• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 89
  • 31
  • 24
  • 20
  • 11
  • 6
  • 4
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 206
  • 102
  • 57
  • 49
  • 45
  • 44
  • 35
  • 33
  • 27
  • 26
  • 25
  • 24
  • 24
  • 24
  • 23
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Einfluss der Blockade des Kaliumkanals Eag1 durch trizyklische und nicht-trizyklische Antidepressiva auf die Überlebenszeit von Patienten mit Glioblastoma multiforme bzw. Hirnmetastasen und Depression: Eine klinische und immunhistochemische Analyse. / Impact of Eag1 inhibition with tricyclic and non-tricyclic antidepressants on survival in patients with glioblastoma multiforme or brain metastases and depression. Clinical and immunhistochemical analysis.

Schell, Julian Michael 20 April 2015 (has links)
No description available.
112

Development of an On-line Planning and Delivery Technique for Radiotherapy of Spinal Metastases

Letourneau, Daniel 31 July 2008 (has links)
The objective of this work is to develop an on-line planning and delivery technique for palliative radiotherapy of spinal metastases using a linear accelerator capable of cone-beam CT (CBCT) imaging. This technique integrates all preparation and delivery steps into a single session equivalent to an initial treatment session. The key technical challenges pertaining to the development and implementation of this novel treatment technique are related to CBCT image performance, efficient system integration, development of on-line planning tools and design of novel quality assurance (QA) phantoms and processes. Hardware and software image corrections were first implemented to make CBCT images suitable for target definition and planning. These corrections reduced CBCT non-uniformity and improved CBCT-number accuracy. The on-line treatment technique workflow and the integration of all the subsystems involved in the process were assessed on a customized spine phantom constructed for the study. The challenges related to the routine QA of the highly integrated on-line treatment technique were addressed with the construction and validation of an integral test phantom. This phantom, which contains point detectors (diodes) allows for real-time QA of the entire image guidance, planning and treatment process in terms of dose delivery accuracy. The integral test phantom was also effective for the QA of high-dose, high-precision spinal radiosurgery. Simulation of the on-line treatment technique on patient data showed that the planning step was the one of the most time consuming tasks due predominantly to manual target definition. A semi-automatic method for detection and identification of vertebrae on CBCT images was developed and validated to streamline vertebra segmentation and improve the on-line treatment efficiency. With a single patient setup at the treatment unit, patient motion during the on-line process represents the main source of geometric uncertainty for dose delivery. Spine intra-fraction motion was assessed on CBCT for a group of 49 patients treated with a palliative intent. The use of surface marker tracking as a surrogate for spine motion was also evaluated. Finally, the complete on-line planning and delivery technique was implemented in a research ethics board (REB) approved clinical study at the Princess Margaret Hospital and 7 patients have been successfully treated at the time of this report with this novel treatment approach.
113

Rectal Cancer : Surgical Strategies and Histopathological Aspects

Hosseinali Khani, Maziar January 2011 (has links)
The management of rectal cancer has changed in many countries over the last two decades and resulted in improved survival for the majority of rectal cancer patients. In this thesis some surgical strategies and histopathological aspects to improve and clarify the management of rectal cancer patients are investigated. Even in the era of TME surgery and radiotherapy, a higher local recurrence rate and shorter survival for rectal cancer patients operated with abdominoperineal resection is reported. In the first paper we describe a new strategy with partial anterior en bloc resection of either the prostate or the vagina, resulting in very low local recurrence rates and excellent long-term survival. Histopathological examination of the specimen lays the foundation for decision making on oncological therapy. A positive circumferential resection margin (CRM) has, in previous papers, been related to a high risk of local recurrence. In the second paper we show that a CRM ≤ 1 mm was not correlated with an increased risk of local recurrence when patients were managed in a multidisciplinary setting with preoperative radiotherapy and optimal TME surgery. As the complexity of rectal cancer management is increasing, demands on organizational structure are growing. In paper three we could show that long-term survival was increased for all rectal cancer patients after the centralization to a single unit. Whether or not to resect the primary rectal tumour in patients with metastatic disease is an ongoing debate in the literature. In paper four, we studied the national management of rectal cancer patients with primary metastatic disease. Nineteen per cent of rectal cancer patients present with Stage IV disease and, at a national level, there is a clear shift to a more selective and restrictive approach. The 30-day mortality was low for patients that underwent a resectional surgery, for patients having an exploratory laparotomy, however, it was high. Overall survival was improved over time even though up to one fourth of patients received no surgical treatment.
114

Avaliacao dos efeitos genotoxico e citotoxico do sup(153)Sm-EDTMP em linfocitos perifericos de pacientes com metastase ossea

SUZUKI, MIRIAM F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:22Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:22Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
115

Evaluation de l’efficacité thérapeutique d’un nouvel inhibiteur des LIM Kinases « Pyr1 » dans le cancer du sein / Evaluation of the therapeutic activity of a new LIM Kinases inhibitor « Pyr1 » in breast cancer

Prunier, Chloé 26 November 2015 (has links)
Le cancer du sein était au premier rang des cancers chez la femme en termes d'incidence et de mortalité en 2008 (GLOBOCAN 2012, IARC). A l'origine de cette mortalité on observe notamment le développement de résistances aux chimiothérapies conventionnelles mais aussi le développement des métastases qui sont responsables de 90% des décès des patientes. Il est donc indispensable d'étendre l'arsenal thérapeutique à la disposition des cliniciens avec de nouvelles molécules actives sur les formes de cancers résistants aux chimiothérapies et ciblant le processus métastatique.Au sein de notre équipe nous avons identifié un nouvel inhibiteur de la LIM Kinase (LIMK) baptisé « Pyr1 ». La LIMK est responsable de la régulation de la dynamique des microtubules et des microfilaments d'actine. Dans un premier article (Prudent et al., Cancer Research, 2012) nous avons montré que Pyr1 avait une activité anti-mitotique et anti-migratoire dans un modèle cellulaire de cancer de l'utérus. De plus une analyse pilote a montré que Pyr1 était efficace dans un modèle murin de leucémie où il augmente la survie des souris. Étant donné que la LIMK est surexprimée dans les cancers du sein et qu'une des conséquences cellulaires d'un traitement par Pyr1 est une stabilisation des microtubules, comme le fait le paclitaxel couramment utilisé pour le traitement des formes invasives de ces cancers , l'objectif de ma thèse a été d'étudier l'efficacité thérapeutique de Pyr1 sur des modèles cellulaires et murins de cancer du sein, et notamment sur les cancers résistants au paclitaxel.Nous avons montré que Pyr1 ralentissait la croissance des tumeurs primaires et réduisait leur taille. Pyr1 est bien toléré et l'effet anti-tumoral est également observé sur des modèles résistants au paclitaxel. Nous avons ensuite étudié l'effet de Pyr1 sur la migration et l'invasion des cellules tumorales en utilisant notamment la microscopie intra-vitale. Nous avons observé que, bien qu'il ne diminue pas la vitesse de migration des cellules tumorales, Pyr1 entraine in vivo un changement morphologique important. Enfin, Pyr1 n'empêche pas la dispersion métastatique mais il prévient de manière efficace la croissance des métastases.Nous en avons conclu que Pyr1 est une molécule intéressante pour le traitement des cancers du sein résistants aux chimiothérapies conventionnelles et également sur le traitement des métastases. / Breast cancer is the most common diagnosed cancer in women worldwide with an increase of 20% and 14% in terms of incidence and mortality, respectively, in 2008 (GLOBOCAN, 2012). This increase is mainly due to the lack of therapeutics that target the development of metastasis responsible for 90% of cancer death. Moreover, the development of resistance to available chemotherapies limits their effectiveness. It's an urgent need to find new drugs that target the metastatic process and are efficient on resistant cancers.Our team has identified a new LIM Kinase (LIMK) inhibitor called “Pyr1”. LIM Kinases are implicated in the dynamic regulation of the actin and microtubule cytoskeleton. We previously published data showing that Pyr1 has an anti-mitotic and anti-migratory activity on a cervical cancer cell line. Moreover, a pilot in vivo study has shown that Pyr1 was efficient in a leukemia mouse model where it increases the lifespan of treated compared to control mice (Prudent et al., 2012).LIM Kinases have been shown to be overexpressed in breast cancer. Moreover the chemotherapeutical agents currently used for this kind of cancer belong to the class of taxanes (such as paclitaxel). Taxanes are cytotoxic compound that directly binds to microtubules and stabilizes them. Since Pyr1 treatment also results in microtubules stabilization, with a complete different mechanism of action, we have decided to investigate the anti-cancer effect of Pyr1 on breast cancer cell lines and xenografts, including paclitaxel resistant models.We showed that Pyr1 decreases primary tumor growth and reduces their size. Pyr1 is well tolerated and the anti-tumor effect is also observed on paclitaxel resistant models. We then studied Pyr1 effects on migration and invasion in vitro and in vivo. Intravital imaging of tumors showed that, whereas Pyr1 didn't slow down tumor cell migration, it induced a cell morphological change. Finally, Pyr1 does not affect metastasis spreading but prevents their growth.These results indicate that LIMK inhibitors, such as Pyr1, may represent a pharmacological alternative for taxanes resistant tumors. Moreover, they could be potent agents to reduce the size of metastasis.
116

Caractérisations phénotypiques et moléculaires de lignées cellulaires issues de cellules tumorales circulantes dans le cancer du colon / Phenotypic and molecular characterization of cell lines derived from circulating tumor cells in colon cancer

Soler, Alexandra 13 November 2018 (has links)
Les cellules tumorales circulantes (CTCs) sont des cellules tumorales provenant de la tumeur primaire et/ou des métastases que l’on retrouve dans la circulation sanguine. Les plus agressives d’entre elles peuvent envahir les organes distants pour former des métastases. Leur faible nombre parmi la multitude de cellules sanguines rend difficile leurs détections et leurs études. C'est pourquoi, le challenge actuel est de pouvoir mettre en culture ces cellules.Dans le cadre de l’éude clinique nationale COLOSPOT, notre laboratoire a pu recueillir des échantillons de patients atteints d’un cancer colorectal métastatique. Grâce à ces prélèvements sanguins, 9 lignées dérivées de CTCs ont pu être établies : CTC-MCC-41, CTC-MCC-41.4, CTC-MCC-41.5A-G.Dans ce projet de thèse, les 9 lignées cellulaires ont été caractérisées au niveau du génome, du transcriptome, du protéome, du sécrétome et fonctionnel, et comparées à des lignées cellulaires tumorales primaires et métastatiques connues, comme effectuée précédemment sur la lignée CTC-MCC-41 (Cayrefourcq et al. 2015)Cette analyse très complète a montré malgré des profils génétiques très différents, toutes les lignées CTCs ont les caractéristiques d’un phénotype intermédiaire épithélial/mésenchymal, des propriétés de cellules souches, la mutation BRAFV600E et la capacité d’éviter divers processus de lutte contre les cellules tumorales comme la résistance à l’anoïkis et l’échappement au système immunitaire. Les études fonctionnelles ont montré que les CTC-MCC pouvaient induire rapidement la formation de tubes avec des cellules endothéliales in vitro, signe d'un potentiel angiogénique.La seconde partie de ce travail de thèse a été d’étudier la transition épithélio-mésenchymateuse (EMT) in vitro. Ce phénomène est une étape clé du processus métastatique des CTCs et implique diverses transformations des cellules à divers niveaux : morphologique, protéique et transcriptomique. Trois méthodes différentes ont été testées pour induire l’EMT au sein des lignées CTCs impliquant deux différents modes d’induction et deux modes de culture. Ces changements ont pu être observés dans les lignées témoins, validant les expérimentations effectuées. Cependant, l’EMT n’a pas été clairement observée sur les lignées CTCs.En conclusion, ces analyses suggèrent que les CTC coliques cultivés à partir de biopsies liquides séquentielles, effectuée durant le traitement d’un même patient, ont des caractéristiques communes. Mais la sélection des clones, avec un phénotype distinct, résistant au traitement, a été observée. D'autres études avec ces lignées CTC-MCC sont en cours, évaluant leur capacité à induire des tumeurs résistantes à des médicaments spécifiques ou à analyser la contribution épigénétique. Ces données peuvent fournir des indications pour la découverte de nouveaux biomarqueurs permettant d'identifier les sous-populations de CTC les plus agressives et pour la mise au point de nouveaux médicaments pour inhiber les CTCs initiatrices de métastases dans le cancer du côlon. / Circulating tumor cells (CTCs) are tumor cells that have been shed from the primary tumor and/or metastases into the bloodstream. The most aggressive ones can invade distant organs to form metastases. Their low number among the multitude of blood cells makes difficult their detection and study. This is why the current challenge in this field of expertise is to be able to culture them ex vivo.In the national COLOSPOT clinical study, our team was able to collect samples of patients with metastatic colorectal cancer. From blood samples of only one patient, 9 cancer cell lines derived from CTCs could be established: CTC-MCC-41, CTC-MCC-41.4, CTC-MCC-41.5A-G.In this project, the 9 CTC-MCC lines have been characterized at the genome, transcriptome, proteome, secretome and functional levels, and compared with primary and metastatic commercial colon cancer cell lines, as previously done on the CTC-MCC-41 line (Cayrefourcq et al., Cancer Res. 2015)These analyses have shown that despite their very different genetic profiles, all CTCs have the characteristics of an epithelial/mesenchymal intermediate phenotype, stemcell like characteristics, with BRAFV600E mutation, and the ability to avoid biological processes such as the resistance to anoïkis and the escape to the immune system. Moreover, functional studies have shown that all CTC-MCC lines can rapidly induce tubes formation with endothelial cells in vitro, a sign of an angiogenic potential.The second part of this thesis work was to study the epithelial-to-mesenchymal transition (EMT) in vitro. This phenomenon is a key step in the metastatic process and involves several cell transformations at various levels: morphological, proteomic and transcriptomic. Three different methods have been tested to induce EMT within these CTC-MCC lines involving two different induction and culture modes. These changes could be observed in the control lines, validating the experiments carried out. However, EMT has not been clearly observed yet on the CTC-MCC lines.In conclusion, this longitudinal study suggest that colorectal CTCs cultured from sequential liquid biopsies, performed during treatment of the same patient, have common characteristics. However, our results strongly suggest that no clonal selection, with a distinct phenotype, resistant to treatment, has occurred. Further studies with these CTC-MCC lineages are in process, evaluating their ability to induce in vivo drug-resistant tumors or to analyze the epigenetic contribution. These data may provide guidance for the discovery of new biomarkers to identify the most aggressive CTC subpopulations and for the development of novel drugs to inhibit metastases-competent CTCs in colon cancer.
117

Fatores prognósticos na ressecção de metástases hepáticas de câncer colorretal

Chedid, Aljamir Duarte January 2002 (has links)
OBJETIVO: Determinar o impacto de fatores prognósticos na sobrevida de pacientes com metástases hepáticas ressecadas e originadas de câncer colorretal. CASUISTICA E MÉTODOS: Foram analisados os prontuários de 28 pacientes submetidos a ressecção hepática de metástases de câncer colorretal de Abril /1992 a Setembro /2001. Foram realizadas 38 ressecções (8 pacientes com mais de uma ressecção no mesmo tempo cirúrgico e 2 pacientes submetidos a re-ressecções). Todos haviam sido submetidos previamente à ressecção do tumor primário. Utilizou-se um protocolo de rastreamento de metástases hepáticas que incluiu revisões clinicas trimestrais, ecografia abdominal e dosagem de CEA até completarem-se 5 anos de seguimento e, após, semestralmente. Os fatores prognósticos estudados foram: estágio do tumor primário, tamanho das metástases > 5cm, intervalo entre ressecção do tumor primário e surgimento da metástase <1 ano, CEA>100ng/ml, margens cirúrgicas <1cm e doença metastática extra-hepática. O estudo foi retrospectivo e a análise estatística foi feita através da curva de Kaplan-Meier, do log rank e da regressão de Cox. RESULTADOS: A morbidade foi 39,3% e a mortalidade operatória foi 3,6%.A sobrevida em 5 anos foi de 35%. Os fatores prognósticos independentes adversos foram: intervalo <1 ano entre ressecção do tumor primário e surgimento da metástase (p=0,047 e RR 11,56) e doença metastática extra-hepática (p=0,004 e RR=57,28). CONCLUSÕES: A ressecção hepática de metástases de câncer colorretal é um procedimento seguro com sobrevida em 5 anos acima dos 30%. Foram fatores prognósticos independentes adversos: doença metastática extra-hepática e intervalo<1ano entre ressecção do tumor primário e surgimento da metástase. / Prognostic factors following liver resection for hepatic metastases from colorectal cancer. BACKGROUND: To determine the impact of prognostic factors on survival of patients with metastases from colorectal cancer that underwent liver resection. METHODS: The records of 28 patients that underwent liver resection for metastases from colorectal cancer between April /1992 and September/2001 were retrospectively analized. Thirty-eight resections were performed (more than one resection in eight patients and two patients underwent re-resections). The primary tumor was resected in all the patients. A screening protocol for liver metastases including clinical examinations every three months, abdominal ultrassonography and CEA level until five years of follow-up and after every six months, was applied. The prognostic factors analized regarding the impact on survival were: Dukes C stage of primary tumor, size of metastasis > 5cm, a disease-free interval from primary tumor to metastasis < 1 year, CEA level > 100ng/ml, resection margins < 1cm and extrahepatic disease. The Kaplan-Meier curves, log rank and Cox regression were used for the statistical analysis. RESULTS: Perioperative morbidity and mortality were 39,3% and 3,6% respectively. The 5-year survival rate was 35%. The independent prognostic factors were: disease-free interval from primary tumor to metastasis < 1year (p=0,047; RR=11,56) and extrahepatic metastatic disease (p=0,004; RR=57,28). CONCLUSIONS: The liver resection for metastases from colorectal cancer is a safe procedure with more than 30% 5-year survival .Disease- free interval from primary tumor to metastasis < 1year and extrahepatic disease were independent prognostic factors.
118

Fatores prognósticos na ressecção de metástases hepáticas de câncer colorretal

Chedid, Aljamir Duarte January 2002 (has links)
OBJETIVO: Determinar o impacto de fatores prognósticos na sobrevida de pacientes com metástases hepáticas ressecadas e originadas de câncer colorretal. CASUISTICA E MÉTODOS: Foram analisados os prontuários de 28 pacientes submetidos a ressecção hepática de metástases de câncer colorretal de Abril /1992 a Setembro /2001. Foram realizadas 38 ressecções (8 pacientes com mais de uma ressecção no mesmo tempo cirúrgico e 2 pacientes submetidos a re-ressecções). Todos haviam sido submetidos previamente à ressecção do tumor primário. Utilizou-se um protocolo de rastreamento de metástases hepáticas que incluiu revisões clinicas trimestrais, ecografia abdominal e dosagem de CEA até completarem-se 5 anos de seguimento e, após, semestralmente. Os fatores prognósticos estudados foram: estágio do tumor primário, tamanho das metástases > 5cm, intervalo entre ressecção do tumor primário e surgimento da metástase <1 ano, CEA>100ng/ml, margens cirúrgicas <1cm e doença metastática extra-hepática. O estudo foi retrospectivo e a análise estatística foi feita através da curva de Kaplan-Meier, do log rank e da regressão de Cox. RESULTADOS: A morbidade foi 39,3% e a mortalidade operatória foi 3,6%.A sobrevida em 5 anos foi de 35%. Os fatores prognósticos independentes adversos foram: intervalo <1 ano entre ressecção do tumor primário e surgimento da metástase (p=0,047 e RR 11,56) e doença metastática extra-hepática (p=0,004 e RR=57,28). CONCLUSÕES: A ressecção hepática de metástases de câncer colorretal é um procedimento seguro com sobrevida em 5 anos acima dos 30%. Foram fatores prognósticos independentes adversos: doença metastática extra-hepática e intervalo<1ano entre ressecção do tumor primário e surgimento da metástase. / Prognostic factors following liver resection for hepatic metastases from colorectal cancer. BACKGROUND: To determine the impact of prognostic factors on survival of patients with metastases from colorectal cancer that underwent liver resection. METHODS: The records of 28 patients that underwent liver resection for metastases from colorectal cancer between April /1992 and September/2001 were retrospectively analized. Thirty-eight resections were performed (more than one resection in eight patients and two patients underwent re-resections). The primary tumor was resected in all the patients. A screening protocol for liver metastases including clinical examinations every three months, abdominal ultrassonography and CEA level until five years of follow-up and after every six months, was applied. The prognostic factors analized regarding the impact on survival were: Dukes C stage of primary tumor, size of metastasis > 5cm, a disease-free interval from primary tumor to metastasis < 1 year, CEA level > 100ng/ml, resection margins < 1cm and extrahepatic disease. The Kaplan-Meier curves, log rank and Cox regression were used for the statistical analysis. RESULTS: Perioperative morbidity and mortality were 39,3% and 3,6% respectively. The 5-year survival rate was 35%. The independent prognostic factors were: disease-free interval from primary tumor to metastasis < 1year (p=0,047; RR=11,56) and extrahepatic metastatic disease (p=0,004; RR=57,28). CONCLUSIONS: The liver resection for metastases from colorectal cancer is a safe procedure with more than 30% 5-year survival .Disease- free interval from primary tumor to metastasis < 1year and extrahepatic disease were independent prognostic factors.
119

ROBO4 dans les cellules métastatiques du cancer du sein : identification et caractérisation fonctionnelle d’isoformes protéiques / ROBO4 in metastatic breast cancer cells : identification and functional characterization of protein isoforms

Le Pape, François 05 December 2017 (has links)
Les métastases osseuses sont des complications fréquentes de nombreux cancers tels que le cancer du poumon, de la prostate et du sein. Chez la femme, 70% des patientes présentant un cancer du sein avancé développent des métastases qualifiées d’ostéolytiques. Le développement de ce type de métastases entraine la destruction massive de l’os causant chez les patientes des fractures pathologiques. Les traitements actuellement dispensés en clinique tels que les bisphosphonates et le dénosumab (anti-RANKL) ne sont pas curatifs mais seulement palliatifs. Pour cette raison, notre laboratoire s’intéresse particulièrement aux évènements moléculaires et cellulaires précoces aboutissant à l’émergence de métastases osseuses. Les récepteurs Roundabout (ROBO) ont été initialement décrits comme des régulateurs cruciaux de la migration neuronale et vasculaire lors du développement. ROBO4 est le dernier récepteur décrit et diverge des autres récepteurs ROBO, notamment par son expression spécifique et limitée aux cellules endothéliales et hématopoïétiques. Toutefois, lors d’une analyse transcriptomique comparative le récepteur ROBO4 a été retrouvé surexprimé dans la lignée tumorale ostéotropique MDA-B02. Les récentes expériences, réalisées par notre équipe, visant à inhiber l’activité du récepteur ROBO4, nous ont permis de considérer le récepteur ROBO4 comme un médiateur de l’ancrage à l’os des cellules tumorales MDA-B02. En effet, L’utilisation d’un anticorps anti-ROBO4 réduit considérablement l'adhérence des cellules MDA-B02 sur les cellules ostéoblastiques MC3T3-E1 in vitro et l’ancrage à l’os in vivo. La surexpression de ROBO4 dans un modèle cellulaire de cancer du sein murin nous a conduit à mettre en évidence la présence de deux formes de la protéine ROBO4 aux propriétés antagonistes : (i) une forme glycosylée détectée exclusivement dans les cellules endothéliales et (ii) une forme non glycosylée, issue d’un transcrit alternatif et présente en forte quantité dans les cellules tumorales MDA-B02. L’identification d’un variant protéique du récepteur ROBO4 aux propriétés fonctionnelles et structurales différentes nous a permis d’envisager de nouvelles pistes dans le décryptage des fonctions de ROBO4 dans le processus tumoral et pourrait conduire à la mise au point de thérapies innovantes pour empêcher la formation de métastases dans la moelle osseuse / Bone metastases are frequent complications of many cancers such as lung, prostate and breast cancer. In women, 70% of patients with advanced breast cancer develop metastases known as osteolytic. The development of this type of metastasis leads to the mass destruction of bone causing pathological fractures in patients. Current clinical treatments such as bisphosphonates and denosumab (anti-RANKL) only slow the progression of the disease. For this reason, our laboratory is particularly interested in early molecular and cellular events leading to the emergence of bone metastases. Roundabout receptors (ROBO) were initially described as crucial regulators of neuronal and vascular migration during development. ROBO4 is the last receptor described and diverges from other ROBO receptors, in particular by its specific expression and limited to endothelial and hematopoietic cells. However, in a comparative transcriptomic analysis, the ROBO4 receptor was found to be overexpressed in the MDA-B02 osteotropic tumor line. Recent experiments carried out by our team, aiming at inhibiting the activity of the ROBO4 receptor, allowed us to consider the ROBO4 receptor as a mediator of MDA-B02 tumor cells anchorage to the bone. Indeed, the use of an anti-ROBO4 antibody considerably reduces the adhesion of the MDA-B02 cells to the MC3T3-E1 osteoblastic cells in vitro and the anchoring to the bone in vivo. Overexpression of ROBO4 in a murine breast cancer cell model led us to demonstrate the presence of two forms of the ROBO4 protein with antagonistic properties: (i) a glycosylated form detected exclusively in endothelial cells and (ii) one unglycosylated form derived from an alternative transcript and present in high amounts in MDA-B02 tumor cells. The identification of a protein variant of the ROBO4 receptor with different functional and structural properties has allowed us to consider new opportunities in decoding the functions of ROBO4 in the tumor process and could lead to the development of innovative therapies to prevent the formation of metastases in the bone marrow
120

Avaliacao dos efeitos genotoxico e citotoxico do sup(153)Sm-EDTMP em linfocitos perifericos de pacientes com metastase ossea

SUZUKI, MIRIAM F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:22Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:22Z (GMT). No. of bitstreams: 0 / Neste estudo, foi determinado o dano celular em linfócitos periféricos após exposição ao 153Sm-EDTMP (Samário-153 etilenodiaminotetrametilenofosfonato) por meio da técnica de análise de micronúcleos e coloração diferencial. O 153Sm-EDTMP é um radiofármaco utilizado para alívio da dor em pacientes com metástase óssea. A análise da freqüência de micronúcleos em amostras sangüíneas de pacientes obtidas uma hora após a administração endovenosa do radiofármaco (41 MBq/kg) mostrou que não houve diferença estatística em relação aos valores basais em células binucleadas. Porém, a análise da distribuição do dano em células mononucleadas mostrou que os pacientes sem tratamento radioterápico prévio apresentaram um aumento significativo na freqüência de células com um micronúcleo e aqueles com tratamento radioterápico prévio, nas células com dois ou mais micronúcleos. Os experimentos in vitro realizados com exposição de sangue total a três concentrações radioativas de 153Sm-EDTMP (0,370; 0,555 e 1,110 MBq/mL) por uma hora mostraram um aumento na freqüência de micronúcleos e de células necróticas e apoptóticas com o aumento da dose de radiação. Foram construídas curvas dose-resposta para os indivíduos sadios e para os pacientes com metástases óssea sem prévio tratamento radioterápico. A comparação das curvas mostrou que os pacientes apresentaram uma radiossensibilidade mais alta que os indivíduos sadios tanto quanto a porcentagem de células com micronúcleos como de células mortas (necróticas e apoptóticas). / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Page generated in 0.0362 seconds