RESUMEN
Endometriosis is a chronic inflammatory gynecological disorder regulated by estrogen and characterized by the growth of endometrial tissue outside the uterus. We have previously demonstrated that mesenchymal stem cells (MSCs) contribute directly to endometriosis. Here, we investigated an indirect effect; we hypothesized that MSCs may also impact the bone marrow (BM) by regulating bone marrow-derived inflammatory cells. Endometriosis was induced in mice by transplanting uterine tissue into recipient mice followed by BM transplant. Control or MSC conditioned BM was injected retro-orbitally. Direct administration of MSCs outside of the setting of BM conditioning did not alter endometriosis. Coculture of an undifferentiated macrophage cell line with MSCs in vitro led to a reduction of M1 and increased M2 macrophages as determined by fluorescence-activated cell sorting and western blot. Conditioning of BM with MSCs and transplantation into a mouse model inhibited endometriotic lesion development and reduced lesion volume by sevenfold compared to BM transplant without MSCs conditioning. Immunohistochemistry and immunofluorescence showed that MSC conditioned BM reduced the infiltration of macrophages and neutrophils into endometriotic lesions by twofold and decreased the proportion of M1 compared to M2 macrophages, reducing inflammation and likely promoting tissue repair. Expression of several inflammatory markers measured by quantitative real-time polymerase chain reaction, including tumor necrosis factor alpha and CXCR4, was decreased in the conditioned BM. Donor MSCs were not detected in recipient BM or endometriotic lesions, suggesting that MSCs actively program the transplanted BM. Taken together, these data show that individual characteristics of BM have an unexpected role in the development of endometriosis. BM remodeling and alterations in the inflammatory response are also potential treatments for endometriosis. Identification of the molecular basis for BM programing by MSCs will lead to a better understanding of the immune system contribution to this disease and may lead to new therapeutic targets for endometriosis.
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Desmoplastic reaction (DR) and inflammation are significant pathological manifestations of tumorigenesis in several cancers. However, the correlation between these stromal reactions and cervical adenocarcinoma has been poorly documented. This investigation elucidated whether DR is a prognostic indicator in early cervical adenocarcinoma patients. Fifty-nine patients with early stage cervical adenocarcinoma (stages I/II) were included in the study. DR was divided into three groups, mature, intermediate, and immature, based on the presence of myxoid stroma and hyalinized keloid-like collagen. Inflammatory cell responses were classified as mild, moderate, and severe. Those stromal reactions were separately evaluated in the invasion front stroma and intratumoral stroma. In both the intratumor and invasion front stroma, intermediate/immature DR was correlated with tumor size, T stage, N stage, lymphovascular invasion, and parametrial infiltration (p < 0.001 to p < 0.05). In addition, in the intratumoral stroma, intermediate/immature DR led to short relapse-free survival and overall survival (p < 0.001). In the invasion front stroma, inflammatory cell responses were associated with DR immaturity and FIGO stage (p < 0.01). These results suggest that the classification of DR maturity is a potential prognostic biomarker in early stage cervical adenocarcinoma patients. DR can be evaluated by routine H&E staining without immunohistochemistry, making it convenient and economical in clinical practice.
Asunto(s)
Adenocarcinoma , Neoplasias Colorrectales , Neoplasias del Cuello Uterino , Humanos , Femenino , Neoplasias Colorrectales/patología , Estadificación de Neoplasias , Células del Estroma , Pronóstico , Colágeno , Adenocarcinoma/diagnóstico , Adenocarcinoma/patología , Factores Inmunológicos , Biomarcadores , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Estudios RetrospectivosRESUMEN
Preterm birth is a major contributor to neonatal mortality and morbidity. Infection results in elevation of inflammation-related cytokines followed by infiltration of immune cells into gestational tissue. CXCL12 levels are elevated in preterm birth indicating it may have a role in preterm labour (PTL); however, the pathophysiological correlations between CXCL12/CXCR4 signalling and premature labour are poorly understood. In this study, PTL was induced using lipopolysaccharide (LPS) in a murine model. LPS induced CXCL12 RNA and protein levels significantly and specifically in myometrium compared with controls (3-fold and 3.5-fold respectively). Highest levels were found just before the start of labour. LPS also enhanced the infiltration of neutrophils, macrophages and T cells, and induced macrophage M1 polarization. In vitro studies showed that condition medium from LPS-treated primary smooth muscle cells (SMC) induced macrophage migration, M1 polarization and upregulated inflammation-related cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor alpha (TNF-α). AMD3100 treatment in pregnant mice led to a significant decrease in the rate of PTL (70%), prolonged pregnancy duration and suppressed macrophage infiltration into gestation tissue by 2.5-fold. Further, in-vitro treatment of SMC by AMD3100 suppressed the macrophage migration, decreased polarization and downregulated IL-1, IL-6 and TNF-α expression. LPS treatment in pregnant mice induced PTL by increasing myometrial CXCL12, which recruits immune cells that in turn produce inflammation-related cytokines. These effects stimulated by LPS were completely reversed by AMD3100 through blocking of CXCL12/CXCR4 signalling. Thus, the CXCL12/CXCR4 axis presents an excellent target for preventing infection and inflammation-related PTL.
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Trabajo de Parto Prematuro , Nacimiento Prematuro , Animales , Quimiocina CXCL12/metabolismo , Citocinas/metabolismo , Femenino , Humanos , Inflamación/metabolismo , Interleucina-6/metabolismo , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/metabolismo , Ratones , Miometrio/metabolismo , Trabajo de Parto Prematuro/genética , Embarazo , Nacimiento Prematuro/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND: Epidemiologic studies have demonstrated an association between endometriosis and the subsequent development of cardiovascular disease. The direct effect of endometriosis on the progression of atherosclerotic, if any, has not been previously characterized. Endometriosis leads to systemic inflammation that could have consequences for cardiovascular health. Here, we reported the effects of endometriosis on the development of atherosclerosis in a murine model. OBJECTIVE: This study aimed to determine the contribution of endometriosis in promoting cardiovascular disease in a murine model of endometriosis. STUDY DESIGN: Endometriosis was induced in 18 apolipoprotein E-null mice, the standard murine model used to study atherosclerosis. Mice of the same strain were used as controls (n=18) and underwent sham surgery without inducing endometriosis. The formation of endometriotic lesions was confirmed after 25 weeks of induction. Atherosclerotic lesions were subjected to hematoxylin and eosin staining followed by measurement of the aortic root luminal area and wall thickness. The whole aorta was isolated, and Oil Red O staining was performed to quantify the lipid deposits or plaque formation; moreover, biochemical assays were carried out in serum to determine the levels of lipids and inflammatory-related cytokines. RESULTS: Apolipoprotein E mice with endometriosis exhibited increased aortic atherosclerosis compared with controls as measured using Oil Red O staining (7.9% vs 3.1%, respectively; P=.0004). Mice with endometriosis showed a significant 50% decrease in the aortic luminal area compared with sham mice (0.85 mm2 vs 1.46 mm2; P=.03) and a significant increase in aortic root wall thickness (0.22 mm vs 0.15 mm; P=.04). There was no difference in the lipoprotein profile (P<.05) between mice with endometriosis and sham mice. The serum levels of inflammatory cytokines interleukin 1 alpha, interleukin 6, interferon gamma, and vascular endothelial growth factor were significantly (P<.05)increased in the endometriosis mice. CONCLUSION: Our study used a murine model to determine the effect of endometriosis on atherosclerosis. Inflammation-related cytokines interleukin 1 alpha, interleukin 6, interferon gamma, and vascular endothelial growth factor (angiogenic factor) released by endometriotic lesions may contribute to the increased cardiovascular risks in women with endometriosis. To reduce the risk of cardiovascular disease, early identification and treatment of endometriosis are essential. Future treatments targeting inflammatory cytokines may help reduce the long-term risk of cardiovascular disease in women with endometriosis.
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Aterosclerosis , Enfermedades Cardiovasculares , Endometriosis , Placa Aterosclerótica , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Inflamación/metabolismo , Interferón gamma , Interleucina-1alfa , Interleucina-6 , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor A de Crecimiento Endotelial VascularRESUMEN
Endometriosis is a gynecological disease affecting 6-10% of women of reproductive age. In addition to gynecologic symptoms, endometriosis is associated with various systemic effects, including inflammation, altered body weight, and behavioral changes. Previous murine studies demonstrate that endometriosis is causally inked to increased pain sensitization, behavioral changes, and low body mass index (BMI). One possible cellular target that may mediate some of these findings is the hypocretin/orexin neurons. This neuronal system plays a role in regulating wakefulness/sleep cycles, pain perception, and appetite. We hypothesize that endometriosis alters activity level of the hypocretin/orexin (Hcrt) neuronal system. Mice underwent endometriosis induction surgeries (endo) or sham surgeries (sham) for the development of the experimental model. Immunocytochemistry was performed on harvested samples from the lateral hypothalamus, and activation levels of Hcrt cells were examined by quantifying the expression of phosphorylation of cAMP-responsive element binding protein (CREB) in these cells after an acute stress in sham and endo mice. Mice with endometriosis had greater Hcrt neurons activation than sham mice. Mice with endometriosis fed with high fat diet showed a lower fat/body weight and fat/lean tissue ratio compared to mice without endometriosis. There was no significant difference in food intake between sham and endometriosis mice. These results demonstrate that endometriosis is associated with low body mass and increased hypocretin/orexin activity, which could be implicated in the behavioral changes and to differences in body composition.
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Endometriosis/metabolismo , Área Hipotalámica Lateral/metabolismo , Neuronas/metabolismo , Orexinas/metabolismo , Animales , Peso Corporal/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Femenino , RatonesRESUMEN
Endometriosis is an estrogen-dependent, inflammatory gynecological disorder characterized by the growth of endometrial cells in lesions outside the uterus. Bone marrow-derived cells (BMDCs) engraft lesions and increase lesion size. Do endometriosis cells regulate differentiation of engrafted BMDCs in the pathogenesis and growth of endometriosis? Here, we report endometriosis derived stromal cells promote the differentiation of BMDCs to stromal, epithelial and leukocyte cell fates through paracrine signaling. In-vitro studies demonstrated that both mRNA and protein levels of vimentin, cytokeratin and PD-1 were significantly increased in BMDCs cocultured with stromal cells from endometriosis (ENDO) patients compared to stromal cells from normal endometrium (CNTL). Increased expression of PD-1 has been reported in malignancy where it promotes T cell quiescence and immune tolerance. Increased PD-1 was also confirmed in-vivo where we showed that PD-1 expression was induced in BMDCs engrafted into endometriotic lesions in a murine model of endometriosis. AMD3100, an antagonist for CXCR4 receptor inhibited PD-1 expression in BMDCs suggesting that PD-1 induction requires CXCL12. These results suggest that endometriosis stimulated BMDC differentiation through paracrine signaling and increased T cell PD-1 expression. Increased PD-1 expression may be one mechanism by which endometriosis avoids immune surveillance.
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Células de la Médula Ósea/metabolismo , Diferenciación Celular , Endometriosis/metabolismo , Regulación de la Expresión Génica , Células Madre Mesenquimatosas/metabolismo , Comunicación Paracrina , Receptor de Muerte Celular Programada 1/biosíntesis , Adolescente , Adulto , Células de la Médula Ósea/patología , Técnicas de Cocultivo , Endometriosis/patología , Femenino , Humanos , Persona de Mediana Edad , Células del Estroma/metabolismo , Células del Estroma/patologíaRESUMEN
Endometriosis is an estrogen-dependent gynecological disorder that affects 10% of reproductive-aged women and causes pelvic pain and infertility. Bone marrow-derived stem cells (BMDCs) are known to engraft endometriosis in association with lesion growth; however, they do not undergo significant clonal expansion. The indirect effects of BMDCs on endometriosis growth and cell proliferation are not well characterized. Here, we demonstrate that BMDCs' co-culture increased endometrial stromal cell proliferation. In vitro studies using endometrial cells showed that BMDCs increased cell proliferation and activation of CDK1 in both an endometriosis cell line and primary endometrial stromal cells from women with endometriosis, however not in normal endometrial cells. In vivo studies using a mouse model of endometriosis showed increased CDK1+ expression associated with engrafted GFP + BMDCs. These results suggest that endometrial cell proliferation is induced by stem cell-derived trophic factors leading to the growth of endometriotic lesions. Targeting the specific signaling molecules secreted by BMDC may lead to novel therapeutic strategies for controlling cell proliferation in endometriosis.
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Proliferación Celular , Endometriosis/metabolismo , Endometrio/metabolismo , Células Madre Mesenquimatosas/metabolismo , Comunicación Paracrina , Células del Estroma/metabolismo , Animales , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Endometriosis/genética , Endometriosis/patología , Endometrio/patología , Femenino , Humanos , Trasplante de Células Madre Mesenquimatosas , Ratones Endogámicos C57BL , Transducción de Señal , Células del Estroma/patologíaRESUMEN
Endometrial cancer is a leading cause of cancer-associated mortality in women and has a poor prognosis in advanced stages. Our previous study revealed that BCL-2-associated athanogene 3 (BAG3) may contribute to enhancing cell viability through downregulation of microRNA (miR)-29b in endometrial cancer cell lines. In addition, a relationship between estrogen receptor α (ERα) and BAG3 was recently reported in several cancer cell types. The present study investigated the relationship between ERα and BAG3 in endometrial cancer cell lines. The results demonstrated that exogenous ERα overexpression enhanced BAG3 expression in the EMTOKA endometrial cancer cell line, which does not endogenously express ERα, but had no effect on BAG3 expression levels in the Ishikawa cell line, which does endogenously express ERα. In addition, ERα overexpression suppressed miR-29b expression and enhanced the expression of Mcl-1, a mediator situated downstream of BAG3, in EMTOKA cells, but not Ishikawa cells. ERα overexpression also enhanced EMTOKA, but not Ishikawa, endometrial cancer cell viability in the presence of cisplatin. These findings suggested that ERα may contribute to enhancing endometrial cancer cell resistance to anticancer agents through BAG3 overexpression.
RESUMEN
Uterine leiomyomas, also known as fibroids or myomas, are a common benign gynecologic tumor found in women of reproductive age. Though advances have been made in understanding leiomyomas, the etiology and pathogenesis of this disease are not fully characterized. Current evidence supports a role of putative human uterine stem/progenitor cells in the onset of uterine disease such as uterine myomas. In this study, we report that increased expression of CXCL12 in leiomyomas recruits bone marrow-derived cells (BMDCs) that may contribute to leiomyoma growth. Tissue was collected from leiomyomas or control myometrium from women with or without leiomyomas. qRT-PCR analysis showed increased expression of CXCL12 and decreased CXCR4 expression in the leiomyoma and myometrium of women with leiomyoma compared with normal myometrium. Increased CXCL12 protein secretion from cultured myoma cells was confirmed by ELISA. Further, we found that BMDCs migration was increased toward leiomyoma conditioned medium compared with conditioned medium from normal myometrium. CXCR4 antagonist AMD3100 completely blocked this migration. Engraftment of BMDCs significantly increased in myoma of mouse uteri treated with CXCL12 compared with placebo. We conclude that CXCL12 may play a role in leiomyomas growth by attracting bone marrow-derived cells to leiomyoma. Therefore, CXCL12 and its receptors are novel targets for leiomyoma therapy.
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Células de la Médula Ósea/metabolismo , Movimiento Celular/fisiología , Quimiocina CXCL12/metabolismo , Leiomioma/metabolismo , Neoplasias Uterinas/metabolismo , Útero/metabolismo , Adulto , Animales , Bencilaminas , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/patología , Movimiento Celular/efectos de los fármacos , Quimiocina CXCL12/antagonistas & inhibidores , Ciclamas , Femenino , Compuestos Heterocíclicos/farmacología , Humanos , Leiomioma/patología , Ratones , Persona de Mediana Edad , Neoplasias Uterinas/patología , Útero/efectos de los fármacos , Útero/patologíaRESUMEN
Adult stem cells have a major role in endometrial physiology, including remodelling and repair. However, they also have a critical role in the development and progression of endometriosis. Bone marrow-derived stem cells engraft eutopic endometrium and endometriotic lesions, differentiating to both stromal and epithelial cell fates. Using a mouse bone marrow transplantation model, we show that bone marrow-derived cells engrafting endometriosis express CXCR4 and CXCR7. Targeting either receptor by the administration of small molecule receptor antagonists AMD3100 or CCX771, respectively, reduced BM-derived stem cell recruitment into endometriosis implants. Endometriosis lesion size was decreased compared to vehicle controls after treatment with each antagonist in both an early growth and established lesion treatment model. Endometriosis lesion size was not effected when the local effects of CXCL12 were abrogated using uterine-specific CXCL12 null mice, suggesting an effect primarily on bone marrow cell migration rather than a direct endometrial effect. Antagonist treatment also decreased hallmarks of endometriosis physiopathology such as pro-inflammatory cytokine production and vascularization. CXCR4 and CXCR7 antagonists are potential novel, non-hormonal therapies for endometriosis.
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Bencilaminas/farmacología , Células de la Médula Ósea/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Ciclamas/farmacología , Endometriosis/tratamiento farmacológico , Endometrio/efectos de los fármacos , Receptores CXCR4/antagonistas & inhibidores , Receptores CXCR/antagonistas & inhibidores , Células Madre Adultas/efectos de los fármacos , Células Madre Adultas/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Trasplante de Médula Ósea/métodos , Endometriosis/metabolismo , Endometrio/metabolismo , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal/efectos de los fármacos , Útero/efectos de los fármacos , Útero/metabolismoRESUMEN
Paclitaxel in combination with carboplatin improves survival among patients with susceptible ovarian cancers, but no strategy has been established against resistant ovarian cancers. BAG3 (Bcl-2-associated athanogene 3) is one of six BAG family proteins, which are involved in such cellular processes as proliferation, migration and apoptosis. In addition, expression of BAG3 with Mcl-1, a Bcl-2 family protein, reportedly associates with resistance to chemotherapy. Our aim in this study was to evaluate the functional role of BAG3 and Mcl-1 in ovarian cancer chemoresistance and explore possible new targets for treatment. We found that combined expression of BAG3 and Mcl-1 was significantly associated with a poor prognosis in ovarian cancer patients. In vitro, BAG3 knockdown in ES2 clear ovarian cancer cells significantly increased the efficacy of paclitaxel in combination with the Mcl-1 antagonist MIM1, with or without the Bcl-2 family antagonist ABT737. Moreover, BAG3 was found to positively regulate Mcl-1 levels by binding to and inhibiting USP9X. Our data show that BAG3 and Mcl-1 are key mediators of resistance to chemotherapy in ovarian cancer. In BAG3 knockdown ES2 clear ovarian cancer cells, combination with ABT737 and MIM1 enhanced the efficacy of paclitaxel. These results suggest that inhibiting BAG3 in addition to anti-apoptotic Bcl-2 family proteins may be a useful therapeutic strategy for the treatment of chemoresistant ovarian cancers.
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Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Resistencia a Antineoplásicos/genética , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/biosíntesis , Neoplasias Ováricas/tratamiento farmacológico , Ubiquitina Tiolesterasa/biosíntesis , Proteínas Adaptadoras Transductoras de Señales/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/biosíntesis , Línea Celular Tumoral , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Paclitaxel/administración & dosificación , Ubiquitina Tiolesterasa/genéticaRESUMEN
INTRODUCTION: Placenta percreta is associated with maternal morbidity and mortality. A hysterectomy is often needed to control the bleeding in such cases. However, it has been advocated that placenta percreta be managed conservatively to avoid massive pelvic bleeding and to preserve the patient's fertility. Here, we present a case of placenta percreta diagnosed by magnetic resonance imaging, and treated with systemic administration of methotrexate. CASE PRESENTATION: A 27-year-old nulliparous Japanese woman at 39 gestational weeks had an uncomplicated vaginal delivery of a 3244-g infant. However, her placenta was not delivered, and we could not remove it manually. Contrast-enhanced magnetic resonance imaging indicated deep myometrial invasion by placental tissue and the whole placenta was strongly enhanced. Seven days post-partum, her serum human chorionic gonadotropin level was 12,656IU/L. Our patient hoped to preserve her uterus for a future pregnancy. She therefore received 13 courses of methotrexate (50mg/week, intravenous injection). Her serum human chorionic gonadotropin level was undetectable 97 days after the first methotrexate injection. At 117 days post-partum, she had a labor-like pain every three minutes and delivered the placenta. Our patient regained normal menses and at follow-up remained in good health. Two years later, she delivered a healthy daughter. CONCLUSION: We should try to detect placenta percreta in high-risk patients by any means. For low-risk patients, we should give a diagnosis swiftly and control any intrauterine infection and massive bleeding.
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Metotrexato/administración & dosificación , Oxitócicos/administración & dosificación , Placenta Accreta/diagnóstico , Placenta Accreta/tratamiento farmacológico , Adulto , Gonadotropina Coriónica/sangre , Femenino , Fertilidad/fisiología , Humanos , Imagen por Resonancia Magnética , Periodo Posparto , Embarazo , Nacimiento a TérminoRESUMEN
Approximately 30% of uterine corpus carcinomas are diagnosed at an advanced stage and have a poor prognosis. Our previous study indicated that BCL2-associated athanogene 3 (BAG3) enhances matrix metalloproteinase-2 (MMP2) expression and binds to MMP2 to positively regulate the process of cell invasion in ovarian cancer cells. Recently, altered miRNA expression patterns were observed in several groups of patients with endometrial cancers. One of the altered miRNAs, miR-29b, reportedly reduces tumor invasiveness by suppressing MMP2 expression. Our aim in the present study was to examine the relationships among BAG3, miR-29b and MMP2 in endometrioid adenocarcinoma cells. We found that BAG3 suppresses miR-29b expression and enhances MMP2 expression, which in turn increases cell motility and invasiveness. Moreover, restoration of miR-29b through BAG3 knockdown reduced MMP2 expression, as well as cell motility and invasiveness. Collectively, our findings indicate that BAG3 enhances MMP2 expression by suppressing miR-29b, thereby increasing the metastatic potential of endometrioid adenocarcinomas.
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Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Neoplasias Endometriales/genética , Metaloproteinasa 2 de la Matriz/genética , MicroARNs/genética , Invasividad Neoplásica/genética , Carcinoma Endometrioide/genética , Carcinoma Endometrioide/patología , Línea Celular Tumoral , Movimiento Celular/genética , Neoplasias Endometriales/patología , Femenino , HumanosRESUMEN
OBJECTIVE: Ovarian cancer is the leading cause of death from gynecologic cancer, reflecting its often late diagnosis and its chemoresistance. We identified a set of microRNAs whose expression is altered upon BAG3 knockdown. Our primary objective was to examine the relationships between BAG3, miR-29b and Mcl-1, an antiapoptotic Bcl-2 family protein, in ovarian cancer cells. METHODS: Ovarian cancer cells were cultured and their responsiveness to paclitaxel was tested. Microarray analysis was performed to identify microRNAs differentially expressed in ES2 BAG3 knockdown ovarian cancer cells and their control cells. Primary ovarian cancer tissues were obtained from 56 patients operated on for ovarian cancer. The patients' clinical and pathological data were obtained from their medical records. RESULTS: BAG3 knockdown increased the chemosensitivity to paclitaxel of ES2 ovarian clear cell carcinoma cells to a greater degree than AMOC2 serous adenocarcinoma cells. qRT-PCR analysis showed that miR-29b expression was significantly upregulated in primary cancer tissue expressing low levels of BAG3, as compared to tissue expressing high levels. Moreover, levels of miR-29b correlated significantly with progression-free survival. Upregulation of miR-29b also reduced levels of Mcl-1 and sensitized ES2 cells to low-dose paclitaxel. CONCLUSIONS: BAG3 knockdown appears to downregulate expression of Mcl-1 through upregulation of miR-29b, thereby increasing the chemosensitivity of ovarian clear cell carcinoma cells. This suggests that BAG3 is a key determinant of the responsiveness of ovarian cancer cells, especially clear cell carcinoma, to paclitaxel and that BAG3 may be a useful therapeutic target for the treatment of ovarian cancer.