected with either hepatitis C virus (HCV) or hepatitis B virus and often have hemochromatosis. Hepatocellular carcinoma (HCC) has emerged in thalassemics only recently as a result of the improvement in thalassemia outcomes. In fact, a prospective study estimated an HCC incidence in β-thalassemia of about 2%. Although data are scanty, HCC screening in thalassemics with risk factors for HCC should be carried out. HCV treatments have some efficacy in HCV infected thalassemics despite partial contraindication to ribavirin and iron overload. However, there are no data on how HCV treatment translates into HCC prevention. Preliminary data suggest that HCC treatment in thalassemics should generally have the same outcomes as in non-thalassemics. Although coexistence of severe comorbidities makes liver transplantation challenging, this therapeutic possibility should not be precluded for well selected HCC β-thalassemia patients. In fact, 2 transfusion dependent adult HCC β-thalassemia patients have recently undergone successful liver transplantation with a good outcome. In conclusion, HCC seems to be a developing issue in thalassemia and HCC screening should be carried out. HCC treatment, including liver transplantation, can be performed in selected patients. A multidisciplinary effort is needed for management.

Effect of 5-Aza-2’-deoxycytidine on immune-associated proteins in exosomes from hepatoma

AIM: To study the effect of 5-Aza-2’-deoxycytidine (5-Aza-CdR) on heat shock protein 70 (HSP70), human leucocyte antigen-I (HLA-I) and NY-ESO-1 proteins in exosomes produced by hepatoma cells, HepG2 and Hep3B.

METHODS: Exosomes derived from HepG₂ and Hep3B cells treated with or without 5-aza-CdR were isolated and purified by ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The number of exosomes was counted under electron microscope. Concentration of proteins in exosomes was measured by bicinchoninic acid protein assay. Expression of HSP70, HLA-I and NY-ESO-1 proteins in exosomes was detected by Western blotting and immunoelectron microscopy. mRNA expression of p53 gene was detected by reverse transcription polymerase chain reaction.

RESULTS: The mRNA expression of p53 gene was increased in both hepatoma cell lines after treatment with 5-Aza-CdR. The number of exosomes and the concentration of total proteins in exosomes were increased significantly after treatment with 5-aza-CdR (P < 0.05). After treatment with 5-Aza-CdR, immunoelectron microscopy and Western blotting showed that the HSP70, HLA-I and NY-ESO-1 proteins were increased in exosomes produced by both hepatoma cell lines.

CONCLUSION: 5-aza-CdR, an inhibitor of DNA methyltransferase, can increase exosomes produced by hepatoma cells and immune-associated protein component of exosomes, which may be mediated by p53 gene up-regulation and 5-Aza-CdR demethylation.

Synergistic interactions between sorafenib and bortezomib in hepatocellular carcinoma involve PP2A-dependent Akt inactivation

BACKGROUND & AIMS

Previously we reported that Akt inactivation determines the sensitivity of hepatocellular carcinoma (HCC) cells to bortezomib. Here we report that combined treatment with sorafenib and bortezomib shows synergistic effects in HCC.

METHODS

HCC cell lines (PLC/PRF/5, Huh-7, and Hep3B) were treated with sorafenib and/or bortezomib and analyzed in terms of apoptosis signal transduction. In vivo efficacy was determined in nude mice with PLC/PRF/5 xenografts.

RESULTS

Pretreatment with sorafenib enhanced bortezomib-induced apoptotic cell death by restoring bortezomib's ability to inactivate Akt in PLC/PRF/5 cells. Knocking down Akt1 by RNA-interference overcame apoptotic resistance to bortezomib in PLC/PRF/5 cells and ectopic expression of active Akt in HCC cells abolished the bortezomib sensitizing effect of sorafenib, indicating Akt inactivation plays a key role in mediating the combinational effects. Moreover, okadaic acid, a protein phosphatase 2A (PP2A) inhibitor, reversed down-regulation of phospho-Akt (P-Akt) expression induced by co-treatment with sorafenib and bortezomib, and 1, 9 di-deoxy-forskolin, a PP2A agonist, restored bortezomib's effect on P-Akt and apoptosis. Importantly, silencing of PP2A by RNA-interference reduced the apoptotic effect induced by sorafenib-bortezomib co-treatment, indicating that PP2A is indispensable for mediating the effects of these drugs. Notably, sorafenib with bortezomib increased PP2A activity in PLC/PRF/5 cells without altering protein levels of PP2A complex or the interaction between PP2A and Akt proteins. Finally, sorafenib plus bortezomib significantly suppressed PLC/PRF/5 xenograft tumor growth, down-regulated P-Akt expression, and up-regulated PP2A activity.

CONCLUSIONS

The combination of sorafenib and bortezomib shows synergy in HCC through PP2A-dependent Akt inactivation.

Changes in the expression of melatonin receptors induced by melatonin treatment in hepatocarcinoma HepG2 cells

Hepatocellular carcinoma (HCC) is one of the most common cancers and its incidence is increasing worldwide. Melatonin, an indoleamine hormone, exerts anti-oxidant, immunomodulatory, anti-aging, and antitumor effects. Previous studies have shown that melatonin can act through specific receptors, including MT(1), MT(2), MT(3) receptors as well as a nuclear receptor belonging to the orphan nuclear receptor family. Recently, we have described their role in the oncostatic and pro-apoptotic effects of melatonin on HepG2 human HCC cells. However, the potential role of the different melatonin cellular receptors on its antiproliferative effects remains unknown. In the present study, we examined the effect of melatonin treatment on HepG2 human HCC cells, analyzing cell cycle arrest and melatonin receptor expression. Melatonin was administered for 2, 4, and 6 days at 1000 or 2500 microm. Melatonin induced a dose- and time-dependent inhibition on cell proliferation. This treatment caused an alteration in the cell cycle, with an increase in the number of cells in G(2)/M phase at both 1000 and 2500 microm melatonin concentrations, and a significant increase on S phase cell percentage by the highest dose. Furthermore, increases in protein expression of MT(1), MT(3), and retinoic acid-related orphan receptor-alpha were found after melatonin treatments. These increases were coincident with a significant induction in the expression of p21 protein, which negatively regulates cell cycle progression. Our results confirm the antitumor effect of melatonin in HCC cells, suggesting that its oncostatic properties are related, at least in part, to changes on the expression of their different subtypes of receptors.