Hirofumi Akashi

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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(More)
Altered expression of microRNAs (miRNA) occurs commonly in human cancer, but the mechanisms are generally poorly understood. In this study, we examined the contribution of epigenetic mechanisms to miRNA dysregulation in colorectal cancer by carrying out high-resolution ChIP-seq. Specifically, we conducted genome-wide profiling of trimethylated histone H3(More)
Gastric cancer is the third most common malignancy affecting the general population worldwide. Aberrant activation of KRAS is a key factor in the development of many types of tumor, however, oncogenic mutations of KRAS are infrequent in gastric cancer. We have developed a novel quantitative method of analysis of DNA copy number, termed digital genome(More)
p53 is the most frequently mutated tumor suppressor gene in human neoplasia and encodes a transcriptional coactivator. Identification of p53 target genes is therefore key to understanding the role of p53 in tumorigenesis. To identify novel p53 target genes, we first used a comparative genomics approach to identify p53 binding sequences conserved in the(More)
Nonsteroidal anti-inflammatory drugs (NSAIDs) have a preventive effect against colorectal cancer. Although inhibition of cyclooxygenase-2 plays a crucial role in the suppression of tumors, precise mechanisms of their action remain to be disclosed. To identify genes involved in the growth-suppressive effect of NSAIDs, we utilized cDNA microarray containing(More)
Interferon regulatory factors (IRFs) are transcription factors known to play key roles in innate and adaptive immune responses, cell growth, apoptosis, and development. Their function in tumorigenesis of gastric cancer remains to be determined, however. In the present study, therefore, we examined epigenetic inactivation of IRF1-9 in a panel of gastric(More)
Interstitial cells of Cajal (ICCs) are detected as a pacemaker of gastrointestinal movement and express c-kit and CD34. Recently, ICCs have implicated pathogenesis in several human diseases presenting gastrointestinal motor dysfunction. This study was performed to clarify the role of ICCs in idiopathic sigmoid megacolon using histological and(More)
p73 and p63 are members of the p53 gene family and have been shown to play an important role in development and homeostasis mainly by regulating the transcription of a variety of genes. A subset of these genes encodes secreted proteins and receptors that may be involved in the communication between adjacent cells. We report here that flotillin-2, a major(More)
This paper describes the Visible Human (VH) part of the Trans-Pacific Demonstrations of the G7 Information Society-Global Interoperability for Broadband Network (GIBN) Projects. Aiming at a world-wide Visible Human Anatomical Co-laboratory, an application (VHP Viewer) was developed, which was used for data transmission testing (Trans-Pacific Demonstration(More)
The nucleotide sequences of cloned Escherichia coli heat-stable toxin 1 (STI) genes isolated from bovine, avian, and porcine origins were determined. They were found to be almost identical to that of Tn1681. The nucleotide sequences were completely preserved in bovine and avian genes, whereas the porcine gene had different sequences at 3 positions in the(More)