Oestrogen‐induced epithelial–mesenchymal transition of endometrial epithelial cells contributes to the development of adenomyosis

Adenomyosis is an oestrogen‐dependent disease caused by a downward extension of the endometrium into the uterine myometrium. Epithelial–mesenchymal transition (EMT) endows cells with migratory and invasive properties and can be induced by oestrogen. We hypothesized that oestrogen‐induced EMT is critical in the pathogenesis of adenomyosis. We first investigated whether EMT occurred in adenomyotic lesions and whether it correlated with serum 17β‐oestradiol (E2) levels. Immunohistochemistry was performed on adenomyotic lesions and corresponding eutopic endometrium samples from women with adenomyosis. Endometria from women without endometrial disorders were used as a control. In the epithelial component of adenomyotic lesions, vimentin expression was up‐regulated and E‐cadherin expression was down‐regulated compared to the eutopic endometrium, suggesting that EMT occurs in adenomyosis. In adenomyosis, the serum E2 level was negatively correlated with E‐cadherin expression in the epithelial components of the eutopic endometrium and adenomyotic lesions, suggesting the involvement of oestrogen‐induced EMT in endometrial cells. In oestrogen receptor‐positive Ishikawa endometrial epithelial cells, oestrogen induced a morphological change to a fibroblast‐like phenotype, a shift from epithelial marker expression to mesenchymal marker expression, increased migration and invasion, and up‐regulation of the EMT regulator Slug. Raloxifene, a selective oestrogen receptor modulator, abrogated these effects. To determine the role of oestrogen‐induced EMT in the implantation of ectopic endometrium, we xenotransplanted eutopic endometrium or adenomyotic lesions from adenomyosis patients into ovariectomized SCID mice. The implantation of endometrium was oestrogen‐dependent and was suppressed by raloxifene. Collectively, these data highlight the crucial role of oestrogen‐induced EMT in the development of adenomyosis and suggest that raloxifene may be a potential therapeutic agent for adenomyosis patients. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Cost-effectiveness of highly active antiretroviral therapy for HIV infection in Taiwan.

BACKGROUND/PURPOSE: Since the late 1980s, the Taiwanese government has provided all HIV-infected citizens with free access to antiretroviral therapy. Recently, there is controversy as to whether or not free access to expensive highly active antiretroviral therapy (HAART) should be continued for HIV-infected patients. This study aimed to evaluate the cost-effectiveness of HAART therapy. METHODS: HAART-associated improvement in survival was obtained by analyzing the follow-up data of all HIV-positive patients identified during April 1984 to March 1997 (pre-HAART era) and May 1997 to April 2003 (HAART era) in Taiwan. Data on quality of life in HIV-positive patients was obtained from a cross-sectional survey of 224 patients using standard gamble method and World Health Organization Quality of Life-BREF instrument. Information regarding the cost of HAART was obtained from the National Health Insurance (NHI). RESULTS: In 2000, the average annual NHI expenditure on HAART per HIV-positive patient receiving HAART was NT$210,018 (US$6177, at an exchange rate of 34.0 NT$/US$). In the AIDS group, the cost was NT$176,441 (US$5189) per life year gained and NT$241,700 (US$7109) per quality-adjusted life year gained. For non-AIDS patients, the corresponding costs were NT$226,156 (US$6652) and NT$332,582 (US$9782), respectively. These estimates have not yet included the additional cost savings from HAART-associated reduction in hospitalization and use of antimicrobial agents for opportunistic infections, and the additional life years gained from the reduction in HIV transmission under the universal availability of HAART. CONCLUSION: HAART for HIV infection is cost-effective, especially when the societal and epidemiologic factors are considered. We recommend that the policy of providing free HAART to all HIV-infected citizens be continued.     

Epigenetic silencing of microRNA-199b-5p is associated with acquired chemoresistance via activation of JAG1-Notch1 signaling in ovarian cancer

Epithelial ovarian cancer is a highly lethal and aggressive gynecological malignancy. The high mortality rate is due in part to the fact that many advanced cancer patients become refractory to current chemotherapeutic agents, leading to tumor recurrence and death. However, the underlying mechanisms leading to chemoresistance remain obscure. Here, we report that the loss of miR-199b-5p due to progressive epigenetic silencing leads to the activation of the JAG1-mediated Notch1 signaling cascade, thereby leading to the development of acquired chemoresistance in ovarian cancer. Using miRCURY LNA™ microRNA array and Q-PCR analyses of two pairs of cisplatin-sensitive and –resistant ovarian cancer cell lines, we identified miR-199b-5p as significantly down-regulated in cisplatin-resistant ovarian cancer cells and confirmed that miR-199b-5p is clinically associated with advanced and poor survival ovarian cancers. Interestingly, the loss of miR-199b-5p could be restored by 5-Aza-dC-mediated demethylation, and methylated specific PCR (MS-PCR), bisulfite-sequencing and pyrosequencing revealed that the promoter region of miR-199b-5p was hypermethylated. Computational and mechanistic analyses identified JAG1 as a primary target of miR-199b-5p. Notably, the reduced expression of miR-199b-5p was found to be inversely correlated with the increased expression of JAG1 using an ovarian cancer tissue array. Enforced expression of miR-199b-5p sensitized ovarian cancer cells to cisplatin-induced cytotoxicity both in vitro and in vivo. Conversely, re-expression of miR-199b-5p and siRNA-mediated JAG1 knockdown or treatment with Notch specific inhibitor γ-secretase (GSI) attenuated JAG1-Notch1 signaling activity, thereby enhancing cisplatin-mediated cell cytotoxicity. Taken together, our study suggests that the epigenetic silencing of miR-199b-5p during tumor progression is significantly associated with acquired chemoresistance in ovarian cancer through the activation of JAG1-Notch1 signaling.     

Targeting VEGFR1- and VEGFR2-expressing non-tumor cells is essential for esophageal cancer therapy

Increasing appreciation of tumor heterogeneity and the tumor-host interaction has stimulated interest in developing novel therapies that target both tumor cells and tumor microenvironment. Bone marrow derived cells (BMDCs) constitute important components of the tumor microenvironment. In this study, we aim to investigate the significance of VEGFR1- and VEGFR2-expressing non-tumor cells, including BMDCs, in esophageal cancer (EC) progression and in VEGFR1/VEGFR2-targeted therapies. Here we report that VEGFR1 or VEGFR2 blockade can significantly attenuate VEGF-induced Src and Erk signaling, as well as the proliferation and migration of VEGFR1⁺ and VEGFR2⁺ bone marrow cells and their pro-invasive effect on cancer cells. Importantly, our in vivo data show for the first time that systemic blockade of VEGFR1⁺ or VEGFR2⁺ non-tumor cells with neutralizing antibodies is sufficient to significantly suppress esophageal tumor growth, angiogenesis and metastasis in mice. Moreover, our tissue microarray study of human EC clinical specimens showed the clinicopathological significance of VEGFR1 and VEGFR2 in EC, which suggest that anti-VEGFR1/VEGFR2 therapies may be particularly beneficial for patients with aggressive EC. In conclusion, this study demonstrates the important contributions of VEGFR1⁺ and VEGFR2⁺ non-tumor cells in esophageal cancer progression, and substantiates the validity of these receptors as therapeutic targets for this deadly disease.     

粉防己碱对离体大鼠心脏钙反常的保护作用

粉防己碱(Tet)能明显抑制离体大鼠心脏钙反常时心肌组织LDH和蛋白的释出,减少无钙灌流时心肌组织Ca~(2+)丢失和Na~+堆积以及复钙灌流时心肌组织Ca~(2+),Na~+堆积和Mg~(2+),K~+丢失,并呈浓度依赖性。此外,钙反常时心肌组织中微量元素Fe,Zn含量下降,Cu含量增加,而Tet可抑制Fe及Zn含量的下降。维拉帕米(Ver)也有类似作用,电镜下,Tet可部分减轻钙反常时心肌组织超微结构的破坏。     

Long-term prognostic effects of plasma epstein-barr virus DNA by minor groove binder-probe real-time quantitative PCR on nasopharyngeal carcinoma patients receiving concurrent chemoradiotherapy

PURPOSE: To evaluate the long-term prognostic impact of plasma Epstein-Barr virus (EBV) DNA concentration measured by real-time quantitative polymerase chain reaction (RTQ-PCR) in nasopharyngeal carcinoma (NPC) patients receiving concurrent chemoradiotherapy (CCRT). METHODS AND MATERIALS: Epstein-Barr virus DNA was retrospectively measured from stock plasma of 152 biopsy-proven NPC patients with Stage II-IV (M0) disease with a RTQ-PCR using the minor groove binder-probe. All patients received CCRT with a median follow-up of 78 months. We divided patients into three subgroups: (1) low pretreatment EBV DNA (<1,500 copies/mL) and undetectable posttreatment EBV DNA (pre-L/post-U), (2) high pretreatment EBV DNA (> or =1,500 copies/mL) and undetectable posttreatment EBV DNA (pre-H/post-U), and (3) low or high pretreatment EBV DNA and detectable posttreatment EBV DNA (pre-L or H/post-D) for prognostic analyses. RESULTS: Epstein-Barr virus DNA (median concentration, 573 copies/mL; interquartile range, 197-3,074) was detected in the pretreatment plasma of 94.1% (143/152) of patients. After treatment, plasma EBV DNA decreased or remained 0 for all patients and was detectable in 31 patients (20.4%) with a median concentration 0 copy/mL (interquartile range, 0-0). The 5-year overall survival rates of the pre-L/post-U, pre-H/post-U, and pre-L or H/post-D subgroups were 87.2%, 71.0%, and 38.7%, respectively (p < 0.0001). The relapse-free survival showed similar results with corresponding rates of 85.6%, 75.9%, and 26.9%, respectively (p < 0.0001). Multivariate Cox analysis confirmed the superior effects of plasma EBV DNA compared to other clinical parameters in prognosis prediction. CONCLUSION: Plasma EBV DNA is the most valuable prognostic factor for NPC. More chemotherapy should be considered for patients with persistently detectable EBV DNA after CCRT.     

Growth hormone receptor modulators

Growth hormone (GH) regulates somatic growth, substrate metabolism and body composition. Its actions are elaborated through the GH receptor (GHR). GHR signalling involves the role of at least three major pathways, STATs, MAPK, and PI3-kinase/Akt. GH receptor function can be modulated by changes to the ligand, to the receptor or by factors regulating signal transduction. Insights on the physico-chemical basis of the binding of GH to its receptor and the stoichiometry required for activation of the GH receptor-dimer has led to the development of novel GH agonists and antagonists. Owing to the fact that GH has short half-life, several approaches have been taken to create long-acting GHR agonists. This includes the pegylation, sustained release formulations, and ligand-receptor fusion proteins. Pegylation of a GH analogue (pegvisomant) which binds but not activate signal transduction forms the basis of a new successful approach to the treatment of acromegaly. GH receptors can be regulated at a number of levels, by modifying receptor expression, surface availability and signalling. Insulin, thyroid hormones and sex hormones are among hormones that modulate GHR through some of these mechanisms. Estrogens inhibit GH signalling by stimulating the expression of SOCS proteins which are negative regulators of cytokine receptor signalling. This review of GHR modulators will cover the effects of ligand modification, and of factors regulating receptor expression and signalling.