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1.
J Nephrol ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31471818

RESUMO

BACKGROUND: Evidence about the reliability of pre-implantation biopsy is still conflicting, depending on both biopsy type and pathologist's expertise. Aim of the study is to evaluate the agreement of general v specialist pathologists and to compare scores on biopsy and whole organs in a set of discarded kidneys. METHODS: 46 discarded kidneys were identified with their corresponding biopsies. The biopsies were reviewed by three general and two specialist pathologists, blinded to the original report, according to Remuzzi score. The intraclass correlation coefficient (ICC) was calculated for both groups. Discarded kidneys were scored according to Remuzzi score by a single specialist pathologist. Biopsies and organs were compared by Wilcoxon signed rank test. Weighted κ coefficients between biopsy and organ scores were also calculated. RESULTS: Specialist pathologists achieved higher values of ICC, reaching excellent or good agreement in most of the parameters, while general pathologists values were mainly fair or good. On whole organs, scores were consistently lower than biopsies, with a significant difference in most of the parameters. Weighted κ coefficient was slight or fair for most of the parameters. CONCLUSIONS: Our data suggests that the creation of a pool of specialist pathologists would improve organ utilization. Moreover, biopsies are not representative of the whole organ. As the Remuzzi score on biopsy is a major reasons for discard, a quota of transplantable kidneys may be erroneously discarded. Refinement in Remuzzi cut-offs based on expert reporting and recognition of sampling error of biopsies in correlation with clinical outcome data should be undertaken.

2.
Chemistry ; 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31432579

RESUMO

Alkoxylation and hydroxylation reactions of 1,5-cyclooctadiene (cod) in an iridium complex with alcohols and water promoted by the reduction of oxygen to hydrogen peroxide are described. The exo configuration of the OH/OR groups in the products agrees with the nucleophilic attack at the external face of the olefin as the key step. The reactions also require the presence of a coordinating protic acid (such as picolinic acid, Hpic) and involve the participation of a cationic diolefin IrIII complex, [Ir(pic)2(cod)]+, which has been isolated. Independently, this cation is also involved in easy alkoxy group-exchange reactions, which are very unusual for organic ethers. DFT studies on the mechanism of the olefin alkoxylation mediated by oxygen show a low-energy PCET step connecting a superoxide-iridium(II) complex with hydroperoxide-iridium(III) intermediates rather than peroxide complexes. Accordingly, a quite more complex reaction with up to four different products occurred on reacting the diolefin-peroxide iridium(III) complex with picolinic acid. Moreover, such hydroperoxide intermediates are the origin of the regio- and stereo-selectivity of the hydroxylation/alkoxylation reactions. If this protocol was applied to the diolefin-rhodium(I) complex [Rh(pic)(cod)] the free alkyl ethers resulted, and the reaction is enantioselective if a chiral aminoacid such as L-proline is used instead of Hpic.

3.
Chem Commun (Camb) ; 55(69): 10281-10284, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31396607

RESUMO

We report two ligand-controlled cascade reactions relying on the intramolecular carbopalladation of skipped dienes. The use of a bulky monodentate phosphine ligand affords [4,5]-spirocycles via sequential double carbopalladation, however bidentate phosphines promote a remote ß-C-elimination process which does not rely on the use of strained or sterically hindered substrates.

4.
Nat Commun ; 10(1): 3690, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31417086

RESUMO

Associative memory is the main type of learning by which complex organisms endowed with evolved nervous systems respond efficiently to certain environmental stimuli. It has been found in different multicellular species, from cephalopods to humans, but never in individual cells. Here we describe a motility pattern consistent with associative conditioned behavior in the microorganism Amoeba proteus. We use a controlled direct-current electric field as the conditioned stimulus, and a specific chemotactic peptide as the unconditioned stimulus. The amoebae are capable of linking two independent past events, generating persistent locomotion movements that can prevail for 44 min on average. We confirm a similar behavior in a related species, Metamoeba leningradensis. Thus, our results indicate that unicellular organisms can modify their behavior during migration by associative conditioning.

6.
G3 (Bethesda) ; 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31427455

RESUMO

In this paper we propose a Bayesian multi-output regressor stacking (BMORS) model that is a generalization of the multi-trait regressor stacking method proposed by Spyromitros-Xioufis et al. (2012; 2016). The proposed BMORS model consists of two stages: in the first stage, a univariate genomic best linear unbiased prediction (GBLUP including genotype × environment interaction GE) model is implemented for each of the traits under study; then the predictions of all traits are included as covariates in the second stage, by implementing a Ridge regression model. The main objectives of this research were to study alternative models to the existing multi-trait multi-environments (BMTME) with respect to (1) genomic-enabled prediction accuracy and (2) potential advantages in terms of computing resources and implementation. We compared the predictions of the BMORS model to those of the univariate GBLUP model using 7 maize and wheat datasets. We found that the proposed BMORS produced similar predictions to the univariate GBLUP model and to the BMTME model in terms of prediction accuracy; however, the best predictions were obtained under the BMTME model. In terms of computing resources, we found that the BMORS is at least 9 times faster than the BMTME method. Based on our empirical findings, the proposed BMORS model is an alternative for predicting multi-trait and multi-environment data, which are very common in genomic-enabled prediction in plant and animal breeding programs.

7.
Science ; 365(6454): 695-699, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31416963

RESUMO

An essential prerequisite for the survival of an organism is the ability to detect and respond to aversive stimuli. Current belief is that noxious stimuli directly activate nociceptive sensory nerve endings in the skin. We discovered a specialized cutaneous glial cell type with extensive processes forming a mesh-like network in the subepidermal border of the skin that conveys noxious thermal and mechanical sensitivity. We demonstrate a direct excitatory functional connection to sensory neurons and provide evidence of a previously unknown organ that has an essential physiological role in sensing noxious stimuli. Thus, these glial cells, which are intimately associated with unmyelinated nociceptive nerves, are inherently mechanosensitive and transmit nociceptive information to the nerve.

9.
Biofabrication ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31404917

RESUMO

Tunable bioprinting materials are capable of creating a broad spectrum of physiological mimicking 3D models enabling in vitro studies that more accurately resemble in vivo conditions. Tailoring the material properties of the bioink such that it achieves both bioprintability and biomimicry remains a key challenge. Here we report the development of engineered composite hydrogels consisting of gelatin and alginate components. The composite gels are demonstrated as a cell-laden bioink to build 3D bioprinted in vitro breast tumor models. The initial mechanical characteristics of each composite hydrogel are correlated to cell proliferation rates and cell spheroid morphology spanning month long culture conditions. MDA-MB-231 breast cancer cells show gel formulation-dependency on the rates and frequency of self-assembly into multicellular tumor spheroids (MCTSs). Hydrogel compositions comprised of decreasing alginate concentrations, and increasing gelatin concentrations, result in gels that are mechanically soft and contain a greater number of cell-adhesion moieties driving the development of large MCTS; conversely gels containing increasing alginate, and decreasing gelatin concentrations are mechanically stiffer, with fewer cell-adhesion moieties present in the composite gels yielding smaller and less viable MCTS. These composite hydrogels can be used in the biofabrication of tunable in vitro systems that mimic both the mechanical and biochemical properties of the native tumor stroma.

10.
BMJ Open ; 9(8): e027766, 2019 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-31427319

RESUMO

INTRODUCTION: Childhood adversity (CA) has been suggested as a key risk factor for suicidal behaviour, but evidence from low/middle-income countries is lacking. In Sri Lanka, CA, in the form of child maltreatment or as a consequence of maternal separation, has been highlighted in primarily qualitative or case series work, as a potentially important determinant of suicidal behaviour. To date, there have been no quantitative studies to investigate CA as a key exposure associated with suicidal behaviour in Sri Lanka. The aim of the research is to understand the association between CA and suicidal behaviour in Sri Lanka and to identify potentially modifiable factors to reduce any observed increased risk of suicidal behaviour associated with CA. METHODS AND ANALYSIS: This is a hospital-based case-control study. Cases (n=200) will be drawn from individuals admitted to the medical toxicology ward of the Teaching Hospital Peradeniya, Sri Lanka, for medical management of intentional self-poisoning. Sex and age frequency-matched controls (n=200) will be recruited from either patients or accompanying visitors presenting at the outpatient department and clinic of the same hospital for conditions unrelated to the outcome of interest. Conditional logistic regression will be used to investigate the association between CA and deliberate self-poisoning and whether the association is altered by other key factors including socioeconomic status, psychiatric morbidity, current experiences of domestic violence and social support. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Ethical Review Committee of the Faculty of Medicine, University of Peradeniya, Sri Lanka. Researchers have been trained in administering the questionnaire and a participant safety and distress protocol has been designed to guide researchers in ensuring participant safety and how to deal with a distressed participant. Results will be disseminated in local policy fora and peer-reviewed articles, local media, and national and international conferences.

11.
Ital J Pediatr ; 45(1): 104, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426830

RESUMO

BACKGROUND: Vaccination represents one of the most effective means of preventing infections for the population and for the public health in general. Recently there has been a decline in vaccinations, also among healthcare workers (HCWs). The aim of the study is to detect the knowledge, skills, attitudes and barriers of HCWs regarding vaccinations in a tertiary children's hospital in order to support clinical management in immunisation practices. METHODS: An observational study was conducted on 255 subjects over a period of 8 months. The 31-item questionnaire considered profession, level of instruction and different ages. It included questions taken from a questionnaire used for a Canadian research and one used by the Bellinzona hospital. A 4-point Likert scale and closed-ended questions were used. A confidence interval of 95%, p value ≤ 0.05, Chi-square, ANOVA and the Kruskal-Wallis test were considered. RESULTS: In the last 5 years less than one third of the sample were vaccinated against flu. 77.8% (n.130) of nurses and 45.8% (n.19) of doctors were not vaccinated (p < 0.0001). As for risk perception, 51.5% of nurses and 90.6% of doctors believe that their risk of contracting influenza is greater than that of the general population. In relation to the injection site, in all the age ranges there was a high level of knowledge except for those aged over 61 who responded incorrectly. Doctors were more prepared (p < 0.0001). 50% of the sample used internet only as a source of information for vaccines. Generally, scientific sources were used infrequently. The higher the education level, the more frequent the utilisation of trustworthy scientific resources and literature. (p = 0.0002). CONCLUSIONS: In line with the attitude observed in recent years, nurses are not inclined to get vaccinated themselves although they agree to having their children vaccinated. HCWs have a good level of knowledge about vaccines and immunisation practices. With the nurses we found that the higher the education level, the greater the knowledge about vaccines which leads to the conclusion that low levels of adherence are not due to a lack of knowledge, but rather, to a low perception of risks. Hence the need to strengthen the vaccination strategies inside the companies.

12.
FEMS Microbiol Ecol ; 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31437273

RESUMO

Based on modern microbiology, we propose a major revision in current space exploration philosophy and planetary protection policy, especially regarding microorganisms in space. Mainly, microbial introduction should not be considered accidental but inevitable. We hypothesize the near impossibility of exploring new planets without carrying and/or delivering any microbial travelers. In addition, although we highlight the importance of controlling and tracking such contaminations-to explore the existence of extraterrestrial microorganisms-we also believe that we must discuss the role of microbes as primary colonists and assets, rather than serendipitous accidents, for future plans of extraterrestrial colonization. This paradigm shift stems partly from the overwhelming evidence of microorganisms' diverse roles in sustaining life on Earth, such as symbioses and ecosystem services (decomposition, atmosphere effects, nitrogen fixation etc). Therefore, we propose a framework for new discussion based on the scientific implications of future colonization and terraforming: (i) focus on methods to track and avoid accidental delivery of Earth's harmful microorganisms and genes to extraterrestrial areas; (ii), begin a rigorous program to develop and explore 'Proactive Inoculation Protocols' (PIP). We outline a rationale and solicit feedback to drive a public and private research agenda that optimizes diverse organisms for potential space colonization.

13.
Neurocirugía (Soc. Luso-Esp. Neurocir.) ; 30(4): 173-178, jul.-ago. 2019. ilus, tab
Artigo em Inglês | LILACS-Express | ID: ibc-ET2-2311

RESUMO

Background: The classic surgical spinal dural closure technique in surgery on intradural lesions is performed with continuous suture or loose stitches using 4-0 to 6-0 polypropylene monofilament or nylon suture. Dural closure with suture causes irritant damage to the dural/arachnoid interface. The penetrating suture causes new dural holes. Even the needle of the suture can cause harm to the patient and the surgeon. For these reasons, other non-penetrating techniques for dural closure have been sought. Objective: The purpose of this review was to show the efficacy of using the titanium clip (U-clip) (Ligaclip-MCA of Ethicon Endo-Surgery, LLC, Medical GmbH, Norderstedt, Germany) with a flat internal surface in spinal neurosurgical procedures, and to evaluate the effects of its use on post-operative magnetic resonance imaging (MRI). Methods: We performed a retrospective analysis of a cohort of 50 consecutive patients who underwent intradural spinal surgeries for intradural spinal lesions in the neurosurgery department of our institution between 2013 and 2018. Results: The mean follow-up period was 27 months. No patient developed a post-operative cerebrospinal fluid (CSF) dural-cutaneous fistula. CSF leakage was not observed in the control MRIs at 6 weeks. Conclusions: We describe, for the first time, the use of this type of U-clip with a flat inner side. The non-penetrating titanium U-clip facilitates effective and rapid dural closure at all spinal levels due to its flat internal face when closed. The U-clips did not cause significant artefacts or distortions on the magnetic resonance imaging


Introducción: La técnica quirúrgica clásica de cierre de la duramadre espinal en cirugía en lesiones intradurales se realiza con sutura continua o puntos sueltos usando monofilamento de polipropileno 4-0 a 6-0 o sutura de nylon. El cierre dural con sutura causa daño irritante a la interfaz dural/aracnoidea. La sutura penetrante causa nuevos agujeros durales. Incluso la aguja de la sutura puede causar daño al paciente y al cirujano. Por estas razones, se han buscado otras técnicas no penetrantes para el cierre de la duramadre. Objetivo: El propósito de esta revisión fue mostrar la eficacia del uso del clip de titanio (U-Clip(R)) (Ligaclip MCA de Ethicon Endo-Surgery, LLC, Medical GmbH, Norderstedt, Alemania) con una superficie interna plana en procedimientos neuroquirúrgicos espinales, y para evaluar los efectos de su uso en los controles de resonancia magnética (RM) postoperatoria. Métodos: Se realizó un análisis retrospectivo de una cohorte de 50 pacientes consecutivos que se sometieron a cirugías intradurales espinales en el departamento de neurocirugía de nuestra institución entre 2013 y 2018. Resultados: El período medio de seguimiento fue de 27 meses. Ningún paciente desarrolló fístula dural-cutánea del líquido cefalorraquídeo (LCR) postoperatoria. No se observó fuga del LCR en las RM de control a las 6 semanas. Conclusiones: Describimos, por primera vez, el uso de este tipo U-Clip(R) con un lado interior plano. El U-Clip(R) de titanio no penetrante facilita el cierre dural efectivo y rápido en todos los niveles espinales debido a su cara interna plana cuando está cerrado. Los U-Clip(R) no causaron artefactos o distorsiones significativas en la RM

14.
Med Clin (Barc) ; 2019 Jun 26.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31255365

RESUMO

BACKGROUND AND OBJECTIVE: This paper aims to describe the type of foot and most frequent podiatric alterations, as well as the level of pain, disability, fatigue and alteration of quality of life in patients with Ehlers-Danlos syndrome (EDS). MATERIALS AND METHODS: Thirty-eight individuals with hypermobile or classic EDS participated. The percentage of pain in the foot and deformities was recorded, and several questionnaires were administered. The type of foot was classified according to the footprint and the Foot Posture Index. RESULTS: There was a high degree of pain, disability, intensity of fatigue and low quality of life in these patients. According to the footprint, 20% presented flat feet, 47% normal feet and 33% cavus feet. CONCLUSIONS: The participants in this study had a high percentage of foot problems related to high levels of pain and limited functionality in the feet. The quality of life of these patients appeared diminished. Foot types were observed according to the footprint and deformities similar to those of the general population.

15.
Vet Ophthalmol ; 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31309693

RESUMO

OBJECTIVE: To provide a comprehensive anatomical description of the normal equine nasolacrimal duct using magnetic resonance imaging, and to develop a practical protocol for performing magnetic resonance dacryocystography (MRD) in horses. ANIMAL STUDIED: The heads of ten fresh horse cadavers with no history of sinonasal or ophthalmologic disorders were used for this study. PROCEDURE: An MRD technique was developed in this study, which consisted of two parts. In the first part, olive oil and gadolinium were compared as contrast medium, using five horses. Two concentrations of gadolinium were used: 0.25 mmol/mL and 0.5 mmol/mL. In the second part, the influence of different head recumbencies using olive oil as the sole contrast medium was studied in the remaining five horses. RESULTS: Injection with olive oil resulted in better distention and a complete filling of the nasolacrimal duct (ND) in all horses. Injection of 0.25 mmol/mL of gadolinium resulted in incomplete filling of the ND, whereas injection of 0.5 mmol/mL of gadolinium resulted in slightly better filling of the duct. The nondependent duct showed better distention compared to the dependent duct when scanning in lateral recumbency. No differences were observed between ducts in a dorsal recumbency. The degree of distention in dorsal recumbency was slightly less than the degree of distention observed in the nondependent ND in lateral recumbency. CONCLUSIONS: Magnetic resonance dacryocystography is a suitable technique for evaluating the nasolacrimal duct and can be performed during a normal magnetic resonance examination.

16.
Hum Pathol ; 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31279874

RESUMO

High-grade urothelial carcinoma (UC) of the bladder is a heterogeneous disease with dismal prognosis. Bladder tumors with basal phenotype are intrinsically aggressive and morphological parameters that define disease staging remain main prognosticators. We intend to evaluate the role of cancer associated fibroblasts (CAF) in the prognosis of bladder cancer and its association with basal and luminal phenotypes. Clinical and pathological parameters, including the immunohistochemical expression of fibroblast activation protein (FAP) and markers of basal (CK5/6, CD44) and luminal (CK20, GATA3) phenotypes, have been investigated in a series of 121 patients with UC of the bladder treated by radical cystectomy with lymph node dissection and their implication in long-term cancer-specific survival has been evaluated. A cytoplasmic immunostaining of FAP in CAFs implies worse disease-specific survival (HR=1.68; P=.048). FAP expression is associated with tumor staging (P<.0001), with best discrimination at T2a/T2b level, and with negative expression of markers of luminal phenotype, such as CK20 (P<.0001) and GATA3 (P=.005). In the multivariate analysis, simultaneous expression of FAP, CK5/6 and CD44 is a strong prognosticator of disease-specific survival (HR=2.3; P=.001), together with nodal invasion (HR=3.47; P<.0001) and bladder infiltration up to deep muscle or beyond (HR=2.47; P=.02). There is not association between positive FAP expression in primary tumor and nodal disease (P=.22). FAP expression in CAFs favors tumor invasion in high-grade invasive UC of the bladder with basal phenotype. This new immunohistochemical marker could be added to the routine immunohistochemical protocol to predict clinical behavior in these patients.

17.
Vet Surg ; 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332823

RESUMO

OBJECTIVE: To determine the long-term return to performance of horses with impinging and/or overriding dorsal spinous processes (ORDSP) treated with interspinous ligament desmotomy (ISLD) and to determine the prognostic value of radiographic and scintigraphic grades. STUDY DESIGN: Retrospective study. ANIMALS: Seventy-one horses with ORDSP treated with ISLD. METHODS: Medical records were reviewed for signalment, physical examination, gait evaluation, and number of interspinous spaces treated. Preoperative radiographic and scintigraphic images were evaluated with grading scales. Follow-up was obtained with a telephone questionnaire. Prognostic value of the number of affected interspinous spaces, radiographic grading, and scintigraphic grading was tested by using a χ2 test. RESULTS: A median follow-up of 35 months (range, 8-64) was available for 56 horses. Fifty-one of 56 (91.1%) horses returned to some level of performance, with 27 of 51 (52.9%) horses achieving equivalent or higher level of performance. Achieving a lower level of performance was attributed to recurrent back pain in nine of 24 (37.5%) horses and to unassociated lameness in nine of 24 (37.5%) horses. Owners of 44 of 56 (78.6%) horses were satisfied with the postoperative performance level, and owners of 46 of 56 (82.1%) horses would recommend the procedure. None of the variables tested influenced the return to performance. CONCLUSION: Interspinous ligament desmotomy allowed horses with ORDSP to return to some level of performance, although fewer returned to an equivalent or higher level of performance than had previously been reported. CLINICAL SIGNIFICANCE: Interspinous ligament desmotomy allows affected horses to return to some level of performance, regardless of the severity of radiographic and scintigraphic findings.

18.
Biochem Biophys Res Commun ; 516(4): 1258-1264, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31301772

RESUMO

BACKGROUND: Multicellular tumor spheroids mimic the functional organization of tumors in vivo, providing biological readouts that predict the behavior of cancer cells more accurately. The current study aimed to evaluate the transcriptome (mRNAs and long non-coding RNAs) of multicellular tumor spheroids from breast cancer cells. METHODS: MCF-7 cell spheroids were used; the transcriptome was analyzed using RNAseq and RNA microarrays; the secretion of macrophage migration inhibitor (MIF), a cytokine exported by the cholesterol efflux regulatory protein, was measured by ELISA. Linc00052 was inhibited using short-hairpin RNAs (shRNAs). RESULTS: We found several differentially regulated mRNAs and lncRNAs in MCF-7 cell spheroids. We also found significant enrichment of the Wnt/B-catenin death receptor and the cholesterol metabolic processes. Interestingly, we also found an increased concentration of MIF. Further, at 12 and 20 days of 3D culture we found 221 and 1146 dysregulated lncRNAs, respectively; including linc00052 (long intergenic non-protein coding RNA 52), which has been involved in breast cancer. Linc00052 knock-down experiments suggest that it could be a key regulator of cholesterol pathways in breast cancer. CONCLUSIONS: Our data shows that tumor spheroids can induce changes in the transcriptome of the cultured cells, including both mRNAs and ncRNA. One of the major changes included the deregulation of cholesterol pathways, of which linc00052 is apparently a key regulator.

19.
Nat Prod Res ; : 1-6, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31339383

RESUMO

The gastroprotective effect of a turmeric acetone extract (TAE) (Curcuma longa L. [Zingiberaceae]) was evaluated and compared against its major curcuminoids; curcumin (CUR), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC). Additionally, to demonstrate the importance of the metabolites' ratio in the extract on the synergistic effect, different mixtures were evaluated. An ethanol-induced gastric injury model was used to evaluate the gastroprotection activity in Wistar rats. The pharmacologic interaction analysis was performed using the Combination Index (CI)-Isobologram Equation method. The CI calculated at 0.5 of affected fraction (fa) for the TAE indicated a synergistic interaction between its components. However, when the proportion of curcuminoids changed from 3.7:1:10 in TAE to a 1:1:1 ratio, the CI implied an antagonistic effect. The binary combinations of curcuminoids (1:1) also showed an antagonistic interaction. The results of this work suggest that the proportion of curcuminoids in the TAE is crucial for the gastroprotective effect against ethanol-induced damage.

20.
BMC Cancer ; 19(1): 728, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337349

RESUMO

BACKGROUND: Breast cancer currently is the most frequently diagnosed neoplasm and the leading cause of death from cancer in women worldwide, which is mainly due to metastatic disease. Increasing our understanding of the molecular mechanisms leading to metastasis might thus improve the pharmacological management of the disease. Epithelial-mesenchymal transition (EMT) is a key factor that plays a major role in tumor metastasis. Some pro-inflammatory cytokines, like IL-6, have been shown to stimulate phenotypes consistent with EMT in transformed epithelial cells as well as in carcinoma cell lines. Since the EMT is one of the crucial steps for metastasis, we studied the effects of metformin (MTF) on EMT. METHODS: Cytotoxic effect of MTF was evaluated in eight primary breast cancer cell cultures by crystal violet assay. EMT markers and downstream signaling molecules were measured by Western blot. The effect of MTF on cell proliferation and cell migration were analyzed by MTT and Boyden chamber assays respectively. RESULTS: We observed that the response of cultured breast cancer primary cells to MTF varied; mesenchymal cells were resistant to 10 mM MTF and expressed Vimentin and SNAIL, which are associated with a mesenchymal phenotype, whereas epithelial cells were sensitive to this MTF dose, and expressed E-cadherin but not mesenchymal markers. Further, exposure of mesenchymal cells to MTF down-regulated both Vimentin and SNAIL as well as cell proliferation, but not cell migration. In an in vitro IL-6-induced EMT assay, primary breast cancer cells showing an epithelial phenotype underwent EMT upon exposure to IL-6, with concomitant activation of STAT3 and NF-κB; addition of MTF to IL-6-induced EMT reversed the expression of the mesenchymal markers Vimentin and SNAIL, decreased pSTAT3 Y705 and pNF-κB S536 and increased E-cadherin. In addition, downregulation of STAT3·activation was dependent on AMPK, but not NF-κB phosphorylation. Further, MTF inhibited cell proliferation and migration stimulated by IL-6. CONCLUSION: These results suggest that MTF inhibits IL-6-induced EMT, cell proliferation, and migration of primary breast cancer cells by preventing the activation of STAT3 and NF-κB. STAT3 inactivation occurs through AMPK, but not NF-κB.

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