Hisanori Kobara

Sirtuin 1 promotes the growth and cisplatin resistance of endometrial carcinoma cells: a novel therapeutic target.

Sirtuin 1 (SIRT1), originally identified as a longevity gene, is induced by caloric restriction, and regulates various cellular functions including DNA repair, cell survival and metabolism via the deacetylation of target proteins such as histone and p53. These functions are considered to act dualistically as preventing or facilitating cancer. This study aimed to clarify the expression and role of SIRT1 in endometrial carcinoma. Because a high-calorie diet was a well-known risk factor for endometrial carcinoma, we first hypothesized that SIRT1 might be downregulated in normal endometrial glandular cells of obese women. However, no correlation was observed between the expression of SIRT1 and body mass index (BMI). In contrast, regardless of BMI, the immunohistochemical expression of SIRT1 was significantly higher in endometrial carcinoma (108 cases) than in normal endometria (60 cases) (P<0.05), and its overexpression was associated with a shorter survival (P<0.05). Our experiments in vivo revealed that SIRT1 accelerated the proliferation of endometrial carcinoma cell lines (HHUA, HEC151, and HEC1B). SIRT1 overexpression significantly enhanced the resistance for cisplatin and paclitaxel in HHUA cells. Although p53 is an important target protein for SIRT1, the selective SIRT1 inhibitor (EX527) significantly suppressed the proliferation and cisplatin resistance of three endometrial carcinoma cell lines regardless of the p53 mutation status. In addition, SIRT1 overexpression in HHUA cells accelerated tumor growth and cisplatin resistance in nude mice, and EX527 significantly suppressed the growth of tumors of HHUA and HEC1B cells. No adverse effect of EX527 was observed in these mice. In conclusion, SIRT1 is involved in the acquisition of the aggressive behavior associated with endometrial carcinoma, and the SIRT1 inhibitor, EX527, may be a useful agent for the treatment of this malignancy.

Placental Mesenchymal Dysplasia: Chronological Observation of Placental Images during Gestation and Review of the Literature

Placental mesenchymal dysplasia (PMD) is characterized by multiple hypoechoic vesicles which are similar to molar changes in the placenta; however, the process of such morphological changes of PMD during pregnancy has not been fully understood. We performed a review of all PMD cases published in English and identified 49 articles including 110 cases. With regard to the gestational age at which the multicystic pattern was seen, approximately 70% of cases were diagnosed at 13-20 weeks of gestation. Another characteristic feature of PMD is varicose dilation of fetal chorionic vessels. As many as 90% of cases were diagnosed as placenta with dilated fetal chorionic vessels in the third trimester. We also report a case of PMD which was found at 10 weeks of gestation according to ultrasonic molar patterns. Serial observations of the placenta using ultrasound and magnetic resonance imaging revealed that multicystic lesions became smaller after 23 weeks. In contrast, dilated placental vessels on the fetal side became apparent at 38 weeks. The present review highlights that placental vesicular lesions of PMD may precede dilation of fetal chorionic vessels during pregnancy. It also indicates the potential of a gradual reduction in size of PMDs placental vesicular lesions by serial study of placental images.

Lipocalin2 enhances the matrix metalloproteinase-9 activity and invasion of extravillous trophoblasts under hypoxia

OBJECTIVES The invasion of extravillous trophoblasts (EVTs) to the decidua and spiral arteries in early pregnancy is a crucial step for a successful pregnancy; however, its mechanisms are not fully understood. Lipocalin2 (LCN2), a multifunctional secretory protein known as neutrophil gelatinase-associated lipocalin (NGAL), reportedly enhanced invasiveness via the activation of matrix metalloproteinase-9 (MMP-9) in several cancer cells. In this study, the expression and function of LCN2 in early placenta were analyzed. METHODS Early placental tissues between 7 and 10 weeks of gestation were obtained from normal pregnant women who underwent elective termination. The expression of LCN2 was examined using immunostaining and RT-PCR. EVTs isolated from these placental tissues and a choriocarcinoma cell line (JAR) were used to investigate the effects of LCN2 on proliferation, invasion potential, and MMP-9 activity under hypoxia using a WST-1 assay, Matrigel invasion assay, and gelatin gel zymography, respectively. RESULTS The immunohistochemical expression of LCN2 was observed in the cytoplasm of EVTs, cytotrophoblasts and the decidua, but not in syncytiotrophoblasts. The addition of recombinant LCN2 did not affect proliferation, but enhanced the invasiveness (500 ng/mL, p < 0.01) and MMP-9 activity of primary cultured EVTs and JAR in a dose-dependent manner. Silencing LCN2 using shRNA reduced the invasiveness (p < 0.01) and MMP-9 activity of JAR. In addition, the hypoxic condition (2% O₂) increased LCN2 expression (p < 0.01), MMP-9 activity, and invasive ability (p < 0.01). CONCLUSIONS LCN2 was involved in the invasiveness of EVTs, especially under hypoxia, via increased MMP-9 activity.

Lipocalin 2 Enhances Migration and Resistance against Cisplatin in Endometrial Carcinoma Cells

Purpose Lipocalin 2 (LCN2) is a secretory protein that is involved in various physiological processes including iron transport. We previously identified LCN2 as an up-regulated gene in endometrial carcinoma, and found that the overexpression of LCN2 and its receptor, SLC22A17, was associated with a poor prognosis. However, the functions and mechanism of action of LCN2 currently remain unclear. Methods The LCN2-overexpressing endometrial carcinoma cell lines, HHUA and RL95-2, and LCN2-low-expressing one, HEC1B, were used. The effects of LCN2 on cell migration, cell viability, and apoptosis under various stresses, including ultraviolet (UV) irradiation and cisplatin treatment, were examined using the scratch wound healing assay, WST-1 assay, and Apostrand assay, respectively. Results LCN2-silencing using shRNA method significantly reduced the migration ability of cells (p<0.05). Cytotoxic stresses significantly decreased the viability of LCN2-silenced cells more than that of control cells. In contrast, LCN2 overexpression was significantly increased cisplatin resistance. These effects were canceled by the addition of the iron chelator, deferoxamine. After UV irradiation, the expression of phosphorylated Akt (pAkt) was decreased in LCN2-silenced cells, and the PI3K inhibitor canceled the difference induced in UV sensitivity by LCN2. The cisplatin-induced expression of pAkt was not affected by LCN2; however, the expression of p53 and p21 was increased by LCN2-silencing. Conclusions These results indicated that LCN2 was involved in the migration and survival of endometrial carcinoma cells under various stresses in an iron-dependent manner. The survival function of LCN2 may be exerted through the PI3K pathway and suppression of the p53-p21 pathway. These functions of LCN2 may increase the malignant potential of endometrial carcinoma cells.

Lipocalin 2 attenuates iron-related oxidative stress and prolongs the survival of ovarian clear cell carcinoma cells by up-regulating the CD44 variant

ABSTRACT Ovarian clear cell carcinoma (CCC) arises from ovarian endometriosis. Intra-cystic fluid contains abundant amounts of free iron, which causes persistent oxidative stress, a factor that has been suggested to induce malignant transformation. However, the mechanisms linking oxidative stress and carcinogenesis in CCC currently remain unclear. Lipocalin 2 (LCN2), a multifunctional secretory protein, functions as an iron transporter as well as an antioxidant. Therefore, we herein examined the roles of LCN2 in the regulation of intracellular iron concentrations, oxidative stress, DNA damage, and antioxidative functions using LCN2-overexpressing (ES2), and LCN2-silenced (RMG-1) CCC cell lines. The results of calcein staining indicated that the up-regulated expression of LCN2 correlated with increases in intracellular iron concentrations. However, a DCFH-DA assay and 8OHdG staining revealed that LCN2 reduced intracellular levels of reactive oxygen species and DNA damage. Furthermore, the expression of LCN2 suppressed hydrogen peroxide-induced apoptosis and prolonged cell survival, suggesting an antioxidative role for LCN2. The expression of mRNAs and proteins for various oxidative stress-catalyzing enzymes, such as heme oxygenase (HO), superoxide dismutase (SOD), and glutathione peroxidase, was not affected by LCN2, whereas the intracellular concentration of the potent antioxidant, glutathione (GSH), was increased by LCN2. Furthermore, the expression of xCT, a cystine transporter protein, and CD44 variant 8-10 (CD44v), a stem cell marker, was up-regulated by LCN2. Although LCN2 increased intracellular iron concentrations, LCN2-induced GSH may catalyze and override oxidative stress via CD44v and xCT, and subsequently enhance the survival of CCC cells in oxidative stress-rich endometriosis.

Predicting the Route of Delivery in Women with Low-Lying Placenta Using Transvaginal Ultrasonography: Significance of Placental Migration and Marginal Sinus

Background/Aims: To examine the significance of placental migration and the presence of a placental marginal sinus to predict the eventual route of delivery in low-lying placenta. Methods: 49 women with a low-lying placenta after 30 weeks’ gestation were studied. The distance between the internal os and leading edge of the placenta was measured weekly using transvaginal ultrasonography until 37 weeks’ gestation. The relationship between the rate of placental migration, the presence of a placental marginal sinus and the eventual mode of delivery was investigated. Results: Although the cesarean section rate was 56.3% (9/16) in the ‘slow’ migration (0–2.0 mm/week) group, no patient (0/33) in the ‘fast’ (>2.0 mm/week) migration group underwent a cesarean section (p < 0.01). The cesarean section rate was 71.4% (5/7) in patients with a placental marginal sinus, significantly greater than the rate of 9.5% (4/42) in patients without a marginal sinus (p < 0.01). Conclusion: A decreased rate of placental migration until 37 weeks’ gestation and the presence of a placental marginal sinus were associated with subsequent cesarean delivery because of antepartum vaginal bleeding. These parameters may be useful for predicting the route of delivery in women with a low-lying placenta.

Fetal goitrous hypothyroidism due to maternal thyroid stimulation-blocking antibody: a case report.

Most fetal goitrous hypothyroidisms are reportedly caused by the maternal use of an antithyroid drug or fetal dyshormonogenesis. However, fetal goitrous hypothyroidism due to the transplacental passage of maternal thyroid stimulation-blocking antibody (TSBAb) is extremely rare. A woman at 28 weeks of gestation was found to have a fetal goiter by ultrasonography. Because the maternal serum showed hypothyroidism with an elevated titer of TSBAb, levothyroxine sodium was administered. The patient delivered a male infant, 3,412 g, with a goiter at term. Umbilical blood revealed primary hypothyroidism with increased TSBAb, and the infant was given levothyroxine sodium. After a month, neonatal thyroid function and TSBAb levels became normal. Attention should be paid to possible fetal hypothyroidism when a fetal goiter is observed to avoid impaired mental development of the neonate.

Immunohistochemical expression of core 2 β1,6‐N‐acetylglucosaminyl transferase 1 (C2GnT1) in endometrioid‐type endometrial carcinoma: a novel potential prognostic factor

It has been reported that the expression of core 2 β1,6‐N‐acetylglucosaminyl transferase 1 (C2GnT1), which synthesizes the core 2 branching structure on O‐glycans, may be associated with the biological aggressiveness of tumour cells. Therefore, the aim of this study was to examine the relationship between the expression of C2GnT1 and clinicopathological parameters of patients with endometrial carcinoma.

Elevated Serum Levels of Estradiol Induce Endometrial Hyperplasia Rather than Carcinoma in a Mouse Model Using a Carcinogen

Objective: Although estrogen has been regarded as a risk factor for endometrial carcinoma, its concentrationdependent carcinogenetic effects remain unclear, because most endometrial carcinomas occur in post-menopausal women, whose serum estrogen levels are relatively low. We previously reported that high levels of estradiol (E2) may suppress endometrial carcinogenesis by up-regulating DNA mismatch repair (MMR) in vitro. The present study was undertaken to further examine the carcinogenetic role of estrogen at various concentrations in vivo. Methods: N-methyl-N-nitrosourea (MNU) was injected into the uterine cavity of 29 mice, and E2 was administered by pellets or orally. Uteri were removed for histological examinations 24 weeks later, and serum E2 levels were measured. The immunohistochemical expression of MMR proteins in uterine epithelia was investigated. Results: Of 29 mice, 8, 8, 8, and 5 showed atrophic, normal, hyperplastic, and carcinomatous endometria, respectively. The mean E2 levels of each group were 0.2 pg/ml, 3.8 pg/ml, 190.0 pg/ml, and 6.7 pg/ml, with significant differences. The expression of the MMR proteins was stronger in mice with elevated E2. Conclusion: Elevated E2 levels preferentially induced endometrial hyperplasia rather than carcinoma, and this may be mediated by MMR proteins. These results indicate that modest E2 is needed, whereas elevated E2 levels are not necessarily advantageous for carcinogenesis, suggesting the importance of low-chronic (un-opposed) estrogen in human endometrial carcinogenesis.

A case of pure-type ovarian squamous cell carcinoma producing granulocyte-colony stimulating factor

Highlights • Pure-type ovarian squamous cell carcinoma (POSCC) is extremely rare.• This is the first report of G-CSF-producing POSCC.• This case was successfully treated with primary surgery and standard chemotherapy.• A tumor with uninfected neutrophilia may be a G-CSF-producing tumor.• 18F-FDG-PET/CT and MRI may be useful for diagnosing G-CSF-producing tumors.