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  • 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.
81

Expression of biomarkers, representing immunosuppressive, cytotoxic or immunomodulating properties of CD8h T lymphocytes in the peripheral blood of patients with immunogenic cancer forms / Imunosupresines, citotoksines bei imunomoduliuojančias savybes atspindinčių žymenų raiška imunogeniškomis vėžio formomis sergančių ligonių periferinio kraujo CD8H T limfocitų populiacijoje

Strioga, Marius 02 July 2010 (has links)
The aim of the study was to evaluate the expression of immunosuppressive (FOXP3, NKG2A), and cytotoxic (perforin) or cytotoxic / immunomodulating (IFNγ) T-cell properties representing biomarkers in the peripheral blood CD8h T-cell population of patients with advanced renal cell carcinoma (RCC) or high risk cutaneous melanoma and healthy controls by multicolour flow cytometry. Determination of the percentage of functionally competing T-cell subsets (especially immunosuppressive) in the CD8hCD57+ T-cell subpopulation in future may serve as one of parameters enabling to assess the overall status of antitumor immune response and select cancer patients most suitable for antitumor immunotherapy while dismissing those to whom it would be ineffective or even harmful. / Darbo tikslas buvo įvertinti imunosupresines (FOXP3, NKG2A), citotoksines (perforin) bei citotoksines / imunomoduliuojančias (IFNγ) savybes atspindinčių žymenų raiškos skirtumus išplitusiu inkstų vėžiu ar didelės rizikos odos melanoma sergančių pacientų periferinio kraujo CD8h T limfocitų populiacijoje, lyginant su kontroline grupe. Skirtingas T limfocitų savybes atspindinčių žymenų raiška buvo tiriama tėkmės citometrijos būdu. Nustatyta, kad inkstų vėžiu ar odos melanoma sergančių pacientų periferiniame kraujyje Įvairių subpopuliacijų (ypač imunosupresinės) nuošimčio nustatymas CD8hCD57+ T limfocitų populiacijoje ateityje gali būti naudingas klinikinėje praktikoje, individualizuojant priešnavikinę imunoterapiją ir selektyviai parenkant tik tuos pacientus, kuriems imuninės sistemos aktyvinimas sukeltų navikinių ląstelių naikinimą, o ne dar labiau gilintų imunosupresiją.
82

Imunosupresines, citotoksines bei imunomoduliuojančias savybes atspindinčių žymenų raiška imunogeniškomis vėžio formomis sergančių pacientų periferinio kraujo CD8h T limfocitų populiacijoje / Expression of biomarkers, representing immunosuppressive, cytotoxic or immunomodulating properties of Cd8h T lymphocytes in the peripheral blood of patients with immunogenic cancer forms

Strioga, Marius 02 July 2010 (has links)
Darbo tikslas buvo įvertinti imunosupresines (FOXP3, NKG2A), citotoksines (perforin) bei citotoksines / imunomoduliuojančias (IFNγ) savybes atspindinčių žymenų raiškos skirtumus išplitusiu inkstų vėžiu ar didelės rizikos odos melanoma sergančių pacientų periferinio kraujo CD8h T limfocitų populiacijoje, lyginant su kontroline grupe. Skirtingas T limfocitų savybes atspindinčių žymenų raiška buvo tiriama tėkmės citometrijos būdu. Nustatyta, kad inkstų vėžiu ar odos melanoma sergančių pacientų periferiniame kraujyje Įvairių subpopuliacijų (ypač imunosupresinės) nuošimčio nustatymas CD8hCD57+ T limfocitų populiacijoje ateityje gali būti naudingas klinikinėje praktikoje, individualizuojant priešnavikinę imunoterapiją ir selektyviai parenkant tik tuos pacientus, kuriems imuninės sistemos aktyvinimas sukeltų navikinių ląstelių naikinimą, o ne dar labiau gilintų imunosupresiją. / The aim of the study was to evaluate the expression of immunosuppressive (FOXP3, NKG2A), and cytotoxic (perforin) or cytotoxic / immunomodulating (IFNγ) T-cell properties representing biomarkers in the peripheral blood CD8h T-cell population of patients with advanced renal cell carcinoma (RCC) or high risk cutaneous melanoma and healthy controls by multicolour flow cytometry. Determination of the percentage of functionally competing T-cell subsets (especially immunosuppressive) in the CD8hCD57+ T-cell subpopulation in future may serve as one of parameters enabling to assess the overall status of antitumor immune response and select cancer patients most suitable for antitumor immunotherapy while dismissing those to whom it would be ineffective or even harmful.
83

La néphrectomie partielle chez les patients atteints du cancer du rein de stade T1b

Meskawi, Malek 04 1900 (has links)
Objectif : La néphrectomie partielle est reconnue actuellement comme le traitement de choix des tumeurs de moins de 7 cm. Le but de notre étude est de comparer le taux de mortalité lié au cancer du rein suite au traitement par néphrectomie partielle ou radicale chez les patients de stade T1b, de présenter la tendance temporelle du taux d'intervention par néphrectomie partielle pour les tumeurs de stade T1b et d’identifier les facteurs sociodémographiques et tumoraux qui influencent le choix thérapeutique entre les deux types de traitement chirurgical. Méthode : Il s’agit d’une étude épidémiologique de type rétrospective. La population de patients provient de la base de donnée SEER (Surveillance, Epidemiology, and End Results) qui regroupe une grande proportion de la population nord-américaine. Dans notre étude, nous avons utilisé l’analyse par régression logistique pour identifier les facteurs sociodémographiques associés à l'intervention par néphrectomie partielle. Dans un deuxième temps, nous avons comparé la mortalité liée au cancer entre les deux options chirurgicales, après association par score de tendance pour diminuer les différences de base entre les deux populations. Nos critères étaient l’âge, la race, le sexe, l’état civil, le niveau socioéconomique, la taille tumorale, le grade nucléaire, l’histologie et la localité du centre hospitalier. L’analyse des données a été faite par le logiciel SPSS. Résultats : Le taux d'interventions par néphrectomie partielle a augmenté de 1,2% en 1988 à 15,9% en 2008 (p <0,001). Les jeunes patients, les tumeurs de petite taille, les patients de race noire, ainsi que les hommes sont plus susceptibles d'être traités par néphrectomie partielle (tous les p < 0,002). Parmi le groupe ciblé, le taux de mortalité lié au cancer à 5 ans et à 10 ans est de 4,4 et de 6,1% pour les néphrectomies partielles et de 6,0 et 10,4% pour les néphrectomies radicales (p = 0,03). Après ajustement de toutes les autres variables, les analyses de régression montrent que le choix entre les deux types de néphrectomie n’est pas associé à la mortalité lié au cancer (hazard ratio: 0,89, p = 0,5). Conclusion : Malgré un contrôle oncologique équivalent, le taux d'intervention par néphrectomie partielle chez les patients ayant un cancer du rein T1b est faible en comparaison à la néphrectomie radicale. / Objectives: To examine utilization rates of partial nephrectomy relative to radical nephrectomy for T1b renal cell carcinoma in contemporary years, to identify sociodemographic and disease characteristics associated with partial nephrectomy use, and to compare effectiveness of partial vs. radical nephrectomy with respect to cancer control outcomes. Materials and Methods: Using the Surveillance, Epidemiology, and End results database, 16,333 patients treated with partial or radical nephrectomy for T1bN0M0 renal cell carcinoma between 1988 and 2008 were identified. Logistic regression models were performed to identify determinants of partial nephrectomy. Subsequently, cumulative incidence rates of cancer-specific and other-cause mortality between partial and radical nephrectomy were assessed, within the matched cohort. Finally, we relied on competing-risks regression analyses for prediction of cancer-specific mortality, after adjusting for other-cause mortality, and vice-versa. Results: The utilization rate of partial nephrectomy increased from 1.2% in 1988 to 15.9% in 2008 (P<0.001). Younger individuals, smaller tumors, persons of black race, as well as men were more likely to be treated with partial nephrectomy in the current cohort (all P≤0.002). In the post-propensity cohort, the 5- and 10-year cancer-specific mortality rates were 4.4 and 6.1% for partial vs. 6.0 and 10.4% for radical nephrectomy, respectively (P=0.03). Following adjustment for other covariates, competing-risks regression analyses showed that nephrectomy type was not statistically significantly associated with cancer-specific mortality, even after adjusting for other-cause mortality (hazard ratio: 0.89, P=0.5). Conclusions: Despite a comparable cancer control outcome, consideration of partial over radical nephrectomy in T1b renal cell carcinoma individuals remains conservative in recent years.
84

CT Urography : Efforts to Reduce the Radiation Dose

Dahlman, Pär January 2011 (has links)
Computed tomography urography (CTU) is today the imaging method used to investigate patients with suspected urinary tract malignancy, replacing the old imaging method intravenous pyelography (IVP) about a decade ago. The downside of this shift was that the effective radiation dose to the examined patient was eight times higher for CTU compared to IVP. Based on four different studies, the present thesis focused on efforts to reduce the CTU radiation dose.   In study I, the number of cysts and solid lesions in the separate scan phases was evaluated in 57 patients undergoing four-phase CTU 1997-98. The number of scans was reduced from four to three when the nephrographic scan was abolished following study I. Study II registered the diameter of renal cell carcinoma (RCC) and the presenting symptoms in the total number of patients (n=232) diagnosed with RCC between 1997 and 2003. The results from study II showed that the critical size for RCCs to cause macroscopic hematuria was ≥ 4 cm. Study III was a dose-escalation study aimed to decide the minimal possible tube load in the unenhanced and excretory phase scans if the low dose images are reviewed together with normal dose corticomedullary phase images. Study III showed that it is possible to reduce the mean effective dose in three phase CTU from 16.2 mSv to 9.4 mSv with a combined low and normal dose CTU protocol. Study IV investigated the changes in the CTU protocol between 1997 and 2008, and the development of the effective radiation dose. Study IV clarified how the CTU protocol has changed between 1997 and 2008 and as a result the mean effective radiation dose to patients undergoing CTU in 2008 is only 39% of the effective dose in 1997.   In conclusion, the findings from the studies included in this thesis have contributed to a reduced radiation dose to patients undergoing CTU. The mean effective dose from CTU is at present only three times higher compared to that from the IVP.
85

Carcinome à cellules claires du rein : phénotype métastatique et résistance aux thérapies ciblées / Clear cell renal cell carcinoma : metastatic phenotype and resistance to anti-angiogenic therapy

Kammerer-Jacquet, Solène-Florence 03 October 2016 (has links)
Le carcinome rénal à cellules claires (ccRCC) est la tumeur du rein la plus fréquente. Il se caractérise par une inactivation fréquente du gène suppresseur de tumeur VHL retrouvée dans 70% des tumeurs conduisant à une transcription des gènes cibles du facteur de transcription HIF dont le VEGF. Il s’agit d’une tumeur agressive métastatique chez 50% des patients. Le sunitinib, un inhibiteur des récepteurs tyrosine kinase anti-angiogénique, est actuellement le plus utilisé en 1ère ligne malgré 30% des patients qui progressent rapidement. L’avènement d’un nouvel anti-angiogénique ciblant MET (cabozantinib) et d’immunomodulateurs (anticorps anti-PD-1, nivolumab) rend cruciale la découverte de facteurs prédictifs de réponse au traitement. Dans une 1ére partie, nous avons étudié une série rétrospective de 98 ccRCC consécutifs pour lesquels nous souhaitions étudiés le statut VHL complet et le corréler à l’expression de PD-L1. De plus, alors que le pronostic est différent entre ccRCC métastatiques synchrones (d’emblée) et métachrones (à distance), leur phénotype n’avait jamais été comparé. Pour cela, nous avons effectué une analyse histologique des principaux facteurs pronostiques, immunohistochimique (CAIX, VEGF, PAR3, PD-1 et PD-L1) et moléculaire (statut complet VHL : délétion, mutation et méthylation du promoteur) corrélée à la survie spécifique. Nous avons démontré que le statut VHL non-inactivé (niVHL) était associé à la présence de métastases synchrones, une composante sarcomatoïde, un infiltrat lymphocytaire dense, une surexpression de VEGF, une expression de PD-L1 et à un mauvais pronostic. Nous avons aussi comparé les phénotypes des ccRCC métastatiques métachrones et synchrones. Ces derniers étaient associés à une  composante sarcomatoïde, une expression cytoplasmique de PAR-3, une surexpression de VEGFA, un statut niVHL et à un mauvais pronostic depuis le diagnostic des métastases. Dans une 2ème partie, nous avons étudié une série rétrospective de 90 ccRCC métastatiques consécutifs traités par sunitinib en première ligne afin d’identifier des facteurs prédictifs de réponse ou de résistance. Nous avons utilisé les mêmes techniques que précédemment avec en plus le statut MET (mutation en NGS et expression en IHC). Les patients ont été classés en résistants primaires, intermédiaires et longs répondeurs en fonction de la durée de leur réponse évaluée par des critères radiologiques (RECIST). Nous avons aussi caractérisé le profil génétique de 73 ccRCC de cette série par CGH array pour lesquels nous disposions de congélation. Les patients résistants primaires avaient plus souvent un mauvais pronostic (score de Heng), des métastases hépatiques, une infiltration de la graisse hilaire. Sur le plan cytogénétique, leurs tumeurs présentaient des altérations génétiques plus nombreuses tant au niveau des gains que des pertes. Parmi ces altérations récurrentes, étaient décrites les gains du 5p, 7p, 8q22.1-qter et la perte de la région 6q21-q25.3. Le modèle de Cox multivarié mettait en évidence 4 facteurs indépendants : le score de Heng, des métastases hépatiques, une infiltration de la graisse hilaire et le gain du 8q qui intégrés dans un nomogramme pronostique avaient un c-index de 0.74 et 0.77 pour la survie sans progression et la survie globale. En conclusion, notre étude a permis d’identifier un sous-type de ccRCC avec un statut niVHL de mauvais pronostic qu’il conviendrait d’étudier de manière plus approfondie sur le plan génomique. De plus, nous avons montré une différence de phénotype entre les ccRCC des patients métastatiques synchrones et métachrones alors que leur prise en charge est actuellement équivalente. Enfin nous avons mis en évidence un nomogramme pronostique dans les ccRCC métastatiques traités par sunitinib en 1ère line. Ce nomogramme s’il est confirmé par une étude prospective plus large pourrait avoir un impact clinique important dans la sélection des patients les plus à même de bénéficier des anti-angiogéniques. / Clear cell renal cell carcinoma (ccRCC) is the most common kidney cancer. It is characterized by frequent inactivation of the tumor suppressor gene VHL found in 70% of tumors leading to the transcription of HIF transcription factor target genes such as VEGF. This is an aggressive tumor with 50% of metastatic patients. Sunitinib, an inhibitor of receptor tyrosine kinase antiangiogenic, is currently the most used in 1st line despite 30% of patients who progress quickly. The advent of a new anti-angiogenic targeting MET (cabozantinib) and immunomodulators (anti-PD-1 antibody, nivolumab) makes crucial discovery of predictors of response to treatment. In the first part, we studied a retrospective study of 98 consecutive ccRCC. We assessed complete VHL status and correlated it with the expression of PD-L1. Moreover, while the prognosis is different between ccRCC synchronous metastatic and metachronous, their phenotype have never been compared. In this purpose, we performed an analysis of the main pathological prognostic factors, immunohistochemical markers (CAIX, VEGF, PAR3, PD-1 and PD-L1) and molecular (VHL status: deletion, mutation and promoter methylation) correlated with specific survival. We demonstrated that non-inactivated VHL tumors (niVHL) were associated with the presence of synchronous metastases, sarcomatoid component, a dense lymphocytic infiltrate, an overexpression of VEGF, an expression of PD-L1 and a poor prognosis. We also compared the phenotypes of metachronous and synchronous metastatic ccRCC. The first ones were associated with sarcomatoid component, cytoplasmic expression of PAR-3 overexpression VEGFA and niVHL status and a poor prognosis even from the diagnosis of metastases. In the second part, we studied a retrospective study of 90 consecutive metastatic ccRCC treated with first line sunitinib to identify predictors of response or resistance. We used the same techniques as above plus the MET status (mutation in Next-Generation sequencing and expression by IHC). Patients were classified as primary-refractory, intermediate and long-term responders depending on the duration of their response as assessed by radiological criteria (RECIST). We also characterized the genetic profile of 73 ccRCC of this series by CGH array for which we had frozen tumor. Primary refractory patients often had poor prognosis (Heng criteria), liver metastases, infiltration of the hilar fat. Cytogenetically, their tumors had many more genetic alterations, both gains as losses. These recurrent alterations were gains of 5p, 7p, 8q22.1-qter and loss of 6q21-q25.3 region. The multivariate Cox model highlighted four independent factors: the score of Heng, liver metastases, infiltration of the hilar fat and gain of 8q which integrated into a prognostic nomogram had a c-index of 0.74 for survival progression-free survival and 0.77 for overall survival. In conclusion, our study identified a subtype of ccRCC with a poor prognosis with niVHL status that should be explored at the genomic level. Furthermore, we showed a phenotype difference between ccRCC synchronous and metachronous metastatic patients whereas their care is currently the same. Finally we have identified a prognostic nomogram in metastatic ccRCC treated with sunitinib in the first line. This nomogram if confirmed by a larger prospective study could have a significant clinical impact in the selection of patients most likely to benefit from anti-angiogenic therapy.
86

Perfil de expressão de microRNAs envolvidos na regulação de genes associados à angiogênese no carcinoma renal das células claras / MicroRna expression profile involved in the regulation of genes associated with angiogenesis in the renal clear cell carcinoma

Oliveira, Rita de Cássia 29 July 2016 (has links)
INTRODUÇÃO: O Carcinoma de Células Renais (CCR) é reposnsável por mais de 200.000 casos a cada ano no mundo, representando cerca de 2% de todos os cânceres. O CCR do tipo células claras (CRCC) é o subtipo mais comum da doença e é responsável por 75 a 80% dos casos, com maiores taxas de invasão local, desenvolvimento de metástases e mortalidade. As novas terapias alvo são baseadas em moléculas e anticorpos antiangiogênicos alterando o curso da doença, mas os resultados até agora não são satisfatórios. OBJETIVOS: Nosso objetivo nesse estudo foi estudar miRNAs e seus possíveis genes alvo relacionados com a angiogênese em CRCC tentando trazer novos conhecimentos relacionados às vias moleculares associadas à doença. MÉTODOS: Os níveis de expressão dos miRNAs miR-99a, 99b, 100, 199a, 106a, 106b, 29a, 29b, 29c, 126, 200a, 200b e seus respectivos genes alvo: mTOR, HIF1-alfa, VHL, PDGF, VEGF, VEGFR1 e VEGFR2 foram avaliados por alfaRT-PCR utilizando amostras de tecido tumoral de 56 pacientes com diagnóstico de CRCC e 5 amostras de tecido renal benigno como controle. Os resultados foram comparados com o tamanho tumoral, grau nuclear de Fuhrman e invasão microvascular, considerando os critérios de risco propostos por Dall\'Oglio et al (2007). RESULTADOS: Encontramos subexpressão da maioria dos genes, exceto VEGFA e PDGF, enquanto que a análise dos miRNAs mostrou subexpressão apenas dos miRs 100 e 126. Comparamos a expressão dos genes com seus possíveis miRNAs reguladores, e encontramos que mTOR apresentou subexpressão, enquanto miR99a apresentou superexpressão na maioria das amostras. Esta relação também ocorreu entre VEGFA e o miR126 e entre os miRNAs 106a, 106b, e seu gene alvo VHL. Considerando os grupos de risco, a superexpressão do miR200b foi associada com pacientes de alto risco (p = 0,01) e a superexpressão do miR126 foi associada com menor grau de Fuhrman (I-II) (p = 0,03). CONCLUSÕES: Os resultados mostram que em CRCC há um desequilíbrio na expressão de genes e miRNAs relacionadas com a angiogênese. Além disso através dos nossos achados podemos especular o papel do miR200b e do miR126 no prognóstico de CRCC / BACKGROUND: There are more than 200,000 cases of renal cell carcinoma (RCC) each year in the world, accounting for approximately 2% of all cancers. RCC clear cell type (ccRCC) is the most common subtype of RCC and accounts for 75 to 80% of the cases with highest rates of local invasion, development of metastasis and mortality. New target therapy is based on antiangiogenic antibodies and molecules, changing the course of the disease, but the results so far are disappointing. OBJECTIVES: Our aim is to study miRNAs and their target genes related to angiogenesis in ccRCC trying to bring some new knowledge to the molecular pathways related to the disease. METHODS: The expression levels of miRNAs miR-99a, 99b, 100; 199a; 106a; 106b; 29a; 29b; 29c; 126; 200a, 200b and their respective target genes: mTOR, HIF1-Î ±, VHL, PDGF, VEGF, VEGFR1 and VEGFR2 were evaluated using alfaRT-PCR.in snap-frozen tumor tissue samples from 56 patients diagnosed with ccRCC and 5 samples of benign renal tissue as control. The results were related to tumor size, Fuhrman nuclear grade and microvascular invasion, considering the risk criteria proposed by Dall\'Oglio et al. (2007). RESULTS: We compared the expression of genes with their possible regulatory miRNAs, and we found that mTOR was underexpressed while miR99a was overexpressed in most samples. This relationship also occurs between VEGFA and miR126 and between miRNAs 106a, 106b, and their target gene VHL. Considering the risk groups the overexpression of miR200b was associated with high-risk patients (p = 0.01) and the overexpression of miR126 was associated with lower Fuhrman grade (I-II) (p = 0.03). CONCLUSIONS: Our results show that in ccRCC there is an unbalance in the expression of genes and miRNAs related to angiogenesis and cell proliferation and survival. Furthermore with our findings we can speculate the role of miR200b and miR126 in the prognostic of ccRCC. We believe that the relationship between miRNAs and their respective genes should be more profoundly searched as markers and possible therapeutic agents in this neoplasia
87

Zur Rolle von epigenetisch dysregulierten microRNAs beim klarzelligen Nierenzellkarzinom

Liep, Julia 04 July 2016 (has links)
Etwa 25 % der Nierenzellkarzinome (RCC) weisen bei Diagnosestellung bereits Metastasen auf. Aufgrund der schlechten Prognose des metastasierten RCC besteht ein dringender Bedarf an neuen Therapieformen sowie an prognostischen und diagnostischen Markern. microRNAs (miRNAs) bieten sich dabei als vielversprechende molekulare Biomarker an. Für den klarzelligen RCC-Subtypen (ccRCC) wurde bereits ein umfangreiches miRNA Expressionsprofil erstellt, mit dem ccRCC-relevante, vorwiegend herunterregulierte miRNAs identifiziert werden konnten. In der vorliegenden Arbeit wurde gezeigt, dass die Expression der miR-141 und miR-145 in RCC-Zelllinien durch epigenetische Mechanismen gehemmt ist und die Promotorbereiche dieser miRNAs stark methyliert vorliegen. In RCC-Zellen konnte eine tumorsuppressive Wirkung dieser miRNAs durch Hemmung der Migration (beide) und Invasion (miR-141) nachgewiesen werden. Durch die gleichzeitige Überexpression der beiden miRNAs kam es zu einer kooperativen Wirkung und so zu einer verstärkten Hemmung der Zellmigration. Weitere Untersuchungen konnten eine Reihe neuer onkogener Targets der miR 141 und miR 145 identifizieren. Dabei zeigte sich ein kooperativer Effekt durch Kombination beider miRNAs auf die Expression der Targets HS6ST2 und LOX. Die Targets LOX und MAP4K4 waren in ccRCC Gewebe auf mRNA-Ebene stark überexprimiert im Vergleich zum umliegenden Normalgewebe. Bei der anschließenden Tissue-Mikroarray-Analyse der Expression auf Proteinebene zeigte sich zudem ein prognostisches Potenzial der Targets LOX und MAP4K4 für das Gesamtüberleben von ccRCC Patienten. Diese Daten verdeutlichen den enormen Einfluss von epigenetisch dysregulierten miRNAs und deren spezifischen Targets auf tumorassoziierte Prozesse. Zudem bietet das Netzwerk aus Epigenetik, miRNAs und deren jeweiligen Targets nicht nur eine Reihe von diagnostischen und prognostischen Möglichkeiten, sondern liefert auch viele Ansatzpunkte für die Entwicklung von neuen therapeutischen Strategien. / Approximately 25 % of diagnosed renal cell carcinoma (RCC) have already metastasized. Due to poor prognosis of metastatic RCC, there is an urgent need for new therapies and prognostic and diagnostic markers to identify high-risk patients. Here microRNAs (miRNAs) might be promising new molecular biomarkers. For the clear cell RCC subtype (ccRCC) a comprehensive miRNA expression profile was already established. In this profiling several ccRCC-associated, predominantly down-regulated miRNAs were identified. In the present study, epigenetic mechanisms were identified to play a significant role in the down regulation of miR-141 and miR-145 in RCC cell lines. In addition, a strong methylation of the corresponding promoter regions was detected at molecular level. In RCC cells a tumor suppressive effect of these miRNAs was shown by decreasing migration (both) and invasion (miR-141) and furthermore, co overexpression of both miRNAs resulted in a cooperative effect with increased inhibition of cell migration. Several new oncogenic targets of miR-141 and miR-145 were identified by further investigations. Here the two miRNAs again showed a cooperative effect, as demonstrated by a significantly increased inhibition of HS6ST2 and LOX expression. In ccRCC tissue the expression of LOX and MAP4K4 was strongly enhanced on mRNA level compared to normal tissue. In the subsequent tissue microarray analysis of protein expression, LOX and MAP4K4 showed a prognostic impact for the overall survival of patients with ccRCC. These results illustrate a huge impact of epigenetically dysregulated miRNAs and of their specific targets on tumor-associated processes. Furthermore, the network of epigenetics, miRNAs and their respective targets will offer a number of diagnostic and prognostic capabilities, but will also provide many opportunities for the development of new therapeutic strategies.
88

The CSN-CRL pathway and two p27kip1 mutants in renal cancer cells

Gummlich, Linda 19 July 2017 (has links)
Nierenzellkarzinome (RCC) gehören zu den häufigsten malignen Tumoren weltweit. Aufgrund der alarmierend hohen Inzidenz- und Sterberate besteht ein dringender Bedarf an neuen therapeutischen Targets zur Behandlung von RCCs. Punktmutationen in der Codesequenz von Proteinen führen zu einer Anhäufung von fehlgefalteten Proteinen in Tumorzellen und erfordern eine stärkere Kontrolle der Proteinqualität. Das Ubiquitin-Proteasome-System (UPS) bietet daher ein ideales therapeutisches Target für die RCC Therapie. Aktuelle Veröffentlichungen deuten auf eine Deregulation des COP9 Signalosome (CSN)-Cullin-RING-Ubiquitin-Ligase-(CRL)-Signalweges hin, einem Bestandteil des UPS. In der vorliegenden Arbeit wurden ausgewählte Komponenten des CSN-CRL Signalweges im RCC Gewebe und in vier RCC Zelllinien untersucht. In immunohistochemischen Studien am klarzelligen RCC-Gewebe konnte keine Hochregulierung einer einzelnen CSN-Untereinheit gezeigt werden. Höchstwahrscheinlich ist der gesamte CSN-Komplex im klarzelligen Nierenkarzinom im Vergleich zu nicht-malignem Nierengewebe stärker exprimiert. Die Untersuchung von vier RCC-Zelllinien zeigte eine interessante Deregulierung der CAND1-Skp2-p27 Achse in einer der Zelllinien. 786-O Zellen wiesen zwei p27Kip1 (p27) Varianten (p27V109G und p27I119T), eine Erhöhung des Skp2 und eine Reduktion des CAND1 Levels auf. Die Expression und Lokalisation von CAND1 wurde weiter in einer größeren RCC-Kohorte untersucht. Dabei zeigte sich eine negative Korrelation zwischen einer hohen zytosolischen CAND1 Expression und dem Gesamtüberleben von Patienten mit klarzelligen renalen Tumoren. Beide p27 Varianten werden durch das UPS abgebaut und binden an das CSN, Skp2, Cdks sowie an Cyclin E. Interessanterweise zeigte die p27 Mutanten beinhaltende Zelllinie 786-O eine höhere Proliferationsrate als die p27-Wildtyp-Zelllinie A498. In einem im Rahmen dieser Arbeit entwickelten Genotypisierungs-Assay konnte eine große RCC-Kohorte nach den beiden p27-Mutanten untersucht werden. In 42,5% der RCC Patienten konnte die Mutante p27V109G heterozygot nachgewiesen werden. Die Präsenz der beiden Mutanten p27V109 und p27I119T im RCC-Gewebe sowie die veränderte Expression von Skp2 und CAND1 machen den CSN-CRL Signalweg zu einem attraktiven therapeutischen Target für die Behandlung von Patienten mit Nierenzellkarzinom. / Renal cell carcinomas (RCC) belong to the most common malignant tumors worldwide. Alarming high incidence and mortality rates elucidate the urgent need for new therapeutic targets in RCCs. Point mutations in protein coding sequences lead to numerous unfolded proteins in cancer cells, requiring effective protein quality control. Therefore, components of the ubiquitin proteasome system (UPS) might be a promising new approach for RCC therapy. Recent publications in renal cancers point to a deregulated COP9 signalosome (CSN)-Cullin-RING Ubiquitin Ligase (CRL) pathway, a segment of the UPS. In the present thesis, selected components of the CSN-CRL pathway were studied in RCC tissues and four RCC cell lines. Immunohistochemistry results did not show an overexpression of a single CSN subunit in clear cell RCC tissues (ccRCC). However, it seems that the CSN holo complex is upregulated in analyzed ccRCCs. Examination of four RCC cell lines revealed a deregulation of the CAND1-Skp2-p27 axis in 786-O cells. These cells harbor two p27Kip1 (p27) mutants (p27V109G and p27I119T), high Skp2 and decreased CAND1 levels. Expression and localization of CAND1 was studied in a larger cohort of RCC tissues and revealed high cytosolic levels of CAND1 to be negatively correlated with overall survival in ccRCC patients. Both p27 variants were found to be degraded by the UPS and bound to the CSN, Skp2, Cdks and cyclin E. Interestingly, 786-O cells appear to grow 3-fold faster than A496 cells expressing p27wt. Further, a large cohort of RCC was screened for both p27 variants using a genotyping assay, specifically designed within the present thesis. 42.5% of the RCC patients harbor p27V109G heterozygously. The occurrence of p27V109G and p27I119T in RCC tissues as well as changed expression of Skp2 and CAND1 make the CSN-CRL pathway an attractive therapeutic target for the treatment of patients with RCC.
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Análise da expressão de RNAs intrônicos não-codificadores em carcinomas de célula renal / Expression analysis of intronic noncoding RNAs in renal cell carcinomas

Brito, Glauber da Costa de 26 November 2007 (has links)
O carcinoma de célula renal (CCR) subtipo célula clara é o câncer mais letal e prevalente do sistema urinário. A transformação maligna no CCR está possivelmente associada à mudanças no perfil de expressão de oncogenes e genes supressores de tumor, e acredita-se que estas alterações sejam críticas para o desenvolvimento do fenótipo maligno. Para identificar novos genes e vias moleculares associadas à transformação maligna no CCR célula clara, foram analisados perfis de expressão gênica de amostras pareadas de tumor e tecido não tumoral adjacente de 6 pacientes. Foi utilizada uma plataforma de microarrays de cDNA contendo 2.292 sondas mapeando éxons de genes codificadores e 822 sondas de RNAs não-codificadores mapeando em regiões intrônicas. A transcrição intrônica foi detectada em todos os tecidos normais e neoplásicos. Utilizando uma combinação de dois testes estatísticos e uma validação por leave-one-out, foi selecionado um subconjunto de 64 transcritos com expressão significativamente alterada em CCR célula clara em relação ao tecido não tumoral adjacente, estando a maior parte (86%) com expressão diminuída em CCR. Entre os transcritos com expressão diminuída, 49 mapearam em regiões não-traduzidas ou éxons de genes codificadores e 6 mapearam em regiões intrônicas de genes codificadores conhecidos. Os níveis de expressão diminuída de SIN3B, TRIP3, SYNJ2BP e NDE1 (p < 0,02), e de transcritos intrônicos derivados dos loci de SND1 e ACTN4 (p < 0,05), foram confirmados em CCR célula clara por Real-time RT-PCR. Um subconjunto de 25 transcritos se mostrou alterado em 6 amostras adicionais de CCR não célula clara, indicando alterações transcricionais comuns em CCR independentemente do subtipo histológico ou do estado de diferenciação do tumor. Além disso, foi analisado o perfil de metilação dos genes com expressão diminuída em tumor SIN3B, TRIP3, SYNJ2BP e GPX3. Nossos resultados indicam um novo conjunto de candidatos a gene supressor de tumor, que 8 podem desempenhar um papel importante na transformação maligna de células renais normais. / The clear cell subtype of renal cell carcinoma (RCC) is the most lethal and prevalent cancer of the urinary system. The carcinogenesis in RCC is thought to be associated with changes in the expression of several genes, and this alteration in gene expression is believed to be critical to the development of the malignant phenotype. To investigate new genes and molecular pathways associated with malignant transformation in clear cell RCC, gene expression profiles of matched samples of tumor and adjacent non-neoplastic tissue obtained from 6 patients were analysed. A custom-built cDNA microarray platform was used, comprising 2,292 probes that map to exons of genes and 822 probes for noncoding RNAs mapping to intronic regions. Intronic transcription was detected in all normal and neoplastic renal tissues. A subset of 64 transcripts with levels significantly deregulated in clear cell RCC relative to the matched non-tumor tissue, mostly (86%) downregulated in CCR, was
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Caractérisation des Carcinomes Papillaires du Rein / Characterisation of Papillary Renal Cell Carcinoma

Albiges-Sauvin, Laurence 17 October 2013 (has links)
Les Carcinomes Papillaires du Rein (pRCC) représentent la seconde forme histologique de cancers du rein . Ils correspondent à une entité hétérogène de tumeurs subdivisées en type I et type II sur leurs caractéristiques anatomopathologiques. Leur pronostic au stade métastatique est inferieur à celui des carcinomes à cellules claires. Les caractéristiques biologiques des pRCC sont mal connues et n’ont pas permis de développer jusqu'à ce jour de thérapeutiques spécifiques.Ce travail propose, en première partie, une synthèse des données disponibles biologiques, anatomo-pathologiques, thérapeutiques et pronostiques des pRCC. Cette synthèse a fait l’objet d’une publication. ( Albiges et al. The Oncologist 2012)Le second volet est dédié à l’analyse de la place du proto-oncogène MET au sein des pRCC de type I et II et plus particulièrement les différentes modalités d’activation de ce gène. Cette analyse (i) caractérise les anomalies quantitatives de l’ADN du gène MET (CGH array pour les pRCC de type II et CGMA pour les pRCC de type I) et leur corrélation au niveau d’expression génique; (ii) recherche l’existence de mutations activatrices du domaine tyrosine kinase par séquençage du gène MET chez les pRCC de type I; et (iii) analyse également les niveaux d’expression du ligand et des co-activateurs de ce récepteur MET. Ces résultats sont en cours de publication (Albiges et al. Clinical Cancer Research)Le troisième et dernier volet de ce travail vise à identifier des pistes biologiques propres aux pRCC par l’analyses de sous groupes distinguable en termes de profils d’expression génique et surtout par l’analyses des anomalies de l’ADN identifiées par CGH array des pRCC de type II, couplées aux données de transcriptome. / Papillary renal cell carcinomas (pRCC) are the second most common form of Renal Carcinomas and belongs to the non clear cell carcinomas family. This tumour type is an heterogeneous group of tumours usually subdivided in type I and type II according to pathological features. The prognosis of pRCC in the metastatic setting is worse to clear cell carcinoma’s prognosis. Biological characteristics of pRCC are poorly known and did not allow the development of specific targeted therapies.This work first presents a synthesis of published data regarding biology, pathology, therapeutics and prognosis of pRCC. This review has been published. (Albiges et al. The Oncologist 2012)Second part is dedicated to the analysis of MET proto-oncogene across pRCC. The main focus is to assess MET activation drivers. This analysis (i) characterises MET gene DNA copy number alterations (CGH array for type II pRCC and CGMA approach for Type I pRCC) and their correlation with gene expression profiling; (ii) assess activating mutations within the tyrosine kinase of MET gene in the type I pRCC; and (iii) investigate expression level of ligand and co-activators of MET receptor. This analysis is under publication. (Albiges et al. Clinical Cancer Research)Third and last part of this work aims at identifing new biological pathway specific to pRCC using clustering of gene expression profiling and DNA abnormalities assessed by CGHarray inthe type II pRCC subtypes with matching gene expression data.

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