The Role of PPARγ in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. This cancer develops mainly in cirrhotic patients. The cirrhotic liver is considered to be a preneoplastic organ, suggesting the rationale for cancer prevention. PPARγ is a nuclear transcription factor whose activation leads to interaction in the metabolism of lipids, insulin sensitization of peripheral cells, anti-inflammatory action. It can also induce differentiation and inhibits proliferation of cancer cells. Until now, data using PPARγ ligands in HCC have demonstrated mainly in in vitro models that its activation could be due to an antiproliferative effect. PPARγ ligand administration has also been associated with a diminution of liver fibrosis in animal models, and potentially also on tumoral cell death. Soma data show that the favorable effect of natural and synthetized PPARγ agonists could also be independent of PPARγ activation. Furthermore, in some situations, PPARγ antagonists have also an anticancer effect. Therefore, we can conclude that the link between activation of the PPARγ pathway and an anticancer activity is suggested but until now not firmly established in HCC

Polymorphismes du gène ABCB1 (MDR1) et impacts fonctionnels dans le transport de xénobiotiques - Particularités chez les sujets Noirs Subsahariens

Les différences interindividuelles observées dans la réponse aux médicaments sont en partie dues aux polymorphismes du gène ABCB1 codant pour la glycoprotéine-P (P-gp), une protéine de transport des médicaments. Cette revue a pour but de faire le point des connaissances sur les polymorphismes du gène ABCB1, leur relevance fonctionnelle et clinique et de préciser les particularités au sein de la population noire subsharienne. Le rôle du gène (ABCB1)MDR1 dans la variabilité pharmacocinétique ou pharmacodynamique a été démontrée clairement in vitro, dans des modèles animaux et lors d’études cliniques. Le polymorphisme C3435T est associé à une diminution de l’expression protéique de la P-gp et, par voie de conséquence, de son activité. L’existence d’une forte association entre les polymorphismes C3435T et G2677T a suggéré alors que la différence fonctionnelle observée peut être attribuée également au deuxième polymorphisme i.e le G2677T (exon 21). Il a été identifié chez les noirs africains de nouveaux polymorphismes et des haplotypes particuliers. Différnts travaux ont démontré également que le gène ABCB1 intervient dans le suivi thérapeutique des patients mis sous immunosuppresseurs, anticancéreux, antidépresseurs, antirétroviraux ou antihypertenseurs. Des perspectives fort intéressantes en pharmacothérapie avec entre autres l’utilisation de modulateurs de la P-gp sont d’actualité.Mots clés: Pharmacogénétique, glycoprotéine-P, médicaments, substances exogènes, Noirs Subsaharien

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

<p>Abstract</p> <p>Background</p> <p>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 <it>in vitro </it>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 <it>in vivo </it>effect in a subcutaneous xenograft model with HepG2 cells.</p> <p>Results</p> <p>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 IC₅₀ranging 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. <it>In vivo</it>, 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.</p> <p>Conclusions</p> <p>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.</p

Effectiveness and tolerability of pegylated interferon alfa-2b in combination with ribavirin for treatment of chronic hepatitis C: the PegIntrust Study

Background and study aims : Large international clinical trials conducted in the past 5 years rapidly improved the treatment of chronic hepatitis C; however, it is unclear whether the advances seen in clinical trials are being paralleled by similar improvements in routine clinical practice. PegIntrust is a Belgian community-based trial evaluating the sustained virological response. Patients and Methods : Observational study of 219 patients receiving pegylated interferon alfa-2b (1.5 mu g/kg/wk) and weight. based ribavirin (800-1200 mg/day) for 48 weeks. Primary study end point was sustained virological response (SVR), defined as undetectable HCV RNA 6 months after the completion of treatment. Results : In total, 108 patients (49.3 %) had undetectable HCV RNA at the end of therapy, 91(41.6%) attaining SVR. Of the 111 patients without an end-of-treatment response, 28 were non-responders, and 21 had virological breakthrough. In total, 134 patients attained early virological response (EVR); 88 (65.7%) of those patients attained SVR. In contrast, 82 (96.5 %) of the 85 patients who did not attain EVR also did not attain SVR. Age, fibrosis score and baseline viral load were identified as important predictors of treatment outcome. The most frequently reported serious adverse events resulting in treatment discontinuation were anemia (n = 10), fatigue/asthenia/malaise (n = 6) and fever (n = 3). Conclusion : Our data indicate that treatment of chronic hepatitis C with PEG-IFN alfa-2b plus weight-based ribavirin results in favourable treatment outcomes in a Belgian cohort of patients treated in community-based clinical practice. (Ada gastroenterol. belg., 2010, 73, 5-11)

Comparison of Sanger sequencing for hepatitis C virus genotyping with a commercial line probe assay in a tertiary hospital

Background: The technique most frequently used to genotype HCV is quantitative RT-PCR. This technique is unable to provide an accurate genotype/subtype for many samples; we decided to develop an in-house method with the goal of accurately identifying the genotype of all samples. As a Belgium National Centre of reference for hepatitis, we developed in-house sequencing not only for 5'UTR and core regions starting from VERSANT LiPA amplicons but also for NS5B regions. The sequencing of VERSANT LiPA amplicons might be useful for many laboratories worldwide using the VERSANT LiPA assay to overcome undetermined results. Methods: 100 samples from Hepatitis C virus infected patients analysed by the VERSANT HCV Genotype 2.0 LiPA Assay covering frequent HCV types and subtypes were included in this study. NS5B, 5'UTR and Core home-made sequencing were then performed on these samples. The sequences obtained were compared with the HCV genomic BLAST bank. Results: All the samples were characterised by the VERSANT LiPA assay (8 G1a, 17 G1b, 6 G2, 11 G3, 13 G4, and 10 G6). It was not possible to discriminate between G6 and G1 by the VERSANT LiPA assay for 8 samples and 27 had an undetermined genotype. Forty-one samples were sequenced for the three regions: NS5B, 5'UTR and Core. Twenty-three samples were sequenced for two regions: 5 UTR and Core and 36 samples were sequenced only for NS5B. Of the 100 samples included, 64 samples were analysed for 5'UTR and Core sequencing and 79 samples were analysed for NS5B sequencing. The global agreement between VERSANT LiPA assay and sequencing was greater than 95%. Conclusions: In this study, we describe a new, original method to confirm HCV genotypes of samples not discriminated by a commercial assay, using amplicons already obtained by the screening method, here the VERSANT LiPA assay. This method thus saves one step if a confirmation assay is needed and might be of usefulness for many laboratories worldwide performing VERSANT LiPA assay in particular

A simple hepatic cyst with elevated serum and cyst fluid CA19-9 levels: a case report

<p>Abstract</p> <p>Introduction</p> <p>Simple hepatic cysts rarely cause symptoms, however, occasionally they become symptomatic due to mass effect, rupture, hemorrhage, and infection. We report a patient with a large hepatic cyst with elevated serum and cyst fluid CA19-9 levels. We studied serum and cyst fluid CA19-9 levels in this patient, before and after the intracystic instillation of minocycline hydrochloride.</p> <p>Case presentation</p> <p>A 76-year-old Japanese woman was diagnosed as having an infected hepatic cyst, by physical examination and enhanced abdominal computed tomography. Serum (170 U/ml; reference: < 37 U/ml) and hepatic cyst fluid (371 U/ml) CA19-9 levels were elevated. After the intracystic instillation of minocycline hydrochloride, necrotic cells in the cyst were drained, and it totally collapsed after 1 week. Cyst fluid CA19-9 levels increased remarkably after the intracystic instillation of minocycline hydrochloride, while serum CA19-9 levels decreased significantly.</p> <p>Conclusion</p> <p>Our study is the first report to reveal the influence of intracystic instillation of minocycline hydrochloride on serum and cyst fluid CA19-9 levels in a patient with a simple hepatic cyst.</p

Immunisation after hepatitis B polyvalent vaccination among children in South Kivu Province Democratic Republic of the Congo

Background. The World Health Organization recommends the integration of vaccination against hepatitis B virus (HBV) into the national immunisation programmes of all highly endemic countries. Protective efficacy, defined as a hepatitis B surface antibody (HBsAb) level ≥10 mIU/mL, is ideally obtained in &gt;90 - 95% of immunised children. The Democratic Republic of the Congo (DRC) implemented this recommendation in 2007 by introducing administration of hepatitis B vaccine in a combined formulation.Objectives. To assess the rate of seroprotection in children who received hepatitis B vaccine in the DRC context.Methods. This descriptive cross-sectional study was conducted during routine postnatal consultations at the General Hospital of Bukavu in South Kivu Province, DRC. A total of 200 infants aged 6 - 12 months and their mothers were consecutively enrolled. All the infants received the three-dose regimen of hepatitis B vaccine 6, 10 and 14 weeks after birth. The mothers were tested for hepatitis B surface antigen and HIV, while HBsAb levels were measured in the infants to determine immune response.Results. Seroprotection was achieved in 84.5% of the infants. No maternal (age, parity, duration of pregnancy, HIV and HBV status) or infant (sex, weight at birth) factors were found to be associated with absence of immunological response.Conclusions. The study demonstrated that the rate of seroprotection in the current vaccination programme against HBV in DRC was lower than desirable but comparable to rates reported in some other African countries. Further studies are needed to assess this finding and to evaluate ways to optimise the seroprotection rate.Â

Oligofructose Promotes Satiety in Healthy Human: A Pilot Study.

Objective: The administration of a fermentable dietary fibre (oligofructose) in rats increases satietogenic gut peptides and lowered spontaneous energy intake. The aim of the study was to assess the relevance of those effects of oligofructose on satiety and energy intake in humans. Design: Single-blinded, crossover, placebo-controlled design, pilot study. Subjects: Volunteers included five men and five women aged 21-39 years, BMI ranging from 18.5 to 27.4 kg/m 2 , were randomly assigned as described below. Interventions: Subjects were included in two 2-week experimental phases during which they received either fibre (oligofructose (OFS)) or placebo (dextrine maltose (DM)); a 2-week washout period was included between crossover phases. In total, 8 g OFS or 8 g DM were ingested twice daily (16 g/day in total). Energy intake, hunger, satiety, fullness and prospective food consumption were assessed with analogue scales at the end of each experimental phase. Results: During breakfast, OFS significantly increases the satiety (P ¼ 0.04) without any difference on other sensations as compared to DM treatment periods. After lunch, no significant differences are observed between treatment period. At dinner, OFS significantly increases satiety (P ¼ 0.04), reduces hunger (P ¼ 0.04) and prospective food consumption (P ¼ 0.05). The energy intake at breakfast and lunch are significantly lower (P ¼ 0.01, 0.03, respectively) after OFS treatment than after DM treatment. Total energy intake per day is 5% lower during OFS than in DM period. Conclusion: Oligofructose treatment increases satiety following breakfast and dinner, reduces hunger and prospective food consumption following dinner. This pilot study presents a rationale to propose oligofructose supplements in the management of food intake in overweight and obese patients. Sponsorship: This project is supported by an FSR grant from the Université catholique de Louvain

Endoplasmic reticulum stress does not contribute to steatohepatitis in obese and insulin resistant high-fat diet fed foz/foz mice

Non-alcoholic fatty liver (steatosis) and steatohepatitis [non-alcoholic steatohepatitis (NASH)] are hepatic complications of the metabolic syndrome. Endoplasmic reticulum (ER) stress is proposed as a crucial disease mechanism in obese and insulin-resistant animals (such as ob/ob mice) with simple steatosis, but its role in NASH remains controversial. We therefore evaluated the role of ER stress as a disease mechanism in foz/foz mice, which develop both the metabolic and histological features that mimic human NASH. We explored ER stress markers in the liver of foz/foz mice in response to a high-fat diet (HFD) at several time points. We then evaluated the effect of treatment with an ER stress inducer tunicamycin, or conversely with the ER protectant tauroursodeoxycholic acid (TUDCA), on the metabolic and hepatic features. foz/foz mice are obese, glucose intolerant and develop NASH characterized by steatosis, inflammation, ballooned hepatocytes and apoptosis from 6 weeks of HFD feeding. This was not associated with activation of the upstream unfolded protein response [phospho-eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme 1α (IRE1α) activity and spliced X-box-binding protein 1 (Xbp1)]. Activation of c-Jun N-terminal kinase (JNK) and up-regulation of activating transcription factor-4 (Atf4) and CCAAT/enhancer-binding protein-homologous protein (Chop) transcripts were however compatible with a ‘pathological’ response to ER stress. We tested this by using intervention experiments. Induction of chronic ER stress failed to worsen obesity, glucose intolerance and NASH pathology in HFD-fed foz/foz mice. In addition, the ER protectant TUDCA, although reducing steatosis, failed to improve glucose intolerance, hepatic inflammation and apoptosis in HFD-fed foz/foz mice. These results show that signals driving hepatic inflammation, apoptosis and insulin resistance are independent of ER stress in obese diabetic mice with steatohepatitis