Junji Hiraga

Publications (10)26.18 Total impact

• Article: [A case of secondary pulmonary malignant lymphoma with multiple pulmonary nodules and spiculation].

  Naohiro Furuhashi, Yasuteru Sugino, Junya Okumura, Yushi Saito, Junji Hiraga, Satoshi Kitagawa
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  ABSTRACT: A 72-year-old man presented to our hospital with fatigue and anemia. Chest CT showed multiple nodular shadows. We first suspected lung cancer and multiple metastatic lesions because some nodules had spiculation. However, PET-CT revealed the small intestine, thyroid and rib as well as these nodules to be positive for FDG uptake, suggesting malignant lymphoma and lung involvement. For diagnosis, lung biopsy by video-assisted thoracic surgery (VATS) was performed. Pathologic examination of the lung biopsy specimen showed diffuse large B-cell lymphoma. We diagnosed secondary pulmonary malignant lymphoma.
  Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 11/2011; 49(11):873-6.
• Article: Role of PET/CT screening in detecting a second primary carcinoma in patients with malignant lymphoma.

  Reona Sakemura, Junji Hiraga, Takahito Okuda, Shinichi Mizuno
  Annals of Hematology 03/2011; 90(12):1485-6. · 2.62 Impact Factor
• Article: Successful immunosuppressive and iron chelation therapy for a severe aplastic anemia patient undergoing hemodialysis due to chronic renal failure.

  Junji Hiraga, Reona Sakemura, Hiroshi Yamashita, Toshimitsu Suzuki, Satoshi Kitagawa, Yasunari Takakuwa, Shinichi Mizuno
  International journal of hematology 03/2011; 93(4):555-7. · 1.17 Impact Factor
• Article: Escape mechanisms from antibody therapy to lymphoma cells: downregulation of CD20 mRNA by recruitment of the HDAC complex and not by DNA methylation.

  Takumi Sugimoto, Akihiro Tomita, Junji Hiraga, Kazuyuki Shimada, Hitoshi Kiyoi, Tomohiro Kinoshita, Tomoki Naoe
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  ABSTRACT: Although rituximab is a critical monoclonal antibody therapy for CD20-positive B-cell lymphomas, rituximab resistance showing a CD20-negative phenotypic change has been a considerable clinical problem. Here we demonstrate that CD20 mRNA and protein expression is repressed by recruitment of a histone deacetylase protein complex to the MS4A1 (CD20) gene promoter in CD20-negative transformed cells after treatment with rituximab. CD20 mRNA and protein expression were stimulated by decitabine (5-Aza-dC) in CD20-negative transformed cells, and was enhanced by trichostation A (TSA). Immunoblotting indicated that DNMT1 expression was first downregulated 1 day after treatment with 5-Aza-dC, but IRF4 and Pu.1, the transcriptional regulators of MS4A1, were still expressed with or without 5-Aza-dC. Interestingly, CpG methylation of the MS4A1 promoter was not observed in CD20-negative transformed cells without 5-Aza-dC. A chromatin immunoprecipitation (ChIP) assay indicated that the Sin3A-HDAC1 co-repressor complex was recruited to the promoter and dissociated from the promoter with 5-Aza-dC and TSA, resulting in histone acetylation. Under these conditions, IRF4 and Pu.1 were continually recruited to the promoter with or without 5-Aza-dC and TSA. These results suggest that recruitment of the Sin3A-HDAC1 complex is related to downregulation of CD20 expression in CD20-negative B-cells after treatment with rituximab.
  Biochemical and Biophysical Research Communications 09/2009; 390(1):48-53. · 2.48 Impact Factor
• Article: Down-regulation of CD20 expression in B-cell lymphoma cells after treatment with rituximab-containing combination chemotherapies: its prevalence and clinical significance.

  Junji Hiraga, Akihiro Tomita, Takumi Sugimoto, Kazuyuki Shimada, Masafumi Ito, Shigeo Nakamura, Hitoshi Kiyoi, Tomohiro Kinoshita, Tomoki Naoe
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  ABSTRACT: Although rituximab is a key molecular targeting drug for CD20-positive B-cell lymphomas, resistance to rituximab has recently been recognized as a considerable problem. Here, we report that a CD20-negative phenotypic change after chemotherapies with rituximab occurs in a certain number of CD20-positive B-cell lymphoma patients. For 5 years, 124 patients with B-cell malignancies were treated with rituximab-containing chemotherapies in Nagoya University Hospital. Relapse or progression was confirmed in 36 patients (29.0%), and a rebiopsy was performed in 19 patients. Of those 19, 5 (26.3%; diffuse large B-cell lymphoma [DLBCL], 3 cases; DLBCL transformed from follicular lymphoma, 2 cases) indicated CD20 protein-negative transformation. Despite salvage chemotherapies without rituximab, all 5 patients died within 1 year of the CD20-negative transformation. Quantitative reverse-transcription-polymerase chain reaction (RT-PCR) showed that CD20 mRNA expression was significantly lower in CD20-negative cells than in CD20-positive cells obtained from the same patient. Interestingly, when CD20-negative cells were treated with 5-aza-2'-deoxycytidine in vitro, the expression of CD20 mRNA was stimulated within 3 days, resulting in the restoration of both cell surface expression of the CD20 protein and rituximab sensitivity. These findings suggest that some epigenetic mechanisms may be partly related to the down-regulation of CD20 expression after rituximab treatment.
  Blood 03/2009; 113(20):4885-93. · 9.90 Impact Factor
• Source

  Available from: Tomohiro Kinoshita

  Article: Clinical significance of nuclear non-phosphorylated beta-catenin in acute myeloid leukaemia and myelodysplastic syndrome.

  Jinglan Xu, Momoko Suzuki, Yousuke Niwa, Junji Hiraga, Tetsuro Nagasaka, Masafumi Ito, Shigeo Nakamura, Akihiro Tomita, Akihiro Abe, Hitoshi Kiyoi, Tomohiro Kinoshita, Tomoki Naoe
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  ABSTRACT: Wnt signaling activates the canonical pathway and induces the accumulation of non-phosphorylated beta-catenin (NPBC) in the nucleus. Although this pathway plays an important role in the maintenance of haematopoietic stem cells as well as in oncogenesis, the significance of nuclear NPBC remains unclear in malignant haematopoiesis. This study examined the expression of nuclear NPBC in bone marrow specimens from 54 and 44 patients with de novo acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS), respectively. On immunohistochemistry with an anti-NPBC antibody, the nuclei were positively stained in 22 and 18 of AML and MDS specimens, respectively. Staining of nuclear NPBC was associated with AML subtypes (M6 and M7), low complete remission (CR) rate, and poor prognosis. Nuclear NPBC was also associated with a high score when using the International Prognostic Scoring System (IPSS) for MDS and with -7/-7q and complex karyotypes. These findings suggest that in situ detection of nuclear NPBC by immunohistochemistry could provide new insights into the pathogenesis and prognosis of AML and MDS.
  British Journal of Haematology 03/2008; 140(4):394-401. · 4.94 Impact Factor
• Article: Epigenetic regulation of CD20 protein expression in a novel B-cell lymphoma cell line, RRBL1, established from a patient treated repeatedly with rituximab-containing chemotherapy.

  Akihiro Tomita, Junji Hiraga, Hitoshi Kiyoi, Manabu Ninomiya, Takumi Sugimoto, Masafumi Ito, Tomohiro Kinoshita, Tomoki Naoe
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  ABSTRACT: Rituximab is a chimeric monoclonal antibody to the surface antigen CD20 and has provided better outcomes against CD20+ B-cell lymphomas than chemotherapy with conventional antitumor drugs alone. Treatment with rituximab poses a considerable problem, however, because of CD20- tumor transformation and subsequent disease progression. We have established a CD20- lymphoma cell line, RRBL1, from a diffuse large B-cell lymphoma with CD20- transformation from CD20+ follicular lymphoma after treatment with rituximab. RRBL1 was CD10+, CD19+, and CD20- by flow cytometry. CD20 expression was not detected by immunohistochemistry. Immunoblotting with whole RRBL1 cell lysate showed a very faint CD20 band only with longer exposures. The level of CD20 messenger RNA (mRNA) expression detected by quantitative reverse transcriptase-polymerase chain reaction analysis was almost 100 times lower than that in CD20+ lymphoma cells. When we treated RRBL1 cells with trichostatin A, an epigenetic drug that modulates histone-acetylation status, we detected dramatically increased CD20 mRNA and protein expression, suggesting that epigenetic mechanisms may explain the CD20- phenotype in RRBL1 cells. Thus, RRBL1 may be useful not only for analyses of mechanisms for the absence of CD20 expression in vitro but also for exploration of therapies against CD20- B-cell malignancies in vivo.
  International Journal of Hematology 08/2007; 86(1):49-57. · 1.27 Impact Factor
• Article: Promoter hypermethylation of the DNA-repair gene O6-methylguanine-DNA methyltransferase and p53 mutation in diffuse large B-cell lymphoma.

  Junji Hiraga, Tomohiro Kinoshita, Toshihito Ohno, Naoyoshi Mori, Haruhiko Ohashi, Shouko Fukami, Atsuhiko Noda, Atsushi Ichikawa, Tomoki Naoe
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  ABSTRACT: The gene for the DNA-repair enzyme O6-methylguanine-DNA methyltransferase (MGMT), which is closely related with cellular sensitivity to alkylating agents, is inactivated by promoter hypermethylation in several human cancers, including malignant lymphoma. Promoter hypermethylation of the MGMT gene is a favorable prognostic factor in diffuse large B-cell lymphoma (DLBCL). Although inactivation of the MGMT gene is closely related to p53 gene mutations in several cancers, the relationship between p53 gene mutation and MGMT inactivation in malignant lymphoma has not been thoroughly examined. We studied the correlation between MGMT hypermethylation and p53 mutation in DLBCL and their impacts on patient prognosis. In a retrospective cohort study, we used a methylation-specific polymerase chain reaction technique to analyze the methylation status of the promoter region of the MGMT gene in 116 DLBCL patients who received cyclophosphamide as part of multidrug combination chemotherapies. Denaturing high-performance liquid chromatography and direct sequencing were used to search for p53 gene mutations in exons 5 through 9 in 96 of the 116 samples. Disease-free survival and overall survival were estimated by the Kaplan-Meier method. Multivariate survival analyses were performed with the Cox proportional hazards model. Forty-five (38.8%) of 116 DLBCL patients showed MGMT promoter hypermethylation. The presence of MGMT hypermethylation was associated with better overall survival (P = .036). MGMT promoter hypermethylation was a prognostic factor that was independent of established prognostic factors, such as age, disease stage, serum lactic dehydrogenase level, and the number of extranodal disease sites (hazard ratio, 2.43; 95% confidence interval, 1.28-4.61; P = .007). p53 mutations were detected in 19 (19.8%) of 96 patients and were identified as a risk factor in the complete remission rate and overall survival (P = .0040, and P = .027, respectively). A correlation between MGMT hypermethylation and p53 mutation or p53 G:C-to-A:T mutation was not observed (P = .88, and P = .31, respectively). MGMT promoter hypermethylation and p53 mutation are useful prognostic markers in DLBCL. The impact of MGMT inactivation on p53 mutation in DLBCL is unclear.
  International Journal of Hematology 11/2006; 84(3):248-55. · 1.27 Impact Factor
• Article: Loss of O6-methylguanine-DNA methyltransferase protein expression is a favorable prognostic marker in diffuse large B-cell lymphoma.

  Toshihito Ohno, Junji Hiraga, Haruhiko Ohashi, Chiho Sugisaki, Eika Li, Haruhiko Asano, Tastuya Ito, Hirokazu Nagai, Yoriko Yamashita, Naoyoshi Mori, Tomohiro Kinoshita, Tomoki Naoe
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  ABSTRACT: Although aberrant promoter hypermethylation of O6-methylguanine-DNA methyltransferase (MGMT) is a favorable prognostic marker in patients with diffuse large B-cell lymphoma (DLBCL), MGMT protein expression has not been thoroughly examined. The aim of this study was to evaluate the clinical implication of MGMT protein expression and its correlation with promoter hypermethylation of the gene. We investigated MGMT protein expression by immunohistochemical analysis of 63 DLBCL patients who received cyclophosphamide as part of multidrug regimens. In addition, promoter methylation of the MGMT gene was analyzed by a methylation-specific polymerase chain reaction assay, and correlations with chemotherapeutic effect and prognosis were statistically evaluated. Immunohistochemical assay results for MGMT protein were negative in 30.2% of patients with newly diagnosed DLBCL. Immunostaining results were closely correlated with the methylation status of the promoter. Promoter DNA methylation of the gene was not detected in 34 (81.0%) of 42 tumor samples determined to be MGMT-positive DLBCL by immunostaining and was detected in 15 (88.2%) of 17 cases of MGMT-negative DLBCL. Overall survival (OS) and disease-free survival (DFS) rates were significantly higher in MGMT-negative patients than in MGMT-positive patients (5-year OS, 81.3% versus 56.6% [P = .0375]; 5-year DFS, 66.3% versus 39.9% [P = .0121]). The combined rate for complete response (CR) plus unconfirmed CR was significantly higher in MGMT-negative patients (15/19, 79.0%) than in MGMT-positive patients (25/44, 56.8%) (P = .0488). A multivariate analysis showed that absence of MGMT expression was an independent prognostic factor for OS (relative risk, 4.09; P = .0258). Lack of MGMT protein expression is associated with aberrant promoter DNA methylation and appears to be a useful marker for predicting the survival of DLBCL patients.
  International Journal of Hematology 06/2006; 83(4):341-7. · 1.27 Impact Factor
• Article: A case of interstitial pneumonia induced by rituximab therapy.

  Junji Hiraga, Yasuhiro Kondoh, Hiroyuki Taniguchi, Tomohiro Kinoshita, Tomoki Naoe
  International Journal of Hematology 03/2005; 81(2):169-70. · 1.27 Impact Factor