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Biomedical subjects

Norifumi Harimoto

Publications and source records attributed to Norifumi Harimoto.

14 recordsLinked to original sources
PubMed2005

The newly established human hepatocyte cell line: application for the bioartificial liver.

BACKGROUND/AIMS: Human hepatocyte cell lines are reported to lose many of their biochemical functions in a hybrid artificial liver support system (HALSS). Differentiation therapy is useful to up-regulate liver function. METHODS: The human hepatoblastoma cell line HepG2 was transfected with HSV/tk gene. Albumin synthesis and ammonia removal activity were evaluated when HepG2/tk was cultured with histone deacetylase inhibitor (FR228) and peroxisome proliferator activated receptor-gamma ligand (pioglitazone). To investigate the function of HepG2/tk in vivo, cell transplantation for 90% hepatectonized rats was conducted. RESULTS: We established stable cell lines which expressed HSV/tk and were sensitive to gancyclovir in vitro and in vivo. Both albumin synthesis rate and ammonia removal rate improved for HepG2/tk incubated with FR228 and pioglitazone for 3 days, which induced nuclear transport of p21. Rats with intrasplenic injection of HepG2/tk precultured for 3 days with FR228 and pioglitazone survived significantly longer than the control rats. The ammonia and total bilirubin concentrations were significantly lower in the test group than in the control group. The injection of gancyclovir inhibited the prolonged survival of the rats with precultured HepG2/tk. CONCLUSIONS: HepG2/tk is safe as well as enhancing high levels of liver function. It will be a potential cell source for HALLS in the future.

Animals↗
PubMed2005

Subsieve-size agarose capsules enclosing ifosfamide-activating cells: a strategy toward chemotherapeutic targeting to tumors.

Localized activation of the prodrug ifosfamide in or close to tumors by implanting encapsulated ifosfamide-activating cells is an efficacious strategy for tumor therapy. The aim of this study was to evaluate the feasibility of subsieve-size agarose capsules for enclosing the cells in this application. Compared with many conventional microcapsules, subsieve-size agarose capsules are about one-tenth the size and have both higher mechanical stability and allow better molecular exchangeability than other systems. Cells that have been genetically modified to express cytochrome P450 2B1 enzyme were encapsulated in subsieve-size agarose capsules of approximately 90 microm in diameter and implanted into preformed tumors in nude mice. Living cells were detected for >1 month after encapsulation in vitro and showed enzymatic activity (i.e., they were able to activate ifosfamide). More significant regression of preformed tumors was observed in the recipients implanted with cell-enclosing capsules compared with those implanted with empty capsules. These results suggest that the strategy of using subsieve-size agarose capsules enclosing cytochrome P450 2B1-expressing cells is feasible for tumor therapy by chemotherapeutic targeting in combination with ifosfamide administration.

Animals↗
PubMed2004

The role of heat shock protein 27 expression in hepatocellular carcinoma in Japan: special reference to the difference between hepatitis B and C.

BACKGROUND: A recent report showed that heat shock protein (HSP)-27 expression was related to histological grade and survival of patients with hepatocellular carcinoma (HCC). AIMS: The aim of this study was to examine the effect of expression of HSP-27 on clinicopathological variables in Japanese patients with HCC. METHODS: An immunohistochemical study for HSP-27 was performed on 60 HCC cases using a monoclonal anti-HSP-27 antibody. We divided 60 patients into two groups, patients with a low expression of HSP-27 (n = 34) and those with a high expression of HSP-27 (n = 26). Forty patients tested positive for the hepatitis C virus (HCV) antibody and 20 tested positive for the hepatitis B surface antigen. RESULTS: There appeared to be no relationship between HSP expression and clinicopathologic factors and no differences were observed between the high expression group and the low expression group. In the hepatitis B virus (HBV) group (n = 20), HSP-27 expression correlated significantly with prognosis, disease-free survival (DFS) and overall survival. High expression was significantly associated with poor prognosis in the HBV group. In contrast, patients with a high expression tended to have a good prognosis in the HCV group (n = 40): DFS and overall survival. CONCLUSIONS: This study showed the possibility that HSP-27 plays different roles in HBV- and HCV-associated HCCs.

Adult↗
PubMed2004

cDNA microarray analysis in hepatocyte differentiation in Huh 7 cells.

The risk of xenozoonosis infections poses the greatest obstacle against the clinical application of a hybrid artificial liver support system (HALSS). Primary human hepatocytes are an ideal source for HALSS, but the shortage of human livers available for hepatocyte isolation limits this modality. To resolve this issue, we previously demonstrated the upregulation of hepatocyte-specific function by spheroid formation in polyurethane foam and by culturing with the histone deacetylase inhibitor, trichostatin A (TSA), in a human hepatoma cell line (Huh 7). In this article we analyze the gene expression profile using cDNA microarray (1281 genes) in spheroid formation or culturing with TSA in Huh 7 to determine the target genes in hepatocyte differentiation. In both the spheroid formation and in the culture with TSA, the Oct-3/4 transcription factor was upregulated more thantwofold, while the early growth response-1 (EGR-1) transactivator was downregulated less than 0.5-fold. These results indicate that expressions of Oct-3/4 and EGR-1 may be key factors in the induction of hepatocyte differentiation in Huh 7.

Cell Culture Techniques↗
PubMed2004

Muscle-targeted interleukin-12 gene therapy of orthotopic hepatocellular carcinoma in mice using in vivo electrosonoporation.

We developed a new potent nonviral gene transfer method into mouse muscles in vivo named "electrosonoporation." We tried in this report to treat murine orthotopic hepatocellular carcinoma (HCC) by muscle-targeted mouse interleukin-12 (mIL-12) gene transfer using in vivo electrosonoporation. I.m. administration of the mIL-12 gene with electrosonoporation elevated serum IL-12 and IFN-gamma and significantly prolonged the survival periods with both growth inhibition of orthotopic HCC and inhibition of spontaneous lung metastasis. The IL-12 gene therapy reduced the number of microvessels and induced more Mac-1-positive cells into HCC. These results show that muscle-targeted mIL-12 gene therapy for orthotopic HCC using in vivo electrosonoporation is very efficient and is thus promising for further clinical trial.

Animals↗
PubMed2003

Histone deacetylase inhibitor trichostatin A induces cell-cycle arrest/apoptosis and hepatocyte differentiation in human hepatoma cells.

Remodeling of the chromatin template by inhibition of HDAC activities represents a potential transcriptional therapy for neoplastic disease. A number of HDAC inhibitors that modulate in vitro cell growth and differentiation have been developed. We analyzed the effects of TSA, a specific and potent HDAC inhibitor, on the human hepatoma cell lines HepG2 and Huh-7. TSA increased levels of acetylated histones H3 and H4 in both HepG2 and Huh-7. It inhibited cell proliferation in vitro and induced G(0)/G(1) arrest in HepG2 and apoptosis in Huh-7. Gene expression of liver-specific functions and liver-enriched transcription factors was upregulated by TSA. TSA upregulated the ammonia removal rate and the albumin synthesis rate of HepG2 and Huh-7. Our results indicate that TSA can induce cell-cycle arrest/apoptosis and hepatocyte differentiation in human liver cancer cell lines.

Albumins↗
PubMed2002

In vivo gene transfer into muscle via electro-sonoporation.

Among the nonviral techniques for gene transfer in vivo, electroporation is simple, potent, inexpensive, and safe. To upregulate the expression levels of the transferred gene, we investigated the applicability of in vivo electro-sonoporation, which consists of a combination of electric pulse and ultrasound, for gene transfer using plasmid DNA encoding luciferase and mouse interleukin-12 (mIL-12). The quadriceps muscles of mice were injected with plasmid DNA, then sonoporated for 5 min, and electroporated by a pair of electrode plates at the middle of the duration of sonoporation. Three days later, mice that had undergone electro-sonoporation demonstrated twofold higher luciferase activity and low tissue damage in quadriceps muscle compared to mice having undergone electroporation alone. Serum mIL-12 levels in mice that had undergone electro-sonoporation (peaking at 25.5 ng/ml) were twofold higher after gene transfer than were those in mice having undergone electroporation alone (peaking at 14.3 ng/ml), and maintained high serum level of 13.9 ng/ml at 28 days after gene transfer. The efficacy of gene transfer via electro-sonoporation was superior when the plasmid DNA solution was 0.85% NaCl compared to albumin microbubble echo-contrast material. These results demonstrated that gene transfer into muscle via electro-sonoporation could provide a new potent nonviral technique for gene transfer in vivo.

Animals↗
PubMed2002

Oncogenic signal transduction and therapeutic strategy for hepatocellular carcinoma.

Discoveries of oncogenic signaling molecules lead to the comprehension of molecular mechanisms of tumor progression, as well as to the development of novel therapeutic tools for hepatocellular carcinoma. We have identified critical functions of intracellular signals transmitted from insulin-like growth factor and Wnt oncoprotein in carcinogenesis. The insulin-like growth factor system activates a number of signaling cascades resulting not only in hepatic mitogenesis, but also in cell survival. The secreted oncoprotein Wnt transforms beta-catenin potentials as a component of cell adhesion complexes with cadherins, into a transcription factor in the nucleus. Here, the important role of such signal transduction is reviewed, and we emphasize its control as a promising approach for the treatment of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed2002

Intrahepatic cholangiocarcinoma: its mode of spreading and therapeutic modalities.

Intrahepatic cholangiocarcinoma (IHCC) is a primary adenocarcinoma of the liver, arising from the intrahepatic bile ducts. The prognosis is generally poor because locoregional extension is usually advanced at the time of diagnosis. Even after a resection, the outcome for patients with advanced IHCC is extremely poor, and the presence of lymph node metastasis has been reported in most previous studies to be the worst prognostic factor after a resection. There are no clear guidelines on lymph node dissection with IHCC. In this article, we review the mode of invasion and the therapeutic modalities: hepatic resection, lymph node dissection, liver transplantation, radiation, and chemotherapy for IHCC.

Adenocarcinoma↗
PubMed2002

Minimally invasive hepatectomy: modulation of systemic reactions to operation or laparoscopic approach?

BACKGROUND: A new concept of surgical stress has been proposed that consists of both aggressiveness of operation and systemic reactions to an operation. METHODS AND RESULTS: We have investigated a possible modulation of such systemic reactions to operation and have demonstrated the following 3 points: (1) coagulation and fibrinolytic systems are independently activated during hepatectomy and such activation can be modulated by protease inhibitors such as nafamostat mesilate and antithrombin III; (2) elevated thromboxane A2 during hepatectomy is characterized in the prostanoid system, the elevation of thromboxane A2 is inhibited by thromboxane A2 synthetase inhibitor, and postoperative liver injury is reduced; (3) cytokine response induced by hepatectomy is modulated by preoperative administration of methylprednisolone, leading to possible prevention of bacterial translocation. Therefore, modulating systemic reactions to hepatectomy may be important for successful minimally invasive hepatectomy. Another important option for minimally invasive hepatectomy is the use of operative procedures such as laparoscope or thoracoscope. We have investigated the usefulness of a laparoscopic hepatectomy from the standpoints of early and long-term outcome after hepatectomy. Laparoscopic hepatectomy, which is a difficult and dangerous procedure, can be a feasible option and can result in better short-term outcome and a similar long-term outcome after hepatectomy when compared with conventional open hepatectomy. Therefore, the laparoscopic approach is also a viable option for minimally invasive hepatectomy. CONCLUSIONS: Modulation of systemic reactions to the operation itself and laparoscopic hepatectomy may be new strategies for performing minimally invasive hepatectomy.

Blood Coagulation↗
PubMedDate not supplied

Role of tissue trace elements in liver cancers and non-cancerous liver parenchyma.

BACKGROUND/AIMS: The role of trace elements in liver fibrosis, carcinogenesis and progression of hepatocellular carcinoma (HCC) has not yet been clarified. The aim of this study is to analyze the characteristics of trace elements in liver cancers and non-cancerous liver and to discuss their role in hepatic fibrosis, hepatocarcinogenesis and progression of HCC. METHODOLOGY: The amount of zinc (Zn), iron (Fe), and copper (Cu) in 20 HCCs, 2 cholangiocellular carcinomas (CCC), 7 metastatic liver cancers (Meta) and their non-tumorous liver parenchyma were measured using an atomic absorption spectrophotometer. RESULTS: The amounts of Zn and Fe in non-tumorous liver parenchyma were reduced by liver fibrosis, and the amounts were lower in HCC tissue compared to non-tumorous liver parenchyma. The amounts of Zn and Cu were higher in HCC than the amounts found in CCC and Meta. The amount of Zn in HCC tissue decreased, but the amount of Fe increased in tumors more than 4cm in diameter. CONCLUSIONS: These results suggest that the decrease in the amount of Zn and Fe found in non-tumorous liver parenchyma correlates with liver fibrosis leading to cirrhosis and hepatocarcinogenesis. Also that decreases in Zn and increases of Fe in HCC tissue correlates with HCC tumor progression.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

A novel intrahepatic arterial chemotherapy after radical resection for advanced hepatocellular carcinoma.

BACKGROUND/AIMS: Advanced hepatocellular carcinoma (HCC) with portal vein invasion and/or intrahepatic metastasis has an unfavorable prognosis even after radical hepatic resection. The aim of this study was to evaluate the effectiveness of a novel postoperative adjuvant chemotherapy given through the hepatic artery and based on biochemical modulation using cisplatin (CDDP) and 5-fluorouracil (5-FU). METHODOLOGY: Fifteen patients with advanced HCC with portal vein invasion into the main trunk and/or intrahepatic metastases of more than 3 segments were included in this study. After radical hepatic resection, the patients were divided to two groups: the adjuvant chemotherapy group (n=7) given the novel arterial infusion regimen with CDDP and 5-FU, and the control group (n=8) given no adjuvant chemotherapy. RESULTS: Three-year survival rate of the adjuvant chemotherapy group tended to be significantly longer compared to that for the control group (p < 0.05). Most of the tumor recurrence was in the remnant liver, 5 cases in both of the groups. Significant difference of the recurrence patterns was recognized, rather than difference of the disease-free survival rate between the two groups. All of the intrahepatic recurrences are multiple in the control group, but in the adjuvant chemotherapy group, 2 cases of the recurrences showed a localized tumor surgically resected. It is noteworthy that the occurrence of multiple recurrence was significantly later in the adjuvant chemotherapy group compared to the control group (18.9 months vs. 6.5 months; p<0.05). CONCLUSIONS: Our data suggest that this novel adjuvant chemotherapy can improve the postoperative prognosis of patients with the advanced HCC.

Aged↗