Preventive effect of caffeine and curcumin on hepato-carcinogenesis in diethylnitrosamine-induced rats.

Chemopreventive effects of caffeine and curcumin were evaluated in the diethylnitrosamine (DEN)-induced hepatocarcinogenic rat model. Animals injected with DEN for 10 weeks (G2-10w) and 14 weeks (G2-14w) were hepato-carcinogenic rats. Animals injected with DEN and treated with curcumin and caffeine for 10 weeks (G3-10w, G4-10w) and 14 weeks (G3-14w, G4-14w) were compared with those in G2. Macroscopic and microscopic features suggested that treatment with caffeine, but not curcumin, for 10 and 14 weeks was effective in inhibiting DEN-induced hepatocarcinogenesis. Immunohistochemical and western blot analysis with proliferating cell nuclear antigen and glutathione S-transferase-P antibodies also showed that expression levels of these hepato-carcinogenic markers were more efficiently reduced by treatment with caffeine than curcumin. Our data demonstrate that caffeine could be a more potent compound than curcumin for prevention of hepatocarcinogenesis in DEN-induced rats.

Assessment of ablative margin after radiofrequency ablation for hepatocellular carcinoma; comparison between magnetic resonance imaging with ferucarbotran and enhanced CT with iodized oil deposition.

BACKGROUND AND PURPOSE: Our aim was to investigate whether magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation could accurately assess ablative margin when compared with enhanced computed tomography (CT) with iodized oil marking. MATERIALS AND METHODS: We enrolled 27 patients with 32 hepatocellular carcinomas in which iodized oil deposits were visible throughout the nodule after transcatheter arterial chemoembolization. For these nodules, radiofrequency ablation was performed after ferucarbotran administration. We then performed T2-weighted MRI after 1 week and enhanced CT after 1 month. T2-weighted MRI demonstrated the ablative margin as a low-intensity rim. We classified the margin into three grades; margin (+): high-intensity area with a continuous low-intensity rim; margin zero: high-intensity area with a discontinuous low-intensity rim; and margin (-): high-intensity area extending beyond the low-intensity rim. RESULTS: In 28 (86%) of 32 nodules, there was agreement between MRI and CT. The overall agreement between for the two modalities in the assessment of ablative margin was good (κ=0.759, 95% confidence interval: 0.480-1.000, p<0.001). In four nodules, ablative margins on MRI were underestimated by one grade compared with CT. CONCLUSION: MRI using ferucarbotran is less invasive and allows earlier assessment than CT. The MRI technique performed similarly to enhanced CT with iodized oil marking in evaluating the ablative margin after radiofrequency ablation.

The effects of the selective mineralocorticoid receptor antagonist eplerenone on hepatic fibrosis induced by bile duct ligation in rat.

The aim of this study was to examine the effects of eplerenone on hepatic fibrosis induced by bile duct ligation (BDL) in rat. Low- (1.0 mg/kg body weight, BW) and high- (4.0 mg/kg BW) dose eplerenone was administered orally for 21 days immediately following BDL. Fibrosis was assessed by measuring the fibrotic area after Sirius red staining. Immunostaining for alpha-smooth muscle actin (SMA), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) was also carried out. Gene expression levels of procollagen-I, transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), tissue inhibitor of metalloproteinases-1 (TIMP-1) and matrix metalloproteinase-13 (MMP-13) in the liver were examined by real-time reverse transcriptase polymerase chain reaction. Plasma angiotensin II (ATII) concentration was measured via radioimmunoassay. The area of hepatic fibrosis and alpha-SMA positivity in the high-dose group was significantly decreased compared with that in the BDL group, but not in the low-dose group. 8-OHdG-positive cells in the low- and high-dose groups were significantly decreased compared with those in the BDL group. Immunostaining of 4-HNE in the high-dose group was significantly lower compared with that in the BDL group. Furthermore, TIMP-1 mRNA levels in the low- and high-dose groups were lower than that in the BDL group. The expression of TGF-beta1, CTGF, procollagen-1 and MMP-13 showed no differences. Plasma ATII concentration in the high-dose group was significantly decreased. Eplerenone attenuated the development of BDL-induced hepatic fibrosis by reducing oxidative stress, suppressing activated hepatic stellate cells and decreasing plasma ATII levels. Eplerenone may prove useful as an alternative treatment for antifibrosis therapy.

Soluble c-kit receptor mobilizes hematopoietic stem cells to peripheral blood in mice.

OBJECTIVE: The mechanisms of mobilization of hematopoietic stem cells (HSC) from bone marrow to peripheral blood (PB) by cytokines are poorly understood. One hypothesis is that cytokines disrupt cytoadhesive interactions of stem cells with bone marrow stroma. The soluble portion of c-kit (s-kit) binds stem cell factor (SCF) and can specifically block the ability of SCF to bind HSC. MATERIALS AND METHODS: To examine stem cell mobilization by s-kit, we prepared PB mononuclear cells from s-kit- or granulocyte colony-stimulating factor (G-CSF)-treated mice and assayed their colony-forming abilities and their long-term reconstituting abilities by transplantation into lethally irradiated Ly-5.2 congenic mice. RESULTS: We confirmed the published findings that human recombinant s-kit can block SCF-stimulated hematopoietic colony growing. We then found that s-kit could mobilize colony-forming cells from bone marrow to PB, and we found long-term reconstitution cells in the PB from s-kit-treated mice. The majority of s-kit-mobilized stem cells were in the CD34(+) cell population. We also tested the additive effect between G-CSF and s-kit. The mean percentages of donor cells in the mice transplanted with Lin(-) cells from the G-CSF-treated mice and the G-CSF/s-kit-treated mice were 44.6% and 64.8%, respectively (p=0.028). CONCLUSIONS: These findings demonstrate that stem cells with long-term engraftment capabilities can be mobilized by s-kit, and that s-kit combined with G-CSF treatment leads to significant enhancement of engraftment efficiency, suggesting mobilization via disruption between c-kit and SCF as the mechanism.

Hepatocyte growth factor exerts a proliferative effect on oval cells through the PI3K/AKT signaling pathway.

Hepatocyte growth factor (HGF) is a potent mitogen for a variety of cells including hepatocytes. While rat oval cells are supposed to be one of hepatic stem cells, biological effects of HGF on oval cells and their relevant signal transduction pathways remain to be determined. We sought to investigate them on OC/CDE22 rat oval cells, which are established from the liver of rats fed a choline-deficient/DL-ethionine-supplemented diet. The oval cells were cultured on fibronectin-coated dishes and stimulated with recombinant HGF, transforming growth factor-alpha (TGF-alpha), and thrombopoietin (TPO) under the serum-free medium condition. HGF treatment enhanced [3H]thymidine incorporation into oval cells in a dose-dependent manner. On the contrary, treatment with TGF-alpha or TPO had no significant effects on [3H]thymidine incorporation into the oval cells. c-Met protein was phosphorylated at the tyrosine residues after the HGF treatment. AKT, extracellular signal-regulated kinase 1/2 (ERK1/2), and p70(s6k) were simultaneously activated after the HGF stimulation, peaking at 30min after the treatment. The activation of AKT, p70(s6k), and ERK1/2 induced by HGF was abolished by pre-treatment with LY294002, a phosphoinositide 3-OH kinase (PI3K) inhibitor, and U0126, a mitogen-activated protein kinase/ERK kinase (MEK) inhibitor, respectively. When the cells were pre-treated with LY294002 prior to the HGF stimulation, the proliferative action of HGF was completely abrogated, implying that the PI3K/AKT signaling pathway is responsible for the biological effect of HGF. These in vitro data indicate that HGF exerts a proliferative action on hepatic oval cells via activation of the PI3K/AKT signaling pathway.

Reduction of hepatocarcinogenesis by ursodeoxycholic acid in rats.

Ursodeoxycholic acid (UDCA) is used worldwide for treatment of primary biliary cirrhosis and chronic liver diseases. However, its action on hepatocarcinogenesis remains to be explored. To clarify its effect, in vivo and in vitro experiments were performed. Ninety Fisher 344 rats were fed a standard diet (Group 1, n = 30), a standard diet supplemented with 0.1% UDCA (Group 2, n = 30) and 0.3% UDCA (Group 3, n = 30). The rats were given an i.p. injection of diethylnitrosamine (DEN) weekly for 6 weeks. Fifteen additional rats were fed 0.3% UDCA supplemented diet without DEN treatment (Group 4). The rats were killed at 5, 10 and 18 weeks after the last injection of DEN. The number of liver tumor and percentage of the GST-P-positive hepatocytes were significantly reduced by UDCA treatment. The PCNA-positive cells were decreased by administration of UDCA at 18 weeks. The increased number of apoptotic cells was observed in the GST-P-negative area at 5, 10 and 18 weeks and in the GST-P-positive area at 18 weeks in the UDCA group. Expression of Bax in mitochondria and cytochrome c in cytosol was increased by UDCA treatment. Caspase 3 activity was also increased in the UDCA groups. The addition of UDCA into the culture of Huh7 and Fao hepatocellular carcinoma (HCC) cells induced apoptosis in a dose-dependent manner. The data of the present study suggest that UDCA treatment reduces hepatocarcinogenesis via inducing apoptosis of 'initiated hepatocytes' as well as inhibiting proliferation.

Effects of Sho-Saiko-to on hepatocarcinogenesis and 8-hydroxy-2'-deoxyguanosine formation.

Oxidative stress plays an important role in hepatocarcinogenesis. Although Sho-saiko-to (TJ-9), a Japanese herbal medicine which has been recently administered to patients with chronic liver disease in Japan, prevents hepatocarcinogenesis, the mechanism by which TJ-9 protects against cancer development is not fully understood. 8-Hydroxy-2'-deoxyguanosine (8-OHdG), a DNA adduct by reactive oxygen species, is known as a parameter of genetic risk for hepatocarcinogenesis. To clarify whether the preventive effect on hepatocarcinogenesis by TJ-9 is dependent on 8-OHdG, the effect on 8-OHdG levels by TJ-9 was examined by using high-performance liquid chromatography-mass spectrometry (LC-MS) in a diethylnitrosamine (DEN)-induced hepatocarcinogenesis model of male Fisher rats. TJ-9 reduced the number of preneoplastic cells, detected as the glutathione S transferase P (GST-P)-positive hepatocytes, and inhibited the development of liver tumors. TJ-9 also significantly decreased the formation of 8-OHdG, as indicated by LC-MS and immunohistochemical analysis. In addition, ornithine decarboxylase (ODC) activity and the number of proliferating cell nuclear antigen (PCNA)-positive cells were not altered. An electron paramagnetic resonance spin-trapping technique showed that TJ-9 scavenges hydroxyl radicals in a dose-dependent manner. In conclusion, the results of the present study suggest that TJ-9 prevents hepatocarcinogenesis in association with inhibition of 8-OHdG formation.