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Biomedical subjects

Isao Miyakawa

Publications and source records attributed to Isao Miyakawa.

At least 19 recordsLinked to original sources
PubMed2006

Relationship between urinary albumin and serum soluble fms-like tyrosine kinase 1 (sFlt-1) in normal pregnancy.

OBJECTIVE: To investigate if the circulating level of soluble fms-like tyrosine kinase 1 (sFlt-1) and vascular endothelial growth factor (VEGF) correlates with urinary albumin excretion in normal pregnancy. STUDY DESIGN: Serum specimens and 24h urine collections were requested from normal pregnant women at 28-30 weeks of gestation and the following laboratory tests were performed: serum creatinine, urinary protein, urinary albumin and creatinine clearance. For the present study, 117 normal pregnant women were selected as subjects. Subjects' serum was tested to determine sFlt-1 and VEGF concentrations by ELISA. The correlation between sFlt-1 or VEGF concentrations in the serum and renal laboratory variables were analyzed. Simple regression was used to evaluate the correlations. RESULTS: A significant association was noted between serum sFlt-1 concentration and urinary albumin excretion (r=0.68; P<.0001). Similarly, a significant association was noted between serum VEGF concentration and urinary albumin excretion (r=-0.39; P<.0001). Other urinary variables showed no correlations with either sFlt-1 or VEGF. CONCLUSION: Even in normal pregnancy, albumin excretion is affected by an increase in placentally derived sFlt-1. If the sFlt-1 level is kept within normal range, only glomerular endothelial cells are affected and this phenomenon does not spread to the endothelial cells of a whole body.

Adult↗
PubMed2006

Bufalin induces apoptosis and the G0/G1 cell cycle arrest of endometriotic stromal cells: a promising agent for the treatment of endometriosis.

Most of the current medical treatments for endometriosis aim to down-regulate the estrogen activity. However, a high recurrence rate after medical treatments has been the most significant problem. Bufalin is a major digoxin-like immunoreactive component isolated from the skin and parotid venom glands of toad and is considered an apoptosis-inducing agent. To apply bufalin to the medical treatment of endometriosis, we investigated the effects of this agent on the cell proliferation and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSC) by a modified methylthiazoletetrazolium (MTT) assay, a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and internucleosomal DNA fragmentation assays. The effect of bufalin on the cell cycle of ECSC was also determined by flow cytometry. The expression of apoptosis- and cell cycle-related molecules was also examined in ECSC using Western blot analysis. Bufalin significantly inhibited the cell proliferation and DNA synthesis of ECSC and induced apoptosis and the G0/G1 phase cell cycle arrest of these cells. The down-regulation of the cyclin A, Bcl-2, and Bcl-X(L) expression with the simultaneous up-regulation of the p21 and Bax expression, and caspase-9 activation was observed in ECSC after bufalin treatment. It is suggested that bufalin induces apoptosis of ECSC by simultaneously suppressing anti-apoptotic proteins and inducing pro-apoptotic proteins. Caspase-9-mediated cascade is involved in this mechanism. Therefore, bufalin could be used as a therapeutic agent for the treatment of endometriosis.

Apoptosis↗
PubMed2006

Intrauterine growth restriction and the proliferation of smooth muscle cells in umbilical vessels.

AIMS: The purpose of this study was to investigate the proliferation of smooth muscle cells in umbilical vessels of fetuses affected by intrauterine growth restriction (IUGR) and to compare the findings with gestational age-matched control cases. METHODS: Sixty umbilical cords from fetuses at 36-37 weeks gestation were examined. Fetuses were divided into three groups: group I, appropriate for dates birthweight; group II, IUGR with reassuring fetal status; and group III, IUGR with abnormal umbilical Doppler waveforms. Umbilical cords were immunostained with an antibody to proliferating cell nuclear antigen and Ki-67; stained smooth muscle cells were subsequently counted. Smooth muscle cell density was determined by counting the total number of cells in a representative area of vessel wall and the wall thickness of each vessel was also measured. RESULTS: Proliferation marker-positive cells were increased in the umbilical vessels of group II compared to group I, and there were more proliferating smooth muscle cells in the umbilical vessels of group III compared to the other two groups. The umbilical vessels of group III showed the highest smooth muscle cell density, but the wall thickness of all vessels was significantly thinner in group III than the other two groups. CONCLUSIONS: This study showed overproliferation of smooth muscle cells in the umbilical vessel walls associated with IUGR. It is hypothesised that hypoxia might induce this overproliferation given the further proliferation in IUGR fetuses with abnormal umbilical Doppler waveforms. Coexistence of a high cell density and lean vessel walls suggests small smooth muscle cells in umbilical vessels with IUGR.

Adult↗
PubMed2005

2C4, a monoclonal antibody against HER2, disrupts the HER kinase signaling pathway and inhibits ovarian carcinoma cell growth.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is overexpressed in 25-30% of ovarian carcinoma cases and a correlation between increased HER2 expression and decreased survival has been demonstrated. HER2 is a ligand-less member of the HER family that functions as the preferred coreceptor for epidermal growth factor receptor (EGFR), HER3, and HER4. METHODS: An approach was developed to target HER2's role as a coreceptor using a monoclonal antibody, 2C4, which sterically hinders HER2's recruitment into a functional HER complex. RESULTS: HER2 was robustly expressed in all eight ovarian carcinoma cell lines; expression of EGFR and HER3 was variable. Even though four of the eight cell lines responded to EGF, 2C4 antibody moderately inhibited in vitro proliferation of only two cell lines (OVCA433 and SK-OV-3). Furthermore, ligand-stimulated p-MAPK expression was inhibited by 2C4 only in these two cell lines after exposure to EGF. Immunoprecipitation and eTag analysis revealed that OVCA433 expressed heterodimers of EGFR/HER2, and these heterodimers were disrupted after treatment with 2C4, whereas OVCA432 cells did not have these heterodimers. In murine xenograft experiments, the in vivo growth of OVCA433, but not of OVCA432, ovarian carcinoma cells was significantly inhibited by 2C4 treatment of the mice. CONCLUSION: 2C4 is able to disrupt the HER signaling pathway and inhibit the in vitro and in vivo growth of ovarian carcinoma cell lines. The response appears limited to lines in which HER2 heterodimers were able to transduce proliferative signals. Our findings suggest a strong rationale to conduct clinical trials of 2C4 in a subset of patients with ovarian tumors.

Animals↗
PubMed2005

Magnetic resonance imaging findings in leiomyoma of the ovary: a case report.

The leiomyoma of the ovary is a very rare form of ovarian neoplasia, while its uterine localization is very common. A 72-year-old woman was admitted for pelvic examination. Transvaginal ultrasonography and magnetic resonance imaging (MRI) revealed a pelvic mass (8 cm x 7 cm). At laparotomy, total hysterectomy and bilateral salpingo-oophorectomy were performed and histologic examination revealed a leiomyoma arising primarily in the ovary.

Aged↗
PubMed2005

Expression of c-Ets1 protein in normal human placenta.

BACKGROUND: The proto-oncogene product c-Ets1 is a transcriptional factor that controls the expression of a number of genes involved in extracellular matrix remodeling such as stromelysin-1 (matrix metalloproteinase-3; MMP-3), collagenase-1, and urokinase-type plasminogen activator (u-PA). To elucidate the involvement of c-Ets1 in the invasive pathway of the trophoblasts, we analyzed c-Ets1 protein expression in placentas by fluorescent immunohistochemistry and Western blot analysis. METHODS: We analyzed serial frozen sections for c-Ets1 protein expression of the chorionic villi and cell column in the first trimester and the basal plate of placenta and amniotic membranes in the third trimester by fluorescent immunohistochemistry. Moreover, we examined the expression of c-Ets1 in the first and the third trimester by Western blot analysis. RESULTS: In the first trimester, c-Ets1 was strongly expressed in the cytoplasm of cytotrophoblasts. Moreover, the cell column that invaded the endometrium had the strongest expression of c-Ets1. In the third trimester, c-Ets1 was detected in both cytoplasm and nucleus of the invading trophoblasts in the basal plate. Furthermore, c-Ets1 was expressed in both cytoplasm and nucleus of the trophoblasts in amniotic membrane. Western blotting revealed that c-Ets1 expressions in the first trimester were stronger than those in the third trimester. CONCLUSION: Our results demonstrate that c-Ets1 expression in normal human placenta correlates to the invasive behavior of the trophoblasts, probably by activating the transcription of matrix-degrading MMPs, including MMP-3, collagenase-1, and u-PA.

Analysis of Variance↗
PubMed2005

Regulation of proliferation, motility, and contractility of human endometrial stromal cells by platelet-derived growth factor.

To evaluate the involvement of platelet-derived growth factor (PDGF) isoforms (PDGF-AlphaAlpha, PDGF-AB, and PDGF-BB) on endometrial tissue remodeling during the perimenstrual period, we investigated the effects of PDGF on the proliferation, motility, invasiveness, and contractility of cultured human endometrial stromal cells (ESC) using a modified methylthiazoletetrazolium assay, a 5-bromo-2'-deoxyuridine incorporation assay, an in vitro wound repair assay, a chemotactic migration assay, a Transwell invasion assay, and a collagen gel contraction assay. All three isoforms of PDGF significantly enhanced the cell proliferation, DNA synthesis, and in vitro wound repair of ESC. Chemotactic migration assay, Transwell invasion assay, and collagen gel contraction assay demonstrated that the PDGF isoforms significantly stimulated both the motility of ESC and the collagen gel contractility of ESC. PDGF-BB showed the strongest effects on these cellular functions of ESC. The present study suggested that PDGF isoforms may promote endometrial tissue repair by enhancing the proliferation and expansion of ESC, stimulating ESC migration, and stimulating the contraction of the collagen gel matrix by ESC. By regulating ESC function during the perimenstrual period, PDGF may help to protect the endometrium from extensive fibrosis and scarring.

Adult↗
PubMed2005

Polo-like kinases (Plks) and cancer.

Deregulated centrosome duplication or maturation often results in increased centrosome size and/or centrosome number, both of which show a positive and significant correlation with aneuploidy and chromosomal instability, thus contributing to cancer formation. Given the role of Polo-like kinases (Plks) in the centrosome cycle, it is not unexpected that deregulated expression of Plks is detected in many types of cancer and is associated with oncogenesis. Extensive studies have shown that Plk1 expression is elevated in non-small-cell lung cancer, head and neck cancer, esophageal cancer, gastric cancer, melanomas, breast cancer, ovarian cancer, endometrial cancer, colorectal cancer, gliomas, and thyroid cancer. Plk1 gene and protein expression has been proposed as a new prognostic marker for many types of malignancies, and Plk1 is a potential target for cancer therapy. In contrast to Plk1, several studies have observed that Plk3 expression is negatively correlated with the development of certain cancers.

Animals↗
PubMed2005

Adenoid cystic carcinoma of the uterine cervix.

Adenoid cystic carcinoma of the uterine cervix is a rare and peculiar variant of adenocarcinoma. This tumor represents 3% of all primary cervical adenocarcinomas, and it is locally aggressive and capable of metastasis to other organs even in its early stage. We report a case of adenoid cystic carcinoma stage IIIb that was successfully treated with radiotherapy. The patient shows no evidence of recurrent tumor at 5 years after radiotherapy. Generally, radiotherapy and chemotherapy are chosen as the first treatment, because this cancer is seen most commonly in the elderly.

Aged↗
PubMed2005

Regulation of proliferation, motility, and contractivity of cultured human endometrial stromal cells by transforming growth factor-beta isoforms.

OBJECTIVE: To evaluate the involvement of transforming growth factor (TGF)-beta isoforms (TGF-beta1, TGF-beta2, and TGF-beta3) on endometrial tissue remodeling during the perimenstrual period. DESIGN: The effects of TGF-beta isoforms on the cell proliferation, motility, and contractivity of cultured human endometrial stromal cells (ESCs) were investigated. SETTING: Research laboratory at a medical school. PATIENT(S): Nine endometrial specimens in the late secretory phase were used. INTERVENTION(S): Endometrial stromal cells were incubated with recombinant human recombinant TGF-beta1, TGF-beta2, and TGF-beta3. MAIN OUTCOME MEASURE(S): The cell proliferation, motility, and contractivity of ESCs were accessed by a modified methylthiazoletetrazolium assay, in vitro wound repair assay, transwell invasion assay, and collagen gel contraction assay. RESULT(S): All three isoforms of TGF-beta significantly inhibited the cell proliferation of ESCs in a dose-dependent manner. In vitro wound repair assay and transwell invasion assay demonstrated that the TGF-beta isoforms significantly inhibited the motility of ESCs. However, the TGF-beta isoforms were shown to have a clear effect on the collagen gel contractivity of ESCs. CONCLUSION(S): These results suggest that TGF-beta isoforms may promote endometrial tissue repair through the inhibition of the proliferation, expansion, and migration of ESCs, and through the stimulation of the contraction of the collagen gel matrix by these cells. Transforming growth factor-beta may be involved in the protection of the endometrium from extensive fibrosis and scarring by regulating ESC function during the perimenstrual period.

Adult↗
PubMed2005

The effect of epidermal growth factor on production of vascular endothelial growth factor by amnion-derived (WISH) cells.

Our objective was to clarify the physiological role of vascular endothelial growth factor (VEGF) by amnion-derived (WISH) cells. WISH cells were cultured, and the effect of epidermal growth factor (EGF), mitogen-activated protein (MAP) kinase kinase or extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors (U0126) or phosphatidylinositol (PI) 3-kinase on the production of VEGF was examined. VEGF was assayed by ELISA. The activation of MAP kinase and akt, which is phosphorylated by PI 3-kinase, were detected by Western blot analysis using anti-phosphorylated MAP kinase antibody and anti-phosphorylated akt antibody. In the time course of VEGF production following EGF treatment, VEGF production showed a significant increase only after 16 (p < 0.01)-32h (p < 0.01). EGF increased the production of VEGF by WISH cells in a dose-dependent manner. The MAP kinase and akt activity were determined by treatment with EGF. VEGF production was significantly decreased following pretreatment with U0126 or wortmannin for two hours before treatment with EGF (p < 0.01, p < 0.01). WISH cells appeared to produce VEGF via a mechanism involving tyrosine kinase activation of EGF receptor and MAP kinase or PI 3-kinase. It is suggested that VEGF may contribute to the neovascularization and proliferation of the placenta and gestational tissue, and EGF may play an important role in regulation of VEGF production in the placenta.

Amnion↗
PubMed2005

Discovery of epigenetically masked tumor suppressor genes in endometrial cancer.

Realization that many tumor suppressor genes are silenced by epigenetic mechanisms has stimulated the discovery of novel tumor suppressor genes. We used a variety of research tools to search for genes that are epigenetically silenced in human endometrial cancers. Changes in global gene expression of the endometrial cancer cell line Ishikawa was analyzed after treatment with the demethylating agent 5-aza-2'-deoxycytidine combined with the histone deacetylase inhibitor suberoylanilide bishydroxamide. By screening over 22,000 genes, candidate tumor suppressor genes were identified. Additional microarray analysis and real-time reverse transcription-PCR of normal and cancerous endometrial samples and search for CpG islands further refined the list. Tazarotene-induced gene-1 (Tig1) and CCAAT/enhancer binding protein-alpha (C/ebpalpha) were chosen for further study. Expression of both genes was low in endometrial cancer cell lines and clinical samples but high in normal endometrial tissues. Bisulfite sequencing, restriction analysis, and/or methylation-specific PCR revealed aberrant methylation of the CpG island in the Tig1 gene of all 6 endometrial cancer cell lines examined and 4 of 18 clinical endometrial cancers, whereas the C/ebpalpha promoter remained unmethylated in endometrial cancers. Chromatin immunoprecipitation showed increased acetylated histone H3 bound to both Tig1 and C/ebpalpha genes after treatment with 5-aza-2'-deoxycytidine and/or suberoylanilide bishydroxamide. Forced expression of either TIG1 or C/EBPalpha led to significant growth reduction of Ishikawa cells. Our data suggest that C/ebpalpha and Tig1 function as tumor suppressor proteins in endometrial cancers and that their reexpression may be a therapeutic target.

Aged↗
PubMed2005

K252a inhibits proliferation of ovarian cancer cells by upregulating p21WAF1.

The furanosylated indolocarbazole, K252a, belongs to a family of microbial alkaloids that also includes staurosporine, which is known to inhibit proliferation, stimulate apoptosis and induce cell cycle arrest of cancer cells. To elucidate the involvement of K252a in ovarian cancer, we investigated the effects of K252a on the ovarian cancer cell line, SK-OV-3. SK-OV-3 cells were treated with K252a, and its effect on cell growth, cell cycle, and related measurements was assessed. MTT assays showed that the ovarian cancer cell line SK-OV-3 cells were sensitive to the growth inhibitory effect of K252a. Cell cycle analysis indicated that their exposure to K252a decreased the proportion of cells in the S-phase and increased the proportion of cells in the G0/G1 phase of the cell cycle. This occurred in concert with altered expression of p21WAF1 protein related to the G0/G1 phase of the cell cycle. These results raise the possibility that K252a may prove particularly effective in treatment of ovarian cancer.

Blotting, Western↗
PubMed2004

Human ovarian carcinoma cells: histone deacetylase inhibitors exhibit antiproliferative activity and potently induce apoptosis.

BACKGROUND: Histone deacetylase inhibitors (HDACIs) can inhibit proliferation, stimulate apoptosis, and induce cell cycle arrest in malignant cells. METHODS: The authors investigated the effects of four HDACIs on nine ovarian carcinoma cell lines in vitro and in vivo. Ovarian carcinoma cells were treated with a variety of HDACIs, and their effects on cell growth, the cell cycle, apoptosis, and related events were investigated. The ability of valproic acid (VPA) to inhibit the growth of ovarian tumors in immunodeficient mice was also assessed. RESULTS: Clonogenic assays showed that all ovarian carcinoma cell lines were sensitive to the growth-inhibitory effects of the HDACIs. Cell cycle analysis indicated that their exposure to HDACIs decreased the proportion of cells in S phase and increased the proportion of cells in the G0/G1 and/or G2/M phases of the cell cycle. Terminal deoxynucleotidyltransferase-mediated uridine triphosphate end-labeling assays demonstrated that HDACIs induced apoptosis, which occurred in concert with alterations in the expression of genes related to apoptosis, cell growth, and malignant phenotype, including the activation of caspase-9 and caspase-3. Chromatin immunoprecipitation analysis revealed a notable increase in levels of acetylated histones associated with the p21 promoter after treatment with suberoylanilide bishydroxamine. In addition, in experiments involving nude mice, VPA significantly inhibited human ovarian tumor growth without toxic side effects. CONCLUSIONS: The results of the current study suggest that HDACIs may be particularly effective in the treatment of ovarian tumors.

Acetylation↗
PubMed2004

Endometriotic cells are resistant to interferon-gamma-induced cell growth inhibition and apoptosis: a possible mechanism involved in the pathogenesis of endometriosis.

In order to evaluate the involvement of cell proliferation and apoptosis in the pathogenesis of endometriosis, we investigated the effects of interferon-gamma (IFN-gamma) on cell growth inhibition and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSC), eutopic endometrial stromal cells with endometriosis (ESCwE) and normal endometrial stromal cells (NESC) by modified methylthiazoletetrazolium assay, 5-bromo-2'-deoxyuridine incorporation assay and internucleosomal DNA fragmentation assay. The expression of apoptosis-related molecules and IFN-gamma receptor 1 was also examined in ECSC, ESCwE and NESC using western blot analysis. IFN-gamma significantly inhibited cell proliferation and DNA synthesis of ESCwE and NESC, and induced apoptosis of these cells. In contrast, IFN-gamma did not show apparent effects on the viable cell number, DNA synthesis, or apoptosis of ECSC. An up-regulated expression of Bcl-2 and Bcl-X(L) proteins was observed in ECSC in comparison with ESCwE and NESC, whereas the levels of Bax, Bad, Fas and Fas ligand proteins in ECSC were similar to those in ESCwE and NESC. IFN-gamma receptor 1 expression was detected in ECSC, ESCwE and NESC. Enhanced expression of anti-apoptotic molecules in the ectopic endometrial cells may contribute to the development of endometriosis by conferring resistance to cytokine-induced apoptosis and increasing the chance that these cells will survive and implant outside the uterus. Further investigations on the regulation of cell proliferation in both the endometriotic and the normal endometrium may be important for the elucidation of the pathogenesis of endometriosis.

Apoptosis↗
PubMed2004

Adenoid cystic carcinoma of Bartholin's Gland. Case report with review of the literature.

Adenoid cystic carcinoma of Bartholin's gland is characterized by slow growth, local invasion, and sometimes distant metastasis. There is no consensus regarding the optimal treatment. We report herein a rare case of stage II adenoid cystic carcinoma of Bartholin's gland that was successfully treated by wide local excision of the tumor and ipsilateral inguinal and pelvic lymphadenectomy. A 54-year-old Japanese woman was admitted complaining of painless, gradually increasing vulvar mass existing from ten years before. Local examination revealed a 3 x 2-cm hard mass in the left labium major. Pathological examination of subsequent excisional biopsy revealed adenoid cystic carcinoma originating in the Bartholin's gland. A wide local resection of the tumor with inguinal and pelvic lymphadenectomy was performed. The tumor was completely excised with free margins. There was no metastasis in the resected lymph nodes. The patient was diagnosed as having stage II vulvar cancer according to the International Federation of Gynecologists and Obstetricians classification (1988). The patient is now healthy without evidence of recurrence at 5 years after surgery. Adenoid cystic carcinoma of Bartholin's cyst at early stage can be treated by wide local excision as a primary surgery.

Bartholin's Glands↗
PubMed2004

Radiological features of adenoid cystic carcinoma of the uterine cervix.

Adenoid cystic carcinoma (ACC) of the uterine cervix is a rare primary neoplasm of the uterus that occurs in post-menopausal women; its radiological findings have not been described previously. We present the MR findings of a case of ACC. The mass exhibited homogeneous low-signal intensity on T1-weighted images. On T2-weighted images, the mass showed high-signal intensity with a lobulated contour and multiple septum-like internal architectures. It also contained spots of very high-signal intensity, which would represent the mucin in the glandular lumen. The multiple septum-like internal architectures probably represented interglandular fibrous stroma. These MRI findings may be helpful for future diagnoses of ACC of the uterine cervix.

Aged↗