Common dysregulation of Wnt/Frizzled receptor elements in human hepatocellular carcinoma

Dysregulation of growth factors and their receptors is central to human hepatocellular carcinoma (HCC). We previously demonstrated that the Frizzled-7 membrane receptor mediating the Wnt signalling can activate the β-catenin pathway and promotes malignancy in human hepatitis B virus-related HCCs. Expression patterns of all the 10 Frizzled receptors, and their extracellular soluble autoparacrine regulators (19 Wnt activators and 4 sFRP inhibitors) were assessed by real-time RT–PCR in 62 human HCC of different etiologies and their matched peritumorous areas. Immunostaining was performed to localise Frizzled on cell types in liver tissues. Regulation of three known Frizzled-dependent pathways (β-catenin, protein kinase C, and C-Jun NH2-terminal kinase) was measured in tissues by western blot. We found that eight Frizzled-potentially activating events were pleiotropically dysregulated in 95% HCC and 68% peritumours as compared to normal livers (upregulations of Frizzled-3/6/7 and Wnt3/4/5a, or downregulation of sFRP1/5), accumulating gradually with severity of fibrosis in peritumours and loss of differentiation status in tumours. The hepatocytes supported the Wnt/Frizzled signalling since specifically overexpressing Frizzled receptors in liver tissues. Dysregulation of the eight Frizzled-potentially activating events was associated with differential activation of the three known Frizzled-dependent pathways. This study provides an extensive analysis of the Wnt/Frizzled receptor elements and reveals that the dysregulation may be one of the most common and earliest events described thus far during hepatocarcinogenesis

Heterogeneity of hepatitis C virus genotypes in France

The genotypes of French hepatitis C virus (HCV) isolates were investigated by amplification of a domain from the non-structural region 3 (NS3) using nested PCR, followed by hybridization with two genotype- specific probes, FI (HCV type I-specific) and F2 (HCV type II-specific). Among 119 HCV RNA-positive sera, 91 % of samples were NS3 PCR positive. Most samples (83·2 %) hybridized with one or the other probe only, whereas a few samples (4·2 %) hybridized with both F1 and F2 probes (HB). A small percentage (3·4%) of samples appeared unable to hybridize with either probe (HN). For some of these samples (HB1, HB2, HN1, HN2, HN3, HN4), part of the NS3, core and envelope regions were sequenced and the corresponding deduced consensus sequences were compared with those of prototype isolates of the four HCV genotypes (types I to IV). A phylogenetic tree was constructed to illustrate the relationship between these isolates. The results obtained showed that (i) HN4 appears to be more closely related to type III than to type IV HCV genotypes, which suggests that in France there may exist additional although minor genotypes besides the two major types, FI and F2. (ii) HB1, HB2, HN1, HN2 and probably HN3 belong to the type II HCV genotype. The association between sequence diversity and putative biological difference for isolates within the same genotype remains to be elucidated

Comparative study of Hepatitis C virus genotypes 1 and 3 in Salvador, Bahia

Hepatitis C virus displays a high degree of genetic mutation, with considerable heterogeneity, motivating clinical and biomolecular investigations. It is necessary to understand the effects of genotypes on the course of the disease, as well as their peculiarities at the regional level. OBJECTIVE: The study objective was to compare epidemiological, biochemical and histological aspects of hepatitis C virus genotypes 1 and 3 in Salvador, Bahia. STUDY DESIGN: Data were collected retrospectively from outpatient medical records. MATERIALS AND METHODS: 127 patients with positive anti-HCV results were selected, based on detectable RNA-HCV (RT-PCR) of genotypes 1a, 1b and 3a. RESULTS: Thirty-nine (30.7%) individuals were infected by subtype 1a, 45 (35.4%) by subtype 1b and 43 (33.9%) by subtype 3a. Most (73.2%) patients were male, with an average age of 47.8 years. The subtype 1b-infected patients had the highest average age (512 ±11.17; P=0.09). The use of illicit injected drugs was more frequent among subtype 3a infected individuals when compared with genotype 1 (6/43; 14% and 3/84; 3.6%, respectively; P=0,06). No significant differences were found for other epidemiological characteristics. Average values for GT, AST, ALT and ferritin did not differ between the groups (64, 78, 109, 276, respectively). Thyroid dysfunction occurred in 7/30 (23.3%) of those infected by genotype 3 (P=0.05). Cryoglobulinemia was also more frequent in this group (5/13, 38%, P=0.02). Most patients presented limited necro-inflammatory activity, stages 2 and 3 by the METAVIR Classification. In some cases, dissociation was noticed between inflammatory activity and fibrosis. No significant differences were found in the histopathological findings of the various genotypes. Younger patients had a significantly smaller degree of necrosis in stomatocytosis (P=0.032) and fibrosis (P=0.012). Intense parenchymatous activity and lymphoid follicles were more frequent among alcohol consumers (P=0.06 and P=0.04, respectively). CONCLUSIONS: In Bahia, genotype 3 dissemination seems to be associated with illicit drug use. The disease evolution depends on a function of complex interactions between virus and host. Age and alcohol consumption stand out as important variables in the development of cirrhosis