Tadao Tanaka

The Jikei University School of Medicine, Edo, Tōkyō, Japan

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Publications (91)200.77 Total impact

  • Placenta 10/2013; 34(10):A15-A16. DOI:10.1016/j.placenta.2013.07.057 · 2.71 Impact Factor
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    ABSTRACT: Despite the use of retroviral vectors, efficiently introducing target genes into immunocytes such as T cells is difficult. In addition, retroviral vectors carry risks associated with the oncogenicity of the native virus and the potential for introducing malignancy in recipients due to genetic carryover from immortalized cells used during vector production. To address these issues, we have established a new virus vector that is based on human herpesvirus 6 (HHV-6), a non-oncogenic lymphotropic herpesvirus that infects CD4(+) T cells, macrophages, and dendritic cells. In the present study, we have altered the cell specificity of the resulting recombinant HHV-6 by knocking out the U2-U8 genes. The resulting virus proliferated only in activated cord blood cells and not in peripheral blood cells. Umbilical cord blood cells produced replication-defective recombinant virus in sufficiently high titer to omit the use of immortalized cells during vector production. HHV-6 vectors led to high rates (>90%) of gene transduction in both CD4(+) and CD8(+) T cells. These viruses showed low-level replication of viral DNA that supported greater expression of the induced genes than that of other methods but that was insufficient to support the production of replication-competent virus. Furthermore, HHV-6 vectors containing short hairpin RNAs against CD4 and HIV Gag remarkably inhibited the production of these proteins and HIV particles. Here we demonstrate the utility of HHV-6 as a new non-carcinogenic viral vector for immunologic diseases and immunotherapy.
    PLoS ONE 02/2013; 8(2):e56027. DOI:10.1371/journal.pone.0056027 · 3.23 Impact Factor
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    ABSTRACT: The pentaspan membrane glycoprotein CD133 (also known as prominin-1) has been widely used as a marker for both cancer and normal stem cells. However, the function of CD133 has not been elucidated. Here we describe a cancer stem cell line established from clear cell carcinoma of the ovary (CCC) and show that CD133 interacts with plakoglobin (also known as γ-catenin), a desmosomal linker protein. We further demonstrate that knockdown of CD133 by RNA interference (RNAi) results in the downregulation of desmoglein-2, a desmosomal cadherin, and abrogates cell-cell adhesion and tumorigenicity of CCC stem cells. We speculate that CD133 may be a promising target for cancer chemotherapy.
    PLoS ONE 01/2013; 8(1):e53710. DOI:10.1371/journal.pone.0053710 · 3.23 Impact Factor
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    ABSTRACT: Cytokine expression in a tumor microenvironment can impact both host defense against the tumor and tumor cell survival. In this study, we sought to clarify whether the cytokine gene expression profile could have clinical associations with ovarian cancer. We analyzed the expression of 16 cytokine genes (IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p35, IL-12p40, IL-15, IFN-γ, TNF-α, IL-6, HLA-DRA, HLA-DPA1 and CSF1) in 50 ovarian carcinomas. Hierarchical clustering analysis of these tumors was carried out using Cluster software and differentially expressed genes were examined between clear cell carcinoma (CCC) and other subtypes. Following this examination we evaluated the biological significance of IL-6 knockdown in CCC. Unsupervised hierarchical clustering analysis of cytokine gene expression revealed two distinct clusters. The relationship between the two clusters and clinical parameters showed statistically significant differences in CCC compared to other histologies. CCC showed a dominant Th-2 cytokine expression pattern driven largely by IL-6 expression. Inhibition of IL-6 in CCC cells suppressed Stat3 signaling and rendered cells sensitive to cytotoxic agents. The unique cytokine expression pattern found in CCC may be involved in the pathogenesis of this subtype. In particular, high IL-6 expression appears likely to be driven by the tumor cells, fueling an autocrine pathway involving IL-6 expression and Stat3 activation and may influence survival when exposed to cytotoxic chemotherapy. Modulation of IL-6 expression or its related signaling pathway may be a promising strategy of treatment for CCC.
    International Journal of Oncology 06/2012; 41(3):1094-100. DOI:10.3892/ijo.2012.1533 · 3.03 Impact Factor
  • Nippon rinsho. Japanese journal of clinical medicine 06/2012; 70 Suppl 4:475-9.
  • Tadao Tanaka · Satoshi Yanagida · Nozomu Yanaihara
    Nippon rinsho. Japanese journal of clinical medicine 06/2012; 70 Suppl 4:695-8.
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    ABSTRACT: Choriocarcinoma is a highly malignant tumor of trophoblastic origin. Most cases occur in association with preceding gestational events. However, on very rare occasions, nongestational choriocarcinoma arises from germ cell or trophoblastic differentiation in different types of carcinoma. This article reports the case of a 58-year-old woman with primary nongestational choriocarcinoma of the uterus that developed 19 years after her final pregnancy and 4 years after menopause. A total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Histopathological examination showed choriocarcinoma of the uterus without components of other germ cell tumors. Karyotype analysis of the tumor cells demonstrated XX. We confirmed its nongestational origin by DNA polymorphism analysis at 15 short tandem repeat loci. After surgery, the patient was given four courses of combination chemotherapy. She is still alive and there has been no evidence of recurrence 3 years after surgery.
    International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists 05/2012; 31(4):364-8. DOI:10.1097/PGP.0b013e318241d556 · 1.67 Impact Factor
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    ABSTRACT: Aim: The optimal chemotherapy regimen for patients with endometrial cancer has not been established. We assessed the feasibility of paclitaxel plus carboplatin (TC) for postoperative chemotherapy in patients with endometrial cancer. Material and Methods: Patients with newly diagnosed endometrial cancer received TC (paclitaxel 180 mg/m2, carboplatin AUC6 mg/mL/min) every three weeks. Treatment was continued until disease progression or completion of six cycles. Toxicities were evaluated every cycle according to NCI-CTCAE version 3.0. Results: Sixty patients were registered from December 2005 through November 2006. Forty-four of 60 (73.3%) cases completed all of the planned six cycles. Grades 3 and 4 hematologic toxicities were observed as follows: leukopenia (61.7%), neutropenia (95.0%), anemia (21.7%), and thrombocytopenia (5.0%). There were six patients who dropped out from the protocol by neutropenia. Grade 3 non-hematologic toxicities were observed as follows: nausea (3.3%), vomiting (1.7%), neuropathy (5.0%), myalgia (6.7%) and constipation (1.7%). No grade 4 non-hematologic toxicity was observed. Conclusion: This TC regimen is feasible for endometrial cancer patients.
    Journal of Obstetrics and Gynaecology Research 05/2012; 39(1). DOI:10.1111/j.1447-0756.2012.01890.x · 0.93 Impact Factor
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    ABSTRACT: Aim: Several previous reports showed that irinotecan hydrochloride plus cisplatin (CPT-P) was a candidate first-line chemotherapy regimen for clear cell adenocarcinoma of the ovary (CCC). However, long-term survival in CCC patients treated with CPT-P as first-line chemotherapy remains to be determined. The aim of the present study was to evaluate the long-term results of CPT-P as first-line chemotherapy for CCC. Material and Methods: We performed a retrospective review of 31 patients with CCC who were treated with CPT-P between 1996 and 2004. Results: The median follow-up period was 91 months. The estimated 8-year overall survival (OS) rate in all patients was 64.5%, while the rate in 18 stage I, 21 stage I/II, and 10 stage III/IV patients was 88.9%, 85.7%, and 20.0%, respectively. The estimated 8-year OS rate in patients with pT1/pT2 disease was 87.0%, while the 3-year OS rate in patients with pT3 disease was 0%. Univariate analysis using the log–rank test revealed that Eastern Cooperative Oncology Group performance-status 1, pT3 stage, and presence of residual disease (stage II-IV) were significantly correlated with shortened patient survival. Multiple regression analysis revealed that pT3 predicted worse OS in patients with CCC than pT1 (P < 0.001) or pT2 disease (P < 0.005). Conclusion: The long-term results suggest CPT-P as a candidate in first-line chemotherapy for CCC in not only stage I, but also in optimally debulked stage II-IV patients with pT1/pT2 disease.
    Journal of Obstetrics and Gynaecology Research 05/2012; 38(12). DOI:10.1111/j.1447-0756.2012.01884.x · 0.93 Impact Factor
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    ABSTRACT: CD147 is a membrane glycoprotein that is expressed in various cancer cells and is involved in tumor invasion and metastasis by inducing stromal fibroblastic cells to produce matrix metalloproteinases. This study was carried out to evaluate the correlation between CD147 expression and various clinicopathologic parameters, including histological grade and prognosis in a small sample set of human ovarian cancer patients. Paraffin-embedded surgical tissue samples from 25 patients with ovarian serous and endometrioid adenocarcinoma were stained with anti-CD147 antibody (monoclonal antibody 12C3: MoAb 12C3) for immunohistochemical analysis. CD147 protein was expressed in 84.0% (21 of 25 cases) of cancerous lesions, but not in normal lesions. CD147 expression by ovarian cancer cells was inversely correlated with overall survival. There was no correlation between CD147 expression and histological grade. These results suggest that measurement of CD147 expression may enhance the understanding of the pathophysiology of epithelial ovarian cancer.
    Journal of Obstetrics and Gynaecology Research 05/2012; 38(9):1211-9. DOI:10.1111/j.1447-0756.2012.01853.x · 0.93 Impact Factor
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    ABSTRACT: A pregnant Japanese female was referred to our hospital due to intrauterine fetal growth restriction. A prenatal diagnosis of right pulmonary agenesis could be made using ultrasonography and fetal magnetic resonance imaging, and a Caesarian section was performed at 34 weeks of gestation. The infant developed a respiratory disorder immediately, received systemic management in the neonatal intensive care unit (NICU), and was discharged at age of 103 days without any severe sequelae.
    Journal of Medical Ultrasonics 04/2012; 40(2):157-162. DOI:10.1007/s10396-012-0410-7 · 0.62 Impact Factor
  • 04/2012; 1(2):108-112. DOI:10.1007/s13691-012-0021-6
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    ABSTRACT: Ovarian clear cell carcinoma (OCCC) has several significant characteristics based on molecular features that are distinct from those of ovarian high-grade serous carcinoma. Cellular glycogen accumulation is the most conspicuous feature of OCCC and in the present study its metabolic mechanism was investigated. The amount of glycogen in cells cultured under hypoxia increased significantly and approximately doubled after 48 h (P<0.01) compared to that under normoxic conditions. Periodic acid-Schiff positive staining also demonstrated intracellular glycogen storage. Western blot analysis revealed that HIF1α, which was overexpressed and stabilized under hypoxic conditions, led to an increase in the levels of cellular glycogen synthase 1, muscle type (GYS1), and conversely to a decrease in inactive phosphorylated GYS1 at serine (Ser) 641. Additional increases were observed in both protein phosphatase 1, which dephosphorylates and thereby induces GYS1 enzyme activity, and glycogen synthase kinase 3 beta (GSK3β) phosphorylated at Ser9, which is inactive on phosphorylation of GYS1 and subsequently induces its enzyme activity. By contrast, the level of PYGM-b decreased. These results indicated that the glycogen accumulation under a hypoxic environment resulted in the promotion of glycogen synthesis, but did not lead to inhibition of glycogen degradation and/or consumption. Under hypoxic conditions, HAC2 cells showed activation of the PI3K/AKT pathway caused by a mutation in exon 20 of PIK3CA, encoding the catalytic subunit p110α of PI3K. The resulting activation of AKT (phosphoSer473) also plays a role as a central enhancer in glycogen synthesis through suppression of GSK3β via phosphorylation at Ser9. Hypoxia decreased the cytocidal activity of cisplatin and doxorubicin to various degrees. In conclusion, the hypoxic conditions together with HIF1 expression and stabilization increased the intracellular glycogen contents and resistance to the anticancer drugs.
    International Journal of Oncology 03/2012; 40(6):2122-30. DOI:10.3892/ijo.2012.1406 · 3.03 Impact Factor
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    ABSTRACT: Adenomyosis patients treated with dienogest are considered to be at higher risk of uterine bleeding; however, the mechanisms which cause severe uterine bleeding in those patients are unknown. This study aims to investigate the risk factors of uterine bleeding among adenomyosis patients treated with dienogest. Clinical data of 51 adenomyosis patients treated with dienogest were retrospectively collected from their medical records. The impact of potential risk factors (age, sagittal square area of the uterus before treatment, and estradiol at the third month of treatment) and confounders (hemoglobin before treatment and prior medical treatments) on the time to treatment discontinuation due to uterine bleeding was assessed using log-rank tests and a Cox proportional hazard model. Age (< 38 years, P = 0.004), hemoglobin before treatment (<12 g/dL, P = 0.047), and estradiol at the third month of treatment (≥ 60 pg/mL, P = 0.027) had statistically significant effects on the time to treatment discontinuation due to uterine bleeding. Age was still statistically significant after controlling for hemoglobin (P = 0.023). Adenomyosis patients treated with dienogest are at higher risk of treatment discontinuation due to uterine bleeding, especially when they are of younger age, have anemia before treatment, and/or have mildly suppressed or unsuppressed estradiol after they started dienogest treatment. Clinicians should pay special attention when they prescribe dienogest for such patients.
    Journal of Obstetrics and Gynaecology Research 03/2012; 38(4):639-44. DOI:10.1111/j.1447-0756.2011.01778.x · 0.93 Impact Factor
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    Nagayoshi Umehara · Tadao Tanaka
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    ABSTRACT: Objective. To investigate the incidence of various antiphospholipid antibodies (aPLs), measured by commercial-based laboratory, with recurrent spontaneous abortion (RSA) patients and the impact of the species, isotype, titer, and number of positive aPLs on reproductive outcome in Japanese. Method. In this retrospective cohort study, 263 patients with RSA without possible causes were investigated. Of 131 patients with one or more positive aPL, 82 pregnant women under anticoagulant therapy were evaluated. Results. The incidence of various aPLs was almost consistent with previous report. Overall, successful pregnancy rate with anticoagulant therapy was 91.4% regardless of aPL profiles. There was no significant difference in the pregnancy maintenance rate between IgG and IgM groups or single positive and multiple positive groups, but there was a tendency for the rate with aspirin to be lower than with aspirin plus heparin in IgG group. Conclusion. aPL profile did not affect the pregnancy maintenance rate when anticoagulant therapy was actively introduced, however in IgG group, we recommend combination therapy with aspirin and heparin.
    ISRN obstetrics and gynecology 03/2012; 2012:819356. DOI:10.5402/2012/819356
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    ABSTRACT: The objective of this study was to ascertain the evidence on ovarian cancer during pregnancy and compile recommendations derived from this information. This was a retrospective study, based on clinical histories from patients diagnosed and treated at 4 independent hospitals for ovarian cancer during pregnancy, between 1992 and 2009. The median age at diagnosis was 30 years (range, 24-41). Out of 10 cases of ovarian cancer, 2 patients showed either bleeding or abdominal pain, while 8 patients were asymptomatic. All 10 cases were diagnosed via ultrasound, and the masses were detected in the first trimester in 7 patients and in the second trimester in 2 patients. Of the diagnosed tumors, 8 cases were epithelial tumors including 6 adenocarcinomas and 2 borderline tumors, and 2 germ cell tumors. The primary ovarian malignancies were at stage I of the disease. Unilateral salpingo-oophorectomy was performed in 9 patients and cystectomy was performed in one patient. Chemotherapy was administered to 4 patients, in 1 case during pregnancy. Neonatal outcome analysis showed a full- or pre-term delivery in 6 cases, abortion in 1 case and therapeutic termination in 3 cases. The majority of cases of ovarian cancer in pregnancy were incidentally detected by ultrasound at an early stage, resulting in good prognosis for the mother and the neonate.
    Oncology letters 03/2012; 3(3):577-580. DOI:10.3892/ol.2011.545 · 1.55 Impact Factor
  • Nippon Laser Igakkaishi 01/2012; 33(2):117-121. DOI:10.2530/jslsm.33.117
  • 01/2012; 28(1):471-475. DOI:10.5180/jsgoe.28.471
  • Nippon Laser Igakkaishi 01/2012; 33(2):136-140. DOI:10.2530/jslsm.33.136
  • Seiji Isonishi · Motoaki Saito · Misato Saito · Tadao Tanaka
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    ABSTRACT: Based on the evidences showing that serum deprivation provokes apoptosis in a variety of cells, we have investigated the effect of serum deprivation on drug sensitivity. After human ovarian cancer cells were preincubated in 0.5 % serum containing medium for 12 hours, cellular drug sensitivities were determined by colony-forming assay. Serum deprivation treatment resulted in significant increase in paclitaxel sensitivity by factors of mean ± SD, 148.6 ± 28.1 and 10.1 ± 1.0 (n = 3; P < 0.001) fold in platinum-resistant C13 and CP70 cells, respectively. Similarly, serum deprivation induced significant docetaxel sensitivity in these cell lines. However, no enhancement effect of serum deprivation was observed in platinum-sensitive 2008 and A2780 cells. Serum deprivation did not have any effect on the sensitivities to cisplatin, vincristin, and doxorubicin in all of these cells. More than 7-fold increase of apoptotic cells were observed in C13 or CP70 cells when they were treated by serum deprivation followed by paclitaxel compared with the treatment of either serum deprivation or paclitaxel alone. Confocal laser microscopy using rhodamine 123 and flow cytometric analysis with 3,3'-dihexyloxacarbocyanine iodide revealed that serum deprivation decreased mitochondrial membrane potential in C13 or CP70 cells, whereas no change was observed in 2008 and A2780 cells. This indicates that serum deprivation induced depolarization specifically in platinum-resistant cells. Electron microscopy revealed that serum deprivation caused regeneration of mitochondrial matrix structure in C13 or CP70 cells where mitochondria were usually destructed and disappeared. These results indicate that serum deprivation confers taxane hypersensitivity specifically in platinum-resistant cells by recovering their impaired mitochondrial functions. The evidence might be clinically beneficial for the development of new chemotherapeutic technology, particularly for the patients with platinum-resistant ovarian cancer.
    International Journal of Gynecological Cancer 11/2011; 21(9):1547-54. DOI:10.1097/IGC.0b013e318231b994 · 1.95 Impact Factor