Yasuyuki Okamoto

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Aberrant DNA methylation is involved in colon carcinogenesis. Although the CpG island methylator phenotype (CIMP) is defined as a subset of colorectal cancers (CRCs) with remarkably high levels of DNA methylation, it is not known whether epigenetic processes are also involved in CIMP-negative tumors. We analyzed the DNA methylation profiles of 94 CRCs and(More)
DNA methylation affects the aggressiveness of human malignancies. Cancers with CpG island methylator phenotype (CIMP), a distinct group with extensive DNA methylation, show characteristic features in several types of tumors. In this study, we initially defined the existence of CIMP in 41 lung adenocarcinomas (AdCas) through genome-wide DNA methylation(More)
The case of a patient with gastric adenosquamous carcinoma with positive cancer cells on intraperitoneal washing cytology (CY1) who achieved a long recurrence-free survival is herein reported. A 74-year-old man was found to have adenosquamous carcinoma of the stomach. Partial gastrectomy was performed, and a pathological examination confirmed a diagnosis of(More)
Meningiomas are among the most common intracranial tumors and are mostly curable by surgical resection. However, some populations of meningiomas with benign histological profiles show malignant behavior. The reasons for this inconsistency are yet to be ascertained, and novel diagnostic criteria other than the histological one are urgently needed. The aim of(More)
BACKGROUND & AIMS Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship. METHODS Pyrosequencing was used to determine the methylation status of(More)
Liver metastasis is a fatal step in the progression of colorectal cancer (CRC); however, the epigenetic evolution of this process is largely unknown. To decipher the epigenetic alterations during the development of liver metastasis, the DNA methylation status of 12 genes, including 5 classical CpG island methylator phenotype (CIMP) markers, was analyzed in(More)
BACKGROUND AND AIMS The majority of gastrointestinal stromal tumors (GISTs) have KIT mutations; however, epigenetic abnormalities that could conceivably potentiate the aggressiveness of GISTs are largely unidentified. Our aim was to establish epigenetic profiles associated with the malignant transformation of GISTs. METHODS Methylation of four tumor(More)
BACKGROUND AND AIM TP53 gene is frequently mutated in gastric cancer (GC), but the relationship with clinicopathological features and prognosis is conflicting. Here, we screened TP53 mutation spectrum of 214 GC patients in relation to their clinicopathological features and prognosis. RESULTS TP53 nonsilent mutations were detected in 80 cases (37.4%),(More)
Takashi Mizushima, Makoto Sasaki, Tomoaki Ando, Tsuneya Wada, Mamoru Tanaka, Yasuyuki Okamoto, Masahide Ebi, Yosikazu Hirata, Kenji Murakami, Tsutomu Mizoshita, Takaya Shimura, Eiji Kubota, Naotaka Ogasawara, Satoshi Tanida, Hiromi Kataoka, Takeshi Kamiya, J. S. Alexander, and Takashi Joh Department of Gastroenterology and Metabolism, Nagoya City University(More)