Yuichiro Miyamoto

Publications (9)16.92 Total impact

• Article: Sequential effects of the proteasome inhibitor bortezomib and chemotherapeutic agents in uterine cervical cancer cell lines.

  Yuichiro Miyamoto, Shunsuke Nakagawa, Osamu Wada-Hiraike, Takayuki Seiki, Michihiro Tanikawa, Haruko Hiraike, Kenbun Sone, Kazunori Nagasaka, Katsutoshi Oda, Kei Kawana, Keiichi Nakagawa, Tomoyuki Fujii, Tetsu Yano, Shiro Kozuma, Yuji Taketani
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  ABSTRACT: Although the prognosis of uterine cervical cancer has improved due to the advances of treatment modalities, survival of recurrent or metastatic cervical cancer remains poor. Cisplatin is an effective radiosensitizer, but its single agent activity in recurrent cervical cancer is disappointing. Inactivation of tumor suppressors through ubiquitin-mediated degradation by human papillomavirus is known to be a critical step in the carcinogenesis of uterine cervix. Bortezomib, a selective inhibitor of the proteasome, has been shown to inhibit the growth of several solid tumors. To determine the role of bortezomib in cervical cancer as a chemotherapeutic agent, we studied its biological properties. Bortezomib efficiently inhibited the proteasomal activities in cervical cancer cells, and an increased expression of tumor suppressors such as p53, hDlg and hScrib became evident. In addition, sequential or concomitant treatment of bortezomib and cisplatin stimulated the expression of p53, hScrib and p21 and the stimulation was markedly influenced by the order of drugs in HeLa cells. We further confirmed that the concomitant use of bortezomib and cisplatin has synergistic inhibitory effects on the growth of xenograft tumors derived from HeLa cells. Our data establish the possibility that the concomitant use of bortezomib and cisplatin could be an alternative choice in cases resistant to conventional chemotherapy, and sequential effects must be considered for advanced and therapy-resistant cervical cancer patients.
  Oncology Reports 10/2012; · 1.84 Impact Factor
• Article: Regulation of SIRT1 determines initial step of endometrial receptivity by controlling E-cadherin expression.

  Akira Shirane, Osamu Wada-Hiraike, Michihiro Tanikawa, Takayuki Seiki, Haruko Hiraike, Yuichiro Miyamoto, Kenbun Sone, Mana Hirano, Hajime Oishi, Katsutoshi Oda, Kei Kawana, Shunsuke Nakagawa, Yutaka Osuga, Tomoyuki Fujii, Tetsu Yano, Shiro Kozuma, Yuji Taketani
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  ABSTRACT: Sirtuin 1 (SIRT1), originally found as a class III histone deacetylase, is a principal modulator of pathways downstream of calorie restriction, and the activation of SIRT1 ameliorates glucose homeostasis and insulin sensitivity. We examined the role of SIRT1 in the regulation of uterine receptivity using Ishikawa and RL95-2 endometrial carcinoma cell lines. Exogenous expression of SIRT1 significantly enhanced E-cadherin expression, while small interfering RNA-mediated depletion of endogenous SIRT1 resulted in a significant reduction of E-cadherin expression. A SIRT1 activator resveratrol elevated E-cadherin expression in a dose dependent manner, while SIRT1 repressors nicotinamide and sirtinol exhibited a dose dependent reduction of E-cadherin expression. We also showed that both forced expression of SIRT1 and activation of SIRT1 promote E-cadherin-driven reporter gene constructs, and SIRT1 is localized at E-cadherin promoter containing E-box elements in Ishikawa cells. Using an in vitro model of embryo implantation, we demonstrate that exogenous expression of SIRT1 and stimulation of SIRT1 activity resulted in the Ishikawa cell line becoming receptive to JAR cell spheroid attachment. Furthermore, resveratrol enhanced E-cadherin and Glycodelin protein expression at sites of intercellular contact, suggesting an additive role of resveratrol in promoting implantation. The initial step of human reproduction depends on the capacity of an embryo to attach and implant into the endometrial wall, and these results revealed the novel mechanism that activation and increased expression of SIRT1 play an important role in uterine receptivity.
  Biochemical and Biophysical Research Communications 07/2012; 424(3):604-10. · 2.48 Impact Factor
• Source

  Available from: Osamu Wada-Hiraike

  Article: Resveratrol promotes expression of SIRT1 and StAR in rat ovarian granulosa cells: an implicative role of SIRT1 in the ovary.

  Yoshihiro Morita, Osamu Wada-Hiraike, Tetsu Yano, Akira Shirane, Mana Hirano, Haruko Hiraike, Satoshi Koyama, Hajime Oishi, Osamu Yoshino, Yuichiro Miyamoto, Kenbun Sone, Katsutoshi Oda, Shunsuke Nakagawa, Kazuyoshi Tsutsui, Yuji Taketani
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  ABSTRACT: Resveratrol is a natural polyphenolic compound known for its beneficial effects on energy homeostasis, and it also has multiple properties, including anti-oxidant, anti-inflammatory, and anti-tumor activities. Recently, silent information regulator genes (Sirtuins) have been identified as targets of resveratrol. Sirtuin 1 (SIRT1), originally found as an NAD+-dependent histone deacetylase, is a principal modulator of pathways downstream of calorie restriction, and the activation of SIRT1 ameliorates glucose homeostasis and insulin sensitivity. To date, the presence and physiological role of SIRT1 in the ovary are not known. Here we found that SIRT1 was localized in granulosa cells of the human ovary. The physiological roles of resveratrol and SIRT1 in the ovary were analyzed. Immunohistochemistry was performed to localize the SIRT1 expression. SIRT1 protein expression of cultured cells and luteinized human granulosa cells was investigated by Western blot. Rat granulosa cells were obtained from diethylstilbestrol treated rats. The cells were treated with increasing doses of resveratrol, and subsequently harvested to determine mRNA levels and protein levels. Cell viability was tested by MTS assay. Cellular apoptosis was analyzed by caspase 3/7 activity test and Hoechst 33342 staining. SIRT1 protein was expressed in the human ovarian tissues and human luteinized granulosa cells. We demonstrated that resveratrol exhibited a potent concentration-dependent inhibition of rat granulosa cells viability. However, resveratrol-induced inhibition of rat granulosa cells viability is independent of apoptosis signal. Resveratrol increased mRNA levels of SIRT1, LH receptor, StAR, and P450 aromatase, while mRNA levels of FSH receptor remained unchanged. Western blot analysis was consistent with the results of quantitative real-time RT-PCR assay. In addition, progesterone secretion was induced by the treatment of resveratrol. These results suggest a novel mechanism that resveratrol could enhance progesterone secretion and expression of luteinization-related genes in the ovary, and thus provide important implications to understand the mechanism of luteal phase deficiency.
  Reproductive Biology and Endocrinology 02/2012; 10:14. · 2.05 Impact Factor
• Source

  Available from: Yuji Ikeda

  Article: Genotype-dependent efficacy of a dual PI3K/mTOR inhibitor, NVP-BEZ235, and an mTOR inhibitor, RAD001, in endometrial carcinomas.

  Keiko Shoji, Katsutoshi Oda, Tomoko Kashiyama, Yuji Ikeda, Shunsuke Nakagawa, Kenbun Sone, Yuichiro Miyamoto, Haruko Hiraike, Michihiro Tanikawa, Aki Miyasaka, Takahiro Koso, Yoko Matsumoto, Osamu Wada-Hiraike, Kei Kawana, Hiroyuki Kuramoto, Frank McCormick, Hiroyuki Aburatani, Tetsu Yano, Shiro Kozuma, Yuji Taketani
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  ABSTRACT: The PI3K (phosphatidylinositol-3-kinase)/mTOR (mammalian target of rapamycin) pathway is frequently activated in endometrial cancer through various PI3K/AKT-activating genetic alterations. We examined the antitumor effect of NVP-BEZ235--a dual PI3K/mTOR inhibitor--and RAD001--an mTOR inhibitor--in 13 endometrial cancer cell lines, all of which possess one or more alterations in PTEN, PIK3CA, and K-Ras. We also combined these compounds with a MAPK pathway inhibitor (PD98059 or UO126) in cell lines with K-Ras alterations (mutations or amplification). PTEN mutant cell lines without K-Ras alterations (n = 9) were more sensitive to both RAD001 and NVP-BEZ235 than were cell lines with K-Ras alterations (n = 4). Dose-dependent growth suppression was more drastically induced by NVP-BEZ235 than by RAD001 in the sensitive cell lines. G1 arrest was induced by NVP-BEZ235 in a dose-dependent manner. We observed in vivo antitumor activity of both RAD001 and NVP-BEZ235 in nude mice. The presence of a MEK inhibitor, PD98059 or UO126, sensitized the K-Ras mutant cells to NVP-BEZ235. Robust growth suppression by NVP-BEZ235 suggests that a dual PI3K/mTOR inhibitor is a promising therapeutic for endometrial carcinomas. Our data suggest that mutational statuses of PTEN and K-Ras might be useful predictors of sensitivity to NVP-BEZ235 in certain endometrial carcinomas.
  PLoS ONE 01/2012; 7(5):e37431. · 4.09 Impact Factor
• Article: Expression of DBC1 is associated with nuclear grade and HER2 expression in breast cancer.

  Haruko Hiraike, Osamu Wada-Hiraike, Shunsuke Nakagawa, Shigehira Saji, Daichi Maeda, Yuichiro Miyamoto, Kenbun Sone, Michihiro Tanikawa, Katsutoshi Oda, Keiichi Nakagawa, Tetsu Yano, Masashi Fukayama, Yuji Taketani
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  ABSTRACT: DBC1/KIAA1967 (deleted in breast cancer 1) is a putative tumor-suppressor gene cloned from breast cancer specimens and is reported to regulate p53-dependent apoptosis through its specific inhibition of SIRT1 deacetylase. Although SIRT1 plays a pivotal role in carcinogenesis by regulating cellular proliferation, survival and death, its role in breast cancer remains controversial. Therefore, we aimed to investigate the expression status and clinicopathological significance of DBC1 and SIRT1 in breast cancer tissues. We evaluated the expression of DBC1 and SIRT1 in breast core-needle biopsy specimens from 48 primary breast cancer patients between 2005 and 2008. These patients were treated with primary systemic chemotherapy and subsequent surgical resection of the lesions. Immunohistochemical expression scores of DBC1 and SIRT1 were evaluated, and the relationship between their expression levels and clinicopathological features of breast cancer was analyzed. The expression was observed exclusively in the nuclei of normal and neoplastic ductal cells. In breast biopsy specimens, positive expression of DBC1 and SIRT1 was noted in 85 and 98% of patients, respectively. Expression of DBC1 was significantly associated with the tumor nuclear grade (P=0.019). DBC1 and SIRT1 expression was inversely correlated with HER2 expression (P=0.026 and 0.003, respectively). Lower expression of DBC1 and SIRT1 indicated a tendency for a favorable pathological response to chemotherapy, although this was not statistically significant. Our results reveal that the expression of DBC1 and SIRT1 in breast tissues is associated with tumor characteristics.
  Experimental and therapeutic medicine 01/2011; 2(6):1105-1109.
• Article: Repression of estrogen receptor beta function by putative tumor suppressor DBC1.

  Satoshi Koyama, Osamu Wada-Hiraike, Shunsuke Nakagawa, Michihiro Tanikawa, Haruko Hiraike, Yuichiro Miyamoto, Kenbun Sone, Katsutoshi Oda, Hiroshi Fukuhara, Keiichi Nakagawa, Shigeaki Kato, Tetsu Yano, Yuji Taketani
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  ABSTRACT: It has been well established that estrogen is involved in the pathophysiology of breast cancer. Estrogen receptor (ER) alpha appears to promote the proliferation of cancer tissues, while ERbeta can protect against the mitogenic effect of estrogen in breast tissue. The expression status of ERalpha and ERbeta may greatly influence on the development, treatment, and prognosis of breast cancer. Previous studies have indicated that the deleted in breast cancer 1 (DBC1/KIAA1967) gene product has roles in regulating functions of nuclear receptors. The gene encoding DBC1 is a candidate for tumor suppressor identified by genetic search for breast cancer. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of the endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. In addition, DBC1 modulates ERalpha expression and promotes breast cancer cell survival by binding to ERalpha. Here we report an ERbeta-specific repressive function of DBC1. Immunoprecipitation and immunofluorescence studies show that ERbeta and DBC1 interact in a ligand-independent manner similar to ERalpha. In vitro pull-down assays revealed a direct interaction between DBC1 amino-terminus and activation function-1/2 domain of ERbeta. Although DBC1 shows no influence on the ligand-dependent transcriptional activation function of ERalpha, the expression of DBC1 negatively regulates the ligand-dependent transcriptional activation function of ERbetain vivo, and RNA interference-mediated depletion of DBC1 stimulates the transactivation function of ERbeta. These results implicate the principal role of DBC1 in regulating ERbeta-dependent gene expressions.
  Biochemical and Biophysical Research Communications 02/2010; 392(3):357-62. · 2.48 Impact Factor
• Article: hScrib, a human homologue of Drosophila neoplastic tumor suppressor, is a novel death substrate targeted by caspase during the process of apoptosis.

  Kenbun Sone, Shunsuke Nakagawa, Keiichi Nakagawa, Shin Takizawa, Yoko Matsumoto, Kazunori Nagasaka, Tetsushi Tsuruga, Haruko Hiraike, Osamu Hiraike-Wada, Yuichiro Miyamoto, Katsutoshi Oda, Toshiharu Yasugi, Koji Kugu, Tetsu Yano, Yuji Taketani
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  ABSTRACT: hScrib, human homologue of Drosophila neoplastic tumor suppressor, was identified as a target of human papillomavirus E6 oncoprotein for the ubiquitin-mediated degradation. Here, we report that hScrib is a novel death substrate targeted by caspase. Full-length hScrib was cleaved by caspase during death ligands-induced apoptosis, which generates a p170 C-terminal fragments in Hela cells. In vitro cleavage assay using recombinant caspases showed that hScrib is cleaved by the executioner caspases. DNA damage-induced apoptosis caused loss of expression of full-length hScrib, which was recovered by addition of capase-3 inhibitor in HaCat cells. TUNEL positive apoptotic cells, which were identified 4 h after UV irradiation in HaCat cells, showed loss of hScrib expression at the adherens junction. Mutational analysis identified the caspase-dependent cleavage site of hScrib at the position of Asp-504. Although MDCK cells transfected with GFP-fused wild-type hScrib showed loss of E-cadherin expression and shrinkage of cytoplasm by UV irradiation, cells transfected with hScrib with Ala substitution of Asp-504 showed resistance to caspase-dependent cleavage of hScrib and intact expression of E-cadherin. These results indicate that caspase-dependent cleavage of hScrib is a critical step for detachment of cell contact during the process of apoptosis.
  Genes to Cells 06/2008; 13(7):771-85. · 2.68 Impact Factor
• Article: Loss of Hugl-1 expression associates with lymph node metastasis in endometrial cancer.

  Tetsushi Tsuruga, Shunsuke Nakagawa, Michiko Watanabe, Shin Takizawa, Yoko Matsumoto, Kazunori Nagasaka, Kenbun Sone, Haruko Hiraike, Yuichiro Miyamoto, Osamu Hiraike, Takeo Minaguchi, Katsutoshi Oda, Toshiharu Yasugi, Tetsu Yano, Yuji Taketani
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  ABSTRACT: Mutation of neoplastic tumor suppressor genes, scribble, discs large, and lethal giant larvae (lgl), causes disruption of cell polarity and overproliferation of Drosophila epithelial cells and neuroblasts. Reduced expression of human homologue of lgl, Hugl-1, has been reported to be involved in development and progression of human colon cancer and malignant melanoma. To explore the association between Hugl-1 expression and clinical character in endometrial cancer, we examined the expression of Hugl-1 in primary endometrial cancer tissues. The expression of Hugl-1 mRNA in 86 primary endometrial cancer tissues was examined using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). All samples were categorized into two groups: Hugl-1 positive and Hugl-1 negative. Clinical data of each group were analyzed by Fisher's exact probability test and survival rates of each group were compared by Kaplan-Meier method and Log-rank test. Loss of Hugl-1 expression had correlation with the higher incidence of lymph node metastasis, but not to the patient's age at onset, distant metastasis, clinical stage, lymph or venous vessel invasion, or histopathological grade of differentiation. The Hugl-1-positive group had poorer prognosis compared with the Hugl-1-negative group. These results indicate that loss of Hugl-1 expression in endometrial cancer may contribute to lymph node metastasis and it can be a factor of poor prognosis.
  Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics 02/2007; 16(9):431-5. · 1.30 Impact Factor
• Article: Repression of estrogen receptor β function by putative tumor suppressor DBC1

  Satoshi Koyama, Osamu Wada-Hiraike, Shunsuke Nakagawa, Michihiro Tanikawa, Haruko Hiraike, Yuichiro Miyamoto, Kenbun Sone, Katsutoshi Oda, Hiroshi Fukuhara, Keiichi Nakagawa, Shigeaki Kato, Tetsu Yano, Yuji Taketani
  [show abstract] [hide abstract]
  ABSTRACT: It has been well established that estrogen is involved in the pathophysiology of breast cancer. Estrogen receptor (ER) α appears to promote the proliferation of cancer tissues, while ERβ can protect against the mitogenic effect of estrogen in breast tissue. The expression status of ERα and ERβ may greatly influence on the development, treatment, and prognosis of breast cancer.Previous studies have indicated that the deleted in breast cancer 1 (DBC1/KIAA1967) gene product has roles in regulating functions of nuclear receptors. The gene encoding DBC1 is a candidate for tumor suppressor identified by genetic search for breast cancer. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of the endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. In addition, DBC1 modulates ERα expression and promotes breast cancer cell survival by binding to ERα.Here we report an ERβ-specific repressive function of DBC1. Immunoprecipitation and immunofluorescence studies show that ERβ and DBC1 interact in a ligand-independent manner similar to ERα. In vitro pull-down assays revealed a direct interaction between DBC1 amino-terminus and activation function-1/2 domain of ERβ. Although DBC1 shows no influence on the ligand-dependent transcriptional activation function of ERα, the expression of DBC1 negatively regulates the ligand-dependent transcriptional activation function of ERβ in vivo, and RNA interference-mediated depletion of DBC1 stimulates the transactivation function of ERβ. These results implicate the principal role of DBC1 in regulating ERβ-dependent gene expressions.
  Biochemical and Biophysical Research Communications.