919 resultados para Benign tumors


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Tumor cells require angiogenesis to deliver nutrients and oxygen to support their fast growth and metabolism. The vascular endothelial growth factor (VEGF) pathway plays an important role in promoting angiogenesis, including tumor-induced angiogenesis. Recent clinical trials have demonstrated the benefit of targeting VEGF in the treatment of glioblastoma. However, the prognostic significance of the expression of VEGFA and its receptors VEGFR1 (FLT1) and VEGFR2 (KDR) are still largely elusive. In the present study, we aimed to investigate the prognostic significance of these three factors, alone or in combination, in glioma patients. Gene mRNA expression was extracted from three independent brain tumor cohorts totaling 242 patients and the association between gene expression and survival was tested. We found that when VEGFA, FLT1 and KDR expressions were considered alone, only VEGFA demonstrated a significant association with patient survival. Patients with high expression of both VEGFA and either receptor had significantly worse survival than patients expressing both factors at a low level. Importantly, we found that those patients whose tumors overexpressed all three genes had a significantly shorter survival compared to those patients with a low level expression of these genes. Our results suggest that a high level expression of VEGFA and its receptors, both FLT1 and KDR, may be required for brain tumor progression, and that these three factors should be considered together as a prognostic indicator for brain tumor patients.

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PURPOSE: LYRIC/AEG-1 has been reported to influence breast cancer survival and metastases, and its altered expression has been found in a number of cancers. The cellular function of LYRIC/AEG-1 has previously been related to its subcellular distribution in cell lines. LYRIC/AEG-1 contains three uncharacterized nuclear localization signals (NLS), which may regulate its distribution and, ultimately, function in cells.

EXPERIMENTAL DESIGN: Immunohistochemistry of a human prostate tissue microarray composed of 179 prostate cancer and 24 benign samples was used to assess LYRIC/AEG-1 distribution. Green fluorescent protein-NLS fusion proteins and deletion constructs were used to show the ability of LYRIC/AEG-1 NLS to target green fluorescent protein from the cytoplasm to the nucleus. Immunoprecipitation and Western blotting were used to show posttranslational modification of LYRIC/AEG-1 NLS regions.

RESULTS: Using a prostate tissue microarray, significant changes in the distribution of LYRIC/AEG-1 were observed in prostate cancer as an increased cytoplasmic distribution in tumors compared with benign tissue. These differences were most marked in high grade and aggressive prostate cancers and were associated with decreased survival. The COOH-terminal extended NLS-3 (amino acids 546-582) is the predominant regulator of nuclear localization, whereas extended NLS-1 (amino acids 78-130) regulates its nucleolar localization. Within the extended NLS-2 region (amino acids 415-486), LYRIC/AEG-1 can be modified by ubiquitin almost exclusively within the cytoplasm.

CONCLUSIONS: Changes in LYRIC/AEG-1 subcellular distribution can predict Gleason grade and survival. Two lysine-rich regions (NLS-1 and NLS-3) can target LYRIC/AEG-1 to subcellular compartments whereas NLS-2 is modified by ubiquitin in the cytoplasm.

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OBJECTIVES: To investigate if the shading sign is an exclusive MRI feature of endometriomas or endometrioid tumors, and to analyze its different patterns. METHODS: Three hundred and fourty six women with adnexal masses who underwent 1.5/3-T MRI were included in this retrospective, board-approved study. The shading sign was found in 56 patients, but five cases were excluded due to lack of imaging follow-up or histological correlation. The final sample included 51 women. The type of tumor and the pattern of shading were recorded for each case. RESULTS: Thirty endometriomas and five endometrioid carcinomas were found. The remaining 16 cases corresponded to other benign and malignant tumors. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 93%, 59%, and 96%, respectively. Restricting the analysis to cystic lesions without solid or fat component, sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 96%, 94%, and 80%. Five shading patterns were identified: layering (15.7%), liquid-liquid level (11.8%), homogenous (45.1%), heterogeneous (11.8%), and focal/multifocal shading within a complex mass (19.6%). No significant correlation was found between these patterns and the type of tumor. CONCLUSIONS: The shading sign is not exclusive of endometriomas or endometrioid tumors. Homogenous shading was the most prevalent pattern in endometriomas and half of the cases with focal/multifocal shading within a complex mass were endometrioid carcinomas.

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RESUMO: As células endoteliais definem e delineiam todo o sistema vascular...Nesta tese procurámos explorar o papel que o ambiente tumoral exerce sobre as células endoteliais. ... Avaliamos também a capacidade anti-angiogénica de alguns derivados do estrogénio... Em suma os nossos resultados mostram a importância de um controlo rigoroso da regulação transcricional...

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BACKGROUND: Rectal and pararectal gastrointestinal stromal tumors (GISTs) are rare. The optimal management strategy for primary localized GISTs remains poorly defined. METHODS: We conducted a retrospective analysis of 41 patients with localized rectal or pararectal GISTs treated between 1991 and 2011 in 13 French Sarcoma Group centers. RESULTS: Of 12 patients who received preoperative imatinib therapy for a median duration of 7 (2-12) months, 8 experienced a partial response, 3 had stable disease, and 1 had a complete response. Thirty and 11 patients underwent function-sparing conservative surgery and abdominoperineal resection, respectively. Tumor resections were mostly R0 and R1 in 35 patients. Tumor rupture occurred in 12 patients. Eleven patients received postoperative imatinib with a median follow-up of 59 (2.4-186) months. The median time to disease relapse was 36 (9.8-62) months. The 5-year overall survival rate was 86.5%. Twenty patients developed local recurrence after surgery alone, two developed recurrence after resection combined with preoperative and/or postoperative imatinib, and eight developed metastases. In univariate analysis, the mitotic index (≤5) and tumor size (≤5 cm) were associated with a significantly decreased risk of local relapse. Perioperative imatinib was associated with a significantly reduced risk of overall relapse and local relapse. CONCLUSIONS: Perioperative imatinib therapy was associated with improved disease-free survival. Preoperative imatinib was effective. Tumor shrinkage has a clear benefit for local excision in terms of feasibility and function preservation. Given the complexity of rectal GISTs, referral of patients with this rare disease to expert centers to undergo a multidisciplinary approach is recommended.

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Abstract Part I : Background : Isolated lung perfusion (ILP) was designed for the treatment of loco-regional malignancies of the lung. In contrast to intravenous (IV) drug application, ILP allows for a selective administration of cytostatic agents such as doxorubicin to the lung while sparing non-affected tissues. However, the clinical results with ILP were disappointing. Doxorubicinbased ILP on sarcoma rodent lungs suggested high overall doxorubicin concentrations within the perfused lung but a poor penetration of the cytostatic agent into tumors. The same holds true for liposomal-encapsulated macromolecular doxorubicin (LiporubicinTM) In specific conditions, low-dose photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial bamer in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vasculature. We therefore hypothesized that Visudyne®-mediated PDT could selectively increase liposomal doxorubicin (LiporubicinTM) uptake in sarcoma tumors to rodent lungs during intravenous (IV) drug administration and isolated lung perfusion (ILP). Material and Methods : A sarcoma tumor was generated in the left lung of Fisher rats by subpleural injection of a sarcoma cell ,suspension via thoracotomy. Ten days later, LiporubicinTM is administered IV or by single pass antegrade ILP, with or without Visudyne® -mediated low-dose PDT pre-treatment of the sarcoma bearing lung. The drug concentration and distribution were assessed separately in tumors and lung tissues by high pressure liquid chromatography (HPLC) and fluorescence microscopy (FNI~, respectively. Results : PDT pretreatment before IV LiporubicinTM administration resulted in a significantly higher tumor drug uptake and tumor to lung drug ratio compared to IV drug injection alone without affecting the blood flow and drug distribution in the lung. PDT pre-treatment before LiporubicinTM-based ILP also resulted in a higher tumor drug uptake and a higher tumor to lung drug ratio compared to ILP alone, however, these differences were not significant due to a heterogeneous blood flow drug distribution during ILP which was further accentuated by PDT. Conclusions : Low-dose Visudyne®-mediated PDT pre-treatment has the potential to selectively enhance liposomal encapsulated doxorubicin uptake in tumors but not in normal lung tissue after IV drug application in a rat model of sarcoma tumors to the lung which opens new perspectives for the treatment of superficially spreading chemoresistant tumors of the chest cavity such as mesothelioma or malignant effusion. However, the impact of PDT on macromolecular drug uptake during ILP is limited since its therapeutic advantage is circumvented by ILP-induced heterogeneicity of blood flow and drug distribution Abstract Part II Background : Photodynamic therapy (PDT) with Visudyne® acts by direct cellular phototoxicity and/or by an indirect vascular-mediated effect. Here, we demonstrate that the vessel integrity interruption by PDT can promote the extravasation of a macromolecular agent in normal tissue. To obtain extravasation in normal tissue PDT conditions were one order of magnitude more intensive than the ones in tissue containing neovessels reported in the literature. Material and Methods : Fluorescein isothiocyanate dextran (FITC-D, 2000kDa), a macromolecular agent, was intravenously injected 10 minutes before (LKO group, n=14) or 2 hours (LK2 group, n=16) after Visudyne® mediated PDT in nude mice bearing a dorsal skin fold chamber. Control animals had no PDT (CTRL group, n=8). The extravasation of FITC-D from blood vessels in striated muscle tissue was observed in both groups in real-time for up to 2500 seconds after injection. We also monitored PDT-induced leukocyte rolling in-vivo and assessed, by histology, the corresponding inflammatory reaction score in the dorsal skin fold chambers. Results : In all animals, at the applied PDT conditions, FITC-D extravasation was significantly enhanced in the PDT treated areas as compared to the surrounding non-treated areas (p<0.0001). There was no FITC-D leakage in the control animals. Animals from the LKO group had significantly less FITC-D extravasation than those from the LK2 group (p = 0.0002). In the LKO group FITC-D leakage correlated significantly with the inflammation (p < 0.001). Conclusions: At the selected conditions, Visudyne-mediated PDT promotes vascular leakage and FITC-D extravasation into the interstitial space of normal tissue. The intensity of vascular leakage depends on the time interval between PDT and FITC-D injection. This concept could be used to locally modulate the delivery of macromolecules in vivo. Résumé : La perfusion cytostatique isolée du poumon permet une administration sélective des agents cytostatiques sans implication de la circulation systémique avec une forte accumulation au niveau du poumon mais une faible pénétration dans les tumeurs. La thérapie photodynamique (PDT) qui consiste en l'application d'un sensibilisateur activé par lumière laser non- thermique d'une longueur d'onde définie permet dans certaines conditions, une augmentation de la pénétration des agents cytostatiques macromoléculaires à travers la barrière endothéliale tumorale. Nous avons exploré cet avantage thérapeutique de la PDT dans un modèle expérimental afin d'augmenter d'une manière sélective la pénétration tumorale de la doxorubicin pegylée, liposomal- encapsulée macromoléculaire (Liporubicin). Une tumeur sarcomateuse a été générée au niveau du poumon de rongeur suivie d'administration de Liporubicin, soit par voie intraveineuse soit par perfusion isolée du poumon (ILP). Une partie des animaux ont reçus un prétraitement de la tumeur et du poumon sous jacent par PDT avec Visudyne comme photosensibilisateur. Les résultats ont démontrés que la PDT permet, sous certaines conditions, une augmentation sélective de Liporubicin dans les tumeurs mais pas dans le parenchyme pulmonaire sous jacent. Après administration intraveineuse de Liporubicin et prétraitement par PDT, l'accumulation dans les tumeurs était significative par rapport au poumon, et aux tumeurs sans PDT. Le même phénomène est observé après ILP du poumon. Cependant, les différences avec ou sans PDT n'étaient pas significatives lié à und distribution hétérogène de Liporubicin dans le poumon perfusé après ILP. Dans une deuxième partie de l'expérimentation, nous avons exploré la microscopie intra-vitale pour déterminer l'extravasion des substances macromoléculaires (FITS) à travers la barrière endothéliale avec ou sans Visudyne-PDT au niveau des chambres dorsales des souris nues. Les résultats montrent qu'après PDT, l'extravasion de FITS a été augmentée de manière significative par rapport au tissu non traité. L'intensité de l'extravasion de FITS dépendait également de l'intervalle entre PDT et injection de FITS. En conclusion, les expérimentations montrent que la PDT est capable, sous certaines conditions, d'augmenter de manière significative l'extravasion des macromolécules à travers la barrière endothéliale et leur accumulation dans des tumeurs mais pas dans le parenchyme pulmonaire. Ces résultats permettent une nouvelle perspective de traitement pour des tumeurs superficielles intrathoraciques chimio-résistent comme l'épanchement pleural malin ou le mésothéliome pleural.

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Neural stem cells have been proposed as a new and promising treatment modality in various pathologies of the central nervous system, including malignant brain tumors. However, the underlying mechanism by which neural stem cells target tumor areas remains elusive. Monitoring of these cells is currently done by use of various modes of molecular imaging, such as optical imaging, magnetic resonance imaging and positron emission tomography, which is a novel technology for visualizing metabolism and signal transduction to gene expression. In this new context, the microenvironment of (malignant) brain tumors and the blood-brain barrier gains increased interest. The authors of this review give a unique overview of the current molecular-imaging techniques used in different therapeutic experimental brain tumor models in relation to neural stem cells. Such methods for molecular imaging of gene-engineered neural stem/progenitor cells are currently used to trace the location and temporal level of expression of therapeutic and endogenous genes in malignant brain tumors, closing the gap between in vitro and in vivo integrative biology of disease in neural stem cell transplantation.

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Spontaneous teratocarcinomas are ovarian or testicular tumors which have their origins in germ cells. The tumors contain a disorganized array of benign differentiated cells as well as an undifferentiated population of malignant stem cells, the embryonal carcinoma or EC cells. These pluripotent stem cells in tissue culture share many properties with the transient pluripotent cells of the early embryo, and might therefore serve as models for the investigation of developmental events ill vitro. The property of EC cells of prime interest in this study is an in vivo phenomenon. Certain EC cell lines are known to be regulated ill vivo and to differentiate normally in association with normal embryonic cells, resulting in chimeric mice. These mice have two genetically distinct cell populations, one of which is derived from the originally malignant EC cells. This has usually been accomplished by injection of the EC cells into the Day 3 blastocyst. In this study, the interactions between earlier stage embryos and EC cells have been tested by aggregating clumps of EC cells with Day 2 embryos. The few previous aggregation studies produced a high degree of abnormality in chimeric embryos, but the EC cells employed had known chromosomal abnormalities. In this study, two diploid EC cell lines (P19 and Pi0) were aggregated with 2.5 day mouse embryos, and were found to behave quite differently in the embryonic environment. P19 containing aggregates generally resorbed early, and the few embryos recovered at midgestation were normal and non-chimeric. Pi0 containing aggregates survived in high numbers to midgestation, and the Pi0 cells were very successful in colonizing the embryo. All these embryos were chimeric, and the contribution by the EC cells to each chimera was very high. However, these heavily chimeric embryos were all abnormal. Blastocyst injection had previously produced some abnormal embryos with high Pl0 contributions in addition to the live born mice, which had lower EC contributions. This study now adds more support to the hypothesis that high EC contributions may be incompatible with normal development. The possibility that the abnormalities were due to the mixing of temporally asynchronous embryonic cell types in the aggregates was tested by aggregating normal pluripotent cells taken from 3.5 day embryos with 2.5 day embryos. Early embryo loss was very high, and histological studies showed that the majority of these embryos died by 6.5 days development. Some embryos escaped this early death such that some healthy chimeras were recovered, in contrast to recovery of abnormal chimeric embryos following Pl0-morula aggregations, and non-chimeric embryos following P19-morula aggregations. This somewhat surprising adverse effect on development following aggregation of normal cell types suggests that there are developmental difficulties associated with the mixing of asynchronous cell types in aggregates. However, the greater magnitude of the adverse effects when the aggregates contained tumor derived cells suggests that EC cells should not be considered the complete equivalent of the pluripotent cells of the early embryo.

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Globally, Prostate cancer (PCa) is the most frequently occurring non-cutaneous cancer, and is the second highest cause of cancer mortality in men. Serum prostate specific antigen (PSA) has been the standard in PCa screening since its approval by the American Food & Drug Administration (FDA) in 1994. Currently, PSA is used as an indicator for PCa - patients with a serum PSA level above 4ng/mL will often undergo prostate biopsy to confirm cancer. Unfortunately fewer than similar to 30% of these men will biopsy positive for cancer, meaning that the majority of men undergo invasive biopsy with little benefit. Despite PSA's notoriously poor specificity (33%), there is still a significant lack of credible alternatives. Therefore an ideal biomarker that can specifically detect PCa at an early stage is urgently required. The aim of this study was to investigate the potential of using deregulation of urinary proteins in order to detect Prostate Cancer (PCa) among Benign Prostatic Hyperplasia (BPH). To identify the protein signatures specific for PCa, protein expression profiling of 8 PCa patients, 12 BPH patients and 10 healthy males was carried out using LC-MS/MS. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR. This approach revealed that significant the down-regulation of Fibronectin and TP53INP2 was a characteristic event among PCa patients. Fibronectin mRNA down-regulation, was identified as offering improved specificity (50%) over PSA, albeit with a slightly lower although still acceptable sensitivity (75%) for detecting PCa. As for TP53INP2 on the other hand, its down-regulation was moderately sensitive (75%), identifying many patients with PCa, but was entirely non-specific (7%), designating many of the benign samples as malignant and being unable to accurately identify more than one negative.

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MicroRNAs (miRNAs) are a class of short (similar to 22nt), single stranded RNA molecules that function as post-transcriptional regulators of gene expression. MiRNAs can regulate a variety of important biological pathways, including: cellular proliferation, differentiation and apoptosis. Profiling of miRNA expression patterns was shown to be more useful than the equivalent mRNA profiles for characterizing poorly differentiated tumours. As such, miRNA expression "signatures" are expected to offer serious potential for diagnosing and prognosing cancers of any provenance. The aim of this study was to investigate the potential of using deregulation of urinary miRNAs in order to detect Prostate Cancer (PCa) among Benign Prostatic Hyperplasia (BPH). To identify the miRNA signatures specific for PCa, miRNA expression profiling of 8 PCa patients, 12 BPH patients and 10 healthy males was carried out using whole genome expression profiling. Differential expression of two individual miRNAs between healthy males and BPH patients was detected and found to possibly target genes related to PCa development and progression. The sensitivity and specificity of miR-1825 for detecting PCa among BPH individuals was found to be 60% and 69%, respectively. Whereas, the sensitivity and specificity of miR-484 were 80% and 19%, respectively. Additionally, the sensitivity and specificity for miR-1825/484 in tandem were 45% and 75%, respectively. The proposed PCa miRNA signatures may therefore be of great value for the accurate diagnosis of PCa and BPH. This exploratory study has identified several possible targets that merit further investigation towards the development and validation of diagnostically useful, non-invasive, urine-based tests that might not only help diagnose PCa but also possibly help differentiate it from BPH.

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Cerebral glioma is the most prevalent primary brain tumor, which are classified broadly into low and high grades according to the degree of malignancy. High grade gliomas are highly malignant which possess a poor prognosis, and the patients survive less than eighteen months after diagnosis. Low grade gliomas are slow growing, least malignant and has better response to therapy. To date, histological grading is used as the standard technique for diagnosis, treatment planning and survival prediction. The main objective of this thesis is to propose novel methods for automatic extraction of low and high grade glioma and other brain tissues, grade detection techniques for glioma using conventional magnetic resonance imaging (MRI) modalities and 3D modelling of glioma from segmented tumor slices in order to assess the growth rate of tumors. Two new methods are developed for extracting tumor regions, of which the second method, named as Adaptive Gray level Algebraic set Segmentation Algorithm (AGASA) can also extract white matter and grey matter from T1 FLAIR an T2 weighted images. The methods were validated with manual Ground truth images, which showed promising results. The developed methods were compared with widely used Fuzzy c-means clustering technique and the robustness of the algorithm with respect to noise is also checked for different noise levels. Image texture can provide significant information on the (ab)normality of tissue, and this thesis expands this idea to tumour texture grading and detection. Based on the thresholds of discriminant first order and gray level cooccurrence matrix based second order statistical features three feature sets were formulated and a decision system was developed for grade detection of glioma from conventional T2 weighted MRI modality.The quantitative performance analysis using ROC curve showed 99.03% accuracy for distinguishing between advanced (aggressive) and early stage (non-aggressive) malignant glioma. The developed brain texture analysis techniques can improve the physician’s ability to detect and analyse pathologies leading to a more reliable diagnosis and treatment of disease. The segmented tumors were also used for volumetric modelling of tumors which can provide an idea of the growth rate of tumor; this can be used for assessing response to therapy and patient prognosis.

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This paper describes a novel framework for automatic segmentation of primary tumors and its boundary from brain MRIs using morphological filtering techniques. This method uses T2 weighted and T1 FLAIR images. This approach is very simple, more accurate and less time consuming than existing methods. This method is tested by fifty patients of different tumor types, shapes, image intensities, sizes and produced better results. The results were validated with ground truth images by the radiologist. Segmentation of the tumor and boundary detection is important because it can be used for surgical planning, treatment planning, textural analysis, 3-Dimensional modeling and volumetric analysis

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This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The most common primary brain tumors are gliomas, evolving from the cerebral supportive cells. For clinical follow-up, the evaluation of the pre- operative tumor volume is essential. Tumor portions were automatically segmented from 2D MR images using morphological filtering techniques. These seg- mented tumor slices were propagated and modeled with the software package. The 3D modeled tumor consists of gray level values of the original image with exact tumor boundary. Axial slices of FLAIR and T2 weighted images were used for extracting tumors. Volumetric assessment of tumor volume with manual segmentation of its outlines is a time-consuming proc- ess and is prone to error. These defects are overcome in this method. Authors verified the performance of our method on several sets of MRI scans. The 3D modeling was also done using segmented 2D slices with the help of a medical software package called 3D DOCTOR for verification purposes. The results were validated with the ground truth models by the Radi- ologist.