Tadamichi Hirano

A novel 3D hepatectomy simulation based on liver circulation: Application to liver resection and transplantation

Hepatectomy is a complicated operative procedure because of its anatomical complexity, vascular variability, and impaired hepatic function due to associated hepatitis or cirrhosis. Thus preoperative detailed topography and precise liver resection volume measurements should be obtained for a curative hepatectomy. The aim of this study was to assess the feasibility and accuracy of a novel three‐dimensional (3D) virtual hepatectomy simulation software in patients who underwent liver resection or living donor liver transplantation. We developed the hepatectomy simulation software, which was programmed to analyze detailed 3D vascular structure and to predict liver resection volume and margins. In 72 patients receiving hepatectomy, the predicted liver resection volumes and margins revealed a significant correlation with the actual value with a mean difference of 9.3 mL (P < .0001) and 1.6 mm (P < .01), respectively. The drainage area by hepatic veins was quantified to achieve reconstruction of the corresponding venous branch. In conclusion, this hepatectomy simulation software reliably predicted an accurate liver resection volume, the cancer‐free margin, and the drainage volume of hepatic vein branches. This software may promote curative hepatectomy and may be used for other interventional therapies in the treatment of liver disease. (HEPATOLOGY 2005.)

Persistent gene expression in rat liver in vivo by repetitive transfections using HVJ-liposome

Most viral vectors are highly immunogenic and are of limited use for somatic gene therapy that requires repetitive administrations. We have developed a highly efficient gene transduction procedure useful for repetitive transfections using liposome containing hemagglutinating virus of Japan (HVJ-liposome). The Escherichia coli β-galactosidase (β-gal) gene was embodied in HVJ-liposome, and introduced directly into the caudal lobe of rat liver that was transiently isolated from a systemic circulation. A 116 kDa β-gal protein was detected in transfected rat liver tissues by Western blot analysis and it was expressed in more than two- thirds of the liver by histological staining. It was found that the transfection efficiency was not affected by repetitive transfections. In support of these findings, antibody response to HVJ-liposome detected in the rat sera was weak and transient. Furthermore, cytotoxic T lymphocytes were not elicited against autologous rat hepatocytes that were transfected in vivo using HVJ-liposome. Thus, our results demonstrate that the isolation of a target liver from systemic circulation and the direct administration of foreign genes using HVJ-liposomes are useful for high gene transduction and persistent gene expression in the liver.

Hepatocyte growth factor promotes remodeling of murine liver fibrosis, accelerating recruitment of bone marrow-derived cells into the liver.

Aim:  Hepatocyte growth factor (HGF) ameliorates liver fibrosis/cirrhosis in animal models, while the participation of bone marrow‐derived cells (BMC) in the repair process of injured organs has recently been reported. In this study we investigated the roles of HGF and BMC in a remodeling process of liver fibrosis.

Safety Evaluation of Hemagglutinating Virus of Japan–Artificial Viral Envelope Liposomes in Nonhuman Primates

We tested, in cynomolgus monkeys, the safety and effectiveness of a hybrid liposome vector, hemagglutinating virus of Japan (HVJ)--artificial viral envelope (AVE) liposomes, for human therapeutic gene transfer in a series of experiments. In a repetitive intramuscular administration study, vehicle control macaques (n = 2), which were treated with HVJ--AVE liposome suspension, received repetitive intramuscular injections of 2 ml of test substance. Human hepatocyte growth factor (HGF) cDNA-inserted expression vector (pUC-SR alpha/HGF) injection animals (n = 2), which were treated with HVJ--AVE liposome suspension containing pUC-SR alpha/HGF, received repetitive intramuscular injection of 2 ml of test substance. General body condition, hematology, blood chemistry, and serum HGF were determined sequentially before treatment and 7, 21, 28, and 29 days after treatment. Elevations in HGF were detected in monkeys injected with pUC-SR alpha/HGF. After this observation period, macaques were killed for autopsy and histological examination. pUC-SR alpha/HGF was detected by polymerase chain reaction (PCR) analysis in the liver, spleen, and at the injection site. In single intravenous administration study, control macaques (n = 4) received a single intravenous injection of 10 ml of physiological saline. Vehicle control animals (n = 5) received a single intravenous injection of 10 ml of HVJ--AVE liposome suspension. DNA-treated animals (n = 7) received a single intravenous injection of 10 ml of HVJ--AVE liposome suspension containing plasmid DNA [pcDNA 3.1(+)]. General body condition, body weight, hematology, blood chemistry, and urine composition were determined sequentially before treatment and 1, 14, 21, and 28 days after treatment. After this observation period, macaques were killed for autopsy and histological examination. pcDNA 3.1(+) was detected by PCR analysis on day 1 in lung, liver, and spleen of all monkeys, in kidney of one of two monkeys, and in heart of one of two monkeys. However, no DNA was detected in any of the tissues examined on days 14, 21, and 28. No virus genomic RNA was detected by reverse transcription (RT)-PCR analysis with HVJ-specific primers. In this series of safety evaluations, the animals tolerated the safety study with no change in body weight or general condition. No hematological changes or alterations in blood chemistry or urine composition was detected. Moreover, no histological changes were observed. This safety evaluation study demonstrates the safety, feasibility, and therapeutic potential of the novel transfection vehicle, HVJ--AVE liposomes, in humans.

Repeated hepatocyte injury promotes hepatic tumorigenesis in hepatitis C virus transgenic mice.

Although hepatitis C virus (HCV) is a well‐known causative agent of hepatocellular carcinoma (HCC), the mechanism by which HCV induces HCC remains obscure. To elucidate the role of HCV in hepatocarcinogenesis, a model of hepatocyte injury was established using HCV core transgenic mice, which were developed using C57BL/6 mice transfected with the HCV core gene under control of the serum amyloid P component promoter. After 18–24 months, neither steatosis nor hepatic tumors were found in transgenic mice. The extent of hepatocyte injury and tumorigenesis were then examined in transgenic mice following repeated administration of carbon tetrachloride (CCl4) using various protocols (20%, 1/week; 10%, 2/week and 20%, 2/week). Serum alanine aminotransferase (ALT) levels did not differ among HCV core transgenic mice and non‐transgenic littermates; however, after 40 weeks, hepatic adenomas preferentially developed in transgenic mice receiving 20% CCl4 once weekly. Moreover, HCC was observed in transgenic mice receiving 2 weekly injections of a 20% solution of CCl4, and was not observed in the non‐transgenic control mice. In conclusion, the HCV core protein did not promote hepatic steatosis or tumor development in the absence of hepatotoxicity. However, the HCV core protein promoted adenoma and HCC development in transgenic mice following repeated CCl4 administration. These results suggest that hepatotoxicity resulting in an increased rate of hepatocyte regeneration enhances hepatocarcinogenesis in HCV‐infected livers. Furthermore, this experimental mouse model provides a valuable method with which to investigate hepatocarcinogenesis.

Hepatocyte growth factor improves survival after partial hepatectomy in cirrhotic rats suppressing apoptosis of hepatocytes

BACKGROUND Liver failure after hepatic resection is still a critical issue in the treatment of hepatic tumors in patients with liver cirrhosis. In the current study, the effect of hepatocyte growth factor (HGF) gene transfer, which is a multipotent growth factor, was examined in rats with liver cirrhosis that underwent 2/3 partial hepatectomy (PH). METHODS Rats were treated with 1 mL of 1% dimethylnitrosoamine (DMN) 3 consecutive days per week for 4 weeks and then received a 2/3 PH. Three days before the PH, human HGF gene plasmid (20 microg) encapsulated in hemagglutinating virus of Japan (HVJ)-liposome was administered through a direct injection in the portal vein. Control cirrhotic rats received empty HVJ-liposome in the same manner. RESULTS HGF gene transfer significantly improved survival after PH in the cirrhotic rats, and it stimulated BrdU uptake in hepatocytes. Although the HGF gene transfer did not change the liver regeneration rate after PH, it suppressed hepatocyte apoptosis and upregulated an antiapoptotic protein, Bcl-xl, but it did not affect the expression of Bax, which is a proapoptotic protein. CONCLUSION HGF gene transfer to cirrhotic livers improves liver failure-associated death after PH upregulating expression of an antiapoptotic protein, Bcl-xl.

Hepatocyte growth factor gene transfer with naked plasmid DNA ameliorates dimethylnitrosamine‐induced liver fibrosis in rats

Aim:  Hepatocyte growth factor (HGF) has various biological properties, including antifibrogenic activity. In the present study, we tested the efficacy of HGF gene therapy using naked plasmid DNA in dimethylnitrosamine (DMN)‐induced liver fibrosis in a rat model.

Long-term safety of autotransfusion during hepatectomy for hepatocellular carcinoma.

PurposeTo evaluate the long-term safety of autotransfusion (AT) in hepatectomy for hepatocellular carcinoma (HCC).MethodsBetween 1988 and 1989, 46 patients with HCC underwent hepatectomy with AT (group 1). For a comparison, we matched 50 patients with HCC who underwent hepatectomy, and received homologous but not autologous blood (group 2). The 10-year cumulative survival curves and cancer-free curves of the two groups were examined, and the pattern of recurrence was compared.ResultsGroup 1 had a significantly higher cumulative 10-year survival rate than group 2, at 20% vs 8%, respectively (P < 0.05). Among the patients who underwent curative resection, those in group 1 had significantly better cumulative survival and cancer-free survival rates than those in group 2, at 27% vs 11% (P < 0.05) and 13% vs 0% (P < 0.05), respectively. Among the patients with stage I–II HCC, those in group 1 had significantly better cumulative survival and cancer-free survival rates than those in group 2, at 30% vs 5% (P < 0.01) and 20% vs 5% (P < 0.05), respectively. However, the rates were similar among patients with stage III–IV disease in both groups. The pattern of recurrence in the two groups was similar.ConclusionAutotransfusion promoted survival in patients undergoing hepatectomy for stage I or II HCC.

Fascin, a novel marker of human hepatic stellate cells, may regulate their proliferation, migration, and collagen gene expression through the FAK-PI3K-Akt pathway

Fascin is a component of actin bundles and may regulate various cellular events. The expression and function of fascin in human hepatic stellate cells (HSCs) has remained largely uncharacterized. Fascin expression in human liver tissue was studied using immunohistochemistry. To identify cells expressing fascin, double immunofluorescent staining with vimentin, α-smooth muscle actin (α-SMA), or fibulin-2 was performed and analyzed with confocal microscopy. In culture experiments, fascin expression and the phosphorylation of focal adhesion kinase (FAK) and Akt in LX-2 cells, a cell line of human HSCs, were investigated using western blot. Specific siRNAs were used to reduce the expression of fascin in LX-2 cells. Proliferation and migration were assayed with a CyQuant assay kit and a Matrigel-coated culture insert system, respectively. Levels of matrix metalloproteinase (MMP)-2 and collagen mRNAs were examined using quantitative RT-PCR. Immunohistochemistry revealed the expression of fascin along sinusoids and overlapping with vimentin and α-SMA in both non-fibrotic and fibrotic liver tissue, but it was almost absent in periportal myofibroblastic cells and did not colocalize with fibulin-2, a marker of portal myofibroblasts. In addition, fascin immunoreactivity was almost undetectable in septa of fibrotic human liver tissue. The expression of fascin in LX-2 cells was confirmed using western blot. Two different specific siRNAs against fascin significantly reduced the number of viable LX-2 cells to 65% compared with control cultures and downregulated the mRNAs levels of types I and III collagen and MMP-2 to 62%, 65%, and 70% of control levels, respectively. This condition also reduced the migration activity of LX-2 cells to 46% of control cells and the phosphorylation level of both FAK and Akt. Fascin may be an excellent novel marker of human HSCs that distinguishes HSCs from periportal myofibroblasts. Fascin may regulate functions of human HSCs through the FAK-phosphoinositide 3-kinase-Akt pathway.

c-Jun N-terminal kinase activation by oxidative stress suppresses retinoid signaling through proteasomal degradation of retinoic acid receptor α protein in hepatic cells.

We previously reported that impaired retinoid signaling causes hepatocellular carcinoma (HCC) through oxidative stress. However, the interaction between oxidative stress and retinoid signaling has not been fully understood. To address this issue, the effects of hydrogen peroxide on the transcriptional activity of RAR/RXR heterodimers, RARα and RXRα proteins and intracellular signaling pathways were examined. The transcriptional activity of RAR/RXR examined by the DR5‐tk‐Luc reporter assay was significantly suppressed. The RARα protein level began to decrease at 6 h after treatment and declined thereafter. However, RARα mRNA were not changed. Activation of extracellular regulated kinases (ERK), p38, c‐Jun N‐terminal kinase (JNK) and Akt was observed after treatment of hydrogen peroxide. SP600125, an inhibitor of JNK, reversed the RARα protein level reduced by hydrogen peroxide. Anisomycin, an activator of JNK, reduced RARα protein. Transfection of wild‐type JNK‐constitutive actively expressing plasmid, but not kinase‐negative JNK‐expressing plasmid caused reduction of RARα protein. Proteasomal degradation of RARα was observed after anisomycin treatment; however, the mutant RARα, of which phosphorylation sites are replaced with alanines, was not degradated. In hepatitis C virus (HCV)‐related human liver tissues, phospho‐JNK and RARα reciprocally expressed with the progression of liver disease. Finally, the staining of 8‐OHdG and thioredoxin was increased with the disease progression. These data indicate that JNK activation by oxidative stress suppresses retinoid signaling through proteasomal degradation of RARα, suggesting that a vicious cycle between aberrant retinoid signaling and oxidative stress accelerates hepatocarcinogenesis. (Cancer Sci 2011; 102: 934–941)