Résumé: De nombreuses études concluent qu'une résection radicale de la tumeur améliore significativement la survie des patients en neuro-oncologie. Toutefois, peu d'écrits se sont concentrés sur l'impact d'une résection radicale sur la qualité de vie (QdV). Afin d'étudier l'effet de l'étendue de la résection chirurgicale sur l'évolution de la QdV, nous avons effectué une étude longitudinale auprès de 35 patients atteints de glioblastome multiforme (GBM). Les patients ont été recrutés alors qu'ils n'avaient reçu aucun traitement. Suite à la chirurgie, les patients ont tous reçu le même protocole de soins standardisés incluant de la chimiothérapie administrée de façon concomitante à la radiothérapie. Les volumes tumoraux ont été obtenus grâce à la délimitation de la tumeur à partir des images obtenues par résonance magnétique et l'étendue de la résection a été déterminée grâce à la comparaison des volumes préopératoires et postopératoires. L'évolution de la QdV a été évaluée à l'aide de la version française validée du Sherbrooke Neuro-Oncoloy Assessment Scale (SNAS), couvrant sept dimensions de la QdV : le bien-être fonctionnel, la sévérité des symptômes/la peur de la mort, le soutien social/l'acceptation de la maladie, l'autonomie pour les soins personnels, la symptomatologie digestive, la fonction neurocognitive et la douleur. Les mesures de QdV ont été effectuées avant l'intervention chirurgicale ainsi que trois mois suivant la chirurgie. En contrôlant pour les effets confondants, soit l'âge, le volume initial de la tumeur, la localisation de la tumeur ainsi que la QdV à la ligne de base (c'est-à-dire avant le début du parcours de soins), les analyses statistiques ont démontré qu'une tumeur plus volumineuse à la ligne de base augmente la douleur et diminue le soutien social/l'acceptation de la maladie (r = 0,41, p = 0,015; r = 0,43, p = 0,009). De plus, une plus grande résection prévient la détérioration du bien-être fonctionnel (r = 0,616, p = 0,005) et des fonctions neurocognitives (r = 0,51, p = 0,026). Nous démontrons également qu'une résection radicale est significativement associée à une amélioration de la survie. Nos résultats indiquent donc qu'une résection plus agressive, en plus d'améliorer la survie des patients, prédit une meilleure évolution de la QdV.||Abstract: Glioblastoma Multiform (GBM) are the most prevalent primary malignant brain tumors. Unfortunately, they are often associated with a grim prognosis. As a first line treatment modality, patients are submitted to surgery. Numerous reports show that aggressive resection significantly improves patients' survival. However, the impact of radical surgical resection on health-related quality of life (HRQOL) has received little attention. The objective of this study was to determine the effect of the initial tumor mass and surgical extent of resection (EOR) on HRQOL for newly diagnosed GBM patients. A longitudinal study has been designed and completed with 35 patients with suspected GBM. None had undergone previous surgery or adjuvant therapy. A quality of life questionnaire, the Sherbrooke Neuro-Oncoloy Assessment Scale (SNAS) was completed before surgery and about 3 months after surgery. EOR was assessed by comparing preoperative and early postoperative contrast-enhanced T1-weighted sequences obtained by magnetic resonance imaging (MRI). Volume measurements were obtained by calculating each tumor area on each axial slice, multiplying each by the appropriate slice thickness (1 mm), and summing up the subvolumes. Results showed that larger baseline tumor volumes induce increased pain (mostly headaches) and decreased social support/acceptance of disease (r = 0.41, p = 0.015; r = 0.43, p = 0.009). Results also showed that compared to biopsies, craniotomies were associated with preserved well-being across nearly all areas of QOL. When extent of resection was analyzed more specifically, results confirmed that larger resections prevented a decrease in functional well-being (r = 0.616, p = 0.005) and neurocognitive functions (r = 0.51, p = 0.026) typically observed as time progresses. Larger resections were also significantly associated with prolonged survival. These results indicate that radical resections avert a decrease in QOL, and thus prolong survival without deteriorating QOL.

Gliomas are the commonest primary tumours of the brain and glioblastoma multiforme (GBM) represents more than 50% of this group. GBM remains a neurosurgical conundrum since patients often succumb to the disease within one year. Surgery followed by radiation and medical regimens over the years have had minimal impact on the prognosis of patients with this cancer and hence, alternative and novel therapeutic modalities are required if the survival of patients with this disease is to be significantly improved. The ATM gene, which is mutated in the disease ataxia-telangiectasia (A-T), is implicated in response to radiation-induced DNA damage, leading to profound radiosensitivity. By reducing the levels of ATM in the radioresistant GBM cells through antisense or RNA interference (RNAi) technology delivered by lentiviruses, malignant GBM tumour cells were successfully sensitised to radiation treatment. In conjunction with surgery, this strategy will provide an enhanced therapeutic intervention especially in the case of GBM where the tumour is untreatable. In this thesis, analysis of the D-3-Phosphoglycerate dehydrogenase promoter in a GBM cell line as well as the development of a novel rat model for GBM using a bioluminescent F98 cell line will also be presented.

Thesis (M.S.)--Northern Michigan University, 2008. / "14-57395." Bibliography: leaves 41-42.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Also available online.

Made available in DSpace on 2015-09-17T15:24:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-16. Added 1 bitstream(s) on 2015-09-17T15:47:58Z : No. of bitstreams: 1 000842459.pdf: 1215251 bytes, checksum: 618e02c015e8c938e811dd12288d82c3 (MD5) / O glioblastoma multiforme (GBM) é o tumor cerebral primário mais comum e letal, e na maioria dos casos leva o paciente à morte em aproximadamente 14 meses após o diagnóstico. O tratamento é realizado com remoção cirúrgica da massa tumoral, seguida de radioterapia e quimioterapia. Entretanto, devido à alta resistência das células tumorais, frequentemente o tumor cresce novamente poucas semanas após a cirurgia. Recentemente demonstramos que HJURP (Holliday Junction-Recognizing Protein), uma nova proteína envolvida em reparo de DNA, está altamente superexpressa em células de glioblastoma. Esta proteína está também superexpressa em outros tipos tumorais, como câncer de pulmão e mama, sendo que maiores níveis de expressão de HJURP correlacionam-se com piores prognósticos de sobrevida em ambos os casos, assim como observamos para os pacientes com GBM. Neste trabalho vimos que os níveis de mRNA de HJURP estão aumentados nas linhagens celulares de GBM T98G, U138MG, U251MG e U343MG, porém não na linhagem U87MG que expressa níveis similares ao de fibroblastos não tumorais. Por análises de western blot, observamos uma redução nos níveis de HJURP após tratamento das células com radiação ionizante, sendo a redução mais proeminente na linhagem U251MG. Vimos ainda que o reparo de quebras na dupla-fita de DNA, induzidas pela radiação ionizante, ocorre de modo similar nas células de GBM U138MG, U251MG e U343MG silenciadas ou não para HJURP. Vimos também que células com silenciamento de HJURP foram mais sensíveis à radiação, apresentando maiores taxas de apoptose e morte celular em relação às células não silenciadas. Além disso, observamos que o silenciamento de HJURP promove senescência precoce na linhagem de GBM U87MG, enquanto que este efeito não é observado na linhagem T98G e em células RO, que são fibroblastos não tumorais. Conjuntamente, estes dados... / Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor, and usually leads the patient to death in approximately 14 months after diagnosis. The treatment consists of surgical removal of the tumor, followed by radiotherapy and chemotherapy. However, due to the high resistance of tumor cells, frequently the tumor grows again a few weeks after surgery. We recently demonstrated that HJURP (Holliday Junction Recognizing Protein), a novel protein involved in DNA repair, is highly overexpressed in glioblastoma cells. This protein is also overexpressed in other tumor types, such as lung and breast cancer, in which higher expression levels are correlated with a poorer survival prognosis, as we also observed for GBM patients. In this study we found that HJURP mRNA levels are increased in the GBM cell lines T98G, U138MG, U251MG e U343MG, while in U87MG cells HJURP levels are similar to that of non-tumoral fibrobalsts. We have also observed that the repair of DNA double-stranded breaks, induced by ionizing radiation, occurs similarly in GBM cells U138MG, U251MG and U343MG when HJURP is silenced or not. We also saw that U87MG and T98G cells were more sensitive to radiation when HJURP is knocked down, presenting higher rates of apoptosis and cell death. Moreover, we observed that HJURP silencing promotes premature senescence in the U87MG cell line, whereas T98G cells and non-tumoral fibroblasts are not significantly affected. Altogether, these data suggests that HJURP is related with the control of DNA repair activity and is required for the maintenance of GBM cells viability.

Orientador : Valéria Valente / Banca: Enilza Maria Espreafico / Banca: Cleslei Fernando Zanelli / Resumo: O glioblastoma multiforme (GBM) é o tumor cerebral primário mais comum e letal, e na maioria dos casos leva o paciente à morte em aproximadamente 14 meses após o diagnóstico. O tratamento é realizado com remoção cirúrgica da massa tumoral, seguida de radioterapia e quimioterapia. Entretanto, devido à alta resistência das células tumorais, frequentemente o tumor cresce novamente poucas semanas após a cirurgia. Recentemente demonstramos que HJURP (Holliday Junction-Recognizing Protein), uma nova proteína envolvida em reparo de DNA, está altamente superexpressa em células de glioblastoma. Esta proteína está também superexpressa em outros tipos tumorais, como câncer de pulmão e mama, sendo que maiores níveis de expressão de HJURP correlacionam-se com piores prognósticos de sobrevida em ambos os casos, assim como observamos para os pacientes com GBM. Neste trabalho vimos que os níveis de mRNA de HJURP estão aumentados nas linhagens celulares de GBM T98G, U138MG, U251MG e U343MG, porém não na linhagem U87MG que expressa níveis similares ao de fibroblastos não tumorais. Por análises de western blot, observamos uma redução nos níveis de HJURP após tratamento das células com radiação ionizante, sendo a redução mais proeminente na linhagem U251MG. Vimos ainda que o reparo de quebras na dupla-fita de DNA, induzidas pela radiação ionizante, ocorre de modo similar nas células de GBM U138MG, U251MG e U343MG silenciadas ou não para HJURP. Vimos também que células com silenciamento de HJURP foram mais sensíveis à radiação, apresentando maiores taxas de apoptose e morte celular em relação às células não silenciadas. Além disso, observamos que o silenciamento de HJURP promove senescência precoce na linhagem de GBM U87MG, enquanto que este efeito não é observado na linhagem T98G e em células RO, que são fibroblastos não tumorais. Conjuntamente, estes dados... / Abstract:Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor, and usually leads the patient to death in approximately 14 months after diagnosis. The treatment consists of surgical removal of the tumor, followed by radiotherapy and chemotherapy. However, due to the high resistance of tumor cells, frequently the tumor grows again a few weeks after surgery. We recently demonstrated that HJURP (Holliday Junction Recognizing Protein), a novel protein involved in DNA repair, is highly overexpressed in glioblastoma cells. This protein is also overexpressed in other tumor types, such as lung and breast cancer, in which higher expression levels are correlated with a poorer survival prognosis, as we also observed for GBM patients. In this study we found that HJURP mRNA levels are increased in the GBM cell lines T98G, U138MG, U251MG e U343MG, while in U87MG cells HJURP levels are similar to that of non-tumoral fibrobalsts. We have also observed that the repair of DNA double-stranded breaks, induced by ionizing radiation, occurs similarly in GBM cells U138MG, U251MG and U343MG when HJURP is silenced or not. We also saw that U87MG and T98G cells were more sensitive to radiation when HJURP is knocked down, presenting higher rates of apoptosis and cell death. Moreover, we observed that HJURP silencing promotes premature senescence in the U87MG cell line, whereas T98G cells and non-tumoral fibroblasts are not significantly affected. Altogether, these data suggests that HJURP is related with the control of DNA repair activity and is required for the maintenance of GBM cells viability. / Mestre

abstract: Patients with malignant brain tumors have a median survival of approximately 15 months following diagnosis, regardless of currently available treatments which include surgery followed by radiation and chemotherapy. Improvement in the survival of brain cancer patients requires the design of new therapeutic modalities that take advantage of common phenotypes. One such phenotype is the metabolic dysregulation that is a hallmark of cancer cells. It has therefore been postulated that one approach to treating brain tumors may be by metabolic alteration such as that which occurs through the use of the ketogenic diet (KD). The KD is high-fat, low-carbohydrate diet that induces ketosis and has been utilized for the non-pharmacologic treatment of refractory epilepsy. It has been shown that this metabolic therapy enhances survival and potentiates standard therapy in mouse models of malignant gliomas, yet the anti-tumor mechanisms are not fully understood. The current study reports that KetoCal® (KC; 4:1 fat:protein/carbohydrates), fed ad libitum, alters hypoxia, angiogenic, and inflammatory pathways in a mouse model of glioma. Tumors from animals maintained on KC showed reduced expression of the hypoxia marker carbonic anhydrase 9 (CA IX), a reduction in hypoxia inducible factor 1-alpha (HIF-1α) and decreased activation of nuclear factor kappa B (NF-κB). Animals maintained on KC also showed a reduction in expression of vascular endothelial growth factor receptor 2 (VEGFR2) and decreased microvasculature in their tumors. Further, peritumoral edema was significantly reduced in animals fed the KC and protein analysis showed significantly altered expression of the tight junction protein zona occludens-1 (ZO-1) and the water channeling protein aquaporin-4 (AQP4), both of which have been implicated in malignant processes in glioma, including the formation of peritumoral edema in patients. Taken together the data suggests that KC alters multiple processes involved in malignant progression of gliomas. A greater understanding of the effects of the ketogenic diet as an adjuvant therapy will allow for a more rational approach to its clinical use. / Dissertation/Thesis / Masters Thesis Biology 2014

Philosophiae Doctor - PhD / Cancer is a group of diseases that arises from irreversible genomic and epigenomic alterations that result in unrestrained proliferation of abnormal cells. Detailed understanding of the molecular mechanisms underlying a cancer would aid the identification of most, if not all, genes responsible for its progression and the development of molecularly targeted chemotherapy. The challenge of recurrence after treatment shows that our understanding of cancer mechanisms is still poor. As a contribution to overcoming this challenge, we provide an integrative multi-omic analysis on glioblastoma multiforme (GBM) for which large data sets on di erent classes of genomic and epigenomic alterations have been made available in the Cancer Genome Atlas data portal. The rst part of this study involves protein network analysis for the elucidation of GBM tumourigenic molecular mechanisms, identification of driver genes, prioritization of genes in chromosomal regions with copy number alteration, and co-expression and transcriptional analysis. Functional modules were obtained by edge-betweenness clustering of a protein network constructed from genes with predicted functional impact mutations and differentially expressed genes. Pathway enrichment analysis was performed on each module to identify statistical overrepresentation of signaling pathways. Known and novel candidate cancer driver genes were identi ed in the modules, and functionally relevant genes in chromosomal regions altered by homologous deletion or high-level amplication were prioritized with the protein network. Co-expressed modules enriched in cancer biological processes and transcription factor targets were identified using network genes that demonstrated high expression variance. Our findings show that GBM's molecular mechanisms are much more complex than those reported in previous studies. We next identified differentially expressed miRNAs for which target genes associated with the protein network were also differentially expressed. MiRNAs and target genes were prioritized based on the number of targeted genes and targeting miRNAs, respectively. MiRNAs that correlated with time to progression were selected by an elastic net-penalized Cox regression model for survival analysis. These miRNA were combined into a signature that independently predicted adjuvant therapy-linked progression-free survival in GBM and its subtypes and overall survival in GBM. The results show that miRNAs play significant roles in GBM progression and patients' survival finally, a prognostic mRNA signature that independently predicted progression-free and overall survival was identified. Pathway enrichment analysis was carried on genes with high expression variance across a cohort to identify those in chemoradioresistance associated pathways. A support vector machine-based method was then used to identify a set of genes that discriminated between rapidly- and slowly-progressing GBM patients, with minimal 5 % cross-validation error rate. The prognostic value of the gene set was demonstrated by its ability to predict adjuvant therapy-linked progression-free and overall survival in GBM and its subtypes and was validated in an independent data set. We have identified a set of genes involved in tumourigenic mechanisms that could potentially be exploited as targets in drug development for the treatment of primary and recurrent GBM. Furthermore, given their demonstrated accuracy in this study, the identified miRNA and mRNA signatures have strong potential to be combined and developed into a robust clinical test for predicting prognosis and treatment response.

Internal ribosome entry site (IRES)-mediated translation is critical for the cell’s ability to respond to stress. Understanding how RNA binding proteins (IRES trans-acting factors; ITAFs) regulate IRESes is crucial to elucidating the mechanism of alternative translation initiation. Furthermore, determining how these ITAFs are regulated is central to understanding their functions in diseased states. I have identified the tumour suppressor programmed cell death 4 (PDCD4) as a novel ITAF of the XIAP and Bcl-xL IRES elements. I demonstrate that under normal conditions, PDCD4 acts to inhibit translation from these IRES elements by preventing formation of the 48S translation initiation complex. Furthermore, I show that in response to treatment with the pro-survival fibroblast growthfactor-2 (FGF-2), S6 kinase 2 (S6K2) phosphorylates PDCD4 leading to its degradation and the subsequent de-repression of XIAP and Bcl-xL translation. Importantly, I demonstrate the clinical significance of this regulation in glioblastoma multiforme (GBM) tumours where the loss of PDCD4 expression correlates with an increase in Bcl-xL protein and poor patient outcome. Additionally, re-expression of PDCD4 down-regulates Bcl-xL and decreases cell viability, and direct inhibition of Bcl-xL by a small molecule antagonist ABT-737 sensitizes GBM cells to the chemotherapeutic doxorubicin. Finally, I demonstrate that PDCD4 can be regulated at multiple levels. Importantly, I identify the RNA binding protein HuR as a regulator of microRNA (miR) -21 induced silencing of PDCD4. I show that HuR can bind the PDCD4 3'UTR and prevent miR-21 binding, and that a loss of PDCD4 expression following H2O2 treatment is mediated via miR-21. These results provide novel insight into the role of PDCD4 as a tumour suppressor and highlight the importance of ITAFs in cancer progression.

Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Lucia Tomášková Supervisor: prof. PharmDr. Tomáš Šimůnek, Ph.D. Title of diploma thesis: Study of exosomes as a drug delivery system in the treatment of glioblastoma Central nervous system disorders are among the most serious diseases affecting humans. They affect not only the patient's life, but also his/her surroundings. Therefore, their therapy, whether at the level of complete cure or alleviation of accompanying symptoms, is a challenge for scientific research. In our research, we focused on glioblastoma multiforme, a brain cancer not yet treatable. The main drawback in therapy is overcoming the blood-brain barrier. Exosomes, such as the body's natural nano-vesicles, have been shown to be a suitable system for delivering drugs to brain tissue. Our research has shown that by a suitable method we are able to obtain sufficient quality exosomes from macrophage and fill them very efficiently with antitumor agents paclitaxel, doxorubicin and temozolomide, while the delivered substances show higher efficacy and fewer side effects than the free form.