Misc - 鈴木　拓

分裂期チェックポイント分子CHFRはNF-κBシグナリングを阻害する

KASHIMA Lisa, MITA Hiroaki, TOYOTA Minoru, SASAKI Yasushi, SUZUKI Hiromu, IDOGAWA Masashi, TOKINO Takashi

生化学    2007年

J-GLOBAL

がんにおけるエピジェネティックな異常の分子機構と診断・治療への応用

豊田 実, 鈴木 拓, 今井 浩三, 篠村 恭久

日本保険医学会誌 = The Journal of the Association of Life Insurance Medicine of Japan ( 日本保険医学会 )  104 ( 4 ) 311 - 316  2006年12月

　概要を見る

DNAメチル化やヒストン脱アセチル化などのエピジェネティックな異常が,がんの発生や進展に重要な役割を果たすことが明らかになりつつある。エピジェネティックな異常により,細胞周期調節やアポトーシス,腫瘍免疫,転移や浸潤に関連する遺伝子が不活化される。異常メチル化はPCR反応を用いて,腫瘍特異的に検出可能であり,がんの診断や抗がん剤感受性のマーカーとして有用と考えられる。エピジェネティックな異常は遺伝子の一次構造に変化を与えないため,メチル化阻害剤やヒストン脱アセチル化阻害剤などの投与により,遺伝子の再発現を誘導することが可能であり,がん治療の分子標的としても注目を集めている。

CiNii

癌のエピジェネティクス異常 (細胞核の世界--ダイナミクスから病態まで) -- (エピジェネティクスとリプログラミング)

豊田 実, 鈴木 拓, 今井 浩三

蛋白質核酸酵素 ( 共立出版 )  51 ( 14 ) 2043 - 2048  2006年11月

CiNii

胃癌における高頻度なWntシグナル活性化とSFRP遺伝子のエピジェネティックな不活化

鈴木 拓, 豊田 実, 野島 正寛, 丸山 玲緒, 時野 隆至, 篠村 恭久, 森 満, 今井 浩三

生物物理化学 = Journal of Electrophoresis   50 ( 3 ) 128 - 128  2006年09月

CiNii

胃癌におけるRasシグナル関連分子のジェネティック・エピジェネティックな異常の解析

山本 英一郎, 豊田 実, 鈴木 拓, 見田 裕章, 丸山 玲緒, 阿部 環, 佐藤 裕信, 多羅澤 功, 西川 紀子, 佐々木 泰史, 時野 隆至, 今井 浩三, 篠村 恭久

日本癌学会総会記事 ( 日本癌学会 )  65回   133 - 133  2006年09月

悪性胸膜中皮腫においてDNAメチル化により制御されるがん抑制遺伝子の網羅的解析

後藤 康洋, 近藤 豊, 横山 俊彦, 谷口 哲郎, 長田 啓隆, 鈴木 拓, 時野 隆至, 豊田 実, 今井 浩三, 長谷川 好規, 下方 薫, 関戸 好孝

日本癌学会総会記事 ( 日本癌学会 )  65回   200 - 200  2006年09月

悪性リンパ腫におけるTIMP-2遺伝子のメチル化と発現抑制

多羅澤 功, 鈴木 拓, 豊田 実, 丸山 玲緒, 阿部 環, 佐藤 裕信, 山本 英一郎, 佐々木 泰史, 石田 禎夫, 時野 隆至, 今井 浩三, 篠村 恭久

日本癌学会総会記事 ( 日本癌学会 )  65回   361 - 361  2006年09月

胃癌におけるRasシグナル関連分子のジェネティック・エピジェネティックな異常の解析

山本 英一郎, 豊田 実, 鈴木 拓, 見田 裕章, 丸山 玲緒, 阿部 環, 佐藤 裕信, 多羅澤 功, 西川 紀子, 佐々木 泰史, 時野 隆至, 今井 浩三, 篠村 恭久

日本臨床分子医学会学術総会プログラム・抄録集 ( 日本臨床分子医学会 )  43回   71 - 71  2006年07月

DNAメチル化のp53経路への関与と消化器癌における分子診断

豊田 実, 丸山 玲緒, 鈴木 拓, 佐々木 泰史, 阿部 環, 佐藤 裕信, 山本 英一郎, 伊東 文生, 時野 隆至, 今井 浩三, 篠村 恭久

日本臨床分子医学会学術総会プログラム・抄録集 ( 日本臨床分子医学会 )  43回   65 - 65  2006年07月

DNA methylation changes in cancer: application to diagnosis and therapy.

Minoru Toyota, Hiromu Suzuki, Yasuhisa Shinomura, Kohzoh Imai

TUMOR BIOLOGY ( KARGER )  27  2006年

研究発表ペーパー・要旨（国際会議）  

p53およびvitamin D受容体(VDR)を標的とした大腸癌治療法の開発

丸山玲緒, 豊田実, 豊田実, 佐々木泰史, 明石浩史, 見田裕章, 鈴木拓, 鈴木拓, 時野隆至, 今井浩三, 篠村恭久

日本消化器病学会雑誌   103  2006年

J-GLOBAL

DNAメチル化によるp53標的遺伝子のサイレンシングとがん化における意義

豊田実, 鈴木拓, 丸山玲緒, 佐々木泰史, 渡邊嘉行, 西川紀子, 阿部環, 佐藤裕信, 見田裕章, 伊東文生, 時野隆至, 今井浩三, 篠村恭久

日本癌学会学術総会記事   65th  2006年

J-GLOBAL

ヒト胃腸癌におけるリボソーム蛋白質L13遺伝子の活性化

KASHIMA Lisa, SASAKI Yasushi, KOBAYASHI Toshihisa, OSHIMA Yuichiro, SUZUKI Hiromu, MITA Hiroaki, TOYOTA Minoru, IMAI Kohzoh, SHINOMURA Yasuhisa, TOKINO Takashi

生化学    2006年

J-GLOBAL

癌エピジェネティクス研究の進展と問題点 (あゆみ エピジェネティクスと疾患) -- (後天性疾患)

鈴木 拓, 森 満

医学のあゆみ ( 医歯薬出版 )  215 ( 2 ) 128 - 131  2005年10月

CiNii

The role of T-fimbrin in the response to DNA damage: Silencing of T-fimbrin by small interfering RNA sensitizes human liver cancer cells to DNA-damaging agents

H Ikeda, Y Sasaki, T Kobayashi, H Suzuki, H Mita, M Toyota, F Itoh, Y Shinomura, T Tokino, K Imai

INTERNATIONAL JOURNAL OF ONCOLOGY ( PROFESSOR D A SPANDIDOS )  27 ( 4 ) 933 - 940  2005年10月

　概要を見る

Fimbrins (also known as plastins) are actin-binding proteins of the cortical cytoskeleton present in all cells and conserved from yeast to mammals. We previously reported that the up-regulation of T-fimbrin, a fimbrin isoform, in association with G2 arrest following DNA damage and that a lack of T-fimbrin expression shortens the radiation-induced G2 arrest in Chinese hamster ovarian cells. In this study, we further investigated the role of T-fimbrin in DNA-damage response using a panel of human liver cancer cell lines and small interfering RNA technology. T-fimbrin was differentially expressed in human liver cancer cell lines. Colony formation assays revealed that cell lines lacking T-fimbrin expression were highly sensitive to DNA damage compared to cell lines that express T-fimbrin. Using siRNA designed to target T-fimbrin, we demonstrated that silencing endogenous T-fimbrin causes a marked increase in the cellular sensitivity to VP-16 and UV irradiation. Moreover, T-fimbrin deletion abrogated UV-mediated cell cycle checkpoint, and consequently led to increased apoptotic cell death in resistant cells. These findings suggest that the status of T-fimbrin expression may be a useful molecular marker for predicting the responsiveness of cancer cells to treatment with chemotherapeutic drugs.

The Ras effector RASSF2 is a novel tumor-suppressor gene in human colorectal cancer

K Akino, M Toyota, H Suzuki, H Mita, Y Sasaki, M Ohe-Toyota, JPJ Issa, Y Hinoda, K Imai, T Tokino

GASTROENTEROLOGY ( W B SAUNDERS CO )  129 ( 1 ) 156 - 169  2005年07月

　概要を見る

Background & Aims: Activation of Ras signaling is a hallmark of colorectal cancer (CRC), but the roles of negative regulators of Ras are not fully understood. Our aim was to address that question by surveying genetic and epigenetic alterations of Ras-Ras effector genes in CRC cells. Methods: The expression and methylation status of 6 RASSF family genes were examined using RT-PCR and bisulfite PCR in CRC cell lines and in primary CRCs and colorectal adenomas. Colony formation assays and flow cytometry were used to assess the tumor suppressor activities of RASSF1 and RASSF2. Immunofluorescence microscopy was used to determine the effect of altered RASSF2 expression on cell morphology. Mutations of K-ras, BRAF, and p53 were identified using single-strand conformation analysis and direct sequencing. Result : Aberrant methylation and histone deacetylation of RASSF2 was associated with the gene's silencing in CRC. The activities of RASSF2, which were distinct from those of RASSF1, included induction of morphologic changes and apoptosis; moreover, its ability to prevent cell transformation suggests that RASSF2 acts as a tumor suppressor in CRC. Primary CRCs that showed K-ras/BRAF mutations also frequently showed RASSF2 methylation, and inactivation of RASSF2 enhanced K-ras-induced oncogenic transformation. RASSF2 methylation was also frequently identified in colorectal adenomas. Conclusions: RASSF2 is a novel tumor suppressor gene that regulates Ras signaling and plays a pivotal role in the early stages of colorectal tumorigenesis.

DOI

Small interfering RNA-Induced CHFR silencing sensitizes oral squamous cell cancer cells to microtubule inhibitors

K Ogi, M Toyota, H Mita, A Satoh, L Kashima, Y Sasaki, H Suzuki, K Akino, N Nishikawa, M Noguchi, Y Shinomura, K Imai, H Hiratsuka, T Tokino

CANCER BIOLOGY & THERAPY ( LANDES BIOSCIENCE )  4 ( 7 ) 773 - 780  2005年07月

　概要を見る

Alterations in the function of cell cycle checkpoints are frequently detected in oral squamous cell carcinomas (OSCCs), and are often associated with the sensitivity of the cancer cells to chemotherapeutic drugs. Recently, a mitotic checkpoint gene, Chfr, was shown to be inactivated by promoter methylation and point mutations in various human tumors. Here we show that the absence of its product, CHFR, is associated with mitotic checkpoint dysfunction, and that cancer cells lacking CHFR are sensitive to microtubule inhibitors. Checkpoint impairment appears to be caused by a prophase defect in this case, as OSCC cells lacking CHFR showed phosphorylation of histone H3 on Ser10 and translocation of cyclin B1 to the nucleus. When CHFR-deficient OSCC cells were treated with a microtubule inhibitor (docetaxel or paclitaxel), significant numbers of apoptotic cells were observed. Moreover, disruption of CHFR using small interfering RNA (siRNA) impaired the mitotic checkpoint, thereby reducing the ability of OSCC cells to arrest at G(2)/M phase and making them more sensitive to microtubule inhibitors. Our results suggest that CHFR could be a useful molecular target for chemotherapy.

Inactivation of the tissue inhibitor of metalloproteinases-2 gene by promoter hypermethylation in lymphoid malignancies

O Galm, H Suzuki, Y Akiyama, M Esteller, MV Brock, R Osieka, SB Baylin, JG Herman

ONCOGENE ( NATURE PUBLISHING GROUP )  24 ( 30 ) 4799 - 4805  2005年07月

　概要を見る

The tissue inhibitor of metalloproteinases-2 (TIMP-2) is known to antagonize matrix metalloproteinase activity and to suppress tumor growth, angiogenesis, invasion and metastasis. We analysed the methylation status of the CpG island in the TIMP-2 promoter region by methylation-specific polymerase chain reaction (MSP) in hematopoietic cell lines. TIMP-2 promoter hypermethylation in the lymphoma cell line Raji and the leukemia cell line KG1a was associated with transcriptional repression. Treatment with the demethylating agent 5-aza-2'-deoxycytidine resulted in TIMP-2 upregulation in both cell lines. TIMP-2 was expressed in the cell lines HL60, U266 and XG1, which carry an unmethylated promoter region. MSP analysis of primary patient samples revealed aberrant methylation of TIMP-2 in 33/90 (36.7%) cases of non- Hodgkin's lymphoma (NHL), but not in normal peripheral blood lymphocytes as well as in nonmalignant bone marrow and lymph nodes. The frequency of TIMP-2 methylation was slightly higher in aggressive NHL subtypes compared to those with an indolent subtype (38.6 versus 33.3%). In contrast, TIMP-2 was not hypermethylated in any of the 40 cases of acute myelogenous leukemia examined. We conclude that promoter hypermethylation of TIMP-2 is a novel epigenetic event in the pathogenesis of lymphoid malignancies and may contribute to a more aggressive NHL phenotype.

DOI

Upregulation of BNIP3 by 5-aza-2 '-deoxycytidine sensitizes pancreatic cancer cells to hypoxia-mediated cell death

T Abe, M Toyota, H Suzuki, M Murai, K Akino, M Ueno, M Nojima, A Yawata, H Miyakawa, T Suga, H Ito, T Endo, T Tokino, Y Hinoda, K Imai

JOURNAL OF GASTROENTEROLOGY ( SPRINGER TOKYO )  40 ( 5 ) 504 - 510  2005年05月

　概要を見る

Background. Pancreatic cancer cells often show resistance to hypoxia-mediated apoptosis, but the molecular mechanism underlying that resistance remains unknown. The purpose of the present study, therefore, was to examine the role of epigenetic gene alteration in the resistance to hypoxia-mediated apoptosis among pancreatic cancer cells. Methods. Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the expression of five genes associated with hypoxia-mediated apoptosis (PUMA, Caspase-8 [CASP8], APAF-1, BNIP3, and BNIP3L) in a panel of pancreatic cancer cell lines. Protein expression was examined by Western blot analysis, using lysates from cells incubated under normoxic or hypoxic conditions. The methylation status of the genes was determined using bisulfite-PCR and sequencing. The percentages of cells that were apoptotic were determined using flow cytometry. Results. Under normoxic conditions, the expression of the BNIP-3 gene varied among the 12 pancreatic cancer cell lines tested, with 50% of them showing no BNIP3 expression at all, whereas expression of the other four genes was readily detected in all 12 cell lines. DNA methylation of BNIP-3's CpG island in the region around the transcription start site of the gene was closely associated with its silencing. The expression of BNIP3 was restored by the methyltransferase inhibitor 5-aza-deoxycytidine (5-aza-dC), as was the hypoxia-mediated pancreatic cancer cell death. Conclusions. BNIP3 expression is silenced in some pancreatic cancer cells by the methylation of its CpG island. Demethylation of BNIP3, using a methyltransferase inhibitor, restores the gene's expression and induces hypoxia-mediated cell death. BNIP-3 may thus be a useful target for new therapies aimed at treating pancreatic cancer.

DOI PubMed CiNii

現代医学の焦点(269)新しい大腸癌抑制遺伝子--SFRP

鈴木 拓, 豊田 実, 野島 正寛

日本臨床 ( 日本臨床社 )  63 ( 4 ) 707 - 719  2005年04月

CiNii