Oral Science International
Online ISSN : 1881-4204
Print ISSN : 1348-8643
Volume 7, Issue 1
Displaying 1-5 of 5 articles from this issue
REVIEW ARTICLES
  • Kyoko Hida, Noritaka Ohga, Takuro Kurosu, Yasunori Totsuka, Masanobu S ...
    2009 Volume 7 Issue 1 Pages 1-10
    Published: 2009
    Released on J-STAGE: July 16, 2010
    JOURNAL FREE ACCESS
    Tumor blood vessels play an important role in tumor progression and metastasis. Thus, targeting tumor blood vessels is an important strategy for cancer therapy, especially for head and neck cancer patients. Tumor blood vessels generally sprout from pre-existing vessels and have been thought to be genetically normal. However, tumor blood vessels have been shown to differ from their normal counterparts, for example, by changes in morphology. The authors isolated tumor endothelial cells (TECs) from mouse tumor xenografts and have shown that the TECs are abnormal. TECs up-regulate many genes and proliferate more rapidly and migrate more than normal endothelial cells (NECs). Furthermore, TECs were found to be cytogenetically abnormal. We conclude that TECs can acquire cytogenetic abnormalities while in a tumor microenvironment.
    To develop ideal antiangiogenic therapies, understanding the crosstalk between blood vessels and the tumor microenvironment is important.
    Here, we provide an overview of the current studies on TEC abnormalities and a discussion about possible mechanisms for how tumor the microenvironment makes TECs abnormal.
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  • Fumihiro Higashino, Kyoko Hida, Tetsuya Kitamura, Noritaka Ohga, Masan ...
    2009 Volume 7 Issue 1 Pages 11-18
    Published: 2009
    Released on J-STAGE: July 16, 2010
    JOURNAL FREE ACCESS
    Multiple gene disorders have been shown to be involved in carcinogenesis. Mutation, translocation and amplification have been identified in so-called oncogenes, and inactivation of antioncogenes by mutation and deletion has been shown. E1AF is an ets-oncogene family transcription factor, and has been shown to upregulate multiple matrix metalloproteinase (MMP) genes that contribute to the malignant phenotype of cancer cells by inducing invasive and metastatic activities. EWS/ETS fusions are frequently observed in Ewing's sarcoma, and we have revealed that EWS/ETS chimeric protein activates telomerase activity by upregulating human telomerase reverse transcriptase (hTERT), but the transcriptional activation of hTERT by EWS/ETS was indirect, and EWS/ETS was seen to function as a co-activator for TERT transcription. A number of oncogenes and cancer-related genes contain AU-rich element (ARE) in non-coding regions of transcribed mRNA. HuR is a RNA-binding protein that has the potential to stabilize ARE-containing mRNAs. HuR is known to shuttle between the nucleus and the cytoplasm via several export pathways. When normal cells are exposed to stress, HuR is exported to the cytoplasm in a chromosome maintenance region 1 (CRM1)-dependent manner. However, we demonstrate that HuR is CRM-1 independently exported to the cytoplasm in oral cancer cells. ARE-mRNAs were also exported to the cytoplasm and stabilized in the oral cancer cells, which were inhibited by HuR knockdown. These findings suggest that transcriptional and translational abnormalities of oncogenes may contribute to the carcinogenesis of oral epithelial cells.
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ORIGINAL ARTICLES
  • Noriko Nagisa, Takayoshi Nakano, Norihiro Hashiguchi, Wataru Fujitani, ...
    2009 Volume 7 Issue 1 Pages 19-25
    Published: 2009
    Released on J-STAGE: July 16, 2010
    Advance online publication: May 05, 2010
    JOURNAL FREE ACCESS
    Recently, significant progress has been made in medical techniques for regenerating bone. However, bone evaluation techniques generally assess bone quantity as opposed to bone quality. The use of c-axis crystallite orientation of biological apatite (BAp) as a bone quality index has recently generated great interest. BAp demonstrates strong crystallographic anisotropy, and preferential alignment of BAp in each bone varies depending on the shape and stress conditions in vivo. In the mandible, complicated bone shape and stress conditions in vivo might be associated with both bone quantity and quality. In this study, we aimed to elucidate changes in the bone microstructure in the mandible using crystallographic orientation of BAp as a bone quality index. Using Crj: CD (SD) IGS female rats, we observed changes in the dentulous mandible during bone growth. Measuring points on the mandible were determined based on its positional relationship with the teeth. For analysis of bone quantity, the area and bone mineral density of cortical bone were evaluated using peripheral quantitative computed tomography (pQCT), while the orientation of the BAp c-axis, as analyzed by a micro-beam X-ray diffraction system, was used to assess bone quality. The results of both bone quantity and quality assessments indicated that changes during bone growth varied depending on the presence of teeth. We concluded that the microstructure (especially the texture) of BAp crystallite changes in correlation with variations in stress distribution in vivo resulting from changes in chewing conditions designed to optimize the dynamic chewing function.
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  • Tomoaki Hida, Kazuya Tominaga, Akio Tanaka
    2009 Volume 7 Issue 1 Pages 26-36
    Published: 2009
    Released on J-STAGE: July 16, 2010
    JOURNAL FREE ACCESS
    Background: Enamel matrix derivative placed in the backs of rats induces numerous eosinophilic round bodies (ERBs) and hard tissue. ERBs were analyzed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and by database analysis. Subsequently, a seven-amino-acid sequence was identified, and an artificial oligopeptide was synthesized with its sequence. The present experiment was carried out to clarify whether or not the peptide induces hard tissue formation in vivo.
    Methods: Synthetic oligopeptide was injected into the backs of 15 rats. After injection, the tissues were excised at various times and prepared for light and immune-light microscopy.
    Results: A white lump was macroscopically observed in each rat back 14 days after injection of 7.5 and 15 mg/mL synthetic oligopeptide, and endochondral ossification and bone formation were microscopically observed in one rat back 14 days after injection of 15 mg/mL synthetic oligopeptide.
    Conclusions: The synthetic oligopeptide is pure, 1,118 dalton, and apparently low-toxicity. It seems to produce hard tissues, such as cartilage and bone tissue.
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