Aki Isobe

Relationship between Metabolic Syndrome and Uterine Leiomyomas: A Case-Control Study

Background/Aims: Uterine leiomyomas are the most common gynecological benign tumor and greatly affect reproductive health and well-being. The pathophysiology and epidemiology of fibroids are poorly understood. Obesity and elevated blood pressure have been reported to be predisposing factors. In this study, we investigated whether fibroids are associated with some criteria of the metabolic syndrome. Methods: The case patients were 213 women who underwent hysterectomy or myomectomy for fibroids, and the control subjects were 159 women who underwent operation for benign indications other than fibroids. Preoperative information on body mass index (BMI), blood pressure (BP), serum triglyceride (TG) and fasting plasma glucose (FPG) was obtained from medical records. The patients were classified as overweight if they had a preoperatively measured BMI of ≧24.0, hypertensive if BP was ≧140/90 mm Hg, hypertriglyceridemic if TG was ≧150 mg/dl, and hyperglycemic if FPG was ≧110 mg/dl. Results: BMI, BP, TG and FPG were significantly higher in the case group compared with the control group. In logistic regression analysis, fibroids were statistically significantly associated with being overweight and hypertensive. With the combination of these risk factors, the risk of fibroids increased. Conclusion: Uterine leiomyomas may share pathogenic features with the development of metabolic syndrome.

Up-Regulation of α5-Integrin by E-Cadherin Loss in Hypoxia and Its Key Role in the Migration of Extravillous Trophoblast Cells during Early Implantation

During early pregnancy, cytotrophoblast cells differentiate into extravillous trophoblast (EVT) cells and invade the uterine spiral arteries. This physiological process is essential for the development of maternal-fetal circulation. Because EVT cells are exposed to a low-oxygen environment during this process, we investigated the role of hypoxia in the mechanism that regulates the invasive behavior of EVT cells. Real-time PCR and immunofluorescent analysis were performed to investigate how hypoxia influences the expression of E-cadherin in villous explants cultures and in trophoblast-derived BeWo cells. We determined that hypoxia induced E-cadherin down-regulation through Snail up-regulation in villous explant cultures. The influence of E-cadherin loss was examined by analyzing the expression of alpha(5)-integrin and phosphorylated focal adhesion kinase (FAK) by Western blot and evaluating trophoblast invasion using a matrigel invasion assay. E-cadherin loss induced the up-regulation of alpha(5)-integrin, which leads to the tyrosine phosphorylation of FAK, resulting in an increase in the invasive activity of EVT cells. An alpha(5)-integrin neutralizing antibody inhibited the invasion of EVT cells by attenuating FAK tyrosine phosphorylation. Immunohistochemical analysis using clinical placental bed biopsies revealed that alpha(5)-integrin was up-regulated and FAK tyrosine phosphorylated (Try(861)) as EVT cells invade the uterine myometrium, whereas E-cadherin expression was down-regulated. These results suggest that alpha(5)-integrin up-regulation induced by E-cadherin loss under hypoxia has a crucial role in regulating the migration of EVT cells. This finding should help us reach a better understanding of the pathogenesis of critical gestational diseases, such as preeclampsia.

The significance of G-CSF expression and myeloid-derived suppressor cells in the chemoresistance of uterine cervical cancer

Granulocyte-colony stimulating factor (G-CSF) producing malignant tumor has been reported to occur in various organs, and has been associated with poor clinical outcome. The aim of this study is to investigate the significance of tumor G-CSF expression in the chemosensitivity of uterine cervical cancer. The clinical data of recurrent or advanced cervical cancer patients who were treated with platinum-based chemotherapy were analyzed. Clinical samples, cervical cancer cell lines, and a mouse model of cervical cancer were employed to examine the mechanisms responsible for the development of chemoresistance in G-CSF-producing cervical cancer, focusing on myeloid-derived suppressor cells (MDSC). As a result, the tumor G-CSF expression was significantly associated with increased MDSC frequencies and compromised survival. In vitro and in vivo experiments demonstrated that the increased MDSC induced by tumor-derived G-CSF is involved in the development of chemoresistance. The depletion of MDSC via splenectomy or the administration of anti-Gr-1 antibody sensitized G-CSF-producing cervical cancer to cisplatin. In conclusion, tumor G-CSF expression is an indicator of an extremely poor prognosis in cervical cancer patients that are treated with chemotherapy. Combining MDSC-targeting treatments with current standard chemotherapies might have therapeutic efficacy as a treatment for G-CSF-producing cervical cancer.

Interleukin 6 Receptor Is an Independent Prognostic Factor and a Potential Therapeutic Target of Ovarian Cancer

Ovarian cancer remains the most lethal gynecologic cancer and new targeted molecular therapies against this miserable disease continue to be challenging. In this study, we analyzed the expressional patterns of Interleukin-6 (IL-6) and its receptor (IL-6R) expression in ovarian cancer tissues, evaluated the impact of these expressions on clinical outcomes of patients, and found that a high-level of IL-6R expression but not IL-6 expression in cancer cells is an independent prognostic factor. In in vitro analyses using ovarian cell lines, while six (RMUG-S, RMG-1, OVISE, A2780, SKOV3ip1 and OVCAR-3) of seven overexpressed IL-6R compared with a primary normal ovarian surface epithelium, only two (RMG-1, OVISE) of seven cell lines overexpressed IL-6, suggesting that IL-6/IL-6R signaling exerts in a paracrine manner in certain types of ovarian cancer cells. Ovarian cancer ascites were collected from patients, and we found that primary CD11b+CD14+ cells, which were predominantly M2-polarized macrophages, are the major source of IL-6 production in an ovarian cancer microenvironment. When CD11b+CD14+ cells were co-cultured with cancer cells, both the invasion and the proliferation of cancer cells were robustly promoted and these promotions were almost completely inhibited by pretreatment with anti-IL-6R antibody (tocilizumab). The data presented herein suggest a rationale for anti-IL-6/IL-6R therapy to suppress the peritoneal spread of ovarian cancer, and represent evidence of the therapeutic potential of anti-IL-6R therapy for ovarian cancer treatment.

Metal Transcription Factor-1 Is Involved in Hypoxia-Dependent Regulation of Placenta Growth Factor in Trophoblast-Derived Cells

Placenta growth factor (PlGF) is a placental angiogenic factor. Metal-responsive transcription factor (MTF)-1 was reported to take part in the hypoxic induction of PlGF in RAS-transformed mouse fibroblasts. We contrarily showed that PlGF mRNA and protein levels decreased under hypoxia in a choriocarcinoma BeWo cell line derived from trophoblast. In this report, we examined whether hypoxia-dependent regulation of the PlGF gene in these cells also depends on MTF-1. We analyzed the effect of hypoxia on MTF-1 expression, and it was revealed to be decreased. Moreover, MTF-1 small interfering RNA treatment decreased PlGF mRNA level. To investigate the transcription of PlGF under hypoxia, we cloned promoter region of the human PlGF. Promoter deletion analysis suggested that triple repeats of metal-responsive element located between -511 and -468 bp in the promoter are important for the hypoxic regulation of PlGF. Treatment with MTF-1 small interfering RNA resulted in the significant decreased luciferase activity in PlGF reporter constructs. Chromatin immunoprecipitation showed the binding of the MTF-1 protein to the promoter region. We examined MTF-1 immunoreactivity in trophoblasts of term placental tissue from patients with normal pregnancies and preeclampsia, which represents a condition of placental hypoxia. Immunoreactivity of the MTF-1 protein was decreased in placentas from pregnant women with preeclampsia when compared with those from normal pregnant women. Taken together, these findings suggest that MTF-1 is involved in hypoxia-dependent regulation of PlGF in trophoblast-derived cells.

Balloon tamponade during cesarean section is useful for severe post-partum hemorrhage due to placenta previa

Aim:  Severe post‐partum hemorrhage during cesarean section due to placenta previa is still one of the leading causes of maternal mortality. The aim of this study was to evaluate the efficiency of intrauterine tamponade with a Sengstaken‐Blakemore tube (SB‐tube) for the treatment of severe post‐partum hemorrhage in cases of placenta previa.

Preclinical Efficacy for AKT Targeting in Clear Cell Carcinoma of the Ovary

The aim of this study was to determine the role of AKT as a therapeutic target in ovarian clear cell carcinoma (CCC), an aggressive, chemoresistant histologic subtype of ovarian cancer. AKT activation was assessed by immunohistochemistry (IHC) using human tissue microarrays of primary ovarian cancers, composed of both CCC and serous adenocarcinoma (SAC). The growth-inhibitory effect of AKT-specific targeting by the small-molecule inhibitor, perifosine, was examined using ovarian CCC cell lines in vitro and in vivo. Finally, the activity of perifosine was examined using in CCC-derived tumors that had acquired resistance to anti-VEGF or chemotherapeutics such as bevacizumab or cisplatin, respectively. Interestingly, AKT was frequently activated both in early-stage and advanced-stage CCCs. Treatment of CCC cells with perifosine attenuated the activity of AKT–mTORC1 signaling, inhibited proliferation, and induced apoptosis. The effect of perifosine was more profound under conditions of high AKT activity compared with low AKT activity. Increased AKT activation and enhanced sensitivity to perifosine were observed in the context of cisplatin-resistant CCC. Treatment with perifosine concurrently with cisplatin significantly enhanced the antitumor effect of cisplatin. Moreover, perifosine showed significant antitumor activity in CCC-derived tumors that had acquired resistance to bevacizumab or cisplatin. Collectively, these data reveal that AKT is frequently activated in ovarian CCCs and is a promising therapeutic target in aggressive forms of ovarian cancer. Implications: AKT-targeted therapy has value in a first-line setting as well as a second-line treatment for recurrent disease developing after platinum-based chemotherapy or bevacizumab treatment. Mol Cancer Res; 13(4); 795–806. ©2014 AACR.

Low Serum Concentrations of Anti-Müllerian Hormone Are Common in 53 Female Childhood Cancer Survivors

Background/Aims: Gonadal dysfunction is one of the major endocrinological late effects among childhood cancer survivors (CCSs). Periodic screening evaluation of gonadotropins and sex steroids has been recommended, although it remains difficult to predict gonadal function and reproductive capacity in childhood. We evaluated the effects of cancer treatments on the ovarian function of Japanese female CCSs by measuring serum levels of anti-Müllerian hormone (AMH) and gonadotropin. Methods: This was a retrospective, cross-sectional study at a single hospital. Results: Among 53 female CCSs, 28 (53%) had a decreased AMH level, while only 16 (30%) had an increased follicle-stimulating hormone (FSH) level. AMH was low in all patients with high FSH, while FSH was not elevated in 43% of patients with a low AMH level. AMH was low in 8 of 9 patients with no breast development, 11 of 14 patients with no spontaneous menstruation, and 3 of 22 patients with regular menstrual cycles. Conclusion: Measurement of AMH concentration is useful as a marker of ovarian reserve in female CCSs for detecting primary gonadal deficiency, particularly among patients without increased gonadotropin levels.

IKKβ Regulates VEGF Expression and Is a Potential Therapeutic Target for Ovarian Cancer as an Antiangiogenic Treatment.

The prolongation of progression-free survival (PFS) in patients with advanced ovarian cancer by antiangiogenic therapy has been shown in several clinical trials. However, although an anti-VEGF antibody (bevacizumab) is the only option currently available, its efficacy is limited and it is not cost effective for use in all patients. Therefore, the development of a novel antiangiogenic drug, especially composed of small-molecule compounds, could be a powerful armament for ovarian cancer treatment. As NF-κB signaling has the potential to regulate VEGF expression, we determined to identify whether VEGF expression is associated with NF-κB activation and to investigate the possibility of a novel IKKβ inhibitor, IMD-0354 (IMMD Inc.), as an antiangiogenic drug. Tissue microarrays from 94 ovarian cancer tissues were constructed and immunohistochemical analyses performed. We revealed that IKK phosphorylation is an independent prognostic factor (PFS: 26.1 vs. 49.8 months, P = 0.011), and is positively correlated with high VEGF expression. In in vitro analyses, IMD-0354 robustly inhibited adhesive and invasive activities of ovarian cancer cells without impairing cell viabilities. IMD-0354 significantly suppressed VEGF production from cancer cells, which led to the inhibition of angiogenesis. In a xenograft model, the treatment of IMD-0354 significantly inhibited peritoneal dissemination with a marked reduction of intratumoral blood vessel formation followed by the inhibition of VEGF expression from cancer cells. IMD-0354 is a stable small-molecule drug and has already been administered safely to humans in other trials. Antiangiogenic therapy targeting IKKβ is a potential future option to treat ovarian cancer. Mol Cancer Ther; 14(4); 909–19. ©2015 AACR.

Hypoxia Represses the Differentiation of Rcho-1 Rat Trophoblast Giant Cells

Background: A hypoxic environment is known to be essential for early placentation. A low oxygen tension induces hypoxia-inducible factor-1 (HIF-1α) which may play an important role as a transcription factor in maintaining the proliferative and undifferentiated phenotype in human trophoblasts. Methods: We analyzed the effect of a low oxygen tension on the rat trophoblast giant cell differentiation pathway using Rcho-1 cells which were derived from rat choriocarcinomas and consist of trophoblast stem cells. Results: We found that a low oxygen tension suppressed the morphological changes and steroidogenesis during differentiation. The anticipated downregulation of the Id-1 transcription factor, a negative regulator of trophoblast giant cell differentiation, was not observed in the hypoxic environment. On the other hand, deferoxamine, which mimics hypoxia and induces HIF-1α, caused downregulation of Id-1 transcription factor and trophoblast giant cell differentiation. Conclusion: These results indicate that hypoxia represses rat trophoblast giant cell differentiation via an HIF-1α-independent pathway.