Small molecule-based promotion of PKCα-mediated β-catenin degradation suppresses the proliferation of CRT-positive cancer cells

Aberrant accumulation of intracellular β-catenin is a well recognized characteristic of several cancers, including prostate, colon, and liver cancers, and is a potential target for development of anticancer therapeutics. Here, we used cell-based small molecule screening to identify CGK062 as an inhibitor of Wnt/β-catenin signaling. CGK062 promoted protein kinase Cα (PKCα)-mediated phosphorylation of β-catenin at Ser33/Ser37, marking it for proteasomal degradation. This reduced intracellular β-catenin levels and consequently antagonized β-catenin response transcription (CRT). Pharmacological inhibition or depletion of PKCα abrogated CGK062-mediated phosphorylation and degradation of β-catenin. In addition, CGK062 repressed the expression of the genes encoding cyclin D1, c-myc, and axin-2, β-catenin target genes, and thus inhibited the growth of CRT-positive cancer cells. Furthermore, treatment of nude mice bearing PC3 xenograft tumors with CGK062 at doses of 50 mg/kg and 100 mg/kg (i.p.) significantly suppressed tumor growth. Our findings suggest that CGK062 exerts its anticancer activity by promoting PKCα-mediated β-catenin phosphorylation/degradation. Therefore, CGK062 has significant therapeutic potential for the treatment of CRT-positive cancers.

N-acetylcysteine enhances neuronal differentiation of P19 embryonic stem cells via Akt and N-cadherin activation

We examined whether N-acetylcysteine (NAC) enhanced embryonic body (EB) formation and neuronal differentiation in terms of EB formation, neuronal marker (microtubule-associated protein 2; MAP-2) expression, and neuron maturation using P19 embryonic stem cells. The size and numbers of EBs were greatly increased, together with the up-regulated N-cadherin expression. Also, MAP-2 expression and neurite outgrowth were much increased with activation of serine/threonine protein kinase (Akt) and blocked by addition of an Akt inhibitor (LY294002). Our results suggested that NAC increased EB formation by up-regulating the N-cadherin expression. Furthermore, NAC-enhanced neuronal differentiation was mediated by activation of Akt.

ROS-dependent regulation of Parkin and DJ-1 localization during oxidative stress in neurons

Mutations in several genes, including Parkin, PTEN-induced kinase 1 (Pink1) and DJ-1, are associated with rare inherited forms of Parkinson's disease (PD). Despite recent attention on the function of these genes, the interplay between DJ-1, Pink1 and Parkin in PD pathogenesis remains unclear. In particular, whether these genes regulate mitochondrial control pathways in neurons is highly controversial. Here we report that Pink1-dependent Parkin translocation does occur in mouse cortical neurons in response to a variety of mitochondrial damaging agents. This translocation only occurs in the absence of antioxidants in the neuronal culturing medium, implicating a key role of reactive oxygen species (ROS) in this response. Consistent with these observations, ROS blockers also prevent Parkin recruitment in mouse embryonic fibroblasts. Loss of DJ-1, a gene linked to ROS management, results in increased stress-induced Parkin recruitment and increased mitophagy. Expression of wild-type DJ-1, but not a cysteine-106 mutant associated with defective ROS response, rescues this accelerated Parkin recruitment. Interestingly, DJ-1 levels increase at mitochondria following oxidative damage in both fibroblasts and neurons, and this process also depends on Parkin and possibly Pink1. These results not only highlight the presence of a Parkin/Pink1-mediated pathway of mitochondrial quality control (MQC) in neurons, they also delineate a complex reciprocal relationship between DJ-1 and the Pink1/Parkin pathway of MQC.

Exercise and diet modification in non-obese non-alcoholic fatty liver disease: analysis of biopsies of living liver donors

BACKGROUND AND AIMS

We evaluated efficacy of exercise and diet modification for steatosis improvement of non-obese non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

We analyzed retrospectively the clinical and histological parameters of consecutive living liver donors, who experienced repeated liver biopsies due to steatosis and were treated using exercise and diet modification.

RESULTS

From 1995 to 2009, among a total of 1365 potential living liver donors with NAFLD seen on the initial liver biopsy, 120 consecutive donors with steatosis ≥ 30% or an estimated donor-recipient weight ratio < 0.8, underwent exercise and diet modification and received follow-up liver biopsy at our institution. Median age was 33 years, and median interval between the two consecutive biopsies was 10 weeks (range, 1-39). At the time of initial biopsy, the number of normal body mass index, overweight, and obese donors was 49 (40.8%), 65 (54.2%), and 6 (5.0%), respectively. After lifestyle modification, weight reduction and steatosis improvement were observed in 92 (76.7%) and 103 (85.8%) donors, respectively, at the time of follow-up biopsy. On multivariate analysis, initially higher steatosis (hazard ratio [HR] 1.03, P = 0.02), total cholesterol reduction ≥ 10% (HR 5.59, P = 0.02), and weight reduction ≥ 5% (HR 6.63, P = 0.03) were significantly associated with ≥ 20% steatosis improvement in 120 donors with NAFLD, after exercise and diet modification.

CONCLUSIONS

Exercise and diet modification were effective in reducing steatosis in potential living liver donors with non-obese NAFLD. Total cholesterol reduction ≥ 10% could be used as a non-invasive predictor for steatosis improvement in liver donors with NAFLD, after exercise and diet modification.

Genetic predisposition of hand-foot skin reaction after sorafenib therapy in patients with hepatocellular carcinoma

BACKGROUND

Sorafenib currently sets the new standard for advanced hepatocellular carcinoma (HCC). It has been suggested that Asian patients with HCC have increased susceptibility to hand-foot skin reaction (HFSR) related to sorafenib therapy. The authors investigated the association between sorafenib-induced HFSR and genetic polymorphisms in Korean patients with HCC.

METHODS

For this prospective cohort study, the authors enrolled 59 consecutive patients with intermediate stage HCC from 5 centers in Korea. All patients received sorafenib 400 mg twice daily in combination with transarterial chemoembolization (TACE). Genotyping was performed on a total of 49 single nucleotide polymorphisms (SNPs) in 8 candidate genes (minor allelic frequency ≥5%). Serum levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF-α) were measured using enzyme-linked immunosorbent assays before therapy and 1 month after therapy.

RESULTS

During a median treatment period of 18 months, 55 patients (93%) developed sorafenib-induced HFSR, including grade 1 reactions in 15 patients, grade 2 reactions in 27 patients, and grade 3 reaction in 13 patients. The SNPs TNF-α -308GG, VEGF -94GG, VEGF 1991CC, VEGF IVS3-28CC, and uridine diphosphate glucuronosyltransferase 1 family-polypeptide A9 (UGT1A9) IVS1-37431AA were associated significantly with the development of high-grade (grade 2 or 3) HFSR in univariate analysis (P < .05). In multivariate analysis, the SNPs VEGF 1991CC (odds ratio, 45.7), TNF-α -308GG (odds ratio, 44.1), and UGT1A9 IVS1-37431AA (odds ratio, 18.7) were identified as independent risk factors for the development of high-grade HFSR (P = .01, P = .02, and P = .02, respectively). He serum TNF-α level measured 1 month after sorafenib therapy was correlated significantly with the development of high-grade HFSR (odds ratio, 3.56; P = .026).

CONCLUSIONS

Differences in the incidence of HFSR may have been caused by ethnic differences in genetic polymorphisms of the TNF-α, VEGF, and UGT1A9 genes, especially in relation to the expression of serum TNF-α after sorafenib therapy.

Is serum alpha-fetoprotein useful for predicting recurrence and mortality specific to hepatocellular carcinoma after hepatectomy? A test based on propensity scores and competing risks analysis

BACKGROUND

Serum alpha-fetoprotein (AFP) is frequently used to predict posthepatectomy outcomes in patients with hepatocellular carcinoma (HCC), but its predictive value is still not established. Therefore, we assessed the prognostic significance of AFP status.

METHODS

Of 525 patients undergoing curative hepatectomy for HCC, 290 had preoperative AFP levels of ≥20 ng/mL (AFP-positive group) and 235 had AFP levels of <20 ng/mL (AFP-negative group). We compared the 2 groups with respect to time-to-recurrence, using the inverse probability of treatment weighted (IPTW) for the entire cohort and propensity score matching, and the cumulative incidence of HCC-specific mortality using competing risks regression.

RESULTS

During follow-up (median duration 64 months, range 2-137 months), HCC recurred in 54.9 % of the AFP-negative group and 52.4 % of the AFP-positive group; there was no death without recurrence. After IPTW adjustment, time-to-recurrence did not differ in the 2 groups (hazard ratio [HR] 0.86, 95 % confidence interval [95 % CI] 0.66-1.12; P = 0.28). In a propensity-score matched cohort (152 pairs), time-to-recurrence data were similar to those obtained by IPTW adjustment (HR 0.91, 95 % CI 0.65-1.25; P = 0.55). There was no difference in recurrence pattern (site and stage) or treatment between the 2 groups even after propensity-score matching. The adjusted HR evaluating the impact of AFP positivity on the risk of HCC-specific mortality was 0.77 (95 % CI 0.54-1.08; P = 0.13) A multivariable competing risks analysis also failed to reveal a significant correlation between baseline AFP level and HCC-specific mortality in the AFP-positive group.

CONCLUSIONS

Preoperative AFP levels are not useful for predicting recurrence or survival endpoints following curative hepatectomy for HCC.

SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of β-catenin

Because we found in a recent study that pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, induces a rapid proliferation of pancreatic cells by up-regulation of β-catenin, we postulated that β-catenin might be a target molecule for pancreatic cancer treatment. We thus speculated whether SIRT1, known to target β-catenin in a colon cancer model, suppresses β-catenin in those pancreatic cancer cells that express PAUF (Panc-PAUF). We further evaluated whether such suppression would lead to inhibition of the proliferation of these cells. The ectopic expression of either SIRT1 or resveratrol (an activator of SIRT1) suppressed levels of β-catenin protein and its transcriptional activity in Panc-PAUF cells. Conversely, suppression of SIRT1 expression by siRNA enhanced β-catenin expression and transcriptional activity. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for reduction of β-catenin. Treatment with MG132, a proteasomal inhibitor, restored β-catenin protein levels, suggesting that SIRT1-mediated degradation of β-catenin requires proteasomal activity. It was reported that inhibition of GSK-3β or Siah-1 stabilizes β-catenin in colon cancer cells, but suppression of GSK-3β or Siah-1 using siRNA in the presence of resveratrol instead diminished β-catenin protein levels in Panc-PAUF cells. This suggests that GSK-3β and Siah-1 are not involved in SIRT1-mediated degradation of β-catenin in the cells. Finally, activation of SIRT1 inhibited the proliferation of Panc-PAUF cells by down-regulation of cyclin-D1, a target molecule of β-catenin. These results suggest that SIRT1 activation may be a therapeutic strategy for treatment of pancreatic cancer cells that express PAUF via the down-regulation of β-catenin.

HLA-DRB1*010101 allele is closely associated with poor virological response to lamivudine therapy in patients with chronic hepatitis B

BACKGROUND/AIMS

We intended to evaluate the association between specific human leukocyte antigen (HLA)-DRB1 gene polymorphism and antiviral response to lamivudine (LAM) therapy in chronic hepatitis B (CHB) patients.

METHODS

Six-digit HLA-DRB1 genotypes were determined using sequence-based typing in 334 CHB patients initially treated with LAM for at least 12 months. Antiviral response was evaluated every 3-6 months during LAM therapy.

RESULTS

Median age of the subjects was 43 years (range, 16-72). Median duration of LAM therapy was 69 months (range, 13-140). Median baseline serum hepatitis B virus (HBV DNA) level was 7.0 log(10) copies/ml (range, 5.5-9.1). At 12 months of LAM therapy, serum HBV DNA was undetectable by solution hybridization method in 308 (88%) patients. Among 25 HLA-DRB1 alleles identified, HLA-DRB1*090102, *080302, and *070101 were the most frequent alleles (>10%). HLA-DRB1*010101 was identified in 5.4% (18/334). The frequency of the HLA-DRB1*010101 allele was significantly lower in patients with virological response at 12 months of LAM therapy than in patients without it (4.2 vs. 19.2%, p = 0.025). The other HLA-DRB1 alleles were not associated with virological response. HBeAg loss/seroconversion and alanine aminotransferase normalization were not associated with HLA-DRB1 alleles.

CONCLUSION

The HLA-DRB1*010101 allele is closely associated with poor virological response to initial LAM therapy in CHB patients.

Single nucleotide polymorphisms associated with metastatic tumour antigen 1 overexpression in patients with hepatocellular carcinoma

BACKGROUNDS/AIMS

Metastatic tumour antigen 1 (MTA1) promotes angiogenesis by stabilizing hypoxia-inducible factor-1α (HIF-1α), which is closely associated with frequent postoperative recurrence and poor survival in patients with HCC. In this study, we determined single nucleotide polymorphisms (SNPs) in angiogenesis-related genes that are associated with MTA1 overexpression in HCC tissues.

METHODS

A total of 376 patients with HCC who had received curative surgical resection or liver transplantation were enrolled (312/21/43; HBV/HCV/NBNC). MTA1 expression was determined via immunohistochemistry. Thirty-three common SNPs sites (frequency ≥5%) in the angiogenic protein gene that are closely connected to one another were selected, including MTA1, VEGF, HIF-1α, FGF-2, and IGF-II.

RESULTS

Expression of MTA1 was detected in 120 HCC tissues (31%). An A allele at position IVS4-81G/A of the MTA1 gene (P = 0.016) and the TT genotype at position +12916C of the VEGF gene (P = 0.023) were significantly associated with MTA1 overexpression. However, the TT genotype at position -13021C (P = 0.011) and the haplotypes CT-CT (-11228C; -13021C) of the IGF-II gene (P(cor) = 0.033) were more common in patients with MTA1-negative HCC. Using multivariate analysis, the A allele at IVS4-81G/A in MTA1 gene (P = 0.015) and a T allele (TT+CT genotype) at -13021C in IGF-II (P = 0.002) were independent risk factors in HCC recurrence after curative surgical resection.

CONCLUSIONS

The genetic polymorphisms IVS4-81G/A in MTA1 and +12916C in VEGF genes were correlated with MTA1 overexpression. The SNPs in MTA1 and IGF-II genes may be important risk factors for the recurrence of HCC.

rtL180M mutation of hepatitis B virus is closely associated with frequent virological resistance to adefovir dipivoxil therapy

BACKGROUND AND AIM

We intended to investigate the effects of pre-existing mutations at reverse transcriptase region of hepatitis B virus (HBV) on the occurrence of virological breakthrough (VB) to adefovir dipivoxil (ADV) in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB).

METHODS

Ninety-seven patients with LAM-resistant CHB were treated with ADV at a dose of 10 mg daily, and were followed for a median period of 13 months. Just before the initiation of ADV therapy, the whole length of reverse transcriptase region of serum HBV-DNA was sequenced using direct sequencing.

RESULTS

All patients had genotype C HBV and mutations in the YMDD motif, specifically, YIDD (65%), YVDD (28%), or both (7%). The rtL180M and rtL80V/I mutations were identified in 68% and 69%, respectively. The cumulative probability of VB was 19% and 27% at 1 and 2 years, respectively. There was no difference in the occurrence of VB with regard to types of YMDD mutation or rtL80V/I. However, interestingly, patients carrying rtL180M experienced VB during ADV monotherapy more frequently than those not carrying rtL180M (2-year cumulative probability of VB: 37% vs 3% at 2 years, P < 0.01). On multivariate Cox proportional hazards analysis, rtL180M (hazard ratio [HR]: 8.62, 95% confidence interval: 1.08-69.09, P = 0.042) and decrease in HBV-DNA for 1 year of treatment (HR: 0.69, 95% CI: 0.51-0.95, P = 0.024) are independently associated with VB.

CONCLUSIONS

The rtL180M mutation of HBV, as well as a small decrease in HBV-DNA after 1 year of treatment might be closely associated with frequent occurrence of virological resistance to ADV in patients with LAM-resistant CHB.

Transforming growth factor beta 1 overexpression is closely related to invasiveness of hepatocellular carcinoma

OBJECTIVES

The study was aimed to investigate the relationship between plasma transforming growth factor beta 1 (TGF-β(1)) expression and the characteristics of hepatocellular carcinoma (HCC).

METHODS

Five hundred and seventy-one patients with HCC were subjected. Plasma TGF-β(1) levels were measured by enzyme-linked immunosorbent assay at diagnosis and compared in accordance with clinical and radiological characteristics.

RESULTS

Plasma TGF-β(1) levels were significantly higher in the diffuse infiltrative type (n = 159) than in the nodular type of HCC (n = 412; 3.94 ± 0.34 vs. 3.79 ± 0.29 log(10) pg/ml; p < 0.001). They were much higher in patients with portal vein thrombosis or extrahepatic metastasis than in those without (3.88 ± 0.34 vs. 3.81 ± 0.29 log(10) pg/ml, p = 0.008; 3.94 ± 0.35 vs. 3.82 ± 0.30 log(10) pg/ml, p = 0.013, respectively). Also, plasma TGF-β(1) levels showed a positive correlation with the size of HCC (r = 0.014, p < 0.001). Additionally, plasma TGF-β(1) levels were inversely related to the survival periods (p < 0.001).

CONCLUSION

TGF-β(1) was overexpressed in invasive types of HCC and it may be involved in the rapid progression of HCC.

Hepatitis B virus X protein inhibits extracellular IFN-α-mediated signal transduction by downregulation of type I IFN receptor

We have previously shown that hepatitis B virus (HBV) protein X (HBX), a regulatory protein of HBV, activates Stat1, leading to type I interferon (IFN) production. Type I IFN secreted from HBX-expressing hepatic cells enforces antiviral signals through its binding to the cognate type I IFN receptor. We therefore investigated how cells handle this detrimental situation. Interestingly, compared to Chang cells stably expressing an empty vector (Chang-Vec), Chang cells stably expressing HBX (Chang-HBX) showed lower levels of IFN-α receptor 1 (IFNAR1) protein, a subunit of type I IFN receptor. The levels of IFNAR1 transcripts detected in Chang-HBX cells were lower than the levels in Chang-Vec cells, indicating that HBX regulates IFNAR1 at the transcriptional level. Moreover, we observed that HBX induced the translocation of IFNAR1 to the cytoplasm. Consistent with these observations, HBX also downregulated Tyk2, which is required for the stable expression of IFNAR1 on the cell surface. Eventually, Chang-HBX cells consistently maintained a lower level of IFNAR1 expression and displayed no proper response to IFN-α, while Chang-Vec cells exhibited a proper response to IFN-α treatment. Taken together, we propose that HBX downregulates IFNAR1, leading to the avoidance of extracellular IFN-α signal transduction.

Applicability of the BCLC staging system to patients with hepatocellular carcinoma in Korea: analysis at a single center with a liver transplant center

Background/Aims

The Barcelona Clinic Liver Cancer (BCLC) staging system is logical for the staging and treatment of hepatocellular carcinoma (HCC) because it was based on survival data. This study evaluated the applicability of the BCLC staging system and reasons for divergence from BCLC-recommended treatments in Korean HCC patients.

Methods

One hundred and sixty consecutive HCC patients were prospectively enrolled. Treatments were generally recommended according to the guideline of the American Association for the Study of Liver Diseases, but patients were also informed about alternative treatments. The final decision was made with patient agreement, and was based on the doctor's preferences when a patient was unable to reach a decision.

Results

There were 2 (1%), 101 (64%), 20 (12.5%), 34 (21.5%), and 3 (1%) patients with very early-, early-, intermediate-, advanced-, and terminal-stage disease, respectively. Only 64 patients (40%) were treated according to BCLC recommendations. The treatment deviated from BCLC recommendations in 68% (69/101) and 79% (27/34) of patients with early and advanced stage, respectively. The main causes of deviation were refusal to undergo surgery, the presence of an indeterminate malignancy nodule, the absence of a suitable donor, or financial problems.

Conclusions

Donor shortage, financial problems, the relatively limited efficacy of molecular targeting agents, and the presence of an indeterminate nodule were the main causes of deviation from BCLC recommendations. Even after excluding cases in which decisions were made by patient preference, only 66% of the HCC patients were treated according to BCLC recommendations. Treatment guidelines that reflect the Korean situation are mandatory for HCC patients.

Noninvasive diagnostic criteria for hepatocellular carcinoma in hepatic masses >2 cm in a hepatitis B virus-endemic area

BACKGROUND

Noninvasive criteria for diagnosing hepatocellular carcinoma (HCC) suggested by the American Association for the Study of Liver Diseases (AASLD) in 2005 consisted of serum α-fetoprotein (AFP) level >200 ng/ml or a typical enhancement pattern (arterial enhancement and portal/delayed washed out) on dynamic imaging of hepatic mass(es) >2 cm in a cirrhotic liver.

AIMS

To validate these criteria in a Korean population and to evaluate whether these criteria are applicable to patients without cirrhosis at a high risk of developing HCC.

METHODS

We prospectively investigated 206 consecutive patients with hepatic mass(es) >2 cm who underwent biopsy or surgical resection. Patients were evaluated by four-phase dynamic computed tomography (CT) and by assays of serum AFP concentrations at baseline. Patients were classified according to the presence of risk factors or cirrhosis, and the diagnostic accuracy of each test was determined.

RESULTS

The positive predictive values (PPV) of typical CT findings or serum AFP >200 ng/ml were 97.8% in cirrhotic patients, 89.6% in high-risk patients without cirrhosis and 82.4% in low-risk patients. The PPVs of typical CT findings alone in these groups were 98.8, 97.6 and 87.5% respectively. In high-risk patients without cirrhosis, the addition of serum AFP levels to typical CT findings minimally increased the diagnostic sensitivity from 81.6 to 87.8% but reduced the PPV from 97.6 to 89.6%.

CONCLUSIONS

Serum AFP concentration is not a suitable diagnostic criterion for HCC. Typical CT findings can be used to diagnose HCC >2 cm both in cirrhotic patients and in high-risk patients without cirrhosis.

Pancreatic adenocarcinoma up-regulated factor (PAUF) enhances the expression of β-catenin, leading to a rapid proliferation of pancreatic cells

It is not yet understood how the enhanced expression of pancreatic adenocarcinoma up-regulated factor (PAUF; a novel oncogene identified in our recent studies), contributes to the oncogenesis of pancreatic cells. We herein report that PAUF up-regulates the expression and transcriptional activity of β-catenin while the suppression of PAUF by shRNA down-regulates β-catenin. The induction of b-catenin by PAUF is mediated by the activities of Akt and GSK-3β, but inhibition of downstream ERK does not reduce β-catenin expression. To test whether PAUF emulates either the Wnt3a-mediated or the protein kinase A-mediated signaling pathway for the stabilization of β-catenin, we examined the phosphorylation status of β-catenin in the presence of PAUF compared with that of β-catenin during treatment with Wnt3a or dibutyryl cAMP, a cell permeable cyclic AMP analogue. PAUF expression induces phosphorylation at Ser-33/37/Thr-41 and Ser-675 of β-catenin but no phosphorylation at Ser-45, indicating that a unique phosphorylation pattern of b-catenin is caused by PAUF. Finally, the expression of PAUF up-regulates both cyclin-D1 and c-Jun, target genes of β-catenin, leading to a rapid proliferation of pancreatic cells; conversely decreased PAUF expression (by shRNA) results in the reduced proliferation of pancreatic cells. Treatment with hexachlorophene (an inhibitor of β-catenin) reduces the proliferation of pancreatic cells despite the presence of PAUF. Taken together, we propose that PAUF can up-regulate and stabilize β-catenin via a novel pattern of phosphorylation, thereby contributing to the rapid proliferation of pancreatic cancer cells.

Radiotherapy plus transarterial chemoembolization for hepatocellular carcinoma invading the portal vein: long-term patient outcomes

PURPOSE

We have evaluated the clinical outcomes of patients after transarterial chemoembolization (TACE) and 3-dimensional conformal radiotherapy for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT).

METHODS AND MATERIALS

A registry database of 412 patients treated with TACE and three-dimensional conformal radiotherapy for HCC with PVTT between August 2002 and August 2008 were analyzed retrospectively. The radiotherapy volume included the PVTT, with a 2- to 3-cm margin to cover adjacent HCC. Intrahepatic primary HCC was managed by TACE before or after radiotherapy.

RESULTS

Median patient age was 52 years old, and 88.1% of patients were male. Main or bilateral PVTT was observed in 200 (48.5%) patients. Median radiation dose was 40 Gy (range, 21-60 Gy) delivered in 2- to 5-Gy fractions. We found that 3.6% of patients achieved a complete response and that 24.3% of patients achieved a partial response. The response and progression-free rates of PVTT were 39.6% and 85.6%, respectively. Median patient survival was 10.6 months, and the 1- and 2-year survival rates were 42.5% and 22.8%, respectively. Significant independent variables associated with overall survival included advanced tumor stage, alpha-fetoprotein level, degree of PVTT, and response to radiotherapy. Forty-one patients (10.0%) showed grade 3-4 hepatic toxicity during or 3 months after completion of radiotherapy. Grades 2-3 gastroduodenal complications were observed in 15 patients (3.6%).

CONCLUSIONS

Radiotherapy is a safe and effective treatment for PVTT in patients with HCC. These results suggested that the combination of TACE and radiotherapy is a treatment option for relieving and/or stabilizing PVTT in patients with advanced HCC.

Radiotherapy plus transarterial chemoembolization for hepatocellular carcinoma invading the portal vein: long-term patient outcomes

PURPOSE

We have evaluated the clinical outcomes of patients after transarterial chemoembolization (TACE) and 3-dimensional conformal radiotherapy for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT).

METHODS AND MATERIALS

A registry database of 412 patients treated with TACE and three-dimensional conformal radiotherapy for HCC with PVTT between August 2002 and August 2008 were analyzed retrospectively. The radiotherapy volume included the PVTT, with a 2- to 3-cm margin to cover adjacent HCC. Intrahepatic primary HCC was managed by TACE before or after radiotherapy.

RESULTS

Median patient age was 52 years old, and 88.1% of patients were male. Main or bilateral PVTT was observed in 200 (48.5%) patients. Median radiation dose was 40 Gy (range, 21-60 Gy) delivered in 2- to 5-Gy fractions. We found that 3.6% of patients achieved a complete response and that 24.3% of patients achieved a partial response. The response and progression-free rates of PVTT were 39.6% and 85.6%, respectively. Median patient survival was 10.6 months, and the 1- and 2-year survival rates were 42.5% and 22.8%, respectively. Significant independent variables associated with overall survival included advanced tumor stage, alpha-fetoprotein level, degree of PVTT, and response to radiotherapy. Forty-one patients (10.0%) showed grade 3-4 hepatic toxicity during or 3 months after completion of radiotherapy. Grades 2-3 gastroduodenal complications were observed in 15 patients (3.6%).

CONCLUSIONS

Radiotherapy is a safe and effective treatment for PVTT in patients with HCC. These results suggested that the combination of TACE and radiotherapy is a treatment option for relieving and/or stabilizing PVTT in patients with advanced HCC.

Up-regulation of Foxo4 mediated by hepatitis B virus X protein confers resistance to oxidative stress-induced cell death

The hepatitis B virus X (HBX) protein, a regulatory protein of the hepatitis B virus (HBV), has been shown to generate reactive oxygen species (ROS) in human liver cell lines; however, the mechanism by which cells protect themselves under this oxidative stress is poorly understood. Here, we show that HBX induces the up-regulation of Forkhead box class O 4 (Foxo4) not only in Chang cells stably expressing HBX (Chang-HBX) but also in primary hepatic tissues from HBX-transgenic mice. HBX also increased ROS, but reduction of the abundance of ROS using N-acetylcystein (NAC) diminished the levels of Foxo4. Elevated Foxo4 was also detected in nuclei of Chang-HBX cells but not in Chang cells stably expressing the vector (Chang-Vec), suggesting that HBX activates the transcriptional activity of Foxo4. When we examined whether HBX bypasses JNK signaling that targets Foxo4, we found that the activity of JNK but not of ERK is required for the up-regulation of Foxo4 even in the presence of HBX. Furthermore, the reduction of Foxo4 levels using siRNA or a JNK inhibitor rendered Chang-HBX cells sensitive to apoptosis under oxidative stress, suggesting that up-regulation of Foxo4 mediated by HBX enhances resistances to oxidative stress-induced cell death. Accordingly, we propose that Foxo4 may be a useful target for suppression in the treatment of HBV-associated hepatocellular carcinoma cells.

Posttransplantation prophylaxis with primary high-dose hepatitis B immunoglobulin monotherapy and complementary preemptive antiviral add-on

A considerable proportion of liver transplantation recipients who receive hepatitis B immunoglobulin (HBIG) monotherapy for hepatitis B virus (HBV) prophylaxis develop resistance to HBIG. We retrospectively assessed the efficacy of HBV prophylaxis in 1524 patients who received primary high-dose HBIG monotherapy (n = 1463) or with a preemptive antiviral add-on as secondary combination therapy (n = 61). At a median follow-up time of 57 months, 106 (7.3%) patients receiving HBIG monotherapy experienced HBV recurrence, with a 10-year HBV recurrence rate of 9.8%, compared to none of the patients receiving preemptive combination therapy (P = 0.047). Thirteen patients (12.3%) with HBV recurrence failed antiviral therapy, leading to death or retransplantation. Response rates to rescue therapy before and after use of adefovir/entecavir were 44.4% and 91.8%, respectively. Acute exacerbation was not associated with treatment failure, but required prolonged treatment. Of 84 surviving patients with HBV recurrence, 44 (52.4%) showed no evidence of blood HBV DNA. The Gly145Arg mutation was found in 11 of 15 (73.3%) patients, whereas 25 of 71 (35.2%), 2 of 29 (6.9%), and 4 of 8 (50%) patients were resistant to lamivudine, adefovir, and entecavir, respectively. In conclusion, our finding of a 10-year HBV recurrence rate of 9.8% in patients receiving high-dose HBIG monotherapy indicates that this treatment is effective but requires complementary measures. Strict surveillance following HBIG monotherapy is necessary to enhance responses to rescue antiviral therapy. Preemptive conversion to combination therapy has a complementary role in prophylaxis with primary high-dose HBIG monotherapy, especially for patients at high risk of HBV recurrence.

Clevudine-induced viral response, associated with continued reduction of HBsAg titer, was durable after the withdrawal of therapy

BACKGROUND

This study was conducted to evaluate the durability of clevudine-induced viral response after the withdrawal of treatment.

METHODS

Patients who showed a complete response [alanine aminotransferase (ALT) normalization and hepatitis B virus (HBV) DNA <4,700 copies/mL for hepatitis B envelope antigen (HBeAg)-negative patients; ALT normalization, HBV DNA <4,700 copies/mL, and HBeAg seroconversion for HBeAg-positive patients] in the previous clevudine phase III trials were followed for an additional 96 weeks without any treatment for hepatitis B.

RESULTS

Of the 63 patients in the study cohort, 73% and 35% of the patients had HBV DNA <141,500 and <4,700 copies/mL, respectively, and 75% of the patients had normal ALT at the end of follow-up. HBeAg seroconversion was maintained in 81% of the patients and hepatitis B surface antigen (HBsAg) loss occurred in 3 patients. Continued HBsAg titer decrease (-0.5 log IU/mL) was observed in the sustained viral responders, suggesting the reduction of covalently closed circular DNA in hepatocytes.

CONCLUSIONS

The clevudine-induced viral response was durable in the majority of patients for 2 years after the withdrawal of treatment.

Could HBx protein expression affect signal pathway inhibition by gefitinib or selumetinib, a MEK inhibitor, in hepatocellular carcinoma cell lines?

Hepatitis B virus X (HBx) protein has been known to play an important role in development of hepatocellular carcinoma (HCC). The aim of this study is to find out whether HBx protein expression affects antiproliferative effect of an epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitor and a MEK inhibitor in HepG2 and Huh-7 cell lines. We established HepG2 and Huh-7 cells transfected stably with HBx gene. HBx protein expression increased pERK and pAkt expression as well as β-catenin activity in both cells. Gefitinib (EGFR-TK inhibitor) inhibited pERK and pAkt expression and β-catenin activity in both cells. Selumetinib (MEK inhibitor) reduced pERK level and β-catenin activity but pAkt expression was rather elevated by selumetinib in these cells. Reduction of pERK levels was much stronger with selumetinib than gefitinib in both cells. The antiproliferative efficacy of selumetinib was more potent than that of gefitinib. However, the antiproliferative effect of gefitinib, as well as selumetinib, was not different between cell lines with or without HBx expression. Signal pathway activation by HBx might not be strong enough to attenuate the antiproliferative effect of EGFR-TK inhibitor. Future experiments are needed to understand the role of HBx protein expression in HCC treatment using molecular targeting agent.