Publications (11)47.12 Total impact
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Article: Constitutive proteasomal degradation of TWIST-1 in epithelial-ovarian cancer stem cells impacts differentiation and metastatic potential.
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ABSTRACT: Epithelial-mesenchymal transition (EMT) is a critical process for embryogenesis but is abnormally activated during cancer metastasis and recurrence. This process enables epithelial cancer cells to acquire mobility and traits associated with stemness. It is unknown whether epithelial stem cells or epithelial cancer stem cells are able to undergo EMT, and what molecular mechanism regulates this process in these specific cell types. We found that epithelial-ovarian cancer stem cells (EOC stem cells) are the source of metastatic progenitor cells through a differentiation process involving EMT and mesenchymal-epithelial transition (MET). We demonstrate both in vivo and in vitro the differentiation of EOC stem cells into mesenchymal spheroid-forming cells (MSFCs) and their capacity to initiate an active carcinomatosis. Furthermore, we demonstrate that human EOC stem cells injected intraperitoneally in mice are able to form ovarian tumors, suggesting that the EOC stem cells have the ability to 'home' to the ovaries and establish tumors. Most interestingly, we found that TWIST-1 is constitutively degraded in EOC stem cells, and that the acquisition of TWIST-1 requires additional signals that will trigger the differentiation process. These findings are relevant for understanding the differentiation and metastasis process in EOC stem cells.Oncogene advance online publication, 20 February 2012; doi:10.1038/onc.2012.33.Oncogene 02/2012; · 6.37 Impact Factor -
Article: TWISTing stemness, inflammation and proliferation of epithelial ovarian cancer cells through MIR199A2/214.
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ABSTRACT: Cancer stem cells are responsible for sustaining the tumor and giving rise to proliferating and progressively differentiating cells. However, the molecular mechanisms regulating the process of cancer stem cell (CSC) differentiation is not clearly understood. Recently, we reported the isolation of the epithelial ovarian cancer (EOC) stem cells (type I/CD44+). In this study, we show that type I/CD44+ cells are characterized by low levels of both miR-199a and miR-214, whereas mature EOC cells (type II/CD44-) have higher levels of miR-199a and miR-214. Moreover, these two micro RNAs (miRNAs) are regulated as a cluster on pri-miR-199a2 within the human Dnm3os gene (GenBank FJ623959). This study identify Twist1 as a regulator of this unique miRNA cluster responsible for the regulation of the IKKbeta/NF-kappaB and PTEN/AKT pathways and its association of ovarian CSC differentiation. Our data suggest that Twist1 may be an important regulator of 'stemness' in EOC cells. The regulation of MIR199A2/214 expression may be used as a potential therapeutic approach in EOC patients.Oncogene 06/2010; 29(24):3545-53. · 6.37 Impact Factor -
Article: Regulation of IKKbeta by miR-199a affects NF-kappaB activity in ovarian cancer cells.
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ABSTRACT: Cancer progression is an abnormal form of tissue repair characterized by chronic inflammation. IkappaB kinase-beta (IKKbeta) required for nuclear factor-kappaB (NF-kappaB) activation plays a critical role in this process. Using EOC cells isolated from malignant ovarian cancer ascites and solid tumors, we identified IKKbeta as a major factor promoting a functional TLR-MyD88-NF-kappaB pathway that confers to EOC cell the capacity to constitutively secrete proinflammatory/protumor cytokines and therefore promoting tumor progression and chemoresistance. Furthermore, we describe for the first time the identification of the microRNA hsa-miR-199a as a regulator of IKKbeta expression. Our study describes the property of ovarian cancer cells to enhance the inflammatory microenvironment as a result of the expression of an active IKKbeta pathway. Identification of these markers in patients' tumor samples may facilitate the adequate selection of treatment and open new venues for the development of effective therapy for chemoresistant ovarian cancers.Oncogene 05/2008; 27(34):4712-23. · 6.37 Impact Factor -
Article: Extrarenal Wilms' tumor of the uterine corpus.
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ABSTRACT: Extrarenal Wilms' tumors (EWT) are rare. In the female genital tract, only 15 cases (6 adults, 9 children) of EWT have been reported. A case of uterine Wilms' tumor in an adult is presented with a review of the literature. A 44-year-old woman presented with a bleeding polypoid cervical mass. Biopsy revealed EWT. She was surgically staged, received chemotherapy, and is without evidence of disease at 1 year follow-up. Prognosis and treatment of EWT may differ by location and patient age. Literature review of uterine Wilms' tumor reveals favorable outcome with (1) focal disease confined to the uterus and (2) adequate surgery, including hysterectomy. The National Wilms' Tumor Study Group recommends adjuvant chemotherapy for all EWT. Radiation may be reserved for patients with residual, metastatic and/or recurrent disease.Gynecologic Oncology 04/2005; 96(3):892-6. · 3.89 Impact Factor -
Article: Detection of telomerase-positive circulating epithelial cells in ovarian cancer patients.
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ABSTRACT: The aim of this study is the detection of circulating tumor cells in peripheral blood of ovarian cancer patients. We applied immunomagnetic beads coated with an epithelial or leukocyte-specific antibody to isolate epithelial cells from peripheral blood and we measured their telomerase activity. Both enrichment methods showed high sensitivity and specificity to isolate ovarian tumor cells from peripheral blood. Our data also suggested that disseminated ovarian tumor cells isolated from ascites consistently express telomerase enzyme. We have tested epithelial cell enriched blood samples from 20 stage III patients, 8 stage IV patients and 30 healthy volunteers for telomerase activity. Telomerase activity was detectable in the blood samples of all stage IV patients (100%) and seven stage m patients (35%), but none of the healthy donors. Our results showed that CA-125 level, an established diagnostic marker for ovarian cancer, is significantly higher in telomerase-positive patients than telomerase-negative patients. In summary, our data demonstrated that this non-invasive blood test is sensitive and specific for detecting disseminated ovarian epithelial cells and telomerase is a potential marker for the detection of circulating ovarian tumor cells.Cancer Detection and Prevention 02/2002; 26(2):158-67. · 2.52 Impact Factor -
Article: Ovarian epithelial carcinoma tyrosine phosphorylation, cell proliferation, and ezrin translocation are stimulated by interleukin 1alpha and epidermal growth factor.
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ABSTRACT: Ezrin is a member of the ezrin, radixin, and moesin family. These proteins are membrane-actin cross-linking proteins. Furthermore, ezrin is an important signal transduction protein that undergoes phosphorylation and translocation on stimulation by growth factors. Ezrin phosphorylation and translocation are thought to be correlated with cell motility, invasion, and carcinoma metastasis. Recently, the authors reported that an ezrin antisense phosphorothionate could significantly inhibit endometrial carcinoma cells' penetration in the Matrigel membrane cancer invasion assay. In the current study, the authors measured ezrin content in clinical ovarian epithelial carcinoma (OVCA) specimens and cell lines and investigated whether interleukin (IL)-1alpha and epidermal growth factor (EGF) induce an invasive phenotype in OVCA cells via ezrin phosphorylation and translocation. Twenty-five normal ovary, 25 primary OVCA, 21 metastatic OVCA tissue (7 in omentum, 16 in ascites), and 3 OVCA cell lines were collected for Western blot detection of ezrin content. The OVCA cell line SKOV3 was treated with IL-1alpha or EGF. Indirect immunofluorescence staining followed by confocal laser scanning and double-staining electron microscopic immunohistochemistry were used to investigate changes in the intracellular distribution of ezrin and cell morphology after IL-1alpha or EGF treatment. The content of ezrin was measured by Western blotting and analyzed by the National Institutes of Health Image computer program. Immunoprecipitation and Western blot techniques were used for ezrin phosphorylation studies. Genistein was used to block tyrosine phosphorylation. (1) Ezrin was overexpressed in OVCA, with the highest values in metastases. (2) Interleukin-1alpha and EGF significantly increased OVCA tyrosine phosphorylation, ezrin translocation, and cell growth. (3) These effects were abolished by treatment with the tyrosine kinase inhibitor, genistein. (4) Treatment with IL-1alpha or EGF induced an invasive phenotype, i.e., membrane ruffling, and process formation. High expression and activation of ezrin appear to be related to OVCA metastatic behavior. Interleukin-1alpha and EGF may regulate OVCA invasive behavior by activating ezrin tyrosine phosphorylation, translocation, and cancer cell proliferation. The authors' results may partially explain why OVCA patients with positive macrophage colony stimulating factor (a chemoattractant of IL-1alpha secreting monocytes) or EGF receptors (c-erb B-2) have a poor prognosis.Cancer 01/2002; 92(12):3068-75. · 4.77 Impact Factor -
Article: The use of the L-plastin promoter for adenoviral-mediated, tumor-specific gene expression in ovarian and bladder cancer cell lines.
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ABSTRACT: A 2.4-kb truncated L-plastin promoter was inserted either 5' to the LacZ gene (Ad-Lp-LacZ) or 5' to the cytosine deaminase (CD) gene (Ad-Lp-CD) in a replication-incompetent adenoviral vector backbone. Infectivity and cytotoxicity experiments with the LacZ and CD vectors suggested that the L-plastin promoter-driven transcriptional units were expressed at much higher levels in explants of ovarian cancer cells from patients and in established ovarian or bladder cancer cell lines than they were in normal peritoneal mesothelial cells from surgical specimens, in organ cultures of normal ovarian cells, or in the established CCD minimal deviation fibroblast cell line. Control experiments showed that this difference was not attributable to the lack of infectivity of the normal peritoneal cells, the normal ovarian cells, or the minimal deviation CCD fibroblast cell line, because these cells showed expression of the LacZ reporter gene when exposed to the replication-incompetent adenoviral vector carrying the cytomegalovirus (CMV)-driven LacZ gene (Ad-CMV-LacZ). The Ovcar-5 and Skov-3 ovarian cancer cell lines exposed to the Ad-Lp-CD adenoviral vector were much more sensitive to the prodrug 5-fluorocytosine (5FC), which is converted from the 5FC prodrug into the toxic chemical 5-fluorouracil, than was the CCD minimal deviation fibroblast cell line after exposure to the same vector. A mouse xenograft model was used to show that the Ad-Lp-CD vector/5FC system could prevent engraftment of ovarian cancer cells in nude mice. Finally, injection of the Ad-Lp-CD vector into s.c. tumor nodules generated a greater reduction of the size of the tumor nodules than did injection of the Ad-CMV-LacZ vectors into tumor nodules. The Ad-Lp-CD vectors were as suppressive to tumor growth as the Ad-CMV-CD vectors. These results suggest that an adenoviral vector carrying the CD gene controlled by the L-plastin promoter (Ad-Lp-CD) may be of potential value for the i.p. therapy of ovarian cancer.Cancer Research 07/2001; 61(11):4405-13. · 7.86 Impact Factor -
Article: Absence of estrogen receptor-beta expression in metastatic ovarian cancer.
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ABSTRACT: To evaluate the expression of estrogen receptor (ER)alpha and ERbeta mRNA and protein in normal ovarian tissue and primary and metastatic tumors. Estrogen receptor alpha and ERbeta expression was studied in normal ovarian biopsies (n = 9) and primary (n = 8) and metastatic ovarian epithelial cancers (n = 8). Ovarian tissue was collected from surgical samples. Estrogen receptor alpha and ERbeta mRNA expression was compared by coamplification of the mRNA of the ERs. Expression was confirmed at the protein level by Western blot analysis using antibodies specific for each receptor. Among eight primary ovarian cancer samples, three had only ERalpha, two had only ERbeta, and three had both. All eight metastatic ovarian cancer tissues expressed only ERalpha mRNA and protein. Biopsies from normal ovaries had ERalpha and ERbeta mRNA and protein. Two of the ovarian epithelial cancer samples were paired and showed the same results. We found varying amounts of ERalpha and ERbeta in normal ovaries, lower levels of ERbeta expression in ovarian epithelial cancer primary tumors, and only ERalpha in metastatic tumors. Our findings indicate that a fundamental difference might exist between primary and metastatic cells, which could be caused by intrinsic or extrinsic factors that regulate ER gene expression.Obstetrics and Gynecology 10/2000; 96(3):417-21. · 4.73 Impact Factor -
Article: Ezrin, a membrane-cytoskeletal linking protein, is involved in the process of invasion of endometrial cancer cells.
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ABSTRACT: In order to study ezrin function in tumor growth and invasion, we used two cell lines of human endometrial cancers. Ishikawa, the low-metastatic endometrial cancer cell line, and its subclone (mEIIL) with high-metastatic activity and higher ezrin expression were treated with a ezrin antisense phosphorothioate oligonucleotides (ePONs) pulse four times before the in vitro growth assay and Matrigel invasion assay. ePONs significantly suppressed the number of both cells that penetrated through Matrigel membrane (inhibition rate; 40.1 +/- 7.5% (Ishikawa), 42.7 +/- 2.4% (mEIIL), mean +/- SD, n = 6, P < 0.05, Student's t-test), whereas they showed no effect on cell proliferation. Ezrin expression at the protein level was inhibited by ePONs. These data suggest that ezrin expression is required for invasion. The association of high ezrin expression in mEIIL and its higher ability to migrate through Matrigel may at least in part indicate functional significance of ezrin in endometrial cancer metastasis.Cancer Letters 12/1999; 147(1-2):31-8. · 4.24 Impact Factor -
Article: Prevalence of epithelial ovarian cancer stem cells correlates with recurrence in early-stage ovarian cancer
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ABSTRACT: Epithelial ovarian cancer stem cells (EOC stem cells) have been associated with recurrence and chemoresistance. CD44 and CK18 are highly expressed in cancer stem cells and function as tools for their identification and characterization. We investigated the association between the number of CD44+ EOC stem cells in ovarian cancer tumors and progression-free survival. EOC stem cells exist as clusters located close to the stroma forming the cancer stem cell "niche". 17.1% of the samples reveled high number of CD44+ EOC stem cells (>20% positive cells). In addition, the number of CD44+ EOC stem cells was significantly higher in patients with early-stage ovarian cancer (FIGO I/II), and it was associated with shorter progression-free survival (P = 0.026). This study suggests that quantification of the number of EOC stem cells in the tumor can be used as a predictor of disease and could be applied for treatment selection in early-stage ovarian cancerJ.Oncol. 2011. -
Article: Molecular phenotyping of human ovarian cancer stem cells unravels the mechanisms for repair and chemoresistance
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ABSTRACT: A major burden in the treatment of ovarian cancer is the high percentage of recurrence and chemoresistance. Cancer stem cells (CSCs) provide a reservoir of cells that can self-renew, can maintain the tumor by generating differentiated cells [non-stem cells (non-CSCs)] which make up the bulk of the tumor and may be the primary source of recurrence. We describe the characterization of human ovarian cancer stem cells (OCSCs). These cells have a distinctive genetic profile that confers them with the capacity to recapitulate the original tumor, proliferate with chemotherapy, and promote recurrence. CSC identified in EOC cells isolated form ascites and solid tumors are characterized by: CD44+, MyD88+, constitutive NFkappaB activity and cytokine and chemokine production, high capacity for repair, chemoresistance to conventional chemotherapies, resistance to TNFalpha-mediated apoptosis, capacity to form spheroids in suspension, and the ability to recapitulate in vivo the original tumor. Chemotherapy eliminates the bulk of the tumor but it leaves a core of cancer cells with high capacity for repair and renewal. The molecular properties identified in these cells may explain some of the unique characteristics of CSCs that control self-renewal and drive metastasis. The identification and cloning of human OCSCs can aid in the development of better therapeutic approaches for ovarian cancer patientsCell Cycle. 8(1).
Top Journals
- Oncogene (3)
- Cancer (1)
- Cancer Research (1)
- Obstetrics and Gynecology (1)
- Gynecologic Oncology (1)
Institutions
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2008–2012
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Yale University
- • Department of Obstetrics, Gynecology and Reproductive Sciences
- • Department of Molecular, Cellular and Developmental Biology
New Haven, CT, USA
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2000
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Yale-New Haven Hospital
New Haven, CT, USA
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