Invasion Of Stromal Cells Research Articles

Three-dimensional Cell Culture Model for Measuring the Effects of Interstitial Fluid Flow on Tumor Cell Invasion

The growth and progression of most solid tumors depend on the initial transformation of the cancer cells and their response to stroma-associated signaling in the tumor microenvironment (1). Previously, research on the tumor microenvironment has focused primarily on tumor-stromal interactions (1-2). However, the tumor microenvironment also includes a variety of biophysical forces, whose effects remain poorly understood. These forces are biomechanical consequences of tumor growth that lead to changes in gene expression, cell division, differentiation and invasion(3). Matrix density (4), stiffness (5-6), and structure (6-7), interstitial fluid pressure (8), and interstitial fluid flow (8) are all altered during cancer progression. Interstitial fluid flow in particular is higher in tumors compared to normal tissues (8-10). The estimated interstitial fluid flow velocities were measured and found to be in the range of 0.1-3 μm s(-1), depending on tumor size and differentiation (9, 11). This is due to elevated interstitial fluid pressure caused by tumor-induced angiogenesis and increased vascular permeability (12). Interstitial fluid flow has been shown to increase invasion of cancer cells (13-14), vascular fibroblasts and smooth muscle cells (15). This invasion may be due to autologous chemotactic gradients created around cells in 3-D (16) or increased matrix metalloproteinase (MMP) expression (15), chemokine secretion and cell adhesion molecule expression (17). However, the mechanism by which cells sense fluid flow is not well understood. In addition to altering tumor cell behavior, interstitial fluid flow modulates the activity of other cells in the tumor microenvironment. It is associated with (a) driving differentiation of fibroblasts into tumor-promoting myofibroblasts (18), (b) transporting of antigens and other soluble factors to lymph nodes (19), and (c) modulating lymphatic endothelial cell morphogenesis (20). The technique presented here imposes interstitial fluid flow on cells in vitro and quantifies its effects on invasion (Figure 1). This method has been published in multiple studies to measure the effects of fluid flow on stromal and cancer cell invasion (13-15, 17). By changing the matrix composition, cell type, and cell concentration, this method can be applied to other diseases and physiological systems to study the effects of interstitial flow on cellular processes such as invasion, differentiation, proliferation, and gene expression.

Three-dimensional Cell Culture Model for Measuring the Effects of Interstitial Fluid Flow on Tumor Cell Invasion

The growth and progression of most solid tumors depend on the initial transformation of the cancer cells and their response to stroma-associated signaling in the tumor microenvironment 1. Previously, research on the tumor microenvironment has focused primarily on tumor-stromal interactions 1-2. However, the tumor microenvironment also includes a variety of biophysical forces, whose effects remain poorly understood. These forces are biomechanical consequences of tumor growth that lead to changes in gene expression, cell division, differentiation and invasion3. Matrix density 4, stiffness 5-6, and structure 6-7, interstitial fluid pressure 8, and interstitial fluid flow 8 are all altered during cancer progression. Interstitial fluid flow in particular is higher in tumors compared to normal tissues 8-10. The estimated interstitial fluid flow velocities were measured and found to be in the range of 0.1-3 μm s-1, depending on tumor size and differentiation 9, 11. This is due to elevated interstitial fluid pressure caused by tumor-induced angiogenesis and increased vascular permeability 12. Interstitial fluid flow has been shown to increase invasion of cancer cells 13-14, vascular fibroblasts and smooth muscle cells 15. This invasion may be due to autologous chemotactic gradients created around cells in 3-D 16 or increased matrix metalloproteinase (MMP) expression 15, chemokine secretion and cell adhesion molecule expression 17. However, the mechanism by which cells sense fluid flow is not well understood. In addition to altering tumor cell behavior, interstitial fluid flow modulates the activity of other cells in the tumor microenvironment. It is associated with (a) driving differentiation of fibroblasts into tumor-promoting myofibroblasts 18, (b) transporting of antigens and other soluble factors to lymph nodes 19, and (c) modulating lymphatic endothelial cell morphogenesis 20. The technique presented here imposes interstitial fluid flow on cells in vitro and quantifies its effects on invasion (Figure 1). This method has been published in multiple studies to measure the effects of fluid flow on stromal and cancer cell invasion 13-15, 17. By changing the matrix composition, cell type, and cell concentration, this method can be applied to other diseases and physiological systems to study the effects of interstitial flow on cellular processes such as invasion, differentiation, proliferation, and gene expression.

Abstract 1480: Regulation of ovarian tumor growth and stromal cell infiltration by the HU177 biomechanical ECM switch

Abstract Accumulating evidence indicates that the malignant behavior of tumors depends not only on tumor cells themselves, but also on the stromal cells that comprise the malignant tumor mass. Experimental findings suggest that stromal cells such as cancer-associated fibroblast (CAF) may play important roles in promoting tumor growth and metastasis as well as regulating the efficacy of certain chemotherapeutic drugs. However, developing novel clinical strategies that selectively and simultaneously impacts tumor and stromal cells remains challenging. Alterations in the integrity and molecular composition of the extracellular matrix (ECM) are hallmarks of tumor progression. Our previous studies have shown that structural remodeling of the ECM can result in localized triggering of what we have termed “biomechanical ECM switches” or changes in the three-dimensional structure of pre-existing ECM molecules. A humanized antibody (TRC093/D93) specifically directed to the HU177 cryptic collagen epitope that is selectively exposed following triggering of a biomechanical ECM switch has been developed, and a human phase-I clinical trial was recently completed with encouraging results. Here we provide evidence that the HU177 biomechanical ECM switch is triggered within human ovarian tumors resulting in the exposure of the HU177 cryptic collagen epitope. The relative exposure of the HU177 cryptic site was significantly (P<0.05) enhanced in biopsies of malignant ovarian tumors as compared to benign ovarian lesions. Selective targeting of the HU177 cryptic collagen epitope by Mab D93 significantly (P<0.05) inhibited SKOV-3 tumor growth by approximately 70% as compared to controls. Tumors from these mice exhibited reduced angiogenesis, elevated levels of apoptosis and a significant reduction in infiltration of alpha smooth muscle cell actin (αSMC-actin) positive stromal fibroblasts. Importantly, while Mab D93 inhibited SKOV-3 tumor cell adhesion to denatured collagen type-I and enhanced the expression of the cyclin dependent kinase inhibitor P27KIP1, it also selectively inhibited (80%) fibroblast migration on denatured collagen type-I that was induced by either FGF-2 or SKOV-3 condition medium. Collectively these studies provide evidence that specific targeting of the HU177 cryptic collagen epitope may represent a highly selective strategy to inhibit ovarian tumor growth in part by limiting stromal cell invasion. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1480. doi:1538-7445.AM2012-1480

Trophoblast-derived chemokine CXCL12 promotes CXCR4 expression and invasion of human first-trimester decidual stromal cells

The aim of this study was to investigate the role of the chemokine (C-X-C motif) ligand 12/chemokine (C-X-C motif) receptor 4 (CXCL12/CXCR4) axis on the crosstalk between human first-trimester trophoblast cells (TCs) and decidual stromal cells (DSCs), to contribute to a better understanding of the molecular mechanisms on the interaction between the mother and embryo during pregnancy. CXCR4 on human first-trimester DSC membranes was detected by flow cytometry. The effects of exogenous CXCL12 or TC-conditioned medium (TCM) on proliferation and invasion of DSCs were examined by measuring proliferating cell nuclear antigen (PCNA) and an invasion assay, respectively. Finally, a co-culture model was established to investigate the effect of CXCL12 secreted from TCs on motility of DSCs. The mean (±SEM) percentage of DSCs positive for CXCR4 was 32.32 ± 7.18%. Human recombinant CXCL12 induced an increase in CXCR4 levels on DSCs via binding to CXCR4 (P < 0.01) but had no effect on the PCNA expression of DSCs. Moreover, both exogenous CXCL12 and TCM reinforced the invasive ability of DSCs via CXCR4 ligation. A co-culture model further confirmed that the enhanced invasiveness of DSCs in co-culture with TCs was inhibited by anti-CXCR4 or anti-CXCL12 neutralizing antibody (both P< 0.01). Human first-trimester DSCs express membrane CXCR4 and TC-derived CXCL12 promotes CXCR4 expression and invasion of DSCs via ligation with CXCR4. Our data highlight the role of CXCL12/CXCR4 axis on the co-operation between TCs and DSCs during human first-trimester pregnancy.

MiR-199a attenuates endometrial stromal cell invasiveness through suppression of the IKK /NF- B pathway and reduced interleukin-8 expression

MicroRNAs have recently been identified as regulators that modulate target gene expression and are suggested to be involved in the development and progression of endometriosis. This study was undertaken to analyze the expression level of microRNA-199a (miR-199a) in paired ovarian endometrioma and eutopic endometrium from women with endometriosis, and to investigate the contribution of miR-199a to the invasive capability of endometrial stromal cells (ESCs). Cell adhesion, migration and Matrigel invasion assays were carried out to measure the invasiveness of ESCs. Bioinformatics prediction, reporter gene assay, PCR, western blotting and ELISA were performed to identify miR-199a targets and related signaling pathways. The results showed that the expression level of miR-199a was lower in the eutopic endometrium from women with endometriosis, and even lower in the paired ovarian endometrioma, compared with the expression in normal controls. Moreover, ectopic expression of miR-199a attenuated ESC adhesion, migration and invasiveness. MiR-199a targeted and inhibited IkappaB kinase beta (IKKβ) in ESCs. Accompanied by IKKβ reduction, miR-199a suppressed nuclear factor-kappa B (NF-κB) pathway activation and interleukin-8 (IL-8) production in ESCs. All these findings suggest that miR-199a, down-regulated in endometriosis, attenuates the invasive capability of ESCs in vitro partly through IKK/NF-κB pathway suppression and reduced IL-8 expression. In conclusion, miR-199a could be involved in the pathogenesis of endometriosis.

G Protein-coupled receptor 30 (GPR30) expression increases in endometrium of patients with endometriosis and GPR30 is involved in human endometrial stromal cell invasion induced by 17β-estradiol (E2)

To analyze endometrial GPR30 expression in women with and without endometriosis, observe the impact of E2 on invasion of human endometrial stromal cell(HESC) and investigate the role GPR30 in mediating the biological function of E2 in HESC.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits invasion of human immortalized endometriotic epithelial and stromal cells through suppression of metalloproteinases

Prostaglandin E2 (PGE2) plays an important role in the pathogenesis of endometriosis. We recently reported that inhibition of COX-2 decreased migration as well as invasion of human endometriotic epithelial and stromal cells. Results of the present study indicates that selective inhibition of PGE2 receptors EP2 and EP4 suppresses expression and/or activity of MMP1, MMP2, MMP3, MMP7 and MMP9 proteins and increases expression of TIMP1, TIMP2, TIMP3, and TIMP4 proteins and thereby decreases migration and invasion of human immortalized endometriotic epithelial and stromal cells into matrigel. The interactions between EP2/EP4 and MMPs are mediated through Src and β-arrestin 1 protein complex involving MT1-MMP and EMMPRIN in human endometriotic cells. These novel findings provide an important molecular and cellular framework for further evaluation of selective inhibition of EP2 and EP4 as potential nonsteroidal therapy for endometriosis in childbearing-age women.

Pyrrolidine dithiocarbamate inhibits nuclear factor- B pathway activation, and regulates adhesion, migration, invasion and apoptosis of endometriotic stromal cells

The activation of nuclear factor-κB (NF-κB) has been implicated in the development and progression of endometriosis. The aim of this study is to investigate the potential application of pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, in the treatment of endometriosis. NF-κB-DNA-binding activity, IκB phosphorylation and expression of nuclear p65 protein in endometriotic ectopic stromal cells (EcSCs), endometriotic eutopic stromal cells (EuSCs) and normal endometrial stromal cells (NESCs) were detected by electrophoretic mobility shift assay and western blot analysis. Adhesion, migration, invasion and apoptosis of EcSCs were observed by means of adhesion, migration, invasion and terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling assay, respectively. Gene and protein expressions of CD44s, matrix metalloproteinase (MMP)-2, MMP-9 and survivin in EcSCs were measured by RT-PCR and western blot analysis. The results showed that PDTC in the absence or presence of interleukin (IL)-1β showed stronger inhibitory effects on NF-κB-DNA-binding activity, IκB phosphorylation and expression of nuclear p65 protein in EcSCs than those in EuSCs or NESCs. PDTC enhanced apoptosis, and suppressed IL-1β-induced cellular adhesion, migration and invasion of EcSCs. Pretreatment of EcSCs with PDTC attenuated IL-1β-induced expressions of CD44s, MMP-2, MMP-9 and survivin at gene and protein levels. All these findings suggest that PDTC induces apoptosis and down-regulates adhesion, migration and invasion of EcSCs through the suppression of various molecules. Therefore, PDTC could be used as a therapeutic agent for the treatment of endometriosis.

Resveratrol Inhibits Development of Experimental Endometriosis In Vivo and Reduces Endometrial Stromal Cell Invasiveness In Vitro1

Endometriosis is a common gynecologic disorder characterized by ectopic attachment and growth of endometrial tissues. Resveratrol is a natural polyphenol with antiproliferative and anti-inflammatory properties. Our objective was to study the effects of resveratrol on human endometriotic implants in a nude mouse model and to examine its impact on human endometrial stromal (HES) cell invasiveness in vitro. Human endometrial tissues were obtained from healthy donors. Endometriosis was established in oophorectomized nude mice by intraperitoneal injection of endometrial tissues. Mice were treated with 17β-estradiol (8 mg, silastic capsule implants) alone (n = 16) or with resveratrol (6 mg/mouse; n = 20) for 10-12 and 18-20 days beginning 1 day after tissue injection. Mice were killed and endometrial implants were evaluated. A Matrigel invasion assay was used to examine the effects of resveratrol on HES cells. We assessed number and size of endometriotic implants in vivo and Matrigel invasion in vitro. Resveratrol decreased the number of endometrial implants per mouse by 60% (P < 0.001) and the total volume of lesions per mouse by 80% (P < 0.001). Resveratrol (10-30 μM) also induced a concentration-dependent reduction of invasiveness of HES by up to 78% (P < 0.0001). Resveratrol inhibits development of endometriosis in the nude mouse and reduces invasiveness of HES cells. These observations may aid in the development of novel treatments of endometriosis.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits adhesion, migration, and invasion of human endometriotic cells

OBJECTIVE: Prostaglandin E2 plays an important role in the pathogenesis of endometriosis. The objective of the present study was to determine functional interaction between PGE2 signaling and adhesion, migration, and invasion of human endometriotic epithelial and stromal cells and to unravel the underlying molecular and cellular mechanisms. DESIGN: Human immortalized endometriotic epithelial and stromal cells were treated with EP2 and EP4 receptor inhibitors, and their effects on adhesion, migration, and invasion of cells were studied and the underlined molecular mechanisms were uncovered. MATERIALS AND METHODS: Adhesion of endometriotic cells with ECM substrate and invasion of endometriotic ells into matrigel were analyzed in vitro. Set of integrins, MMPs and TIMPS proteins were analyzed by western blot. RESULTS: Results of the present study indicated that selective inhibition of EP2 and EP4-mediated PGE2 signaling: (i) suppressed expression and/or activity specific integrin receptors a2b1, avb3, a5b1, and a3b1 and thereby decreased adhesion of human endometriotic epithelial and stromal cells to extracellular matrix substrates collagen I, collagen IV, vitronectin, fibronectin, and laminins; and (ii) suppressed expression and/or activity of MMP1, MPP2, MMP3, MMP7 and MMP9 and increased expression of TIMP1, TIMP2, TIMP3, and TIMP4 and thereby decreased migration and invasion of human endometriotic epithelial and stromal cells. CONCLUSION: These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential nonestrogen or nonsteroidal therapy to expand the spectrum of currently available treatment options for endometriosis in child-bearing age women. Further, our results suggest potential opportunities for translational studies that could lead to preclinical and clinical-phase trials.

Imatinib decreases endometrial stromal cell transmesothial migration and proliferation in the extracellular matrix of modeled peritoneum

To characterize imatinib's effect on endometrial stromal cell (ESC) attachment, proliferation, and invasion in modeled peritoneum. In vitro study. Academic medical center. Twelve normally cycling women. Imatinib treatment in ESCs from women without endometriosis. Rate of ESC attachment, proliferation, and invasion. Imatinib treatment at 10 μM had no effect on ESC attachment. Treatment with 0.5 μM, 2 μM, and 10 μM of imatinib reduced ESC proliferation by 30%, 72%, and 76%, respectively. The 0.1 μM dose of imatinib had no effect on proliferation. Treatment with 5 μM and 10 μM of imatinib reduced ESC invasion by 30% and 73%, respectively. The 2 μM dose had no effect on invasion. Imatinib treatment reduces ESC proliferation and invasion in modeled peritoneum without altering attachment. Imatinib may have a therapeutic role in endometriosis treatment.

Enhanced invasion of stromal cells from adenomyosis in a three-dimensional coculture model is augmented by the presence of myocytes from affected uteri

To compare endometrial stromal cell invasion from women with and without adenomyosis and the effect of myometrial cells using a three-dimensional coculture. Case-controlled blinded comparison. University department. Premenopausal women with and without uterine adenomyosis. Human endometrial stromal and myometrial cells were grown in a three-dimensional coculture with crossover between cells from uteri with and without adenomyosis. Surface-enhanced laser desorption/ionization-time of flight-mass spectrometry proteomic analysis was performed on culture supernatants. Depth of stromal cell invasion into collagen matrix and protein expression profiles. The depth of invasion for adenomyosis stromal cells (AS) was statistically significantly higher than controls (CS) whether grown on plain collagen, control muscle (CM), or adenomyosis muscle (AM). Coculture with AM enhanced invasion of both CS and AS. Enhanced invasion by AS was more marked in cocultures with AM than CM. Proteomic analysis identified differences that may account for the invasiveness and also many similarities between secretory products related to the disease status. Enhanced stromal invasion in adenomyosis is influenced by the myometrium in the in vitro coculture model. This suggests that adenomyosis may be a disease of both the endometrial stroma and myometrium.

The role of angiocidin in sarcomas

Angiocidin, first identified as a tumor-associated thrombospondin-1 (TSP-1) receptor, is a key mediator of tumor progression. TSP-1, an extracellular protein produced by stromal cells, up-regulates gelatinases and tumor cell invasion in epithelial malignancies. The authors recently developed 2 angiocidin-inhibitory peptides that block angiocidin-TSP-1 binding. They hypothesized that angiocidin mediates increased gelatinase expression and tumor cell invasion in sarcomas through its interaction with TSP-1. Angiocidin, TSP-1, and gelatinase expression was evaluated in low-grade and high-grade sarcoma specimens. The authors established 3 distinct cell lines from a patient with an extraskeletal osteosarcoma: EXOS-N (normal mesenchymal), EXOS-P (primary osteosarcoma), and EXOS-M (lung metastasis). Each was evaluated for angiocidin, gelatinase, and gelatinase inhibitor (tissue inhibitors of metalloproteinase) expression and for invasive capacity. Their responsiveness to TSP-1 was determined. The role of angiocidin in up-regulating gelatinase expression and invasion was studied using the authors' angiocidin-inhibitory peptides. Expression of angiocidin, TSP-1, and gelatinases correlated with tumor grade. Angiocidin expression, gelatinase activity, and invasiveness in the EXOS cell lines correlated with phenotype; EXOS-N cells did not express angiocidin or gelatinases and were not invasive; EXOS-M cells were 5 times more invasive than EXOS-P cells and exhibited greater angiocidin and gelatinase expression. EXOS cell gelatinase activity and invasiveness increased 4- to 5-fold in response to TSP-1. Inhibition of angiocidin with the authors' inhibitory peptides blocked TSP-1-promoted increases in gelatinase activity and tumor cell invasion. Angiocidin promotes gelatinase up-regulation and tumor cell invasion in sarcomas. Angiocidin-inhibitory peptides are potent inhibitors of sarcoma cell invasion in vitro, suggesting a potential therapeutic role for these peptides in the treatment of sarcomas.

Selective inhibition of prostaglandin E 2 signaling inhibits migration and invasion of human endometriotic epithelial and stromal cells through multiple mechanisms

OBJECTIVE: Prostaglandin E2 (PGE2) plays central role in the pathogenesis of endometriosis. We have shown that selective inhibition of COX-2 prevents survival, migration, and invasion (Endocrinology, 2008), and inhibition of EP2 and EP4 induces apoptosis (Molecular Endocrinology, 2009) of human endometriotic epithelial and stromal cells. In this study, we determined molecular association between PGE2 signaling and migration and invasion potential of human endometriotic cells. DESIGN: Human endometriotic and endometrial tissues from proliferative phase of the menstrual cycle and human immortalized endometriotic epithelial cells 12Z and stromal cells 22B. MATERIALS AND METHODS: Spatial expression of PGE2 receptors EP1, EP2, EP3 and EP4 were studied in human ectopic (n=12) and eutopic endometria (n=12) using immunohistochemistry. PGE2 signaling was inhibited using pharmacological and genomic approaches in endometriotic epithelial cells 12Z and stromal cells 22B, and their effects on migration and invasion of endometriotic cells and the underlined molecular mechanisms were determined (n=3). RESULTS: Our data indicated that EP2 and EP4 were highly (P<0.05) expressed in glandular epithelium and stoma of ectopic compared to eutopic endometria. EP1 was expressed at very low level in both ectopic and eutopic endometria. EP3 was undetectable in both endometria. Selective inhibition of EP2 and EP4 receptors inhibited (P<0.05) migration and invasion of endometriotic epithelial cells 12Z and stromal cells 22B in a cell-specific manner. This effect was mediated through inhibition of metalloproteinases MMP2 and MMP9 activities via suppression of ERK1/2, AKT, NFkB and b-catenin pathways. CONCLUSIONS: Our results suggest that selective inhibition of EP2 and EP4 could be used as novel non-estrogen hormonal therapy for endometriosis, pending in vivo studies.

Lipopolysaccharide promoted proliferation and invasion of endometriotic stromal cells via induction of cyclooxygenase-2 expression

Lipopolysaccharide-enhanced cyclooxygenase 2 (COX-2) expression and prostaglandin E2 (PGE2) production were compared in endometriotic stromal cells (ESCs) and eutopic endometrial stromal cells. Lipopolysaccharide promotes the proliferation and invasion of ESCs via up-regulation of COX-2 and PGE2 expression, suggesting that pelvic inflammation may promote the progression of endometriosis.

Selective Inhibition of Prostaglandin E2 Receptors EP2 and EP4 Induces Apoptosis of Human Endometriotic Cells through Suppression of ERK1/2, AKT, NFκB and β-CATENIN Pathways and Activation of Intrinsic Apoptotic Mechanisms

Endometriosis is a benign chronic gynecological disease of reproductive age women characterized by the presence of functional endometrial tissues outside the uterine cavity. It is an estrogen-dependent disease. Current treatment modalities to inhibit biosynthesis and actions of estrogen compromise menstruation, pregnancy, reproductive health of women, and fail to prevent reoccurrence of disease. There is a critical need to identify new specific signaling modules for non-estrogen targeted therapies for endometriosis. In our previous study, we reported that selective inhibition of cyclooxygenase-2 prevented survival, migration and invasion of human endometriotic epithelial and stromal cells which was due to decreased PGE2 production. In this study, we determined mechanisms through which prostaglandin E2 (PGE2) promoted survival of human endometriotic cells. Results of the present study indicate that: (i) PGE2 promotes survival of human endometriotic cells through EP2 and EP4 receptors by activating ERK1/2, AKT, NFκB, and β-catenin signaling pathways; (ii) selective inhibition of EP2 and EP4 suppresses these cell survival pathways and augments interactions between proapoptotic proteins (Bax and Bad) and antiapoptotic proteins (Bcl-2/Bcl-XL), facilitates the release of cytochrome C and thus activates caspase-3/PARP-mediated intrinsic apoptotic pathways; and (iii) these PGE2 signaling components are more abundantly expressed in ectopic endometriosis tissues compared to eutopic endometrial tissues during the menstrual cycle in women. These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential therapy, including non-estrogen target, to expand the spectrum of currently available treatment options for endometriosis in women.

Selective Inhibition of Prostaglandin E2 Receptors EP2 and EP4 Induces Apoptosis of Human Endometriotic Cells through Suppression of ERK1/2, AKT, NFκB, and β-Catenin Pathways and Activation of Intrinsic Apoptotic Mechanisms

Endometriosis is a benign chronic gynecological disease of reproductive-age women characterized by the presence of functional endometrial tissues outside the uterine cavity. It is an estrogen-dependent disease. Current treatment modalities to inhibit biosynthesis and actions of estrogen compromise menstruation, pregnancy, and the reproductive health of women and fail to prevent reoccurrence of disease. There is a critical need to identify new specific signaling modules for non-estrogen-targeted therapies for endometriosis. In our previous study, we reported that selective inhibition of cyclooxygenase-2 prevented survival, migration, and invasion of human endometriotic epithelial and stromal cells, which was due to decreased prostaglandin E(2) (PGE(2)) production. In this study, we determined mechanisms through which PGE(2) promoted survival of human endometriotic cells. Results of the present study indicate that 1) PGE(2) promotes survival of human endometriotic cells through EP2 and EP4 receptors by activating ERK1/2, AKT, nuclear factor-kappaB, and beta-catenin signaling pathways; 2) selective inhibition of EP2 and EP4 suppresses these cell survival pathways and augments interactions between proapoptotic proteins (Bax and Bad) and antiapoptotic proteins (Bcl-2/Bcl-XL), facilitates the release of cytochrome c, and thus activates caspase-3/poly (ADP-ribose) polymerase-mediated intrinsic apoptotic pathways; and 3) these PGE(2) signaling components are more abundantly expressed in ectopic endometriosis tissues compared with eutopic endometrial tissues during the menstrual cycle in women. These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential therapy, including nonestrogen target, to expand the spectrum of currently available treatment options for endometriosis in women.

Lipopolysaccharide promoted proliferation and invasion of endometriotic stromal cells via induction of cyclooxygenase-2

OBJECTIVE: An important recent general concept is that of endometriosis as a local pelvic inflammatory process with altered function of immune-related cells and of endometriotic cells in the peritoneal environment. A number of studies suggest that the peritoneal fluid (PF) of women with endometriosis contains increased levels of a variety of local products, such as growth factors, cytokines and prostaglandins. We conducted this study to evaluate the effect of lipopolysaccharide (LPS) on the expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in endometriotic stromal cells (ESC) and on their proliferation and invasion.

17ß-estradiol-induced human endometrial stromal cell invasion is dependent on c-fos-mediated matrix metalloproteinase-9 expression

OBJECTIVE: To observe the effect of 17ß-estradiol on invasion of human endometrial stromal cell (ESC) and investigate the role of c-fos and matrix metalloproteinase-9 (MMP-9) gene in mediating the biological function of 17ß-estradiol in ESC.

Increased matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 secretion but unaffected invasiveness of endometrial stromal cells in adenomyosis

To investigate cell invasiveness and the production of matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 in endometrial stromal cells (ESCs) of adenomyosis. Prospective study. Tertiary university hospital. Twenty-one women with adenomyosis (study group) and 25 women without adenomyosis (control group). Endometrial stromal cells were purified from eutopic endometrium and were cultured in vitro. Matrigel invasion assay and measurement of MMP-2, MMP-9, TIMP-1, and TIMP-2 concentrations. Endometrial stromal cell invasiveness of adenomyosis was not different from that of the control group (0.95 vs. 1, using the latter as the bench mark) in ESCs cultured alone. After the ESCs were cultured with IL-6, anti-IL-6, or GM6001 for 24 hours, the indices of cell invasion were not different between the two groups. MMP-2 (median 7.3 vs. 3.5 ng/mL) and TIMP-1 (median 12.1 vs. 3.9 ng/mL), but not MMP-9 and TIMP-2, secreted by ESCs in women with adenomyosis were much higher than those in women without adenomyosis. The formation of adenomyosis does not result from altered invasiveness of ESCs. The concomitant elevation of MMP-2 and TIMP-1 may partially justify why invasiveness was not increased, but other enzymes should also be considered.