Satoru Kakizaki

A ligand for peroxisome proliferator activated receptor γ inhibits cell growth and induces apoptosis in human liver cancer cells

Background and aims: Induction of apoptosis of cancer cells through ligands of nuclear hormone receptors (NHRs) is a new approach in cancer therapy. Recently, one of the NHRs, peroxisome proliferator activated receptor γ (PPARγ), has been shown to influence cell growth in certain cancer cells although its effect on hepatocellular carcinoma (HCC) has not been analysed. Methods: Experiments were conducted using three human liver cancer cell lines, PLC/PRF/5, Hep G2 and HuH-7, in vitro. These cells were exposed to troglitazone, a synthetic ligand for PPARγ, and the effects on cell growth were analysed. Results: Expression of PPARγ mRNA was detected in all three liver cancer cell lines. Activation of PPARγ by troglitazone caused a marked growth inhibition in a dose dependent manner in three hepatoma cell lines. The DNA fragmentation ELISA assay and Hoechst 33258 staining revealed that the growth inhibitory effect by adding troglitazone was due to apoptosis of PLC/PRF/5, which strongly expressed PPARγ. Troglitazone also induced activation of the cell death protease, caspase 3, but not caspase 8, in PLC/PRF/5 cells. However, expression levels of antiapoptotic factor bcl-2 and apoptosis inducing factor bax were not affected. Conclusion: Our study showed that PPARγ was expressed in human liver cancer cells and that the ligand for PPARγ, troglitazone, inhibited the growth of these cells by inducing apoptosis through caspase 3 activation, indicating that troglitazone could be potentially useful as an apoptosis inducer for the treatment of HCC.

Hepatocellular carcinoma with portal vein tumor thrombosis: clinical characteristics, prognosis, and patient survival analysis.

Hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is associated with a poor prognosis. New therapeutic modalities, such as continuous hepatic arterial infusion chemotherapy (CHAIC), have recently been reported to be promising strategies. The aim of this study was to evaluate the clinical characteristics, prognosis, and survival of patients with PVTT according to treatment regimen. One hundred ninety-three patients with HCC complicated with PVTT at the time of diagnosis were included in this study. All patients were newly diagnosed to have HCC and were observed from January 1992 to December 2003. CHAIC was performed using an implanted drug delivery system with low-dose cisplatin and 5-fluorouracil. Clinical characteristics, prognosis, and patient survival were analyzed by the Kaplan-Meier method and Coxs proportional hazards model. The mean age of the patients complicated with PVTT was 64.3±10.3 years (range, 20–88 years). The survival of the 193 patients with PVTT was 37.5%, 24.0%, 18.9%, and 8.3% at 1, 2, 3, and 5 years, respectively. According to treatment, the survival of patients who underwent surgical treatment was the best, followed by CHAIC, transcatheter arterial infusion/embolization, and supportive care. The 3-year survivals for each treatment regimen were 53.0%, 19.3%, 15.0%, and 4.0%, respectively. Although the survival of patients who received surgical treatment was best, such patients were restricted. There was no difference in survival between treated and untreated patients demonstrating Child-Pugh grade C. In Child B patients, treatment for HCC significantly increased survival (P<0.01). Coxs proportional hazards model revealed the Child-Pugh classification to be an independent prognostic factor for patients with HCC and PVTT (P<0.01). We conclude that the prognosis of HCC with PVTT was quite poor. The treatment did not improve the survival of Child C patients. As a result, the prevention, early diagnosis, and development of new treatment strategies are required.

HLA antigens in patients with interferon-α-induced autoimmune thyroid disorders in chronic hepatitis C

BACKGROUND/AIMS To determine the immunological predisposition to autoimmune thyroid disorders induced by interferon-alpha therapy, human leukocyte antigen (HLA) was analyzed in patients with chronic hepatitis C who developed autoimmune thyroid disorders during or after treatment with interferon-alpha. METHODS Four hundred and thirty-nine patients with chronic hepatitis C (278 males and 161 females, aged 20-73 years) were treated with interferon-alpha (natural-alpha, 169; alpha-2a, 82; alpha-2b, 188) for 24 weeks. RESULTS Seventeen of 439 (3.9%) patients developed symptomatic autoimmune thyroid disorders; these included nine cases of hyperthyroidism and eight cases of hypothyroidism. The incidence of HLA-A2, B46 and Cw7 increased in patients with interferon-alpha-induced autoimmune thyroid disorders. Especially, the incidence of HLA-A2 (15/17; 88.2%) was significantly higher than that observed in the general population in Japan (corrected p-value (p(c)): p(c)<0.003). The odds ratios for the relative risk of the autoimmune thyroid disorders were A2, 10.6 [95% confidence interval, 2.4-46.5]; B46, 4.8 [1.6-14.0]; and Cw7, 3.0 [1.1-7.9]. CONCLUSIONS Our study revealed that HLA-A2 is highly linked to the autoimmune thyroid disorders induced by interferon-alpha-therapy in patients with chronic hepatitis C.

Zinc supplementation enhances the response to interferon therapy in patients with chronic hepatitis C.

We evaluated the synergistic effect of zinc supplementation on the response to interferon (IFN) therapy in patients with intractable chronic hepatitis C in a pilot study using natural IFN‐α with or without zinc. No clinical differences were observed between patients treated with IFN alone (n=40) and IFN with polaprezinc (IFN + Zn, n=35). All patients were positive for HCV genotype Ib and had more than 105 copies of the virus/mL serum. Ten million units of natural IFN‐α was administered daily for 4 weeks followed by the same dose every other day for 20 weeks. In the IFN + Zn group, patients received an additional dose of 150 mg/day polaprezinc orally throughout the 24‐week IFN course. No additional side‐effects of polaprezinc were noted but four out of 40 IFN alone treatment and three out of 35 IFN + Zn group withdrew because of side‐effects. Complete response (CR) was defined as negative HCV RNA in the serum on PCR and normal aminotransferase level 6 months after therapy. Incomplete response (IR) was normal liver enzyme and positive serum HCV RNA. Both of them were evaluated at the 6 months after the completion of the treatment. Patients with higher levels of serum HCV (more than 5 × 105 copies/mL) had little response in both treatment groups. Patients with moderate amount of HCV (105 to 4.99 × 105/mL) showed high response rates in combination group (CR: 11/27, 40.7%; CR + IR 15/27, 64.3%), better than IFN alone (CR: 2/15, 18.2%; CR + IR: 2/15, 18.2%). Serum zinc levels were higher in patients with IFN + Zn group than in the IFN group. Our results indicate that zinc supplementation enhances the response to interferon therapy in patients with intractable chronic hepatitis C.

Primary liver cancers with nonalcoholic steatohepatitis.

Nine patients with hepatocellular carcinoma (HCC) in nonalcoholic steatohepatitis (NASH) (six men and three women, median age 71.5 years) and one patient with intrahepatic cholangiocarcinoma (ICC), a 50-year-old man, in NASH are described. Most patients were associated with obesity, diabetes, hypertension, hypercholesterolemia, or hypertriglyceridemia. Seven patients showed insulin resistance and hyperinsulinemia. All patients except one met the criteria for metabolic syndrome. An HCC or ICC diagnosis was confirmed by tumor biopsy, surgery or autopsy except in two patients, who were diagnosed by computed tomography or hepatic angiography. The underlying liver disease was liver cirrhosis in six patients and chronic liver disease including mild hepatic fibrosis in four patients. The treatment of liver cancers consisted of surgery, radio-frequency ablation (RFA), transcatheter arterial embolization and transcatheter arterial infusion. Although the follow-up period was relatively short (median 27.5 months, average 32.1 months), all postoperative and post-RFA patients have not had a recurrence of HCC to date, except for one patient who had a palliative operation with intra-arterial infusion of anticancer drugs through an implanted reservoir port. Older age and liver cirrhosis are considered risk factors for HCC in NASH, and regular screening of these patients is necessary. Diabetes may contribute to the development of ICC in NASH. Curative therapy (surgery or RFA) and weight loss by the active therapeutic intervention (nutritional care and exercise therapy) after curative therapy may help us improve the prognosis of HCC in NASH.

New Insights on the Xenobiotic-Sensing Nuclear Receptors in Liver Diseases – CAR and PXR-

The xenobiotic receptors CAR and PXR constitute two important members of the NR1I nuclear receptor family. They function as sensors of toxic byproducts derived from the endogenous metabolism and of exogenous chemicals, in order to enhance their elimination. They regulate numerous genes which are involved in drug and xenobiotic metabolism, including Phase I (cytochrome P450), Phase II (conjugation catalyzed by sulfotransferases, glucuronosyltransferases and glutathione S-transferases), and transporters (multidrug resistance proteins, multidrug resistance-associated proteins, and organic anion-transporting polypeptides). Although CAR and PXR were initially characterized as xenosensors, it is now evident that CAR and PXR also trigger pleiotropic effects on physiological or pathological functions. Recent studies have shown that the activation of CAR and PXR alters lipid metabolism, glucose homeostasis, and inflammation. Therefore, in addition to regulating drug elimination pathways, they also play important roles in regulating metabolic pathways. As a result, these receptors may be closely associated with the pathogenesis of many diseases. However, the pathophysiological roles of CAR and PXR are not fully understood. The purpose of this review is to discuss the physiological and pathological roles of CAR and PXR in liver diseases.

The role of the nuclear receptor constitutive androstane receptor in the pathogenesis of non-alcoholic steatohepatitis

Background: Non-alcoholic fatty liver disease is a common liver injury, but the pathophysiological mechanisms leading to the development of non-alcoholic steatohepatitis (NASH) remain unclear. The pathological roles of the nuclear receptor constitutive androstane receptor (CAR), a key regulator of drug-metabolising enzymes, in the development of NASH were investigated. Methods and results: CAR+/+ and CAR−/− mice were given a methionine and choline-deficient (MCD) diet to establish a dietary model of NASH. Increases in serum alanine aminotransferase (ALT) and in infiltration of inflammatory cells were dominant in CAR+/+ mice at 8 weeks. There was no significant difference in the lipid concentration of the liver—namely, the first hit between CAR+/+ and CAR−/− mice. The index of lipid peroxidation increased in liver of the CAR+/+ mice, as demonstrated by 8-iso-prostaglandin F2α (F2-isoprostanes). Western blotting analysis showed that nuclear translocation of CAR occurred in CAR+/+ mice fed the MCD diet. As a result, the CAR activation caused the lipid peroxidation—namely, the second hit. The expressions of cytochrome P450 (CYP)2B10, 2C29, 3A11 all increased considerably in the CAR+/+ mice. Furthermore, α smooth muscle actin immunohistochemistry and Sirius red staining showed an increase in the degree of fibrosis in CAR+/+ mice fed the MCD diet at 16 weeks. The mRNA expressions of collagen α1(1) and the tissue inhibitor of metalloproteinase-1 were found to be elevated in CAR+/+ mice. Conclusion: CAR caused the worsening of the hepatic injury and fibrosis in the dietary model of NASH. Our results suggest that the CAR nuclear receptor may thus play a critical role in the pathogenesis of NASH.

Endoscopic treatment of rectal carcinoid tumors.

BACKGROUND: Various methods have been reported for the endoscopic treatment of rectal carcinoid tumors. The present study was designed to identify the optimal treatment strategy for an endoscopic resection. METHODS: Forty rectal carcinoid tumors of 38 patients were treated endoscopically. The indication criteria, complete resection rate, selection of treatment, local recurrence, distant metastases, and complications were analyzed. All tumors were estimated to measure 1 cm or less in diameter, without muscular invasion, atypical features, and lymph node metastases to the pararectal region. RESULTS: Complete resection of the lesions was obtained in 75.0% (30/40). The complete resection rates were 20.0% (1/5) by conventional polypectomy, 84.6% (22/26) by a two-channel endoscopic mucosal resection, and 77.8% (7/9) by endoscopic submucosal dissection. The 10 cases that did not show a clear submucosal layer after initial endoscopic treatment received additional endoscopic microwave coagulation therapy. There were no local or distant recurrences in the followed-up periods (median, 6.4 years). No difference was observed in the complete resection rate between two-channel endoscopic mucosal resection and endoscopic submucosal dissection. CONCLUSIONS: Small carcinoid tumors measuring less than 1 cm in diameter can therefore be managed endoscopically with no recurrence or spread. The selection of endoscopic treatment should be made after taking such factors as cost-effectiveness, expertise, and experience into careful consideration.

A Prospective Randomized Controlled Study of Long-Term Combination Therapy Using Ursodeoxycholic Acid and Bezafibrate in Patients With Primary Biliary Cirrhosis and Dyslipidemia

OBJECTIVES:The aim of this study was to assess the long-term prognosis, efficacy, and safety of combination therapy using ursodeoxycholic acid (UDCA) and bezafibrate (BF) for primary biliary cirrhosis (PBC) patients exhibiting dyslipidemia.METHODS:We performed a prospective, randomized, controlled, multicenter study to compare the long-term clinical results between combination therapy and UDCA monotherapy for patients refractory to UDCA monotherapy. Twenty-seven consecutive PBC patients were enrolled.RESULTS:The median treatment period in the UDCA and UDCA+BF groups was 107 and 110 months, respectively. The serum alkaline phosphatase (ALP) levels and the Mayo risk score in the combination therapy group (mean 290 IU/l and 0.91, respectively) were significantly lower than those in the UDCA monotherapy group (mean 461 IU/l and 1.42, respectively) at 8 years after the beginning of the study (P<0.05). The serum creatinine levels in the combination therapy group (mean 0.94 mg/dl) were significantly higher than those in the UDCA monotherapy group (mean 0.56 mg/dl) at 8 years after the beginning of the study (P<0.05). However, the survival rate was not significantly different between the groups. We observed dose reduction or discontinuation of the administration of BF, but not UDCA, due to renal dysfunction or muscle pain.CONCLUSIONS:Long-term combination therapy significantly improved the serum ALP levels and the Mayo risk score. However, the survival rate was not significantly different between the groups. In addition, long-term combination therapy significantly increased the serum creatinine levels. We should pay close attention to adverse events during this long-term combination therapy.

Functional gastrointestinal disorders in adolescents and quality of school life

The prevalence of functional gastrointestinal disorders (FGID) in adolescents and their relationship to quality of school life (QOSL) are not fully understood. This study investigated the relationship between FGID and QOSL.