Eing-Mei Tsai

Phthalates induce proliferation and invasiveness of estrogen receptor-negative breast cancer through the AhR/HDAC6/c-Myc signaling pathway

The environmentally present group of chemical phthalates, or phthalate esters, has been recognized as a rising threat to public health, including cancer. While most studies have addressed the estrogenic effects of phthalates in malignancies of the breast and the prostate, little is known about their role in the etiology of hormone‐independent cancer. Here we show that treatments with the phthalates n‐butyl benzyl phthalate (BBP) and dibutyl phthalate (DBP) at 1 μM induced proliferation (BBP, 3.2‐fold; DBP, 3.2‐fold), migration (BBP, 2.6‐fold; DBP, 2.6‐fold), invasion (BBP, 2.7‐fold; DBP, 3.1‐fold), and tumor formation (EC50: BBP, 0.12 μM; DBP, 0.22 μM) in estrogen receptor (ER)‐negative breast cancer cells (MDA‐MB‐231). We further demonstrate that phthalates stimulated the cell surface aryl hydrocarbon receptor (AhR) and triggered the downstream cyclic AMP (cAMP)‐PKA‐CREB1 signaling cascade. The pathway led to increased expression of HDAC6, which facilitated nuclear assembly of the β‐catenin‐LEF1/TCF4 transcriptional complex and transactivation of the c‐Myc oncogene. This nongenomic pathway emanated from the phthalateinduced AhR promoted tumorigenesis of ER‐negative breast cancer. Collectively, our findings revealed a novel oncogenic mechanism of phthalates in breast cancer independent from their estrogenic activities.—Hsieh, T.‐H., Tsai, C.‐F., Hsu, C.‐Y., Kuo, P.‐L., Lee, J.‐N., Chai, C.‐Y., Wang, S.‐C., Tsai, E.‐M. Phthalates induce proliferation and invasiveness of estrogen receptor‐negative breast cancer through the AhR/HDAC6/c‐Myc signaling pathway. FASEB J. 26, 778–787 (2012). www.fasebj.org

Decreased Plasma Visfatin Concentrations in Women With Gestational Diabetes Mellitus

Objective: To test the hypothesis that plasma visfatin concentrations will be lower in women with gestational diabetes mellitus, we evaluated women with gestational diabetes mellitus and healthy pregnant women, and then correlated their plasma visfatin concentrations with body mass index (BMI) and various other parameters. Methods: A total of 40 women were evaluated: 20 women with gestational diabetes mellitus and 20 healthy pregnant women to serve as control subjects. Plasma visfatin concentrations were analyzed using an enzyme-linked immunosorbent assay. Results: Plasma visfatin concentrations were significantly lower in the gestational diabetes mellitus group (9.4 ± 3.8 ng/mL) than in the healthy control group (12.6 ± 4.5 ng/mL) (P = .023). A negative correlation was found between plasma visfatin concentrations and maternal (age (r = -0.399, P = .011), first trimester body weight (r = -0.350, P = .027), and first trimster BMI (r = -0.336, P = .034). Multiple linear regression analysis revealed that maternal age (P = .017) and gestational diabetes mellitus/no gestational diabetes mellitus (P = .044) were independently related to plasma visfatin concentrations. However, no relationship was found with either gestational age at the time of sampling or first trimester BMI. Conclusions: Our results show that there are decreased concentrations of plasma visfatin in gestational diabetes mellitus subjects and this may indicate that visfatin plays a role in the pathogenesis of gestational diabetes mellitus. However, further experiments are needed to clarify this role.

G-2548A Polymorphism of the Leptin Gene Is Correlated with Extreme Obesity in Taiwanese Aborigines

We examined the genetic associations of the G‐2548A polymorphism in the promoter of the leptin (LEP) gene and the Gln223Arg (Q223R) polymorphism of the leptin receptor (LEPR) gene with obesity. Two hundred twenty‐six obese aboriginal subjects (BMI ≥ 27 kg/m2) and 182 aboriginal subjects with normal weight (BMI < 25 kg/m2) participated in this study. The polymorphisms of LEP G‐2548A and LEPR Q223R were genotyped by polymerase chain reaction/restriction fragment length polymorphism, and their anthropometric characteristics were measured. Levels of leptin, triglycerides, and cholesterol were measured after overnight fasting. We found that the frequencies of the LEP G/G homozygote (22.6%) with Mendelian recessive (χ2 = 7.89, p = 0.005) and codominant (χ2 = 7.93, p = 0.02) models to be higher in the extremely obese subjects (BMI ≥ 35 kg/m2) than in normal weight subjects (6.9%) but not in moderately obese subjects (35 > BMI ≥ 27 kg/m2). There was no difference in genotypic frequency of the LEPR Q223R polymorphism between the extreme obese and control groups. We suggest that the LEP −2548 G/G homozygote plays a genetic recessive role in the development of extreme obesity in Taiwanese aborigines.

Comparative study of human eutopic and ectopic endometrial mesenchymal stem cells and the development of an in vivo endometriotic invasion model

OBJECTIVE To elucidate the role of endometrial stem-progenitor cells in the etiology of endometriosis and to develop an animal model to study the invasion ability of endometrial cells. DESIGN Gene expression and cell function studies were designed. SETTING Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. PATIENT(S) Human endometrial mesenchymal stem cells (MSCs) were isolated from 22 different endometrium biopsies after surgery for treatment of endometriosis. INTERVENTION(S) Endometrial MSCs developed from eutopic and ectopic endometrial tissues. MAIN OUTCOME MEASURE(S) Characterization of MSC phenotypes (i.e., differentiation induction and gene expression by flow cytometric analysis); comparative study of cell functions (i.e., cell growth, migration, and invasion assays). The invasion of implants in an animal model was examined by histologic staining. RESULT(S) We compared the characteristics of eutopic and ectopic endometrial MSCs from the same endometrial donor. Although both showed similar mesenchymal cell phenotypes, ectopic endometrial MSCs showed distinctly greater ability of cell migration and invasion. Furthermore, in an in vivo cell invasion model using cells grown in scaffold and transplantation in immune-deficient mice, the ectopic endometrial MSCs were found to form many new blood vessels and to invade surrounding tissue. CONCLUSION(S) These results indicate unique invasion and angiogenesis characteristics of ectopic endometrial MSCs that may underlie the pathogenesis of ectopic endometriosis. The animal invasion model will be useful for future characterization of endometrial MSCs.

Arctigenin, a dietary phytoestrogen, induces apoptosis of estrogen receptor-negative breast cancer cells through the ROS/p38 MAPK pathway and epigenetic regulation

This study investigates the anticancer effect of arctigenin (ATG), a natural lignan product of Arctium lappa L., in human breast cancer MDA-MB-231 cells. Results indicate that ATG inhibits MDA-MB-231 cell growth by inducing apoptosis in vitro and in vivo. ATG triggers the mitochondrial caspase-independent pathways, as indicated by changes in Bax/Bcl-2 ratio, resulting in AIF and EndoG nuclear translocation. ATG increased cellular reactive oxygen species (ROS) production by increasing p22(phox)/NADPH oxidase 1 interaction and decreasing glutathione level. ATG clearly increases the activation of p38 MAPK, but not JNK and ERK1/2. Antioxidant EUK-8, a synthetic catalytic superoxide and hydrogen peroxide scavenger, significantly decreases ATG-mediated p38 activation and apoptosis. Blocking p38 with a specific inhibitor suppresses ATG-mediated Bcl-2 downregulation and apoptosis. Moreover, ATG activates ATF-2, a transcription factor activated by p38, and then upregulates histone H3K9 trimethylation in the Bcl-2 gene promoter region, resulting in Bcl-2 downregulation. Taken together, the results demonstrate that ATG induces apoptosis of MDA-MB-231 cells via the ROS/p38 MAPK pathway and epigenetic regulation of Bcl-2 by upregulation of histone H3K9 trimethylation.

Comparison of tension-free vaginal tape and transobturator tape procedure for the treatment of stress urinary incontinence

Purpose of review The aim of this review was to assess the recent evidence on the effectiveness and complications of tension-free vaginal tape (TVT) and transobturator tape (TOT) procedures for female stress urinary incontinence between January 2008 and March 2009. Recent findings A meta-analysis of recent studies revealed that the short-term objective cure rate was borderline worse in the TOT group compared with TVT [odds ratio (OR) 0.62; 95% confidence interval (CI) 0.37–1.00; P = 0.05]. Bladder perforation (OR 12.23; 95% CI 2.86–52.34) was significantly more common, whereas groin/thigh pain was significantly less in the TVT group (OR 0.32; 95% CI 0.11–0.92; P = 0.022). Postoperative urinary retention was slightly more in women undergoing TVT than those undergoing TOT (OR 1.6; 95% CI 0.90–3.12; P = 0.06). The rates of vaginal erosion (OR 0.34; 95% CI 0.09–1.33), de-novo urgency (OR 1.21; 95% CI 0.52–2.79) and urinary tract infection (OR 0.88; 95% CI 0.56–1.38) were comparable in both procedures. In addition, TVT appeared to be more obstructive than TOT, as evidenced by ultrasonographic and urodynamic findings. Changes in sexual function need further investigation because this issue has not been well studied for either sling procedure. Summary TOT has the advantages over TVT with shorter operative time and a relatively lower complication rate. For women with intrinsic sphincter deficiency, however, TVT appears to be a better option because it is more obstructive.

Breast tumor-associated osteoblast-derived CXCL5 increases cancer progression by ERK/MSK1/Elk-1/snail signaling pathway.

The skeleton is the most common metastatic site for breast cancer, with bone metastasis causing pain as well as risk of pathological fractures. Interaction between tumors and the bone microenvironment creates a vicious cycle that accelerates both bone destruction and cancer progression. This study is the first to analyze the soluble factors secreted by breast tumor-associated osteoblasts (TAOBs), which are responsible for promoting cancer progression. The addition of CXCL5 (chemokine (C-X-C motif) ligand 5), present in large amounts in TAOB-condition medium (TAOB-CM), mimicked the inductive effect of TAOB-CM on breast cancer epithelial–mesenchymal transition, migration and invasion. In contrast, inhibition of CXCL5 in OBs decreased TAOB-mediated cancer progression. Inducement of MCF-7 and MDA-MB-231 cancer progression by TAOB-derived CXCL5 is associated with increased Raf/MEK/ERK activation, and mitogen- and stress-activated protein kinase 1 (MSK1) and Elk-1 phosphorylation, as well as Snail upregulation. Activation of Elk-1 facilitates recruitment of phosphorylated MSK1, which in turn enhances histone H3 acetylation and phosphorylation (serine 10) of Snail promoter, resulting in Snail enhancement and E-cadherin downregulation. Moreover, mice treated with anti-CXCL5 antibodies showed decreased metastasis of 4T1 breast cancer cells. Our study suggests that inhibition of CXCL5-mediated ERK/Snail signaling is an attractive therapeutic target for treating metastases in breast cancer patients.

Increased Serum Retinol-Binding Protein 4 Concentrations in Women With Gestational Diabetes Mellitus

The authors hypothesized that serum retinol-binding protein 4 (RBP4) concentrations will be higher in gestational diabetes mellitus (GDM) subjects. This study tested both women with GDM and healthy pregnant women and correlated their serum RBP4 concentrations with body mass index (BMI) and a variety of other parameters. Also, since there is no information on the relationship between RBP4 concentrations in maternal and fetal serum, this study measured these at delivery and examined whether there were correlations between the cord serum RBP4 levels and maternal serum RBP4 concentrations, neonatal birth weights, and gestational age at delivery. A total of 40 women were evaluated: 20 women with GDM and 20 healthy pregnant women to serve as control subjects. Serum RBP4 concentrations were analyzed with the use of an enzyme-linked immunosorbent assay kit. Serum RBP4 concentrations at glucose challenge test (GCT) were significantly higher in the GDM group (42.4 ± 13.8 ng/mL) than in the healthy control group (32.0 ± 8.7 ng/mL; P = .007). BMI at GCT (P = .003) and GDM/no GDM (P = .014) were significantly correlated to serum RBP4 concentrations at GCT by multiple linear regression analysis. In GDM subjects, serum RBP4 concentrations immediately after delivery were significantly lower than those at GCT (30.1 ± 11.0 ng/mL, 42.4 ± 13.8 ng/mL; P < .001), but there was no such difference in normal subjects (30.9 ± 10.0 ng/mL, 32.0 ± 8.7 ng/mL; P = .581). Cord serum RBP4 concentrations were significantly lower than maternal serum RBP4 concentrations at delivery (10.9 ± 3.8 ng/mL, 30.5 ± 10.4 ng/mL; P < .001). Only fetal birth weight (P = .049) was independently related to cord serum RBP4 concentrations at delivery by multiple linear regression analysis. This study found increased serum RBP4 concentrations at GCT in GDM subjects, and GDM was significantly correlated to serum RBP4 levels after adjustment for the effect of BMI. Lower RBP4 concentrations were found at delivery in GDM subjects. Maternal serum RBP4 concentrations were significantly higher than cord serum RBP4 concentrations, and fetal birth weights were independently correlated to cord serum RBP4 concentrations. These findings may indicate that RBP4 plays a role in the pathogenesis of GDM. However, further experiments are required to clarify this role and find a possible regimen for GDM treatment.

miRNA-199a-5p regulates VEGFA in endometrial mesenchymal stem cells and contributes to the pathogenesis of endometriosis.

It is believed that endometrial miRNAs contribute to the aetiology of endometriosis in stem cells; however, the mechanisms remain unclear. Here we collected serum samples from patients with or without endometriosis and characterized the miRNA expression profiles of these two groups. MicroRNA‐199a‐5p (miR‐199a‐5p) was dramatically down‐regulated in patients with endometriosis compared with control patients. In addition, we found that the tumour suppressor gene, SMAD4, could elevate miR‐199a‐5p expression in ectopic endometrial mesenchymal stem cells. Up‐regulation of miR‐199a‐5p suppressed cell proliferation, motility and angiogenesis of these ectopic stem cells by targeting the 3′ untranslated region of VEGFA. Furthermore, we established an animal model of endometriosis and found that miR‐199a‐5p could decrease the size of endometriotic lesions in vivo. Taken together, this newly identified miR‐199a‐5p module provides a new avenue to the understanding of the processes of endometriosis development, especially proliferation, motility and angiogenesis, and may facilitate the development of potential therapeutics against endometriosis. Copyright

The effect of maternal betel quid exposure during pregnancy on adverse birth outcomes among aborigines in Taiwan

In considering documented developmental toxicity and teratogenicity found in earlier research, maternal betel quid chewing may very well be linked to a higher risk of adverse birth outcomes. The aim of this study was to investigate the significance of betel quid chewing, together with the use of cigarettes or alcohol, either independently or combined, on birth-related outcomes. A total of 1264 aboriginal women who had just given birth in 10 hospitals in Southern and Eastern Taiwan were recruited. Information on their maternal and newborn characteristics was obtained from medical charts and by performing personal interviews using a validated questionnaire. Maternal areca nut chewing during pregnancy was found to be significantly associated with both birth weight loss (-89.54 g) and birth length reduction (-0.43 cm). A significantly lower male newborn rate (aOR=0.62) was observed among aboriginal women with a habit of betel quid chewing during pregnancy. The use of this substance conveyed a 2.40- and 3.67-fold independent risk of low birth weight and full-term low birth weight, respectively. An enhanced risk (aOR=3.26-5.99) of low birth weight was observed among women concomitantly using betel quid, cigarette and alcohol during gestation. Our findings suggest that betel quid chewing during pregnancy has a substantial effect on a number of birth outcomes, including sex ratio at birth, lower birth weight and reduced birth length.