Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by H Suzuki
Total Records ( 7 ) for H Suzuki
  Y Yamazaki , I Usui , Y Kanatani , Y Matsuya , K Tsuneyama , S Fujisaka , A Bukhari , H Suzuki , S Senda , S Imanishi , K Hirata , M Ishiki , R Hayashi , M Urakaze , H Nemoto , M Kobayashi and K. Tobe
 

Nonalcoholic fatty liver disease (NAFLD) is an abnormal liver metabolism often observed with insulin resistance and metabolic syndrome. Calorie restriction is a useful treatment for NAFLD and reportedly prolongs the life spans of several species in which sirtuin plays an important role. In this study, we examined whether the activation of SIRT1, a mammalian ortholog of sirtuin, may ameliorate the development of NAFLD. Monosodium glutamate (MSG) mice, which exhibited obesity and insulin resistance, were treated with SRT1720, a specific SIRT1 activator from the age of 6–16 wk. Sixteen-week-old MSG mice exhibited increased liver triglyceride content and elevated levels of aminotransferase. SRT1720 treatment significantly reduced these levels without affecting body weight or food intake. These results suggested that the administration of SRT1720 ameliorated the development of NAFLD in MSG mice. The expressions of lipogenic genes, such as sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase, and the serum lipid profiles, including free fatty acids, were elevated in MSG mice and were reduced by SRT1720 treatment. SRT1720 treatment also reduced the expressions of lipogenic genes in cultured HepG2 cells. Furthermore, SRT1720 treatment decreased the expressions of marker genes for oxidative stress and inflammatory cytokines in the liver of MSG mice. Taken together, SRT1720 treatment may reduce liver lipid accumulation, at least in part, by directly reducing the expressions of lipogenic genes. The reduction of oxidative stress and inflammation may also be involved in the amelioration of NAFLD.

  H Suzuki , S Igarashi , M Nojima , R Maruyama , E Yamamoto , M Kai , H Akashi , Y Watanabe , H Yamamoto , Y Sasaki , F Itoh , K Imai , T Sugai , L Shen , J. P. J Issa , Y Shinomura , T Tokino and M. Toyota
 

A subset of colorectal cancers (CRCs) show simultaneous methylation of multiple genes; these tumors have the CpG island methylator phenotype (CIMP). CRCs with CIMP show a specific pattern of genetic alterations, including a high frequency of BRAF mutations and a low frequency of p53 mutations. We therefore hypothesized that genes inactivated by DNA methylation are involved in the BRAF- and p53-signaling pathways. Among those, we examined the epigenetic inactivation of insulin-like growth factor-binding protein 7 (IGFBP7) expression in CRCs. We found that in CRC cell lines, the silencing of IGFBP7 expression was correlated with high levels of DNA methylation and low levels of histone H3K4 methylation. Luciferase and chromatin immunoprecipitation assays in unmethylated cells revealed that p53 induces expression of IGFBP7 upon binding to a p53 response element within intron 1 of the gene. Treating methylated CRC cell lines with 5-aza-2'-deoxycytidine restored p53-induced IGFBP7 expression. Levels of IGFBP7 methylation were also significantly higher in primary CRC specimens than in normal colonic tissue (P < 0.001). Methylation of IGFBP7 was correlated with BRAF mutations, an absence of p53 mutations and the presence of CIMP. Thus, epigenetic inactivation of IGFBP7 appears to play a key role in tumorigenesis of CRCs with CIMP by enabling escape from p53-induced senescence.

  H Suzuki , E Yamamoto , M Nojima , M Kai , H. o Yamano , K Yoshikawa , T Kimura , T Kudo , E Harada , T Sugai , H Takamaru , T Niinuma , R Maruyama , H Yamamoto , T Tokino , K Imai , M Toyota and Y. Shinomura
 

Altered expression of microRNA (miRNA) is strongly implicated in cancer, and recent studies have shown that the silencing of some miRNAs is associated with CpG island hypermethylation. To identify epigenetically silenced miRNAs in gastric cancer (GC), we screened for miRNAs induced by treatment with 5-aza-2’-deoxycytidine and 4-phenylbutyrate. We found that miR-34b and miR-34c are epigenetically silenced in GC and that their downregulation is associated with hypermethylation of the neighboring CpG island. Methylation of the miR-34b/c CpG island was frequently observed in GC cell lines (13/13, 100%) but not in normal gastric mucosa from Helicobacter pylori-negative healthy individuals. Transfection of a precursor of miR-34b and miR-34c into GC cells induced growth suppression and dramatically changed the gene expression profile. Methylation of miR-34b/c was found in a majority of primary GC specimens (83/118, 70%). Notably, analysis of non-cancerous gastric mucosae from GC patients (n = 109) and healthy individuals (n = 85) revealed that methylation levels are higher in gastric mucosae from patients with multiple GC than in mucosae from patients with single GC (27.3 versus 20.8%; P < 0.001) or mucosae from H. pylori-positive healthy individuals (27.3 versus 20.7%; P < 0.001). These results suggest that miR-34b and miR-34c are novel tumor suppressors frequently silenced by DNA methylation in GC, that methylation of miR-34b/c is involved in an epigenetic field defect and that the methylation might be a predictive marker of GC risk.

  M Idogawa , Y Sasaki , H Suzuki , H Mita , K Imai , Y Shinomura and T. Tokino
 

Purpose: Gene transfer involving p53 is viewed as a potentially effective cancer therapy, but does not result in a good therapeutic response in all human cancers. The activation of p53 induces either cell cycle arrest or apoptosis. Cell cycle arrest in response to p53 activation is mediated primarily through the induction of the cyclin-dependent kinase inhibitor p21. Because p21 also has an inhibitory effect on p53-mediated apoptosis, the suppression of p53-induced p21 expression would be expected to result in the preferential induction of apoptosis. However, p21 also has tumor-suppressive properties. In this study, we developed an adenovirus vector that expresses p53 and suppresses p21 simultaneously to enhance p53-mediated apoptosis.

Experimental Design: We constructed a replication-deficient recombinant adenovirus (Ad-p53/miR-p21) that enabled cocistronic expression of the p53 protein and artificial microRNAs that targeted p21, and examined the therapeutic effectiveness of this vector in vitro and in vivo.

Results: The levels of p21 were significantly attenuated following infection with Ad-p53/miR-p21. In colorectal and hepatocellular carcinoma cells, infection with Ad-p53/miR-p21 augmented apoptosis as compared with an adenovirus that expressed p53 alone (Ad-p53/miR-control). Ad-p53/miR-p21 also significantly increased the chemosensitivity of cancer cells to adriamycin (doxorubicin). In a xenograft tumor model in nude mice, tumor volume was significantly decreased following the direct injection of Ad-p53/miR-p21 into the tumor, as compared with the injection of Ad-p53/miR-control.

Conclusion: These results suggest that adenovirus-mediated transduction of p53 and p21-specific microRNAs may be useful for gene therapy of human cancers.

  A. M Burroughs , Y Ando , M. J. L de Hoon , Y Tomaru , T Nishibu , R Ukekawa , T Funakoshi , T Kurokawa , H Suzuki , Y Hayashizaki and C. O. Daub
 

Animal microRNA sequences are subject to 3' nucleotide addition. Through detailed analysis of deep-sequenced short RNA data sets, we show adenylation and uridylation of miRNA is globally present and conserved across Drosophila and vertebrates. To better understand 3' adenylation function, we deep-sequenced RNA after knockdown of nucleotidyltransferase enzymes. The PAPD4 nucleotidyltransferase adenylates a wide range of miRNA loci, but adenylation does not appear to affect miRNA stability on a genome-wide scale. Adenine addition appears to reduce effectiveness of miRNA targeting of mRNA transcripts while deep-sequencing of RNA bound to immunoprecipitated Argonaute (AGO) subfamily proteins EIF2C1–EIF2C3 revealed substantial reduction of adenine addition in miRNA associated with EIF2C2 and EIF2C3. Our findings show 3' addition events are widespread and conserved across animals, PAPD4 is a primary miRNA adenylating enzyme, and suggest a role for 3' adenine addition in modulating miRNA effectiveness, possibly through interfering with incorporation into the RNA-induced silencing complex (RISC), a regulatory role that would complement the role of miRNA uridylation in blocking DICER1 uptake.

  A Komaru , N Kamiya , H Suzuki , T Endo , M Takano , M Yano , K Kawamura , T Imamoto and T. Ichikawa
  Objective

To determine the association between obesity and prostate cancer in Japanese recurrence after primary treatment with radical prostatectomy.

Methods

The subjects were 173 Japanese patients with prostate cancer who had been treated with radical prostatectomy at Chiba University Hospital between April 1997 and March 2007. Clinicopathological characteristics and biochemical recurrence outcomes after radical prostatectomy were compared between the three body mass index cohorts.

Results

Mean body mass index was 23.4 kg/m2 with a standard deviation of 2.4, and mean follow-up period was 37.4 months. Operative time was longer and estimated blood loss was much more in obese patients. Patients with pT3≥ had significantly higher serum prostate-specific antigen, total cholesterol levels, Gleason's sum and positive of surgical margin than pT2 patients. Recurrence rate was significantly higher in the 26.5 kg/m2 and hyperlipidemia groups in pT3≥ patients.

Conclusions

Obesity is an independent predictor of disease recurrence in Japanese patients with pT3≥ prostate cancer who underwent radical prostatectomy. Obese patients who underwent radical prostatectomy require vigilant follow-up care.

  M Ishii , H Inoshita , G Kusaba , S Hagiwara , H Suzuki , M Aizawa , I Ohsawa , H Ohi , Y Eishi , S Horikoshi and Y. Tomino
 

A 49-year-old man with pulmonary sarcoidosis was admitted to our hospital because of nephrotic syndrome. Renal biopsy revealed membranous nephropathy and granulomatous interstitial nephritis. DNA and cell membrane constituents of Propionibacterium acnes were detected in the patient’s glomeruli and tubular epithelial cells. Treatment with corticosteroids and an antimicrobial agent resulted in remission of the nephrotic syndrome. This is the second case in which components of P. acnes were found in renal tissue, suggesting latent pathogenesis of P. acnes infection in renal sarcoidosis.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility