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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.
41

Diagnosis of Steatosis, Precancerous Lesions and Hepatocellular Carcinoma Using Infrared Microspectroscopy / Diagnostic de la stéatose, des lésions précancéreuses et du carcinome hépatocellulaire par microspectroscopie infrarouge

Peng, Chengyuan 17 June 2015 (has links)
Carcinome hépatocellulaire (CHC) est le sixième cancer et la deuxième cause de mortalité par cancer dans le monde. Dans la majorité des cas, le CHC se développe sur une maladie chronique associée à des étiologies variées telles que l'infection par le virus de l'hépatite B ou l’hépatite C, la consommation excessive d'alcool et des maladies métaboliques. Le développement des maladies chroniques du foie qui conduisent à la cirrhose puis au cancer induisent des modifications de la composition chimique des cellules et des tissus. En effet, la carcinogenèse hépatique est un processus en plusieurs étapes caractérisé par la progression de nodules de régénération, de nodules dysplasiques de bas grade puis de grade et enfin du CHC. Le traitement du CHC reste difficile et la transplantation du foie est la seule option thérapeutique curative à long terme. Le problème est qu'il n'y a pas de marqueur objectifs et quantifiables pour contrôler la qualité d’un greffon. Des biomarqueurs spécifiques marquant la progression du CHC font également défauts.Dans ce travail de thèse, nous avons évalué l’intérêt de la microspectroscopie infrarouge (IR) pour le diagnostic de la stéatose, qui est le facteur le plus important affectant la reprise de la fonction hépatique après greffe de foie. La microspectroscopie infrarouge permet de détecter de façon qualitative et quantitative les caractéristiques biochimiques liées aux différents constituants moléculaires présents dans l'échantillon biologique. Nos travaux ont montré que la progression de la stéatose hépatique correspond non seulement à l'accumulation de lipides, mais également à des changements spectaculaires dans la composition qualitative du tissu. En effet, le bas grade de stéatose présente une diminution de la teneur en glycogène et une augmentation concomitante de lipides par rapport au foie normal. La stéatose intermédiaire montre une augmentation de glycogène et des changements majeurs sont observés en ce qui concerne les lipides, avec une contribution significative des acides gras estérifiés, des chaînes de carbone allongées et des lipides insaturés. Ces caractéristiques sont encore plus prononcées dans les hauts degrés de stéatose. De plus, nous avons mis en évidence que des changements biochimiques majeurs se produisent dans la partie non-stéatosique du tissu malgré son aspect normal sur le plan histologique, ce qui suggère que l’organe dans son ensemble reflète le degré de la stéatose.La deuxième partie de la thèse est focalisée la carcinogenèse hépatique. Il s’agit d’un processus en plusieurs étapes qui se caractérise dans la plupart des foies cirrhotiques par la progression de nodules hyperplasiques de régénération vers des lésions précancéreuses telles que les nodules dysplasiques de bas grade puis de haut grade et enfin le CHC. Le diagnostic différentiel entre nodules dysplasiques en particulier de haut garde et CHC reste extrêmement difficile. Nous avons abordé le potentiel de la microspectroscopie IR pour le diagnostic des nodules cirrhotiques. Nous avons observé de profondes modifications de la composition biochimique du foie pathologique. En effet, des changements importants ont été détectés dans la composition des lipides, des protéines et des sucres mettant en évidence la reprogrammation métabolique dans la carcinogenèse. Les principaux changements ont été observés dans le domaine de fréquence 950-1480 cm-1 dans lequel plusieurs bandes permettaient la discrimination des nodules cirrhotiques, dysplasiques et tumoraux. Enfin, nous avons montré que le diagnostic peut être réalisé à l’aide d’un microscope de laboratoire qui peut être facilement mis en œuvre en milieu hospitalier. / Hepatocellular carcinoma (HCC) is the sixth most common neoplasm and the second most common cause of death in the world. Hepatocarcinogenesis is a multistep process characterized in patients with chronic liver diseases by a spectrum of hepatic nodules that mark the progression from regenerative nodules to dysplastic lesions followed by HCC. Liver transplantation remains the curative therapeutic option able to treat both the HCC and the underlying liver disease. The issue is that there is no objective and quantifiable marker for quality control of liver graft. Specific biomarkers of early stages of HCC are also an unmet need.In this study, we have evaluated the potential of infrared (IR) microspectroscopy for the diagnosis of steatosis, one of the most important factors affecting the liver allograft function. Vibrational microspectroscopy, such as Fourier transform infrared microspectroscopy (FTIR), allows detecting spectral characteristics associated with different molecular components present in the biological sample, both qualitatively and quantitatively. Our first working hypothesis was that the progression of liver steatosis corresponds not only to the accumulation of lipids but also to dramatic changes in the qualitative composition of tissue. Indeed, a lower grade of steatosis showed a decrease in glycogen content and concomitant increase in lipids in comparison with normal liver. Intermediate steatosis exhibited an increase in glycogen and major changes in lipids, with a significant contribution of esterified fatty acids with elongated carbon chains and unsaturated lipids, and these features were more pronounced in a high grade of steatosis. Furthermore, we have shown, that FTIR approach allows a systemic discrimination of morphological features, leading to a separate investigation of steatotic vesicles and the non-steatotic counterpart of the tissue. This highlighted the fact that dramatic biochemical changes occur in the non-steatotic part of the tissue also despite its normal histological aspect, suggesting that the whole tissue reflects the grade of steatosis. The second part of the thesis focused on hepatocarcinogenesis; a multistep process that is characterized in most cirrhotic livers by the progression from hyperplastic regenerative nodules to low grade dysplastic nodules (LGDN), high grade dysplastic nodules (HGDN) and finally small HCC which corresponds either to vaguely nodular well differentiated HCC so called early HCC or to distinctly nodular moderately differentiated hepatocellular carcinomas. Since the differential diagnosis between precancerous dysplastic nodules and early HCC remains extremely difficult, we addressed the potential of FTIR microspectroscopy for grading cirrhotic nodules. The study was focused on 39 surgical specimens including normal livers as controls, dysplastic nodules, early HCC and the progressed HCC. Profound alterations of the biochemical composition of the pathological liver were demonstrated by FTIR microspectroscopy. Indeed, dramatic changes were observed in lipids, proteins and sugars highlighting the metabolic reprogramming in carcinogenesis. The major changes were observed in the frequency domain 950-1480 cm-1 in which several bands allowed significant discrimination of cirrhotic nodules, dysplastic lesions and HCC. Finally, a significant discrimination between benign, dysplastic nodules and early HCC remained possible using a FTIR microscope equipped with a laboratory-based infrared source that can be easily implemented in hospital environment. In conclusion, our study positions FTIR microspectroscopy as a versatile and powerful approach for investigating liver diseases, such as steatosis, dysplastic lesions and cancer. Further studies on larger series of patients as well as on biopsies will allow confirming the clinical reliability of such spectral signatures. Therefore, we anticipate that FTIR microspectroscopy will open new avenue in clinical diagnosis.
42

Identification of PLK1 as a proviral factor for the hepatitis B virus replication : A possible target for antiviral and anticancerous drug development / Développement et utilisation d'ARN interférents dirigés contre PLK1 dans le cadre d'une infection chronique par le virus de l'hépatite B

Foca, Adrien 14 December 2018 (has links)
Dans les régions de fortes endémicités, 70-80% des carcinomes hépatocellulaires sont induits par le VHB. Bien qu’un vaccin prophylactique très efficace existe, il n’est d’aucune utilité pour les 250 millions de personnes chroniquement infectées. Les traitements actuels pour contrôler l'infection chronique par le VHB montrent des limites et le besoin de nouvelles thérapies se fait ressentir. La Polo-like kinase-1 (PLK1), qui joue un rôle essentiel dans la mitose et est surexprimée dans de nombreux cancers, représente une cible prometteuse. Outre son rôle lors de la division cellulaire, PLK1 est impliquée dans la régulation de l'expression des gènes en interphase. Il a été montré que la protéine X du VHB (HBx) active PLK1 dans des modèles de cellules murines. Cependant, il restait à déterminer si PLK1 jouait un rôle au niveau de la réplication du VHB dans des hépatocytes quiescents. Des études récentes ont mis en évidence un lien positif entre l'activation de PLK1 et la réplication du VHB. Le but de ce projet de thèse a été d'étudier le(s) mécanisme(s) par le(s)quel(s) PLK1 jouait un rôle positif sur la réplication virale, avec pour objectif futur d'explorer l’inhibition de PLK1 comme cible antivirale. L'interaction entre PLK1 et la réplication du VHB a d'abord été décrite à l'aide du modèle HepAD38. Dans ce contexte, l'ADN viral est intégré dans le génome hôte, sous le contrôle d'un système d'expression Tet-off. La transcription de l'ARN prégénomique (pgRNA), à la base de la réplication virale, est initiée par la suppression de tétracycline. Dans ce contexte, l'augmentation de l'expression de PLK1 est corrélée avec la régulation négative de deux protéines; SUZ12 et ZNF198, faisant partie de complexes de remodelage de la chromatine. L'inhibition de PLK1 bloque la réplication du VHB, en agissant au niveau de la transcription virale. D'autre part, dans les modèles de réplication du VHB qui miment au mieux une infection, comprenant les hépatocytes primaires humains (PHH) et les cellules non transformées/différenciées HepaRG (dHepaRG), où le VHB se réplique dans des cellules quiescentes, nous avons mis en évidence que: 1) L'inhibition pharmacologique de PLK1 bloque la réplication virale, semblablement en perturbant l’encapsidation du pgRNA via une interaction avec la protéine core du VHB (HBc). 2) Un knocking-down de PLK1 en utilisant des ARN interférents délivrés par nanoparticules lipidiques résulte en une forte baisse de la production de pgRNA et dans la sécrétion des antigènes HBeAg/HBsAg, sans impact sur la viabilité cellulaire. Ce projet a donc permis la preuve de concept que PLK1 pouvait être une cible thérapeutique afin de controler la réplication du VHB. De plus, grâce à la technologie de délivrance par nanoparticules lipidiques d’ARN interférents, nous avons pu cibler spécifiquement les hépatocytes, augmentant de ce fait la spécificité et l’efficacité de nos traitements. Un travail sur la compréhension précise des méchanismes cellulaires impliqués permettra de mieux cerner cette interaction hôte/virus afin de poursuivre le développement de stratégies antivirales innovantes portant sur l’inhibition de PLK1. De manière significative, l'inhibition de PLK1 est non toxique pour les cellules quiescentes par rapport à des cellules cancéreuses à fort taux réplicatif, ce qui fait de PLK1 une cible thérapeutique attrayante. Des inhibiteurs spécifiques sont déjà en essais cliniques pour certains cancers (e.g., Volasertib pour le traitement de la leucémie myéloïde aiguë) et pourraient servir de thérapie bimodale dans le cadre de patients infectés par le VHB, en inhibant la réplication virale, ainsi qu’en prévenant l'émergence de cellules néoplasiques. L'inhibition de la PLK1 est une approche antivirale innovante, qui, en combinaison avec les thérapies actuelles de type IFN-α ou analogues nucléotidiques offre de grandes promesses pour endiguer l'infection chronique par le VHB mais également prévenir les événements carcinogéniques / In highly HBV endemic regions, 70-80% of hepatocellular carcinoma cases are attributable to this virus. Despite the existence of an HBV vaccine, the World Health Organization estimates 240 million individuals are chronically infected with HBV worldwide. Current antiviral treatments to control chronic HBV infections, and consequently reduce the incidence of liver cancer, are ineffective. New and effective therapies are needed not only for fighting the virus but also to prevent HCC emergence or progression. The polo-like-kinase 1 (PLK1), which plays pivotal roles in mitosis and is over-expressed in many human cancers, represents a promising druggable target in oncology. Beside its role during cell division, PLK1 is also thought to be involved in gene expression regulation during interphase. It was shown that the X protein (HBx) could activate PLK1 in murine cell transformation models. Yet it remained to be determined whether PLK1 could also play a role for HBV replication in non-dividing hepatocytes. Our, and collaborators, recent studies have identified a positive link between PLK1 activation and HBV replication. The goal of this thesis project was to investigate the mechanism(s) by which PLK1 exerts a positive effect on HBV replication, with the future goal of exploring PLK1 as an antiviral target. The interplay between PLK1 and HBV replication was firstly described using the HepAD38 cellular model of HBV replication. In this context, the HBV DNA is stably integrated into the host genome, under control of a Tet-off expression system. Transcription of HBV pregenomic RNA (pgRNA), the template of viral replication, is initiated by tetracycline removal. It has been shown that in HBV-replicating HepAD38 cells, increased PLK1 expression correlates with down-regulation of two proteins that are components of chromatin modifying complexes; SUZ12 protein of the PRC2 complex, and ZNF198 of the LSD1-CoREST-HDAC1 complex. PLK1 inhibition was described to inhibit HBV replication by reducing viral transcription. How PLK1 regulates HBV transcription remains unknown. On the other hand, in HBV replication models that resemble physiologic HBV infection, comprised of Primary Human Hepatocytes (PHH) and non-transformed/differentiated HepaRG cells (dHepaRG), where HBV replicates in non-transformed and non-dividing cells, thus enabling the study of the inter-phasic role of PLK1, irrespective of its well-established cell division implication, we have demonstrated that: 1) A pharmacological inhibition of PLK1 suppressed HBV replication by a different mechanism, likely targeting the packaging of pgRNA by the HBV core antigen (HBc). 2) Knocking-down PLK1 using siRNA delivered by lipid nanoparticles (LNP siPLK1) results in a strong drop of HBV DNAs, RNAs and HBe/HBsAg secretion without affecting the cell viability. This thesis project brought the proof of concept that PLK1 could be a drug target in HBV infection. Furthermore, the use of LNP allowed us to improve the delivery of siPLK1 to hepatocytes. Significantly, PLK1 inhibition is not toxic to quiescent cells in comparison to fast growing cancer cells, rendering PLK1 an attractive therapy target. High level of viremia in chronic HBV patients is a risk factor for progression to liver cancer. PLK1 specific inhibitors are already in clinical trials for other types of cancer (e.g., acute myeloid leukaemia) and could serve as bimodal therapy in HBV infected patients, by inhibiting virus replication as well as preventing emergence and spreading of neoplastic cells. This project was part of a full-working group of experts and thus, has beneficiated of a strong support. The proximity of the oncology-specialized hospital, the Centre Léon Bérard provided us with fresh hepatic biopsy [etc...]
43

Characterization of Staphylococcal nuclease and tudor domain containing protein 1 (SND1) as a molecular target in Hepatocellular carcinoma and Non-alcoholic steatohepatitis

Jariwala, Nidhi H 01 January 2017 (has links)
CHARACTERIZATION OF STAPHYLOCOCCAL NUCLEASE AND TUDOR DOMAIN CONTAINING PROTEIN 1 (SND1) AS A MOLECULAR TARGET IN HEPATOCELLULAR CARCINOMA AND NON-ALCOHOLIC STEATOHEPATITIS Nidhi Jariwala, PhD A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Integrative Life Sciences Virginia Commonwealth University, 2017 Devanand Sarkar, M.B.B.S., PhD. Associate Professor, Department of Human and Molecular Genetics Virginia Commonwealth University Richmond, Virginia SND1, a subunit of the miRNA regulatory complex RISC, has been implicated as an oncogene in hepatocellular carcinoma (HCC). Oncoprotein SND1 regulates gene expression at a post-transcriptional level in multiple cancers including hepatocellular carcinoma (HCC). In the present study, we characterize oncogenic functions of SND1 in HCC employing a novel transgenic mouse model (Alb/SND1) and present SND1 as a potential molecular target in HCC management. We show that Alb/SND1 mice develop spontaneous HCC with partial penetrance and exhibit more highly aggressive HCC induced by chemical carcinogenesis. Livers from Alb/SND1 mice exhibit a relative increase in inflammatory markers and spheroid-generating tumor initiating cells (TiC). Mechanistic investigations defined roles for Akt and NF-κB signaling pathways in promoting TiC formation in Alb/SND1 mice. Intravenous administration of the selective SND1 inhibitor 3', 5'-deoxythymidine bisphosphate (pdTp) inhibited tumor formation without effects on body weight or liver function. We conclude that SND1 drives pro-oncogenic transcriptomic and proteomic changes in hepatocyte resulting in aggressive HCC. SND1 specific RNA interactome is identified with RNA immunoprecipitation sequencing (RIPSeq) approach. With an adjusted p value of2-fold enrichment over control, 282 mRNAs were identified to significantly associate with SND1 protein. We focused on the tumor suppressor Protein Tyrosine Phosphatase non-receptor type 23 (PTPN23) because its regulation by SND1 and its role in HCC are not known. In current study, we confirm that SND1 post-transcriptionally downregulates PTPN23. Pursuing functional studies with tetracycline inducible overexpression system, we validate that PTPN23 inhibits tyrosine kinase signaling, proliferation, epithelial to mesenchymal transition, migration, invasion and in vivo tumorigenesis. Alb/SND1 mice also manifest steatosis and fibrosis at one year of age. Coupled with a pro-inflammatory hepatic phenotype, we conclude that Alb/SND1 livers present NASH. High fat diet causes severe NASH and aggressive NASH induced HCC in Alb/SND1 mice. Serum and hepatic lipid profiling shows that hepatocyte specific SND1 overexpression associate with elevated triglyceride and cholesterol LDL levels. Contrarily, hepatocyte specific deletion of SND1 (SND1ΔHEP) in vivo, significantly protects against age dependent steatosis. Association of SND1 in NASH pathology is novel discovery and we present preliminary evidence confirming role of SND1 in promoting NASH.
44

SND1-Targeted Gene Therapy for Hepatocellular Carcinoma

Mckiver, Bryan D 01 January 2018 (has links)
Staphylococcal nuclease and tudor-domain containing 1 (SND1) is an oncogene for a wide variety of cancers, including hepatocellular carcinoma (HCC). SND1 is a multifunctional protein regulating gene expression of proto-oncogenes and tumor suppressor genes, making SND1 a prime target for developing cancer therapeutics. This notion is especially attributed to HCC as most patients are diagnosed in advanced stages and the therapeutic options available for these patients are severely limited. In this study, we evaluated the therapeutic potential of a replication-defective adenovirus vector delivering SND1 shRNA (Ad.SND1sh) to human HCC cell lines, HepG3, HuH-7, and Hep3B. Adenovirus infection in HCC cells was confirmed by Western blotting and immunofluorescence. The efficacy of Ad.SND1sh to knockdown SND1 expression was confirmed via Western blot, qRT-PCR, and immunofluorescence. Ad.SND1sh did not significantly affect proliferation of the three human HCC cells but significantly inhibited their invasive and migratory capacities, as determined by wound healing and Matrigel invasion assays, respectively. As a corollary, Ad.SND1sh treatment resulted in a decrease in mesenchymal markers, such as N-cadherin, Twist, Snail, and Slug, without affecting levels of epithelial marker E-Cadherin, indicating that SND1 knockdown induces mesenchymal conversion in HCC cells. Additionally, reductions in liver cancer stem cell marker CD133 and HCC marker α-fetoprotein (AFP) were observed with SND1 knockdown. HCC cells with aberrant expression of these markers are associated with tumor initiation, recurrence, and multi-drug resistance. Our findings indicate that Ad.SND1sh may potentially be an effective therapy for advanced HCC and needs to be studied further for its clinical application.
45

Gene Transfer of Angiogenesis Inhibitor Vasostatin for Suppression of Hepatocellular Carcinoma

Chien, Hsin-Fan 22 August 2007 (has links)
Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide. Current therapeutic approaches for HCC including surgical resection and trans-arterial embolization (TAE) remain largely ineffective, underscoring the need for development of novel therapeutic strategies. Because HCC is high vascularized, continuous administration angiogenesis inhibitor using gene therapy approach may facilitate long-term blockade tumor vasculature, thereby perturbing the growth of HCC. Vasostatin 112 (VS112) encodes an alternatively spliced fragment of angiogenesis inhibitor vasostatin, which encompasses residues 1-64 and 133-180 of calreticulin. In this study, recombinant adenovirus encoding VS112 (Ad-VS112) was generated to evaluate its potential for suppression of orthotopic Novikoff hepatoma in syngenic Sprague-Dawley (SD) rats. Adenovirus-mediated VS112 overexpression significantly inhibited the migration and tube formation of endothelial cells, indicating the anti-angiogenic potency of VS112 gene delivery. However, VS112 overexpression had no influence on the viability of N1-S1 Novikoff hepatoma cells. To investigate the prophylactic effect of VS112 expression on hepatoma growth, N1-S1 cells were infected with Ad-VS112 or adenovirus encoding green fluorescent protein (Ad-GFP) then implanted into the liver of SD rats. After 14 days, rats implanted with VS112-expressing showed significantly reduced incidence and size of hepatoma compared with those implanted with Ad-GFP-infected cells. To investigate the therapeutic efficacy of VS112 gene delivery, the SD rats were implanted with N1-S1 cells on day 0, treated with adenovirus vectors (2 x 1010 plaques forming units) via intravenous route on day 1, then sacrificed on day 14 to monitor hepatoma growth. By measuring tumor weight, it was found that Ad-VS112-treated rats exhibited significantly decreased tumor burden compared with control groups, which was in accordance with their lower serum GOT level. Histological analysis revealed a significant reduction of vWF-positive blood vessels in Ad-VS112-treated tumors, which was accompanied with a decrease in Ki-67-positive proliferating cells and an increase in TUNEL-positive apoptotic cells. Moreover, the expression of pro-inflammatory nuclear factor kappa B (NF£eB) and cyclooxgenase II (COXII) was also effectively attenuated in Ad-VS112-treated hepatoma. In conclusion, prior or post VS112 gene delivery potently suppresses the growth of orthotopic hepatoma,thereby holding promises for future treatment of HCC.
46

Signaling and mechanism of HDGF in liver carcinogenesis

Kuo, Hsiao-Mei 30 August 2010 (has links)
Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide. An extensive array of growth factors and their receptors have been identified and may act as positive and negative modulators in different stages of liver carcinogenesis. Hepatoma-derived growth factor (HDGF) is a novel growth factor identified from conditioned medium of Huh-7 hepatoma cell line. HDGF has growth stimulating activity for various types of cells. Recent evidence indicates that HDGF upregulation is associated with poor survival outcome and tumor progression in HCC, non-small cell lung carcinoma and melanoma. However, the exact function and molecular mechanism of HDGF overexpression during HCC progression remain largely unknown. In the first project (Chapter 2) of this thesis study, we started with characterizing in HDGF release and response to exogenous HDGF between benign HepG2 and malignant SK-Hep-1 hepatoma cells. It was found that serum deprivation significantly stimulated the HDGF secretion in SK-Hep-1 cells but not HepG2 cells. Interestingly, SK-Hep-1 cells did not increase the secretion of vascular endothelial growth factor (VEGF), a potent angiogenic factor, during serum deprivation. Besides, SK-Hep-1 cells were more responsive to the growth- and migration-promoting effect of exogenous HDGF. We also validated the angiogenic functions of recombinant HDGF protein in vitro and in vivo. In the second project (Chapter 3), we investigated the influence of cellular HDGF level on the neoplastic potential of hepatoma cells. Adenovirus vectors encoding HDGF, Ad-HDGF, and antisense HDGF, Ad-HDGF (-), were generated to modulate the cellular HDGF levels in SK-Hep-1 cells. Adenovirus-mediated HDGF gene delivery increased the HDGF expression and release, and stimulated the proliferation, migration and anchorage-independent growth of SK-Hep-1 cells. In contrast, infection with Ad-HDGF (-) reduced the HDGF expression and secretion, and attenuated the oncogenic behaviors of SK-Hep-1 cells. Implanting HDGF-overexpressing SK-Hep-1 cells led to the accelerated growth of xenografted hepatoma in SCID mice while implantation of HDGF-downregulated SK-Hep-1 cells caused retarded tumor growth. Histological analysis revealed the increased proliferation and neovascularization in HDGF-overexpressing tumors. This could be attributed to elevated VEGF expression and activation of the nuclear factor kappa B (NF£eB) activities by HDGF upregulation in SK-Hep-1 cells. In the third project (Chapter 4), we delineated the mechanism underlying HDGF-induced VEGF secretion and activation of NFB pathway in SK-Hep-1 cells. Adding recombinant HDGF protein enhanced the VEGF release by SK-Hep-1 cells particularly during serum starvation. This was associated with a concomitant increment in VEGF protein and mRNA levels in SK-Hep-1 cells. Like many mitogens, HDGF increased the production of reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide in a dose-dependent manner. Pretreatment with antioxidants abolished the HDGF-induced VEGF secretion. NF£eB is a pivotal transcription factor for regulation of pro-inflammatory cytokines and genes such as VEGF and cycloxygenase¡V2 (COX-2). Application of HDGF stimulated NF£eB-driven luciferase activities. This was correlated with a dose- and time-depedent increment of NF£eB (p65) by HDGF. HDGF treatment also elevated the COX-2 protein levels and activities in SK-Hep-1 cells. In addition, blockade of COX-2 by NS-398 attenuated the HDGF-induced VEGF secretion, suggesting the involvement of COX-2. Finally, it was found that HDGF stimulated the phosphorylation of Akt, Erk1/2, and p38 MAPK. Inhibition of Akt by LY294002 also diminished the HDGF-induced VEGF secretion. These studies suggest that HDGF induces oxidative stress to activate NF£eB/COX-2/Akt pathway, thereby stimulating VEGF expression and release. In summary, this thesis study brings functional and mechanistic insights on how aberrant HDGF expression contributes to angiogenesis and tumorigenesis during liver carcinogenesis.
47

Développement de virus HSV-1 (virus de l'herpes simplex de type 1) oncolytiques ciblés pour traiter les carcinomes hépatocellulaires

Pourchet, Aldo 28 September 2010 (has links) (PDF)
Le premier objectif a été de sélectionner des promoteurs de gènes cellulaires actifs spécifiquement dans les HCC à l'aide d'une recherche bibliographique puis en utilisant la base de donnée UniGene. Leur activité a été vérifiée par RT-qPCR et CHIP dans des lignées modèles HCC et dans des hépatocytes. Ces promoteurs ont été clonés en amont de la luciférase dans la région intergénique 20 du génome HSV-1 afin d'étudier leur force d'activité, 2 types de cinétiques et leur activité différentielle en fonction du type cellulaire et dans le contexte d'une infection virale. Le deuxième objectif a été de construire des virus oncolytiques ciblés pour l'expression de la protéine Us3, une protéine virale impliquée dans le contrôle de la réponse apoptotique induite par HSV-1. L'expression de la protéine Us3 est placée sous contrôle d'un promoteur cellulaire spécifique d'HCC. L'hypothèse est qu'en l'absence d'activité du promoteur cellulaire dans les cellules non HCC, la protéine Us3 ne sera pas synthétisée et, par conséquent, l'apoptose qui ne sera pas réprimée, inhibera le cycle de réplication et par conséquent, la production virale dans les cellules saines. Dans les cellules HCC, le promoteur actif permettra la réplication virale aboutissant à la destruction de lamasse tumorale. Un virus HSV-1 Us3- a été construit en utilisant la technique de recombinaison en plasmide BAC (Bacterial artificial chromosome), puis 2 virus oncolytiques en réintroduisant le gène Us3 sous contrôle du promoteur ANGPTL3 ou du promoteur HRE (hypoxia responsive element). Leur comportement oncolytique a été étudié en réalisant des courbes de croissance sur lignées cellulaires d'HCC et cellules hepatocyte-like.
48

Especificidade de anticorpos antimúsculo liso em portadores de hepatite crônica pelo vírus C

Cabral, Milena Santana 16 June 2011 (has links)
Submitted by Pós graduação Farmácia (ppgfar@ufba.br) on 2017-05-25T20:04:40Z No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / Approved for entry into archive by Patricia Barroso (pbarroso@ufba.br) on 2017-06-01T17:35:33Z (GMT) No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / Made available in DSpace on 2017-06-01T17:35:34Z (GMT). No. of bitstreams: 1 MILENA SANTANA CABRAL.pdf: 2324817 bytes, checksum: efec4e0396dc2673dceb720f82342942 (MD5) / FAPESB e CNPq / A infeção crônica pelo VHC tem como principal característica a associação com diversas manifestações autoimunes. Dentre estas, a aumentada expressão de autoanticorpos não-órgão específicos, como os anticorpos antimúsculo liso, com possível importância na patogênese da doença. Objetivos: (1) Determinar a prevalência de anticorpos antimúsculo liso e sua distribuição conforme o gênero em portadores de HCC; (2) caracterizar a reatividade sorológica dos anticorpos antimúsculo liso usando como referência os padrões de fluorescência previamente determinados; (3) estabelecer as associações entre a reatividade sorológica dos anticorpos antimúsculo liso com os dados clínicos e laboratoriais dos portadores de hepatite C; (4) caracterizar imunoquimicamente os anticorpos frente a antígenos purificados. Pacientes: Foram avaliados 100 portadores de HCC, sem tratamento antiviral prévio, com diagnóstico clínico, sorológico, virológico, e histopatológico, acompanhados no C-HUPES. Métodos: Anticorpos antimúsculo liso e antinúcleo foram pesquisados por imunofluorescência indireta e a especificidade imunoquímica investigada através de imunoblot. Dosagens de fator reumatóide, haptoglobina e IgG foram realizadas por nefelometria. Crioglobulinas foram determinadas por crioprecipitação em tubo e por gel-difusão e a ALT por método cinético. Os dados de genótipo e histopatológico foram obtidos dos prontuários. Resultados: Anticorpos antimúsculo liso foram detectados em 21% dos pacientes (55 homens, 45 mulheres), sendo o padrão de fluorescência AML-v o mais frequentemente observado (81%). A associação de padrões mais prevalente foi AML-v e AML-m (71%). A maioria dos títulos dos autoanticorpos foi baixa, com apenas quatro amostras apresentando títulos superiores a 1/40. Apenas uma amostra apresentou padrão glomerular com título maior que 1/40, e não foi encontrado padrão tubular. Das três proteínas associadas aos AML, os portadores de HCC com AML positivos apresentaram maior frequência de reatividade para a actina-F, ocorrendo em 29% das amostras. A associação entre os AML e este antígeno alvo foi significante (P=0,005). Não houve associação estatisticamente significante entre os antígenos desmina e miosina, com os AML, e a prevalência de reatividade para esses antígenos foi inferior. Com o uso do imunoblot comercial, foi encontrada a presença do autoanticorpo anti-LC1 em 52% das amostras positivas para AML e em 15% das amostras negativas para esse mesmo anticorpo. Foi encontrada também a presença do anti-SLA/LP em 14% das amostras positivas para AML e em 8% das amostras que não apresentavam este autoanticorpo. Os anticorpos AMA-M2 e anti-LKM1 não foram encontrados em nenhum dos grupos avaliados. Conclusões: Uma prevalência de 21% para AML foi encontrada neste estudo, com uma relação homem/mulher de 1,1/1. A presença de AML não foi associada a qualquer dos dados demográficos, clínicos e laboratoriais deste grupo de portadores de HCC, nem associada à lesão tecidual. Determinar os padrões de fluorescência e título das amostras é relevante na detecção dos AML. Apenas a minoria dos AML de portadores de HCC reconhecem as proteínas actina-F, desmina e miosina. Foi documentado elevada expressão de anticorpos anti-LC1 neste grupo de portadores de HCC. / The main characteristic in HCV chronic infection is the association with various autoimmune manifestations. Among them, the increased expression of non-organ specific autoantibodies, such smooth muscle antibody, which possible role in HCV pathogenesis. Objectives: (1) Determine the prevalence of smooth muscle antibodies and their distribution according gender in patients with chronic hepatitis C; (2) characterize the serological reactivity of these autoantibodies in accordance with predetermined patterns of fluorescence; (3) establish associations between serologic reactivity of them with clinical and laboratory data from these patients; (4) characterize the antibodies immunochemically with purified antigens. Patients: 100 HCV carriers before treatment had been evaluated, with previous clinical, serological, virological and histopathological diagnosis, from C-HUPES. Methods: Smooth muscle and antinuclear antibodies were performed by indirect immunofluorescence and immunochemical reactivity was determined by immunoblot. Rheumatoid factor, haptoglobin and IgG were quantified by nephelometry. Cryoglobulins were determined by cryoprecipitation in tube and gel-diffusion and the determination of ALT by UV kinetics. Genotype and histophatological data were obtained from medical records. Results: 21% of HCV carriers presented anti-smooth muscle antibodies (55 men, 45 women); with the AML-v pattern the most found (81%). Also, the AML-v and AML-m patterns were the association more prevalent (71%). The titles of most autoantibodies were low, but four samples showed titles above 1/40. Only one sample showed glomeruli pattern with titles greater than 1/40, and no tubular pattern was found. In the imunoblot, the HCV carriers AML positive presented a major reactivity for F-actin (29%), which association with these autoantibody was significant (P=0.005). There was no association between AML with desmin and myosin, which reactivities of the AML to these proteins were low. Autoantibodies anti-LC1 was found in 52% of samples AML positive and in 15% of samples AML negative. It was also found the presence of anti-SLA/LP in 14% of positive samples for AML and in 8% of the negative samples. AMA-M2 antibodies and anti-LKM1 were not found in any of these groups. Conclusions: This study found an AML prevalence of 21%, with 1.1/1 men/women relation. The AML presence was not associated with any of the demographic, clinical and laboratory data from the HCV carries evaluated or associated with tissue lesion. Determine fluorescence patterns and sample titles are relevant to detect these antibodies. Only the minority of the AML from HCV carriers evaluated recognized the proteins F-actin, desmin and myosin. High expression of anti-LC1 antibodies were found in these HCV carries.
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Lebertransplantation bei Patienten mit hepatozellulärem Karzinom. Eine retrospektive Studie am Universitätsklinikum Leipzig im Zeitraum von 1994 bis 2010. Charakterisierung des Patientenkollektivs und Analyse von Einflussfaktoren auf Überleben und Outcome.

Kienlein, Andreas 07 June 2016 (has links)
Für Lebertransplantationen bei Patienten mit hepatozellulärem Karzinom stellt sich angesichts der defizitären Organspendesituation die berechtigte Frage, unter welchen Bedingungen diese Form der Therapie ein gutes Outcome für die Patienten verspricht und somit keine Verschwendung der ohnehin knappen Ressourcen darstellt. Ziel dieser Arbeit war es, ein Kollektiv aus 98 Patienten, die an einem hepatozellulären Karzinom erkrankten und im Zeitraum von 1994 bis einschließlich 2010 am Universitätsklinikum Leipzig eine Lebertransplantation erhielten, retrospektiv zu charakterisieren und den Einfluss mehrerer Faktoren auf das Outcome der Patienten zu untersuchen. Bei den Faktoren handelte es sich um die Wartezeit, den präoperativen Einsatz der TACE, den präoperativen AFP-Serumspiegel, sowie die Tumorzahl und -größe. Der Nachbeobachtungszeitraum lag bei 3 Jahren. Die Charakterisierung des Kollektivs erbrachte folgende Ergebnisse: Das Kollektiv bestand zu rund 80% aus Männern. Das mediane Alter zum Zeitpunkt der Transplantation lag bei 59 Jahren. Die Transplantationszahlen bei HCC-Patienten sind am UKL seit Einführung des MELD-Scores 2006 deutlich angestiegen. Die mediane Wartezeit hat sich seit Einführung des MELD-Scores nicht wesentlich verändert. Sie betrug 7,3 Monate in der Prä-MELD-Ära und 6,9 Monate in der MELD-Ära. Mit über 60% war der Alkoholabusus die häufigste Ursache für die Entstehung des hepatozellulären Karzinoms. An zweiter Stelle stand die Hepatitis-C-Infektion. In der Diagnostik des HCC spielte die Computertomographie die größte Rolle. Die Sensitivität des AFP zur Erfassung des HCC (>400 ng/ml) war mit Werten unter 30% sehr niedrig. Die TACE war die mit Abstand am häufigsten durchgeführte, neoadjuvante Maßnahme. Zum Zeitpunkt der Transplantation befanden sich rund 75% der Patienten in einem Stadium bis maximal T2. Das Auftreten von solitären und multifokalen HCCs war in etwa gleich häufig (46,9% vs. 53,1%). Die Milan-Kriterien waren bei knapp 39% der Patienten im postoperativen Explantat-Befund überschritten. Nach Transplantation traten bei 26 Patienten Abstoßungsreaktionen auf. 8 Patienten mussten aufgrund eines Transplantatversagens retransplantiert werden. Das postoperative Überleben (intention-to-treat) betrug 75,5% (6 Monate), 71,4% (1 Jahr) und 63,3% (3 Jahre). Die entsprechenden Rezidivraten lagen bei 11,2%, 14,3% und 22,4%. Rezidiven traten am häufigsten in der Spenderleber auf, gefolgt von einem Befall der Lymphknoten und Knochen. Ein signifikanter Einfluss auf das Outcome der Patienten konnte für das AFP, die Tumorzahl und die Milan-Kriterien nachgewiesen werden: Präoperative AFP-Spiegel unter 100 ng/ml zeigten eine signifikant niedrigere Rezidivrate. Multifokale Tumoren waren mit einem signifikant schlechteren 3-Jahres-Überleben verknüpft. Bei Erfüllung der Milan-Kriterien (im postoperativen Explantat-Befund) war die Rezidivrate signifikant und die Überlebensrate deutlich besser. Für die Wartezeit konnte seit Einführung des MELD-Scores eine positive Entwicklung festgestellt werden. Das 3-Jahresüberleben hat sich bei Wartezeiten unter 12 Monaten um 22,5% verbessert. Die Rezidivrate ist bei Wartezeiten über 12 Monate um 15,3% gesunken. Für den Einfluss der TACE auf das Outcome der Patienten konnten keine signifikanten Unterschiede festgestellt werden. Auch andere Studien belegten bisher lediglich einen Vorteil für das erfolgreiche Downstaging gegenüber Patienten, bei denen die TACE erfolglos blieb. Für die Untersuchung des tatsächlichen Nutzens einer TACE vor Transplantation werden daher Studien mit höherem Evidenzgrad benötigt.:Bibliographische Beschreibung 1 Abkürzungsverzeichnis 2 1 Einleitung 3 1.1 Hepatozelluläres Karzinom 3 1.1.1 Epidemiologie 3 1.1.2 Ätiologie 3 1.1.3 Symptome 4 1.1.4 Diagnostik 4 1.1.5 Stadieneinteilung 8 1.1.6 Staging und Therapieoptionen 10 1.2 Lebertransplantation 15 1.2.1 Indikationen 15 1.2.2 Prinzip 15 1.2.3 Nachsorge 16 1.2.4 Begriffsklärungen 17 2 Fragestellung 21 3 Patienten und Methoden 22 3.1 Patienten 22 3.2 Methoden 22 3.2.1 Datenerhebung 22 3.2.2 Statistische Auswertung 23 4 Ergebnisse 25 4.1 Charakterisierung des Kollektivs 25 4.1.1 Allgemeines 25 4.1.2 Vor der Transplantation 26 4.1.3 Histopathologischer Befund 34 4.1.4 Nach der Transplantation 39 4.2 Einflussfaktoren auf das Outcome nach LTX 44 4.2.1 Wartezeit (nach Allokationssystem) 44 4.2.2 Transarterielle Chemoembolisation 48 4.2.3 Alpha-Fetoprotein 50 4.2.4 Tumorzahl und -größe 54 5 Diskussion 58 5.1 Charakterisierung des Kollektivs 58 5.1.1 Allgemeines 58 5.1.2 Vor der Transplantation 59 5.1.3 Histopathologischer Befund 60 5.1.4 Nach der Transplantation 62 5.2 Einflussfaktoren auf das Outcome nach LTX 63 5.2.1 Wartezeit (nach Allokationssystem) 63 5.2.2 Transarterielle Chemoembolisation (TACE) 66 5.2.3 Alpha-Fetoprotein 69 5.2.4 Tumorzahl und -größe 72 6 Zusammenfassung 76 Abbildungsverzeichnis 78 Tabellenverzeichnis 79 Literaturverzeichnis 81 Danksagung 91 Erklärung zur Datenaufbewahrung 92 Erklärung über die eigenständige Abfassung der Arbeit 93
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A Statistical Framework for Classification of Tumor Type from microRNA Data / Ett statistiskt ramverk för klassificering av tumörtyp från mikroRNA data

Röhss, Josefine January 2016 (has links)
Hepatocellular carcinoma (HCC) is a type of liver cancer with low survival rate, not least due to the difficulty of diagnosing it in an early stage. The objective of this thesis is to build a random forest classification method based on microRNA (and messenger RNA) expression profiles from patients with HCC. The main purpose is to be able to distinguish between tumor samples and normal samples by measuring the miRNA expression. If successful, this method can be used to detect HCC at an earlier stage and to design new therapeutics. The microRNAs and messenger RNAs which have a significant difference in expression between tumor samples and normal samples are selected for building random forest classification models. These models are then tested on paired samples of tumor and surrounding normal tissue from patients with HCC. The results show that the classification models built for classifying tumor and normal samples have high prediction accuracy and hence show high potential for using microRNA and messenger RNA expression levels for diagnosis of HCC. / Hepatocellulär cancer (HCC) är en typ av levercancer med mycket låg överlevnadsgrad, inte minst på grund av svårigheten att diagnosticera i ett tidigt skede. Syftet med det här projektet är att bygga en klassificeringsmodell med random forest, baserad på uttrycksprofiler av mikroRNA (och budbärar-RNA) från patienter med HCC. Målet är att kunna skilja mellan tumörprover och normala prover genom att mäta uttrycket av mikroRNA. Om detta mål uppnås kan metoden användas för att upptäcka HCC i ett tidigare skede och för att utveckla nya läkemedel. De mikroRNA och budbärar-RNA som har en signifikant skillnad i uttryck mellan prover från tumörvävnad och intilliggande normal vävnad väljs ut för att bygga klassificaringsmodeller med random forest. Dessa modeller testas sedan på parade prover av tumörvävnad och intilliggande vävnad från patienter med HCC. Resultaten visar att modeller som byggs med denna metod kan klassificera tumörprover och normala prover med hög noggrannhet. Det finns således stor potential för att använda uttrycksprofiler från mikroRNA och budbärar-RNA för att diagnosticera HCC.

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