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Kenichi Harada

Publications and source records attributed to Kenichi Harada.

49 records · Page 3Linked to original sources
PubMed2002

Aberrant promoter methylation and silencing of the RASSF1A gene in pediatric tumors and cell lines.

Aberrant promoter methylation of tumor suppressor genes has not been fully investigated in pediatric tumors. Therefore, we examined the methylation status of nine genes (p16(INK4A), MGMT, GSTP1, RASSF1A, APC, DAPK, RARbeta, CDH1 and CDH13) in 175 primary pediatric tumors and 23 tumor cell lines using methylation-specific PCR. We studied the major forms of pediatric tumors--Wilms' tumor, neuroblastoma, hepatoblastoma, medulloblastoma, rhabdomyosarcoma, osteosarcoma, Ewing's sarcoma, retinoblastoma and acute leukemia. The most frequently methylated gene in both primary tumors and cell lines was RASSF1A (40, 86%, respectively). However, the rates of RASSF1A methylation in individual tumor types varied from 0 to 88%. RASSF1A methylation was tumor specific and was absent in adjacent non-malignant tissues. Methylation of the other genes was relatively rare in tumors and non-malignant tissues (less than 5%). Neuroblastoma patients with methylation of RASSF1A were significantly older than patients without methylation (P=0.008). There was no relationship between methylation status and other clinico-pathologic parameters. We treated six cell lines lacking RASSF1A mRNA with 5-aza-2'deoxycytidine to examine the relationship between methylation and transcriptional silencing. In five of six cell lines, restoration of RASSF1A mRNA was confirmed by RT-PCR. Our findings indicate that aberrant promoter methylation of RASSF1A may contribute to the pathogenesis of many different forms of pediatric tumors.

Alleles↗
PubMed2002

Aberrant methylation of the CDH13 (H-cadherin) promoter region in colorectal cancers and adenomas.

Expression of the cadherin family member CDH13 (H-cadherin) is reduced in several human tumors, and it has been hypothesized that this gene functions as a tumor suppressor gene. Previously, we reported that the 5' region of CDH13 is frequently methylated in breast and lung cancers. Here we confirmed the promoter activity of 5' region of CDH13 by luciferase assay and examined its aberrant methylation in colorectal cancers, cell lines, and adenomas. Methylation status was investigated by methylation-specific PCR (MSP) and by bisulfite DNA sequencing of cloned DNA of PCR amplicons. In cell lines, we examined the correlation between methylation status and mRNA expression by reverse transcription-PCR. Aberrant methylation of CDH13 was present in 7 of 13 (54%) cell lines, and expression was absent in 6 of 13 (46%) cell lines. CDH13 expression was present in six cell lines that showed only the unmethylated form by MSP and in one cell line that showed both the methylated and unmethylated forms. Treatment with 5-aza-2'-deoxycytidine restored CDH13 expression in methylated cell lines. In surgically resected samples, 17 of 35 (49%) cases of primary colorectal cancer, 2 of 33 (6%) cases of corresponding nonmalignant colorectal mucosa, and 8 of 19 (42%) adenomas were methylated. Sequence data after bisulfite treatment indicated that primary cancers and two cell lines with loss of expression were highly methylated compared with nonmalignant colorectal epithelial cells, especially at the attachment sites of primers for MSP, although there was heterogeneity in methylation status. Our results suggest that CDH13 expression is frequently silenced by aberrant methylation in colorectal cancers and adenomas and that methylation of CDH13 commences at an early stage of multistep colorectal tumorigenesis.

Adenoma↗
PubMed2002

Presence of simian virus 40 DNA sequences in human lymphomas.

Simian virus 40 (SV40)--a potent oncogenic virus--has been associated previously with some types of human tumours, but not with lymphomas. We examined human tumours for the presence of specific SV40 DNA sequences by PCR and Southern blotting. Viral sequences were present in 29 (43%) of 68 non-Hodgkin lymphomas, and in three (9%) of 31 of Hodgkin's lymphomas. Viral sequences were detected at low frequencies (about 5%) in 235 epithelial tumours of adult and paediatric origin, and were absent in 40 control tissues. Our data suggest that SV40 might be a cofactor in the pathogenesis of non-Hodgkin lymphomas.

Adult↗
PubMed2002

Primary squamous cell carcinoma of the liver producing parathyroid hormone-related protein.

We report here an autopsy case of primary squamous cell carcinoma of the liver in a 63-year-old man who had hypercalcemia and an elevated serum level of parathyroid hormone-related protein. At autopsy, primary squamous cell carcinoma of the liver was found, without distinct preceding or associated hepatic or biliary diseases; no extrahepatic primary focus of squamous cell carcinoma was found. Bone involvement was not demonstrated, either radiologically or pathologically. Immunohistochemically, parathyroid hormone-related protein was detectable in the squamous cell carcinoma cells and it may have been responsible for the hypercalcemia. Such a case has not been reported so far in the English-language or the Japanese literature.

Carcinoma, Squamous Cell↗
PubMed2002

Lipopolysaccharide induces overexpression of MUC2 and MUC5AC in cultured biliary epithelial cells: possible key phenomenon of hepatolithiasis.

Bacterial infection, bile stasis, mucin hypersecretion, and an alteration of the mucin profile such as an aberrant expression of gel-forming apomucin (MUC2 and MUC5AC) in the intrahepatic biliary tree are thought to be important in the lithogenesis of hepatolithiasis. So far, there have been no detailed studies linking bacterial infection to altered mucus secretion of biliary epithelium. In this study, the influence of lipopolysaccharide (LPS), a bacterial component, on apomucin expression in cultured murine biliary epithelial cells was examined with emphasis on the participation of tumor necrosis factor (TNF)-alpha. It was found that LPS up-regulated the expression of MUC2 and MUC5AC in cultured murine biliary epithelial cells. LPS also induced the expression of TNF-alpha in biliary epithelial cells and its secretion into the culture medium. The up-regulation of these apomucins was inhibited by pretreatment with TNF-alpha antibody. TNF-alpha alone also induced the overexpression of MUC2 and MUC5AC in cultured biliary epithelial cells. This overexpression was inhibited by pretreatment with calphostin C, an inhibitor of protein kinase C. These findings suggest that LPS can induce overexpression of MUC2 and MUC5AC in biliary epithelial cells via synthesis of TNF-alpha and activation of protein kinase C. This mechanism might be involved in the lithogenesis of hepatolithiasis.

Animals↗
PubMed2002

Investigation of the distribution and excretion of okadaic acid in mice using immunostaining method.

This paper describes the distribution and excretion of okadaic acid (OA) administered orally to mice and examined by immunostaining method. Five min after administration, OA was systemically distributed, being detected in the lung, liver, heart, kidney, and small and large intestine. The swollen small intestinal villi contained OA, causing the separation of epithelial cells from villi and erosion, which developed within 1h. Bleeding and edema in the lung were also found, and the distribution of OA coincided with these injuries. Although a considerable amount of OA was accumulated in the liver, no symptoms, such as bleeding, were observed. The detection of OA continued for 2 weeks in the liver and blood vessels. Excretion from kidney, cecum and large intestine began even after 5 min of the administration, and the excretion from intestine continued for 4 weeks.

Administration, Oral↗
PubMed2002

Damaged interlobular bile ducts in primary biliary cirrhosis show reduced expression of glutathione-S-transferase-pi and aberrant expression of 4-hydroxynonenal.

BACKGROUND/AIMS: Chronic inflammation induces oxidative stress by producing reactive oxygen species. We investigated how the oxidative stress associated with chronic cholangitis induce bile duct damages in primary biliary cirrhosis. METHODS: The intracellular status of lipid peroxidation due to oxidative stress and that of glutathione, an endogenous cytoprotective molecule, were examined in primary biliary cirrhosis and controls by immunostaining of 4-hydroxynonenal and glutathione-S-transferase-pi. The former is a by-product of lipid peroxidation, and the latter is involved in the formation of intracellular glutathione. RESULTS: In the damaged bile ducts of primary biliary cirrhosis, glutathione-S-transferase-pi expression was markedly reduced, reflecting reduction of intracellular glutathione, and perinuclear expression of 4-hydroxynonenal was frequent, reflecting active lipid peroxidation associated with biliary epithelial damages. There was diffuse/luminal expression of 4-hydroxynonenal in the bile ducts frequent in primary biliary cirrhosis and controls, likely reflecting absorption of 4-hydroxynonenal, also a component of oxidized low-density lipoprotein, from bile via scavenger receptor class B type 1 on biliary epithelium. CONCLUSIONS: The data suggest that lipid peroxidation in the bile ducts with reduced expression of glutathione-S-transferase-pi, may be an important pathologic process leading to the bile duct damage of primary biliary cirrhosis.

Aldehydes↗
PubMed2002

Type1 and type2 memory T cells imbalance shown by expression of intrahepatic chemokine receptors relates to pathogenesis of primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is characterized by the immunopathologic destruction of interlobular bile ducts. Generally, immunereaction induced by the antigenetic stimulation is divided to cellular and humoral reactions, which are regulated by type1 and type2 memory T cells, respectively. The relative strength of type1 and type2 responses is an important factor in the pathophysiology of immune-mediated diseases. Chemokine receptors are disproportionally expressed in type1 and type2 T cells, providing a basis for tissue-specific recruitment of helper and cytotoxic T cell subsets. In this study, the expression of CXC chemokine receptor 3 (CXCR3) and CC chemokine receptor 4 (CCR4), which are preferentially expressed on type1 and type2, respectively, were examined to clarify their imbalance in the PBC liver tissue (23 cases). As a control, 16 livers of chronic viral hepatitis (CVH) were used. Reverse transcription-polymerase chain reaction and semiquantitative analysis revealed that the relative ratio of CXCR3/CCR4 mRNAs was higher in early PBC (0.76+/-0.56) rather than in advanced PBC (0.25+/-0.11), and was comparable to that in active CVH (0.67+/-0.43). By immunohistochemistry, the ratio of CXCR3-/CCR4-positive mononuclear cells in portal tracts of early PBC (4.77+/-1.70) is significantly higher than that of advanced PBC (3.11+/-1.26), and also than that of mild and of active CVH. In early PBC, mononuclear cells positive for CXCR3 were dense around the damaged bile ducts. These data suggest that the enhanced shift toward type1 occurs in portal tracts of early PBC and that the imbalance of type1/type2 changes during the course of PBC. This study provides further support for the state of enhanced type1 response in early PBC and potentially offers a possibility to suppress the bile duct lesions and to prevent the progression of PBC from early to advanced stages by reversing the type1/type2 imbalance.

Journal Article↗
PubMed2002

Overlap of idiopathic portal hypertension and scleroderma: report of two autopsy cases and a review of literature.

Idiopathic portal hypertension (IPH) is characterized by dense fibrosis of portal tracts and portal venous obliteration. Little is known about the etiopathogenesis of IPH. Association of various autoimmune diseases such as systemic lupus erythematosus in IPH suggests that IPH may share immunological disturbances with such autoimmune diseases. We recently experienced two autopsy cases presenting with both diffuse scleroderma and IPH. Dense fibrosis was found in both the dermis and intrahepatic portal tract of these cases. In addition, small vascular damages were commonly observed to various degrees in these fibrotic areas of both organs. The activation of fibroblasts and vascular damages mediated by various growth factors and cytokines reportedly involved in the dermis in scleroderma might have also been operative in portal tracts in these two cases of IPH. A review of literature disclosed eight overlapping cases of IPH and scleroderma (middle- to old-aged females), and scleroderma was diagnosed earlier than IPH. These findings suggest that similar pathogenetic processes are operative in the dermis as well as in the portal tracts of the liver in these cases.

Female↗
PubMed2002

Granulomatous phlebitis of small hepatic vein.

Several cases of granulomatous phlebitis of small hepatic veins are reported in the literature, though the etiology remains unclear. We experienced a similar case of granulomatous phlebitis involving terminal hepatic venules and this case will be reported in comparison with two previous cases presenting in our laboratory. A 39-year-old-female had a long course of medical treatment for epilepsy. She suffered from acute liver injury after prolonged fever for more than 1 week. Leukocytosis (11,100/ micro L) without eosinophilia, and inflammatory reactions such as C-reactive protein (21.0 mg/dL) were pointed out. She suffered from transient disseminated intravascular coagulation, but these abnormalities recovered with antibiotic and steroid therapy. Liver biopsy revealed granulomatous lesions mainly involving terminal hepatic venules. The possibility of tuberculosis was excluded by a negative Thiel-Nielsen stain and a negative molecular study for bacterial deoxyribonucleic acid of Mycobacteria species. Extrahepatic involvements were not clear clinically. This case and the previous two cases shared granulomatous phlebitis of the intrahepatic small hepatic veins, as well as clinical features suggestive of bacterial infection. Clinicians should be aware of such a rare clinicopathological entity.

Adult↗
PubMed2002

Autoimmune hepatitis associated with bile duct injury resembling chronic non-suppurative destructive cholangitis.

Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are representative autoimmune liver diseases in which hepatocytes and intrahepatic bile ducts, respectively, are selectively damaged by autoimmune mechanisms. Bile duct injury and loss is characteristic of PBC and chronic non-suppurative destructive cholangitis (CNSDC), in particular, is a histological hallmark of PBC. In this report, we present an unusual case of AIH accompanied by CNSDC-like bile duct injury in a 46-year-old woman. The patient's serum aminotransferase level was abnormally high. The serum levels of alkaline phosphatase, gamma-GTP and IgG were also elevated, but the IgM level was within normal limits. The titer of antismooth muscle antibody (SMA) was 1:80, while antinuclear autoantibody (ANA) and the M2 fraction of antimitochondrial antibody (AMA) were both negative. Liver biopsy disclosed CNSDC-like bile duct injuries and severe interface hepatitis and lobular hepatitis with perivenular zonal necrosis were observed. The aggregate score of the International Autoimmune Hepatitis Group corresponded to the category of probable AIH. Immunohistochemically, histocompatibility leukocyte antigen-DR, which is aberrantly expressed in the damaged bile ducts of PBC, was not found in the injured bile ducts of this case. Laboratory data were much improved by treatment with prednisone, but ursodeoxycholic acid was not effective. Although the possibility of an overlapping syndrome of AIH- and AMA-negative PBC could not be excluded, this case was diagnosed as AIH with CNSDC-like bile duct lesions.

Anti-Inflammatory Agents↗
PubMed2002

[A case of hydronephrosis associated with appendiceal abscess].

An appendiceal abscess was complicated with right hydronephrosis in a 76-year-old woman who complained of general fatigue and fever. Ultrasonography demonstrated right hydronephrosis, and retrograde pyelography confirmed the hydronephrosis and showed ureteral stenosis. Computed tomography scan revealed a low-density area measuring 38 x 35 mm in size, anterior to the right ureter. Ureteroscopy and the biopsy of the mucosa was carried out, but malignant cells were not found. An exploratory laparotomy was performed. The mass had developed from the cecum and involved the ureter, requiring ileocecal excision, left partial ureterectomy and ureteric substitution with a Boari's flap. The histological diagnosis was an appendiceal abscess. The postoperative course was uneventful.

Abscess↗