Osamu Yokosuka

Hepatitis A virus VP3 may activate serum response element associated transcription.

Background: Hepatitis A virus (HAV) infection is a major public health problem worldwide. The infection does not induce any visible cytopathic effects or interfere with macromolecular synthesis in host cells. However, the hepatitis B and C viruses have recently been reported to activate intracellular signals. To clarify the effects of HAV infection on intracellular signalling, we examined the influence of 9 FLAG- tagged HAV proteins (VP2, VP3, VP1-2A, 2B, 2C, 3A, 3BC, 3C and 3D) on signal transduction pathways. Methods: Viral protein expression vectors were co-transfected into HeLa cells with reporter Plasmids controlled by a synthetic promoter containing direct repeats of the cyclic AMP response element (CRE), serum response factor (SRF), activator protein 1 (AP-1), nuclear factor kB (NF-kB) or serum response element (SRE). Cells were harvested 42 h after transfection and luciferase assays were performed. Viral protein activation twice that of the control was defined as significant. Results: VP3 induced an SRE-associated signal 2.2 ± 0.3 times higher than that of control. VP3 did not activate CRE-, SRF-, AP-I- or NF-kB- associated signalling. The other HAV proteins tested also failed to induce these pathways. Conclusions: HAV interacts with the host signalling mechanism, and HAV VP3, different from HBX and hepatitis C core protein, may activate only SRE-associated intracellular signalling, a pathway associated with cell proliferation and differentiation.

Sustained viral response is rarely achieved in patients with high viral load of HCV RNA by excessive interferon therapy

Adequate dosing of interferon (IFN) and its cost-effectiveness for sustained virological response were evaluated in relation to viral load and subtype. Prospective analysis of IFN therapy on 326 patients with chronic hepatitis C free from cirrhosis was performed using 9 or 6 million unit (MU) of IFN for six months daily and/or three times a week. Sustained virological response was achieved in 50–94% of patients with ≤2 × 104 copies/ml (competitive RT-PCR) or <100 × 103 copies/ml (Amplicor monitor) of HCV RNA by 468–1206 MU of IFN, but response was only 0–25% of the patients with ≥2 × 105.5 copies/ml (competitive RT-PCR) or >200 × 103 copies/ml (Amplicor monitor), even with 468–1206 MU of IFN. A high sustained rate was demonstrated in patients with 100–200 × 103 copies/ml of HCV RNA by 901–1206 MU of IFN, in comparison to that with ≤900 MU of IFN. Multivariate analysis showed that IFN dose had a significant value for the efficacy of IFN therapy in patients presenting 100–200 × 103 copies/ml of HCV RNA. Cost efficacy analysis indicated that it cost approximately

Absence of the AKT1 pleckstrin homology domain mutation in Japanese gastrointestinal and liver cancer patients

10,000,

Hepadna Viruses and Hepatocarcinogenesis

26,000, and

The Effect on Gastric Emptying of Telaprevir-Based Triple Therapy for Chronic Hepatitis C Patients

50,000–227,000 for one person-viral eradication in the patients with <100, 100–200, and >200 × 103 copies/ml, respectively. High-dose IFN is only cost effective in patients with intermediate viral loads, and IFN therapy could be recommended in patients with <200 × 103 copies/ml of HCV RNA.

Abstract A39: The exploration of novel strategy for treatment of pancreactic ductal adenocarcinoma targeting tumor microenvironment with multi-kinase inhibitors

The phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway regulates many cellular processes involved in cell survival, proliferation, and motility (1). The aberrant activation of this pathway has been reported in many types of cancers, and the altered expression and mutation of numerous Akt-related signaling components have been implicated in the genesis and progression of human cancers (2). Regarding Akt, Parson et al. analyzed mutations in the catalytic domains of 340 serine/threonine kinase genes, including AKT1, AKT2 and AKT3. Genetic mutation in the AKT2 gene was detected in 1.0% (2/204) of colorectal cancers, although the physiological significance of this remains unclear (3). In addition to this AKT2 kinase domain mutation, the pleckstrin homology (PH) domain of AKT1 was somatically mutated in 8% (5/61) of breast cancers, 6% (3/51) of colorectal cancers, and 2% (1/50) of ovarian cancers (4). The authors identified a G to A point mutation at nucleotide 49 of exon 4, which resulted in a lysine to glutamic acid substitution at amino acid 17 (E17K). This mutation caused the aberrant activation of Akt by means of pathological localization to the plasma membrane. Moreover, this E17K mutation possessed in vitro and in vivo transforming activity and may indicate a new mechanism of PI3K-Akt pathway activation. Some mutations are specific to ethnic populations. One example is epidermal growth factor receptor (EGFR) mutations in lung cancer, which have a high frequency in women and Asians, but are relatively rare in Caucasians (5). However, the frequency of this E17K mutation

Predictors of the efficacy of interferon therapy in chronic hepatitis C virus infection. Tokyo-Chiba Hepatitis Research Group

Since the discovery of Australian antigen, the rate of hepatitis B (HBV) infection among patients with hepatocellular carcinoma (HCC) has been studied in various parts of the world. In 1971, Tong et al. reported that 44 of 55 (88%) patients with HCC in Taiwan were positive for hepatitis B surface antigen (HBsAg) by the agar gel diffusion test [1]. Subsequently, many studies in Africa and Asia showed that the positivity rate for HBsAg varied from 35% to 90% in patients with HCC [2]. When additional serum testings for anti-HBs and anti-HBc (core) were included, HBV infection rates reached 75%–81% in Africa [3], the USA [4], and Japan [5] (Table 3.1). These data indicate that the majority of patients with HCC had a previous infection or current antigenemia.

Nucleotide change of codon 38 in the X gene of hepatitis B virus genotype C is associated with an increased risk of hepatocellular carcinoma.

Aim: We evaluated food intake in telaprevir-based triple therapy (telaprevir, pegylated-interferon, and ribavirin) and its relation to Gastric Emptying (GE).

Role of IL28B genotype in older hepatitis C virus-infected patients

Background and Aim: Pancreatic ductal adenocarcinoma (PDAC) is an almost uniformly lethal disease in humans. Previously, we have reported a genetically engineered mouse PDAC progression model which has pancreatic-specific transforming growth factor-beta receptor type II knockout in the context of Kras activation (Ijichi H, et al 2006). This model shows PDAC with 100% penetrance and recapitulates the signature of human PDAC well. Using this model, we explored novel treatment for PDAC. Materials and Methods: At first, to investigate whether the mice model is suitable for the drug screening, the mice were treated with gemcitabine (12.5 mg/kg) by intraperitoneal (i.p.) injection or S-1 (8.4 mg/kg) per oral, which are the standard drug for human PDAC. To the next, for single agent treatment, mice were treated orally 6 times a week with vehicle (0.5 % carboxymethyl cellulose, CMC), sunitinib (40 mg/kg), and axitinib (30mg/kg), both of which are multikinase inhibitors targeting vascular endothelial growth factor receptor (VEGFR) and platelet derived growth factor receptor (PDGFR) from the 3 weeks of age. For combined agent experiment, mice were treated orally with vehicle (0.5 % CMC) or axitinib from the 3 weeks of age and also treated with saline or gemcitabine, i.p. twice a week from the 4 weeks of age. Treatment continued until 8 weeks of age. Moreover, for the survival analysis, the drug treatment was continued until the mice became distressed according to the same schedule stated above. In vivo anti-tumor effect and survival time were assessed. Immunostaining of tumor tissue for caspase 3, Ki67, CD31, F4/80 and VEGF was performed. Azan staining also performed for the assessment of fibrosis in the tumor. Results: Gemcitabine and S-1 showed antiproliferative effect and prolonged overall survival of these mice compared to control, as well as human cases. Median survival time of single use of axtinib and sunitinib group was significantly longer (p <0.01) than that of control group. Axitinib and sunitinib group showed significantly stronger anti-tumor effect in vivo (p <0.01). In the combined treatment experiment, gemcitabine plus axitinib-treated group showed statistically significant longer survival and more anti-tumor effect than that of gemcitabine or axtinib alone-treated group (p <0.01). Axitinib and sunitinib group showed significantly higher caspase 3 stainng and lower Ki67 staining than that of control (p <0.01). Microvessel density (CD 31 staining) of axitinib and sunitinib group was significantly lower than that of control (p <0.01). F4/80 staining was significantly lower in axitinib and sunitinib-treated group than that of control (p <0.05). VEGF expression of axitinib and sunitinib group was significantly lower than that of control a (p <0.001). Azan staining showed significantly lower fibrosis in axitinib and sunitinib-treated group compared to control (p <0.01). Conclusion: Targeting not only cancer cells but also tumor microenvironment, such as angiogenesis, infiltration of immune cells, and fibrosis, with the use of multikinase inhibitors in addition to gemcitabine, may be a promising therapeutics for PDAC.