Yuiko Nemoto

Publications (15)54.56 Total impact

• Article: Detection of Merkel cell polyomavirus in cervical squamous cell carcinomas and adenocarcinomas from Japanese patients.

  Masayuki Imajoh, Yumiko Hashida, Yuiko Nemoto, Hiroyoshi Oguri, Nagamasa Maeda, Mutsuo Furihata, Takao Fukaya, Masanori Daibata
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  ABSTRACT: BACKGROUND: Merkel cell polyomavirus (MCPyV) was identified originally in Merkel cell carcinoma (MCC), a rare form of human skin neuroendocrine carcinoma. Evidence of MCPyV existence in other forms of malignancy such as cutaneous squamous cell carcinomas (SCCs) is growing. Cervical cancers became the focus of our interest in searching for potentially MCPyV-related tumors because: (i) the major histological type of cervical cancer is the SCC; (ii) the uterine cervix is a common site of neuroendocrine carcinomas histologically similar to MCCs; and (iii) MCPyV might be transmitted during sexual interaction as demonstrated for human papillomavirus (HPV). In this study, we aimed to clarify the possible presence of MCPyV in cervical SCCs from Japanese patients. Cervical adenocarcinomas (ACs) were also studied. RESULTS: Formalin-fixed paraffin-embedded tissue samples from 48 cervical SCCs and 16 cervical ACs were examined for the presence of the MCPyV genome by polymerase chain reaction (PCR) and sequencing analyses. PCR analysis revealed that 9/48 cervical SCCs (19 %) and 4/16 cervical ACs (25 %) were positive for MCPyV DNA. MCPyV-specific PCR products were sequenced to compare them with reference sequences. The nucleotide sequences in the MCPyV large-T (LT)-sequenced region were the same among MCPyV-positive cervical SCCs and AC. Conversely, in the MCPyV viral protein 1 (VP1)-sequenced, two cervical SCCs and three cervical ACs showed several nucleotide substitutions, of which three caused amino acid substitutions. These sequencing results suggested that three MCPyV variants of the VP1 were identified in our cases. Immunohistochemistry showed that the LT antigen was expressed in tumor cells in MCPyV-positive samples. Genotyping of human HPV in the MCPyV-positive samples revealed that infected HPVs were HPV types 16, 31 and 58 for SCCs and HPV types 16 and 18 for ACs. CONCLUSIONS: This study provides the first observation that MCPyV coexists in a subset of HPV-associated cervical cancers from Japanese patients. The prevalence of MCPyV in these lesions was close to that observed in the cutaneous SCCs. Further worldwide epidemiological surveys are warranted to determine the possible association of MCPyV with pathogenesis of cervical cancers.
  Virology Journal 08/2012; 9(1):154. · 2.34 Impact Factor
• Article: Pure Red Cell Aplasia in a Patient with Trrisomy X Chromosome Abnormality and Reactivated Epstein-Barr Virus Infection

  Masanori Daibata, Hisanori Machida, Yuiko Nemoto, Hirokuni Taguchi
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  ABSTRACT: We describe a woman with a congenital chromosome anomaly, 47,XXX, who developed chronic pure red cell aplasia (PRCA).The patient had serologic reactivity consistent with that of reactivated Epstein-Barr virus (EBV) infection, as judged by high titers for anti-EBV viral capsid antigen (VCA) immunoglobulin G (IgG) and anti-early antigen (EA) IgG.Detection of EBV genome in peripheral blood cells and cell-free serum also supported the diagnosis. Although EBV infection has been implicated in the pathogenesis of acute PRCA, the viral infection rarely results in a chronic disease state. So far, only 1 case of EBV-associated chronic PRCA has been reported, to the best of our knowledge. Chronic PRCA also is known to occur on an autoimmune basis. Individuals carrying an extra X chromosome, such as XXY and XXX, are prone to development of immune abnormalities. Our patient had an anti-DNA autoantibody and a positive result of the direct Coombs test. The pathogenesis of PRCA in this case seemed to involve multiple factors. In addition to the infectious agent, host factors may have played a role. Although the etiologic link between chronic PRCA and trisomy X remains to be elucidated, our findings suggest the importance of karyotype analysis as well as search for infectious agents in patients with chronic PRCA.
  International Journal of Hematology 04/2012; 77(4):354-358. · 1.27 Impact Factor
• Article: Promoter methylation of the bone morphogenetic protein 6 gene in multiple myeloma.

  Yumiko Hashida, Yuiko Nemoto, Masayuki Imajoh, Masanao Murakami, Ayuko Taniguchi, Naoki Komatsu, Akihito Yokoyama, Masanori Daibata
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  ABSTRACT: Bone morphogenetic proteins (BMPs), which belong to the transforming growth factor-β superfamily, are multifunctional signaling molecules that have become of increasing interest in cancer research. Recent observations suggest that alterations in BMPs and BMP signaling are associated with tumorigenesis and disease progression in various types of malignancies. This study investigated the methylation status of the BMP6 gene promoter in various types of plasma cell proliferative disorders by combined bisulfite restriction analysis. While BMP6 methylation was not detected in any samples from monoclonal gammopathies of undetermined significance, intramedullary multiple myeloma (MM), plasma cell leukemia or solitary plasmacytoma, both case studies and cell line studies showed that multiple extramedullary plasmacytoma (MEP) consistently carried a methylated BMP6 promoter. The BMP6 methylation-positive MEP was an aggressive form of MM with extremely high levels of serum lactate dehydrogenase (LDH). Bisulfite sequencing analysis confirmed intensive methylation at CpG sites of the BMP6 promoter region. The methylation of BMP6 was correlated with decreased levels of mRNA transcripts. Expression of BMP6 was restored by the demethylating agent 5-aza-2'-deoxycytidine, suggesting that the methylation is associated with transcriptional silencing. Our study implied that BMP6 promoter methylation is not a common event in MMs, but occurs in aggressive MEP. These findings warrant further investigation to clarify whether BMP6 methylation together with elevated LDH could be a marker of poor prognosis in MEP patients who should be considered for early intensive treatment.
  Oncology Reports 11/2011; 27(3):825-30. · 1.84 Impact Factor
• Article: Presence of Merkel cell polyomavirus in Japanese cutaneous squamous cell carcinoma.

  Masanao Murakami, Masayuki Imajoh, Takuya Ikawa, Hideki Nakajima, Mikio Kamioka, Yuiko Nemoto, Takako Ujihara, Jumpei Uchiyama, Shigenobu Matsuzaki, Shigetoshi Sano, Masanori Daibata
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  ABSTRACT: Merkel cell polyomavirus (MCPyV) was first identified in Merkel cell carcinoma (MCC) as a new tumor virus. Studies have also reported differing frequencies of MCPyV detection in other skin cancers in western countries. Little is known about geographical differences of MCPyV prevalence in non-MCC tumors. We examined the existence of MCPyV in non-MCC skin cancers including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in Japanese patients. Paraffin-embedded tissues of cutaneous SCC (n=30) and BCC (n=10) from Japanese patients were tested for the presence of MCPyV by polymerase chain reaction (PCR) with primer sets directed against the genes encoding large-T antigen 3 (LT3) and viral protein 1 (VP1). This was followed by DNA fragment sequencing and immunohistochemistry. PCR analysis targeting the LT3 gene showed that the viral sequences were found in 4 of 30 (13%) SCC cases. Nested PCR detected the VP1 region in four cases. Sequencing analysis of these PCR-amplified fragments showed a close homology to the previously published MCPyV sequences. Immunohistochemistry with the monoclonal antibody to MCPyV LT-antigen showed positive staining in 2 of 4 LT3 PCR-positive cases. On the other hand, our BCC samples were all negative for MCPyV. This study suggested that Japanese cutaneous SCC is infrequently associated with MCPyV. Further worldwide epidemiological surveys are warranted to determine the possible association of MCPyV with pathogenesis of non-MCC skin cancers.
  Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 10/2010; 50(1):37-41. · 3.12 Impact Factor
• Article: Epstein-Barr virus-infected subcutaneous panniculitis-like T-cell lymphoma associated with methotrexate treatment.

  Yuiko Nemoto, Ayuko Taniguchi, Mikio Kamioka, Yoko Nakaoka, Makoto Hiroi, Akihito Yokoyama, Hideaki Enzan, Masanori Daibata
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  ABSTRACT: Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a lymphoid proliferation or lymphoma in patients treated with MTX. We report a case of Epstein-Barr virus (EBV)-positive subcutaneous panniculitis-like T-cell lymphoma (SPTCL) in a 60-year-old Japanese man treated with MTX for rheumatoid arthritis (RA). SPTCL is a rare cytotoxic T-cell lymphoma characterized by involvement of subcutaneous fat mimicking panniculitis. The patient, who had been on MTX therapy for RA, manifested high fever and lumbago. Physical examination showed multiple subcutaneous nodules on the trunk including axillary and inguinal regions. Biopsy of the inguinal nodule showed profuse infiltration of CD8(+) T-cell lymphoma cells in the subcutaneous adipose tissues. A diagnosis of SPTCL was made according to the diagnostic criteria of World Health Organization classification. EBV-encoded small RNA in situ hybridization revealed that the lymphoma cells contained EBV genome. The cells were positive for EBV latent membrane protein 1, but not for EBNA2. After discontinuation of MTX, the nodules regressed spontaneously. Studies have reported that most MTX-LPDs are B-cell type lymphomas and Hodgkin lymphoma. To the best of our knowledge, EBV-positive SPTCL has not been reported in patients receiving MTX. Our case emphasizes the importance of clinical and virological characterization of MTX-associated SPTCL.
  International journal of hematology 09/2010; 92(2):364-8. · 1.17 Impact Factor
• Article: Promoter methylation of the bone morphogenetic protein-6 gene in association with adult T-cell leukemia.

  Ayuko Taniguchi, Yuiko Nemoto, Akihito Yokoyama, Norihiro Kotani, Shosuke Imai, Taro Shuin, Masanori Daibata
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  ABSTRACT: Bone morphogenetic proteins (BMP), belonging to the transforming growth factor-beta superfamily, are multifunctional regulators of cell proliferation, differentiation and apoptosis in various types of malignant cells. In this study, we investigated BMP-6 promoter methylation in patients with various types of leukemias. The BMP-6 methylation was found preferentially in adult T-cell leukemia (ATL) (49 of 60, 82%) compared with other types of leukemias studied including acute myeloid leukemia (3 of 67, 5%), acute lymphoblastic leukemia (6 of 38, 16%) and chronic lymphocytic leukemia (1 of 21, 5%). Among subtypes of ATL, the BMP-6 gene was more frequently methylated in aggressive ATL forms of acute (96%) and lymphoma (94%) types than less malignant chronic ATL (44%) and smoldering ATL (20%). We also analyzed the methylation status of peripheral blood mononuclear cells from healthy donors and nonmalignant lymph nodes with reactive lymphadenopathy, none of which showed detectable BMP-6 methylation in this study. The BMP-6 methyaltion was correlated with decreased mRNA transcript and protein expression. Expression of BMP-6 was restored by the demethylating agent 5-aza-2'-deoxycytidine, suggesting that methylation was associated with the transcriptional silencing. Serial analysis demonstrated an increasing methylation of CpG sites in the BMP-6 promoter and the resultant suppression of BMP-6 expression as ATL progressed. These findings suggested that BMP-6 promoter methylation is likely to be a common epigenetic event at later stages of ATL and that the methylation profiles may be useful for the staging of ATL as well as for evaluation of the individual risk of developing the disease.
  International Journal of Cancer 11/2008; 123(8):1824-31. · 5.44 Impact Factor
• Article: Promoter hypermethylation of the bone morphogenetic protein-6 gene in malignant lymphoma.

  Masanori Daibata, Yuiko Nemoto, Kentaro Bandobashi, Norihiro Kotani, Masayuki Kuroda, Mutsumi Tsuchiya, Heiwa Okuda, Tetsuya Takakuwa, Shosuke Imai, Taro Shuin, Hirokuni Taguchi
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  ABSTRACT: Bone morphogenetic proteins (BMP), belonging to the transforming growth factor-beta superfamily, are important regulators of cell growth, differentiation, and apoptosis. The biological effects of BMPs on malignant lymphoma, however, remain unknown. Promoter methylation of the BMP-6 gene in lymphomas was investigated. We investigated BMP-6 promoter methylation and its gene expression in various histologic types of 90 primary lymphomas and 30 lymphoma cell lines. The effect of BMP-6 promoter hypermethylation on clinical outcome was also evaluated. BMP-6 was epigenetically inactivated in subsets of lymphomas. The silencing occurred with high frequency in diffuse large B-cell lymphoma (DLBCL) and Burkitt's lymphoma in association with aberrant BMP-6 promoter methylation. The methylation was observed in 60% (21 of 35) of DLBCL cases and 100% (7 of 7) of DLBCL cell lines, and in 83% (5 of 6) of Burkitt's lymphoma cases and 86% (12 of 14) of Burkitt's lymphoma cell lines. In contrast, other histologic types of primary lymphomas studied had little or no detectable methylation (1 of 49; 2%). The presence of BMP-6 promoter hypermethylation in DLBCL statistically correlated with a decrease in disease-free survival (P = 0.014) and overall survival (P = 0.038). Multivariate analysis showed that the methylation profile was an independent prognostic factor in predicting disease-free survival (P = 0.022) and overall survival (P = 0. 046). BMP-6 promoter was hypermethylated more often in aggressive types of lymphomas, and the hypermethylation is likely to be related to the histologic type of lymphomas. BMP-6 promoter methylation may be a potential new biomarker of risk prediction in DLBCL.
  Clinical Cancer Research 07/2007; 13(12):3528-35. · 7.74 Impact Factor
• Article: Absence of Chlamydia psittaci in ocular adnexal lymphoma from Japanese patients.

  Masanori Daibata, Yuiko Nemoto, Kazuto Togitani, Atsuki Fukushima, Hisayuki Ueno, Kazunobu Ouchi, Hideto Fukushi, Shosuke Imai, Hirokuni Taguchi
  British Journal of Haematology 04/2006; 132(5):651-2. · 4.94 Impact Factor
• Article: In vitro Epstein-Barr virus-immortalized lymphoma cell line carrying t(9;14)(p13;q32) chromosome abnormality, derived from splenic lymphoma with villous lymphocytes.

  Masanori Daibata, Takahiro Taguchi, Yuiko Nemoto, Shinji Iwasaki, Yuji Ohtsuki, Hirokuni Taguchi
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  ABSTRACT: We herein describe splenic lymphoma with villous lymphocytes (SLVL) carrying t(9;14)(p13;q32). The t(9;14)(p13;q32) is a rare reciprocal chromosome translocation found in a subset of B-cell malignancies, mainly in low-grade non-Hodgkin's lymphomas. In t(9;14)(p13;q32), PAX-5 gene on 9p13 is involved with the immunoglobulin heavy-chain gene on 14q32. It has been thought that the deregulated expression of PAX-5 as a result of t(9;14)(p13;q32) may contribute to abnormal cell proliferation. Although continuous cell lines are invaluable tools for studying lymphomagenesis in the t(9;14)(p13;q32)-bearing lymphomas, establishment of such cell lines is extremely difficult since they are usually mature B-cell malignancies. In an attempt to transform the SLVL cells into a proliferating cell line, we examined the responses of the cells to infection by Epstein-Barr virus (EBV). SLVL cells were found to be susceptible to immortalization by EBV, resulting in a permanent cell line. The cell line, designated SL-15, possessed the t(9;14)(p13;q32). Genotype analysis and immunophenotype profiles confirmed that the cell line arose from the primary lymphoma cells. The cells had characteristic cytoplasmic villi. SL-15 cells has been growing over 2 years equivalent to 350-400 population doubling levels without proliferative crisis that is often observed in EBV-positive lymphoblastoid cell lines. Furthermore, SL-15 cells, when inoculated into nude mice, formed t(9;14)(p13;q32)-bearing tumors with cytoplasmic villi. The validated SLVL-derived cell line provide a useful model system to study molecular biology of t(9;14)(p13;q32)-bearing B-cell malignancies as well as lymphomagenesis of SLVL in vitro and in vivo.
  International Journal of Cancer 02/2006; 118(2):513-7. · 5.44 Impact Factor
• Article: Pure red cell aplasia in a patient with trisomy X chromosome abnormality and reactivated Epstein-Barr virus infection.

  Masanori Daibata, Hisanori Machida, Yuiko Nemoto, Hirokuni Taguchi
  [show abstract] [hide abstract]
  ABSTRACT: We describe a woman with a congenital chromosome anomaly, 47,XXX, who developed chronic pure red cell aplasia (PRCA). The patient had serologic reactivity consistent with that of reactivated Epstein-Barr virus (EBV) infection, as judged by high titers for anti-EBV viral capsid antigen (VCA) immunoglobulin G (IgG) and anti-early antigen (EA) IgG. Detection of EBV genome in peripheral blood cells and cell-free serum also supported the diagnosis. Although EBV infection has been implicated in the pathogenesis of acute PRCA, the viral infection rarely results in a chronic disease state. So far, only 1 case of EBV-associated chronic PRCA has been reported, to the best of our knowledge. Chronic PRCA also is known to occur on an autoimmune basis. Individuals carrying an extra X chromosome, such as XXY and XXX, are prone to development of immune abnormalities. Our patient had an anti-DNA autoantibody and a positive result of the direct Coombs test. The pathogenesis of PRCA in this case seemed to involve multiple factors. In addition to the infectious agent, host factors may have played a role. Although the etiologic link between chronic PRCA and trisomy X remains to be elucidated, our findings suggest the importance of karyotype analysis as well as search for infectious agents in patients with chronic PRCA.
  International Journal of Hematology 06/2003; 77(4):354-8. · 1.27 Impact Factor
• Article: Simian virus 40 in Japanese patients with lymphoproliferative disorders.

  Masanori Daibata, Yuiko Nemoto, Mikio Kamioka, Shosuke Imai, Hirokuni Taguchi
  British Journal of Haematology 05/2003; 121(1):190-1. · 4.94 Impact Factor
• Article: Epstein-Barr virus in concomitant gastric carcinoma and adult T-cell leukemia/lymphoma.

  Masanori Daibata, Yuiko Nemoto, Shigeki Takemoto, Isao Miyoshi, Hirokuni Taguchi
  The American Journal of Medicine 05/2003; 114(6):509-10. · 5.43 Impact Factor
• Article: Epstein-Barr virus (EBV)-positive pyothorax-associated lymphoma (PAL): chromosomal integration of EBV in a novel CD2-positive PAL B-cell line.

  Masanori Daibata, Takahiro Taguchi, Yuiko Nemoto, Tsuyako Saito, Hisanori Machida, Shosuke Imai, Isao Miyoshi, Hirokuni Taguchi
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  ABSTRACT: Pyothorax-associated lymphoma (PAL) is a clinico-pathological entity arising in the pleural cavity of patients with long-standing inflammatory pyothorax. PAL is closely associated with Epstein-Barr virus (EBV), but how this virus contributes to the development of the lymphoma is unknown. We have successfully obtained a novel EBV-infected PAL cell line, designated Pal-1. The cell line and its source coexpressed CD2 and CD20 molecules, but other representative B- and T-cell markers such as CD1, CD3, CD5, CD7, CD10 and CD19 were not found. The B-cell origin of Pal-1 cells was proven by rearrangement of the immunoglobulin heavy- and light-chain genes without rearranged T-cell receptor genes. Both the cell line and primary tumour cells carried monoclonal EBV genome. Although EBV genome is known to be maintained as circular extrachromosomal DNA, neither circular nor linear extrachromosomal EBV DNA was detectable in Pal-1 cells by in situ lysis gel analysis. Fluorescence in situ hybridization demonstrated viral integration at a marker chromosome mostly consisting of the centromere region of chromosome 1. The viral integration event may enhance a chromosomal instability at the insertion site. This cell line represents the first example of EBV integration in PAL and could enable the study of the potential role of integrated viral infection in the development of PAL as well as mechanism of the aberrant phenotype expression.
  British Journal of Haematology 07/2002; 117(3):546-57. · 4.94 Impact Factor
• Article: Detection of human herpesvirus 6 and JC virus in progressive multifocal leukoencephalopathy complicating follicular lymphoma

  Masanori Daibata, Nobuo Hatakeyama, Mikio Kamioka, Yuiko Nemoto, Makoto Hiroi, Isao Miyoshi, Hirokuni Taguchi
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  ABSTRACT: Progressive multifocal leukoencephalopathy (PML), a demyelinating infectious disease caused by JC virus (JCV), occurs almost exclusively in immunocompromised patients usually with malignant diseases. We report here a Japanese female with follicular lymphoma who subsequently developed PML. In addition to JCV, human herpesvirus 6 (HHV-6) was detected in the affected brain lesions of the patient by polymerase chain reaction and by in situ hybridization. HHV-6, recognized as a neurotropic virus, is known to be reactivated during immunosuppression and can cause fatal complications such as encephalitis/encephalopathy. It is likely that impaired immunity associated with lymphoma and the additional immunosuppression following cytopenia-inducing chemotherapies predisposed the patient to reactivated HHV-6 infection. Although it remains to be clarified whether HHV-6 plays an important role as a co-agent with JCV in causing demyelination of the brain, our observation alerts physicians to the possible association of HHV-6 with the pathogenesis of PML. Am. J. Hematol. 67:200–205, 2001. © 2001 Wiley-Liss, Inc.
  American Journal of Hematology 05/2001; 67(3):200 - 205. · 4.67 Impact Factor
• Article: Constitutional t(3;11)(p21;q23) in a Family, Including One Member with Lymphoma: Establishment of Novel Cell Lines with this Translocation

  Masanori Daibata, Yuiko Nemoto, Naoki Komatsu, Hisanori Machida, Isao Miyoshi, Hirokuni Taguchi
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  ABSTRACT: We describe a family with an inherited constitutional chromosome translocation (3;11)(p21;q23). Of three proven translocation carriers, one had duodenal malignant lymphoma (B-cell diffuse lymphoma, medium-sized cell type). The t(3;11)(p21;q23) was detected not only in hematopoietic cells including the patient's lymphoma cells, non-pathological bone marrow, and phytohemagglutinin-stimulated peripheral blood, but also in fibroblasts of the skin. We have successfully established an Epstein-Barr virus-transformed B-cell line and a Herpesvirus saimiri-transformed T-cell line from the patient, and found that both cell lines also carried this translocation. The patient's asymptomatic mother and sister had the same chromosomal abnormality. Chromosomal abnormalities of the 11q23 band occur frequently in various hematopoietic malignant disorders, and 3p21 has been linked to the pathogenesis of several solid tumors including carcinomas of the kidney, lung, and breast. Although 11q23 is known to recombine with many different chromosomal segments, t(3;11)(p21;q23) has not been reported to our knowledge. Further assessment is warranted to clarify if this constitutional translocation predisposes to certain malignancies. Our cell lines carrying the novel chromosome translocation would be useful for the molecular analysis of the rearranged genes involving both 3p21 and 11q23.
  Cancer Genetics and Cytogenetics.