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ABSTRACT: OBJECTIVE: Visceral fat accumulation and metabolic syndrome incidence among women increase after menopause; therefore, fat metabolic changes and fat redistribution may occur according to menstrual status. The aim of our study was to clarify differences in subcutaneous and visceral adipose tissue metabolism between premenopausal and postmenopausal women, using metabolomics. METHODS: Thirty-nine (16 premenopausal and 23 postmenopausal) women were recruited through elective gynecologic surgery, and both subcutaneous and visceral adipose tissues were collected during surgical operation. Metabolite profiling of adipose tissue was performed by capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. RESULTS: Sedoheptulose 7-phosphate, a midproduct of the pentose phosphate pathway, was significantly higher (P < 0.05) in visceral adipose tissues of premenopausal women. Dihydroxyacetone phosphate and fructose-1,6-biphosphate, midproducts of glycolysis, were significantly higher (P < 0.05) in subcutaneous adipose tissues of postmenopausal women. The concentrations of fatty acid metabolites-heptanoate (C7:0; premenopausal vs postmenopausal, 4.07 [0.72] vs 2.64 [0.28] nmol/g), octanoate (C8:0; 3.52 [0.29] vs 5.20 [0.29] nmol/g), and pelargonate (C9:0; 8.03 [0.49] vs 10.66 [0.44] nmol/g)-in the visceral fat (but not in subcutaneous fat) of postmenopausal women were significantly higher (P < 0.05) than those in the visceral fat of premenopausal women. CONCLUSIONS: Fatty acid metabolites increase in visceral fat (but not in subcutaneous fat) after menopause. The change in fatty acid metabolism in visceral adipose tissues might be related to metabolic syndrome in postmenopausal women.
Menopause (New York, N.Y.) 06/2013; · 3.08 Impact Factor
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ABSTRACT: OBJECTIVE: The aim of this study is to clarify the association between estrogen and glucocorticoid levels in adipose tissues of premenopausal and postmenopausal women. METHODS: Forty (15 premenopausal and 25 postmenopausal) women aged 22 to 79 years were recruited through elective gynecological surgical operation, and both subcutaneous and visceral fat were collected during the surgical operation. Messenger RNA (mRNA) expressions of 11β hydroxysteroid dehydrogenase type 1 (HSD1), which catalyzes cortisone to cortisol, and 17β-HSD1 and 17β hydroxysteroid dehydrogenase type 2 (HSD2), which catalyze the interconversion of estrone (E1) and estradiol (E2), were measured by real-time reverse transcription polymerase chain reaction. The levels of E1, E2, cortisol, and cortisone in adipose tissues were measured by liquid chromatography tandem mass spectrometry. RESULTS: The visceral fat area was significantly increased (P < 0.01) in postmenopausal women compared with that in premenopausal women. The cortisol/cortisone ratio (P < 0.01) and the expression of 11β-HSD1 mRNA (P < 0.001) in visceral fat, but not in subcutaneous fat, in postmenopausal women were significantly higher than those in premenopausal women. There was a significant correlation (r = 0.69, P < 0.05) between the E1/E2 ratio of visceral fat and body mass index in postmenopausal women. A significant correlation (r = 0.54, P < 0.05) between the cortisol/cortisone ratio and the E1/E2 ratio of visceral fat was observed in postmenopausal women. CONCLUSIONS: The expression of 11β-HSD1 mRNA in visceral fat increases in postmenopausal women, and the E1/E2 ratio in visceral fat may be associated with local glucocorticoid levels after menopause.
Menopause (New York, N.Y.) 11/2012; · 3.08 Impact Factor
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ABSTRACT: We examined the effect of gefitinib (ZD1839), a selective epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, on cytotoxicity to cisplatin, EGFR downstream signaling, apoptosis and the association between the inhibition of DNA repair by gefitinib and the expression of DNA-dependent protein kinase (DNA-PK) using three ovarian cancer cell lines. In the presence of gefitinib, cisplatin-induced growth inhibition and apoptosis were significantly enhanced in Caov-3 and RMG-1 cells, which express EGFR, and in A2780, which lacks EGFR but expresses HER-2. Gefitinib significantly inhibited the cisplatin-induced ERK and Akt activation in Caov-3 and RMG-1 cells but not in A2780 cells. In all three cell lines, there was delayed repair of DNA intrastrand cross-links damaged by cisplatin used in combination with gefitinib, compared with cisplatin alone. The reduction in DNA-PK levels persisted when cells were exposed to combinations of cisplatin and gefitinib in all cell lines. Moreover, the delayed repair was cancelled by anti-HER2 small-interfering RNA transfection in A2780 cells. These results suggest that combination therapy with cisplatin and gefitinib may increase the therapeutic efficacy of cisplatin by blocking EGFR downstream signaling and/or inhibiting DNA repair in ovarian cancer.
Cancer biology & therapy 04/2012; 13(6):408-16. · 2.64 Impact Factor
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ABSTRACT: Rho, a Ras-related small GTPase, and Rho-associated coiled coil-containing protein kinase (Rho kinase, ROCK1 and ROCK2) are key regulators of focal adhesion, actomyosin contraction, and thus cell motility. Rho/ROCK kinases also play roles in proliferation, differentiation, apoptosis and oncogenic transformation. In the present study, we have shown that Rho/ROCK pathway inhibition by fasudil, an orally administered inhibitor of Rho kinases, enhanced cisplatin-induced growth inhibition and apoptosis in human ovarian cancer cell lines. Fasudil inhibited hypoxia inducible factor (HIF)-1α protein expression. Knockdown of RhoA, ROCK1 or ROCK2 also attenuated the expression of HIF-1α. Furthermore, knockdown of HIF-1α using small interfering RNA enhanced cisplatin-induced growth inhibition and apoptosis as did inhibition of the Rho/ROCK pathway by fasudil, the Rho/ROCK inhibitor Y27632, or by Rho/ROCK knockdown. Therefore, the Rho/ROCK pathway may modulate HIF-1α signal transduction and blockade of Rho/ROCK enhances the efficacy of cisplatin by inhibiting HIF-1α in ovarian cancer cells. Our findings suggested that the Rho/ROCK pathway may be a new target for molecular targeting therapies against ovarian cancer.
Cancer biology & therapy 01/2012; 13(1):25-33. · 2.64 Impact Factor
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ABSTRACT: Estrogen (E2) has direct in vivo and in vitro effects, such as inducing neurite outgrowth, on neurons. We investigated the morphological changes and intracellular signaling pathway induced by E2 in neuroblastoma (SH-SY5Y) cells. The effect of medroxyprogesterone acetate (MPA) or progesterone (P4) on the E2-induced neurite outgrowth was also examined using SH-SY5Y cells. Neurite outgrowth was induced by E2 in association with the phosphorylation of Akt, and these effects of E2 were abolished by MPA but not by P4. Progesterone receptor antagonist RU486 blocked the inhibitory effects of MPA. Estrogen receptor antagonist ICI 182,780 and phosphatidylinositol 3-kinase inhibitor LY294002 inhibited the E2-induced neurite outgrowth. Because the Rho family of small GTPases has been shown to be involved in the regulation of neurite outgrowth, we examined the cross-talk among Rac1, Cdc42 and RhoA in the E2-induced neurite outgrowth. E2 immediately increased the Rac1 and Cdc42 activity and decreased the RhoA activity. E2-induced neurite outgrowth was attenuated in cells expressing dominant-negative mutants for Rac1 or Cdc42. These results suggest that regulation of Rho family GTPase activity by E2 is important for the neurite outgrowth in neuroblastoma cells, and that MPA may have an antagonistic effect against E2.
Molecular and Cellular Neuroscience 08/2011; 48(3):217-24. · 3.66 Impact Factor
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ABSTRACT: The objective of this study was to evaluate the antitumor efficacy of trabectedin in clear cell carcinoma (CCC) of the ovary, which is regarded as an aggressive, chemoresistant, histologic subtype.
Using 6 human ovarian cancer cell lines (3 CCC and 3 serous adenocarcinomas), the antitumor effects of trabectedin were examined in vitro, and we compared its activity according to histology. We next examined the antitumor activity of trabectedin in both cisplatin-resistant and paclitaxel-resistant CCC cells in vitro. Then, the in vivo effects of trabectedin were evaluated using mice inoculated with CCC cell lines. Using 2 pairs of trabectedin-sensitive parental and trabectedin-resistant CCC sublines, we investigated the role of mTOR in the mechanism of acquired resistance to trabectedin. Finally, we determined the effect of mTOR inhibition by everolimus on the antitumor efficacy of trabectedin in vitro and in vivo.
Trabectedin showed significant antitumor activity toward chemosensitive and chemoresistant CCC cells in vitro. Mouse xenografts of CCC cells revealed that trabectedin significantly inhibits tumor growth. Greater activation of mTOR was observed in trabectedin-resistant CCC cells than in their respective parental cells. The continuous inhibition of mTOR significantly enhanced the therapeutic efficacy of trabectedin and prevented CCC cells from acquiring resistance to trabectedin.
Trabectedin is a promising agent for CCC as a first-line chemotherapy and as a second-line treatment of recurrent CCC that had previously been treated with cisplatin or paclitaxel. Moreover, trabectedin combined with everolimus may be more efficacious for the management of CCC.
Clinical Cancer Research 06/2011; 17(13):4462-73. · 7.74 Impact Factor
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ABSTRACT: We aimed to clarify which steroid receptor is involved in the inhibitory effect of medroxyprogesterone acetate (MPA) on estrogen-induced endothelial nitric oxide synthase (eNOS) phosphorylation in human umbilical vein endothelial cells (HUVEC). The progesterone/glucocorticoid receptor (GR) antagonist RU-486 and introduction of GR siRNA caused attenuation of the inhibitory effect of MPA on the estrogen-induced eNOS phosphorylation and eNOS activity in HUVEC.
Fertility and sterility 11/2010; 95(3):1168-70. · 3.97 Impact Factor
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ABSTRACT: We investigated the effects of dienogest (DNG), which has a profile similar to that of natural progesterone (P4), on the favorable effects of estrogen in endothelial function.
(1) Human umbilical vein endothelial cells were treated with medroxyprogesterone acetate (MPA), DNG, or P4 with or without estradiol (E2), and then we examined nitric oxide (NO) production, phosphorylation of Akt, ERK, and endothelial NO synthase. (2) Twenty women with surgical menopause were randomly allocated to four groups: control (no treatment), E2 alone, E2 + MPA, and E2 + DNG. The treatment groups were treated with transdermal E2 (0.72 mg) for 2 days or E2 + MPA (2.5 mg/d) or E2 + DNG (2 mg/d) for a week starting 1 week after the operation; the control group did not use hormone. We examined the changes in the flow-mediated dilatation (FMD) of the brachial artery using ultrasonography.
(1) Although MPA attenuated E2-induced NO production and phosphorylation of Akt, extracellular signal-regulated kinase, and endothelial NO synthase, neither DNG nor P4 inhibited E2 effects. (2) A significant decrease in FMD was observed 1 week after the operation in all groups. E2 significantly ameliorated endothelial impairment (FMD, 3.4% +/- 0.9% to 7.6% +/- 1.3%) in the E2-alone group (P < 0.05), but E2 + MPA could not ameliorate endothelial impairment (3.3% +/- 1.1% to 3.5% +/- 1.0%). However, FMD in the E2 + DNG group significantly increased (2.9% +/- 0.5% to 8.7% +/- 1.0%; P < 0.05).
These results suggest that DNG did not inhibit the restoration of vasodilatation by E2. DNG may have an advantage compared with MPA on the endothelial function in postmenopausal women receiving hormone therapy.
Menopause (New York, N.Y.) 04/2010; 17(3):615-21. · 3.08 Impact Factor
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ABSTRACT: We examined the molecular mechanisms of the antiestrogenic effects of clomiphene citrate (CC) in the endometrium using two types of cell lines, Ishikawa and EM-E6/E7/hTERT cells. CC or ICI182780 inhibited 17beta-estradiol (E2)-induced endometrial cell proliferation and transcriptional activation of the estrogen response element (ERE) gene. We directly visualized the ligand-estrogen receptor (ER)alpha interaction using green fluorescent protein (GFP)-tagged ER alpha in a single living cell. Whereas E2 changed the nuclear localization of GFP-ER alpha to a punctate distribution within 5 min, CC or ICI182780 changed the slower and less mobilization of GFP-ER alpha compared with E2. Pretreatment with CC or ICI182780 partly prevented the E2-induced nuclear redistribution of GFP-ER alpha. Fluorescence recovery after photobleaching revealed that GFP-ER alpha mobility treated with E2 was more rapid than that treated by CC or ICI182780. As coactivator recruitment to the ER is essential for ER-dependent transcription, we examined the interaction between ER alpha and steroid receptor coactivator-1 (SRC-1). The complex formation between ER alpha and SRC-1 was significantly increased by E2 but was prevented in the presence of CC or ICI182780 by coimmunoprecipitation. Moreover, the E2-induced colocalization of GFP-ER alpha and SRC-1 was prevented in the presence of CC or ICI182780 according to an immunofluorescence assay. We also observed that the reduction of SRC-1 using small interfering RNA for SRC-1 resulted in the inhibition of E2-induced cell proliferation and transcriptional activation of the ERE gene. Collectively, these results suggest that CC may inhibit E2-induced endometrial epithelial cell proliferation and ERE transactivation by inhibiting the recruitment of SRC-1 to ER alpha.
Endocrinology 11/2009; 151(1):394-405. · 4.46 Impact Factor
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ABSTRACT: Estrogen has both rapid and longer term direct effects on cardiovascular tissues mediated by the two estrogen receptors, ESR1 and ESR2. Previous work identified that estrogen regulates the expression of inducible nitric oxide synthase (NOS2A) in vascular smooth muscle cells (VSMC). ESR2 knockout mice have vascular dysfunction due to dysregulation of NOS2A expression and these mice are hypertensive (Zhu et al. Science 2002 295 505-508). Here, we report studies to examine the differential regulation of NOS2A gene expression by ESR1 and 2. Immunoblotting and RT-PCR studies revealed that different VSMC lines expressed different levels of ESR1 and ESR2 protein and mRNA. VSMC from different vascular beds were studied, including aortic VSMC expressing ESR1 and radial (Rad) VSMC expressing ESR2. E(2) inhibited NO production and NOS2A protein expression in aortic VSMC. Human NOS2A promoter-reporter studies revealed suppression of NOS2A reporter activity by E(2) in aortic VSMC, and stimulation of NOS2A reporter activity by E(2) in Rad arterial VSMC. In heterologous expression studies of COS-7 cells lacking endogenous ER, E(2) treatment of COS-7 cells did not alter NOS2A reporter activity in the presence of ESR1, while reporter activity increased 2.3-fold in the presence of ESR2. Similar experiments in COS-7 cells using the selective estrogen receptor modulator raloxifene showed that raloxifene caused a reduction in NOS2A reporter activity with ESR1 coexpression and an increase with ESR2 coexpression. Rat VSMC expressing ESR2 but not ESR1 also showed increased NOS2A reporter activity with E(2) treatment, an effect lost when ESR1 was introduced into the cells. Taken together, these data support that hNOS2A transcription is regulated positively by ESR2 and negatively by ESR1 in VSMC, supporting differential actions of these two estrogen receptors on a physiologically relevant gene in VSMC.
Journal of Endocrinology 09/2008; 199(2):267-73. · 3.55 Impact Factor
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ABSTRACT: Hypoxic response of endothelial cells (EC) is an important component of tumor angiogenesis. Especially, hypoxia-inducible factor-1 (HIF-1)-dependent EC-specific mechanism is an essential component of tumor angiogenesis. Recently, the Rho/Rho-associated kinase (ROCK) signaling has been shown to play a key role in HIF-1alpha induction in renal cell carcinoma and trophoblast. The present study was designed to investigate whether low oxygen conditions might modulate HIF-1alpha expression through the Rho/ROCK signaling in human umbilical vascular ECs (HUVEC). Pull-down assay showed that hypoxia stimulated RhoA activity. Under hypoxic conditions, HUVECs transfected with small interfering RNA of RhoA and ROCK2 exhibited decreased levels of HIF-1alpha protein compared with nontargeted small interfering RNA transfectants, whereas HIF-1alpha mRNA levels were not altered. One of ROCK inhibitors, fasudil, inhibited hypoxia-induced HIF-1alpha expression without altering HIF-1alpha mRNA expression. Furthermore, proteasome inhibitor prevented the effect of fasudil on HIF-1alpha expression, and polyubiquitination was enhanced by fasudil. These results suggested that hypoxia-induced HIF-1alpha expression is through preventing HIF-1alpha degradation by activating the Rho/ROCK signaling in ECs. Furthermore, hypoxia induced both vascular endothelial growth factor (VEGF) and VEGF receptor-2 expression through the Rho/ROCK/HIF-1alpha signaling in HUVECs. Thus, augmented VEGF/VEGF receptor-2 autocrine mechanism stimulated HUVEC migration under hypoxic conditions. In summary, the Rho/ROCK/HIF-1alpha signaling is an essential mechanism for hypoxia-driven, VEGF-mediated autocrine loop in ECs. Therefore, fasudil might have the antimigratory effect against ECs in tumor angiogenesis.
Molecular Cancer Therapeutics 07/2008; 7(6):1551-61. · 5.23 Impact Factor
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ABSTRACT: The numbers of ectopic pregnancies have increased because of the popularization of assisted reproductive techniques. However, the retroperitoneal space is an exceptional location for ectopic pregnancy because the entrance to the retroperitoneal space is unknown. A woman 31 years of age who had received bilateral salpingectomy because of a right tubal ectopic pregnancy and a left hydrosalpinx 4 years earlier was treated by in vitro fertilization and embryo transfer (IVF-ET). Ultrasonography and magnetic resonance imaging (MRI) revealed a gestational sac attached to the inferior vena cava in the midabdomen of the retroperitoneal space. Single-dose methotrexate administration was administered twice. However, because of sudden upper abdominal pain with a drastic decline of hemoglobin, an emergent laparotomy was performed. The hematoma and a gestational sac were removed from the aorta and inferior vena cava. Ectopic pregnancy following IVF-ET in a patient with bilateral salpingectomy is likely to be the cause of implantation at this unusual site. An unusual ectopic pregnancy has a high risk of life-threatening massive bleeding. Intensive transabdominal ultrasound scanning and whole abdominal MRI should be performed for the early diagnosis of unruptured ectopic pregnancy.
American Journal of Perinatology 02/2008; 25(1):33-6. · 1.32 Impact Factor
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ABSTRACT: Diverse estrogen actions are controlled via estrogen receptors (ERs). Mechanisms of action of ERs are modulated by various factors such as ER subtypes, conformation of the ER-ligand complex, and recruitment of coregulator complexes to a target gene promoter. Estrogen exerts divergent actions on vascular cells; namely it increases endothelial cell and inhibits smooth muscle cell growth, resulting in a vasoprotective action. We particularly focused on these divergent effects and examined the mechanisms. The effects of raloxifene, which shows estrogen-like vasoprotective actions, were also examined. To examine the effects of 17beta-estradiol (E(2)) and raloxifene on human aortic smooth muscle cells (HASMCs) and human umbilical venous endothelial cells (HUVECs), we evaluated the effect of E(2) and raloxifene on transcriptional activity, recruitment of the coregulator complex to a target gene promoter, and acetylation of histone of both the IGF-I and COX-2 genes. Treatment with E(2) or raloxifene increased both IGF-I and cyclooxygenase (COX)-2 mRNA expression in HUVECs, whereas they attenuated the serum-induced increase of these genes in HASMCs. Treatment by E(2) and raloxifene induced recruitment of coactivator complex and histone acetylation at both the IGF-I and COX-2 gene promoter in HUVECs. In contrast, in HASMCs, E(2), and raloxifene attenuated the serum-induced recruitment of coactivator complexes and histone acetylation at both the IGF-I and COX-2 gene promoters. Estrogen and raloxifene exert divergent transcriptional regulation on both mRNA expression and the remodeling of IGF-I and COX-2 gene promoters in HUVECs vs. HASMCs.
Endocrinology 01/2008; 148(12):6092-9. · 4.46 Impact Factor
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Limei Yin,
Ken-Ichirou Morishige,
Toshifumi Takahashi,
Kae Hashimoto,
Seiji Ogata,
Seiji Tsutsumi,
Keiko Takata,
Tsuyoshi Ohta,
Jun Kawagoe, Kazuhiro Takahashi,
Hirohisa Kurachi
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ABSTRACT: Vascular endothelial growth factor (VEGF)-induced endothelial cell migration is an important component of tumor angiogenesis. Rho and Rho-associated kinase (ROCK) are key regulators of focal adhesion, stress fiber formation, and thus cell motility. Inhibitors of this pathway have been shown to inhibit endothelial cell motility and angiogenesis. In this study, we investigated the antiangiogenic effect of fasudil, one of the ROCK inhibitors. Fasudil inhibited VEGF-induced endothelial cell migration, viability, and tube formation in vitro in human umbilical vein endothelial cells. VEGF-induced endothelial cell migration was reduced by fasudil associated with loss of stress fiber formation, focal adhesion assembly, and with the suppression of tyrosine phosphorylation of focal adhesion proteins. Furthermore, fasudil inhibited VEGF-induced phosphorylation of myosin light chain, which is one of the main substrates of ROCK. Therefore, the effect of fasudil was suggested to be ROCK dependent. Fasudil not only inhibited VEGF-induced cell proliferation but also reversed the protective effect of VEGF on apoptosis, which resulted in the decrease of cell viability. Moreover, fasudil inhibited VEGF-induced angiogenesis in a directed in vivo angiogenesis assay. These data are the first demonstration that fasudil has antiangiogenic properties. Therefore, fasudil might be useful for the treatment of angiogenesis-related diseases, especially cancer.
Molecular Cancer Therapeutics 06/2007; 6(5):1517-25. · 5.23 Impact Factor
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ABSTRACT: We longitudinally examined the changes of brachial to ankle distensibility using pulse wave velocity (PWV) throughout pregnancy and its difference between normal pregnancy and pregnancy-induced hypertension (PIH) groups.
One hundred and eighty-three pregnant women were included in this study. The PWV examinations were performed in a longitudinal way during the first, second, and third trimesters of pregnancy, and immediately and 1 month after delivery.
In normal pregnancies, the PWV significantly decreased at the second trimester, increased from the third trimester through immediately after delivery, and decreased again at 1 month after delivery. In PIH patients, it increased in proportion to the progression of gestation.
We monitored the longitudinal changes in PWV and constructed a PWV normogram during pregnancy. The predictive value of PWV and blood pressure for PIH was higher than that of blood pressure alone, suggesting the usefulness of measuring PWV to predict PIH.
American journal of obstetrics and gynecology 09/2006; 195(2):464-9. · 3.28 Impact Factor
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Masakazu Doshida,
Masahide Ohmichi,
Seiji Tsutsumi,
Jun Kawagoe,
Toshifumi Takahashi,
Botao Du,
Akiko Mori-Abe,
Tsuyoshi Ohta,
Maki Saitoh-Sekiguchi, Kazuhiro Takahashi,
Hirohisa Kurachi
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ABSTRACT: Vascular endothelial senescence is involved in human atherosclerosis. Telomerase activity is known to be critical in cellular senescence and its level is modulated by regulation of telomerase catalytic subunit (telomerase reverse transcriptase (TERT)) at both the transcriptional and post-transcriptional levels. Since the cardioprotective effect of estrogen itself has not been ruled out, we examined that of raloxifene, which has been classified as a selective estrogen receptor modulator, on the proliferation and telomerase activity of human umbilical vein endothelial cells (HUVECs). Raloxifene, like estrogen, clearly induced the telomerase activity and human TERT (hTERT) expression via estrogen receptor (ER) alpha and ERbeta. Treatment with raloxifene for 5 days significantly induced cell growth, and either cotreatment with a telomerase inhibitor, 3'-azido-3'-deoxythymidine, or transfection with hTERT-specific small interfering RNA significantly attenuated the raloxifene-induced cell growth. Raloxifene also induced the phosphorylation of Akt, and pretreatment with a phosphatidylinositol 3-kinase inhibitor, LY294002, significantly attenuated the raloxifene-induced telomerase activity. In addition, raloxifene induced both the phosphorylation of hTERT and IkappaB. Moreover, cotreatment with an IkappaBalpha phosphorylation inhibitor, BAY-11-7082, or a specific NFkappaB nuclear translocation inhibitor, SN50, significantly attenuated the raloxifene-induced telomerase activity and the association of NFkappaB with hTERT. These results show that raloxifene induced the up-regulation of telomerase activity not only by the transcriptional regulation of hTERT but also by post-translational regulation of the phosphorylation of Akt and hTERT and the association of hTERT with NFkappaB in HUVECs. Thus, the up-regulation of telomerase activity in vascular endothelial cells might be one mechanism contributing to the potential atheroprotective effect of raloxifene.
Journal of Biological Chemistry 09/2006; 281(34):24270-8. · 4.77 Impact Factor
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Tsuyoshi Ohta,
Masahide Ohmichi,
Tadashi Hayasaka,
Seiji Mabuchi,
Maki Saitoh,
Jun Kawagoe, Kazuhiro Takahashi,
Hideki Igarashi,
Botao Du,
Masakazu Doshida,
Ishida Gabriela Mirei,
Teiichi Motoyama,
Keiichi Tasaka,
Hirohisa Kurachi
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ABSTRACT: The phosphatidylinositol 3-kinase (PI3K)/Akt cascade has an important role in the resistance of ovarian cancer cells to cisplatin in vitro; however, there have been no reports about whether blocking the PI3K/Akt cascade enhances the sensitivity to cisplatin in vivo. We investigated whether inhibition of PI3K increased the efficacy of cisplatin in an in vivo ovarian cancer model. Blocking the PI3K/Akt cascade with a PI3K inhibitor (wortmannin) increased the efficacy of cisplatin-induced inhibition of intraabdominal dissemination and production of ascites in athymic nude mice inoculated ip with the Caov-3 human ovarian cancer cell line. In addition, wortmannin increased the efficacy of cisplatin-induced apoptosis in tumors cells. There were no detectable side effects in mice treated with wortmannin. Moreover, the antitumor effect of cisplatin detected in mice inoculated with Caov-3 cells stably transfected with empty vector was significantly attenuated, compared with mice inoculated with Caov-3 cells stably transfected with a dominant-negative Akt, K179M-Akt. We confirmed that wortmannin blocked Akt phosphorylation and the downstream targets of the PI3K/Akt cascade, such as BAD (Bcl-2-associated death protein) and nuclear factor-kappaB in vivo by immunohistochemical staining and Western blotting. In accordance with the previously reported in vitro results, these in vivo results support the idea that combination therapy with cisplatin and a PI3K inhibitor would increase the therapeutic efficacy of cisplatin.
Endocrinology 05/2006; 147(4):1761-9. · 4.46 Impact Factor
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ABSTRACT: To examine the correlation between the pulsatility and resistance indices (PI and RI) of the intraovarian artery on the day of follicle aspiration and the oocyte quality, intrafollicular oxidative stress, and luteinization. Pulsatility index and RI on the day of hCG administration also were measured.
Prospective study.
Obstetrics and gynecology department of a university medical school in Japan.
Thirty-five patients in an IVF-ET program.
The PI and RI of the intraovarian artery were measured by transvaginal color ultrasonographic pulsed wave Doppler on the day of hCG administration and the day of follicle aspiration. Follicular fluids and the granulosa cells were collected at follicle aspiration.
The PI and RI of the intraovarian artery blood flow on the day of hCG administration and of follicle aspiration, as well as the rate of development of mature oocytes, follicular fluid steroid levels, and the incidence of apoptosis in the granulosa cells.
The PI and RI on the day of follicle aspiration were correlated positively with the rate of mature oocytes retrieved (PI: r = 0.429; RI: r = 0.348), were correlated negatively with the incidence of apoptotic mural (PI: r = -0.383; RI: r = -0.459) and cumulus (PI: r = -0.378; RI: r = -0.469) granulosa cells, and were negatively correlated with the concentration of P in the follicular fluid (PI: r = -0.429; RI: r = -0.359). The PI and RI on the day of hCG administration were negatively correlated only with the total number of retrieved oocytes (PI: r = -0.393; RI: r = -0.374).
The PI and RI of the intraovarian artery blood flow measured on the day of follicle aspiration may be good indicators of the follicle luteinization and oxidation as well as of oocyte quality.
Fertility and sterility 03/2006; 85(2):366-70. · 3.97 Impact Factor
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Maki Saitoh,
Masahide Ohmichi, Kazuhiro Takahashi,
Jun Kawagoe,
Tsuyoshi Ohta,
Masakazu Doshida,
Toshifumi Takahashi,
Hideki Igarashi,
Akiko Mori-Abe,
Botao Du,
Seiji Tsutsumi,
Hirohisa Kurachi
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ABSTRACT: The mechanism of medroxyprogesterone acetate (MPA)-induced cell proliferation in human breast cancer cells remains elusive. We examined the mechanism by which MPA affects the cyclin D1 expression in progesterone receptor (PR)-positive T47D human breast cancer cells. MPA (10 nM) treatment for 48 h induced proliferation of the cells (1.6-fold induction). MPA induced cyclin D1 expression (3.3-fold induction), and RU486, a selective PR antagonist, blocked the MPA-induced cell proliferation and cyclin D1 expression (23% inhibition). MPA increased both the protein level (2.2-fold induction) and promoter activity (2.7-fold induction) of cyclin D1 in MCF-7 cells transfected with PRB but not with PRA. Although MPA transcriptionally activated cyclin D1 expression, cyclin D1 promoter does not have progesterone-responsive element-related sequence. We further examined the mechanism for the regulation of the cyclin D1 expression. Because the cyclin D1 promoter contains three putative nuclear factor-kappaB (NFkappaB)-binding motifs and NFkappaB is a substrate of Akt, we investigated the effect of the phosphatidylinositol 3-kinase (PI3K)/Akt/NFkappaB cascade on the responses of cyclin D1 to MPA. MPA induced the transient phosphorylation of Akt (2.7-fold induction at 5 min), and treatment with PI3K inhibitor (wortmannin) attenuated the MPA-induced up-regulation of cyclin D1 expression (40% inhibition) and cell proliferation (40% inhibition). MPA also induced phosphorylation of inhibitor of NFkappaBalpha (IkappaBalpha) (2.3-fold induction), and treatment with wortmannin attenuated the MPA-induced IkappaBalpha phosphorylation (60% inhibition). Treatment with an IkappaBalpha phosphorylation inhibitor (BAY 11-7085) or a specific NFkappaB nuclear translocation inhibitor (SN-50) attenuated the MPA-induced up-regulation of both cyclin D1 expression (80 and 50% inhibition, respectively) and cell proliferation (55 and 34% inhibition, respectively). Because MPA induced a transient phosphorylation of Akt and the cyclin D1 promoter contains no progesterone-responsive element-related sequence, the MPA-induced cell proliferation through PRB by up-regulation of cyclin D1 expression via the PI3K/Akt/NFkappaB cascade may be a nongenomic mechanism.
Endocrinology 12/2005; 146(11):4917-25. · 4.46 Impact Factor
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Toshifumi Takahashi,
Masahide Ohmichi,
Jun Kawagoe,
Chika Ohshima,
Masakazu Doshida,
Tsuyoshi Ohta,
Maki Saitoh,
Akiko Mori-Abe,
Botao Du,
Hideki Igarashi, Kazuhiro Takahashi,
Hirohisa Kurachi
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ABSTRACT: In the present study, to examine the dynamic changes in the localization of nuclear estrogen receptor (ER)alpha induced by growth factors, we used time-lapse confocal microscopy to directly visualized ERalpha fused with green fluorescent protein (GFP-ERalpha) in single living cells treated with epidermal growth factor (EGF) or IGF-I. We observed that 17beta-estradiol (E2) changed the normally diffuse distribution of GFP-ERalpha throughout the nucleoplasm to a hyperspeckled distribution within 10 min. Both EGF and IGF-I also changed the nuclear distribution of GFP-ERalpha, similarly to E2 treatment. However, the time courses of the nuclear redistribution of GFP-ERalpha induced by EGF or IGF-I were different from that induced by E2 treatment. In the EGF-treated cells, the GFP-ERalpha nuclear redistribution was observed at 30 min and reached a maximum at 60 min, whereas in the IGF-I-treated cells, the GFP-ERalpha nuclear redistribution was observed at 60 min and reached a maximum at 90 min. The EGF-induced redistribution of GFP-ERalpha was blocked by pretreatment with a MAPK cascade inhibitor, PD98059, whereas the IGF-I-induced redistribution of GFP-ERalpha was blocked by pretreatment with a phosphatidylinositol 3-kinase inhibitor, LY294002. Analysis using an activation function-2 domain deletion mutant of GFP-ERalpha showed that the change in the distribution of GFP-ERalpha was not induced by E2, EGF, or IGF-I treatment. These data suggest that MAPK and phosphatidylinositol 3-kinase cascades are involved in the nuclear redistribution of ERalpha by EGF and IGF-I, respectively, and that the activation function-2 domain of ERalpha may be needed for the nuclear redistribution of ERalpha.
Endocrinology 10/2005; 146(9):4082-9. · 4.46 Impact Factor
