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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.

Prostate cancer and bone cell interactions : implications for metastatic growth and therapy

Nordstrand, Annika January 2017 (has links)
The skeleton is the most common site of prostate cancer bone metastasis, and at present, there are no curable treatments for these patients. To further understand what stimulates tumor cell growth in the bone microenvironment and to find suitable therapies, reliable model systems are needed. For this purpose, we have developed an in vitro co-culture system that can be used to study interactions between tumor cells and murine calvarial bones. To validate the model, we measured the release of collagen fragments and monitored changes in expression levels of genes normally expressed during active bone remodeling. One of the major reasons why prostate cancer cells colonize bone is the abundance of tumor-stimulating factors, such as insulin-like growth factors (IGFs), present in this milieu. We found that the IGF-1 receptor (IGF-1R) was one of the most highly activated receptor tyrosine kinases in tumor cell lines stimulated with bone conditioned media. Since IGF-1 is known to be a strong survival factor for tumor cells, we hypothesized, that concurrent inhibition of IGF-1R signaling can enhance the effects of apoptosis-inducing therapies, such as castration. We used our co-culture model to target human prostate cancer cell lines, PC-3 and 22Rv1, with simvastatin (an inhibitor of the mevalonate pathway and an inducer of apoptosis), in combination with anti-IGF-1R therapy. Tumor cell viability declined with either one of the therapies used alone, and the effect was even more pronounced with the combined treatment. The hypothesis was also tested in rats that had been inoculated with rat prostate cancer cells, Dunning R3327-G, into the tibial bone, and treated with either anti-IGF-1R therapy, castration, or a combination of both therapies. Immunohistochemistry was used to evaluate therapeutic effects on tumor cell proliferation and apoptosis, as well as tumor cell effects on bone remodeling. The tumor cells were found to induce an osteoblastic response, both in vivo in rats, and in vitro using the co-culture model. Interestingly, the therapeutic response differed depending on whether tumor cells were located within the bone marrow cavity or if they had leaked out into the knee joint cavity, highlighting the role of the microenvironment on metastatic growth and therapeutic response. Therapies targeting the IGF-1R have been tested in clinical trials, unfortunately with disappointing results. By immunohistochemical evaluation of bone metastases from patients with castration-resistant prostate cancer, we found a large variance in IGF-1R staining within this group of patients. Hence, we postulate that the effects of anti-IGF-1R therapies could be more beneficial in patients with high tumoral IGF-1R-activity than in IGF-1R negative cases. We also believe that side effects, such as hyperglycemia, associated with anti-IGF-1R therapy, could be reduced if this treatment is administered only to selected patients and for shorter time periods. In a separate study, using whole-genome expression data from bone metastases obtained from prostate cancer patients, we present evidence that a high activity of osteoblasts is coupled to a high activity of osteoclast. Moreover, we found that high bone remodeling activity is inversely related to tumor cell androgen receptor (AR) activity. The results from this study may be of importance when selecting therapy for patients with bone metastatic cancer, especially when bone-targeting therapies are considered, and could aid in the search for novel therapeutic targets. In summary, we present an in vitro model for studies of the bidirectional interplay between prostate cancer cells and the bone microenvironment. We also demonstrate the importance of IGF-1 in prostate cancer bone metastases and suggest that inhibition of IGF-1R signaling can be used to treat prostate cancer as well as to enhance effects of other treatments such as androgen deprivation therapy. Furthermore, we emphasize the possibility of molecular tumor characterization when designing treatment plans for individual patients, thereby maximizing the therapeutic effects.

The impact of Survivin, WRAP53β, and Hypoxia on treatment response in Head and Neck Cancer

Tiefenböck-Hansson, Katharina January 2017 (has links)
Squamous cell carcinoma (SCC) is the most common histological type of cancer in the head and neck region and arises in the epithelial mucosa of the upper aerodigestive tract. Approximately one and a half million people are living with the diagnosis. Despite efforts in prevention and advances in treatment, the 5-year survival rate still lies around 60%, and recurrences and second primary tumors remain a problem. Moreover, treatment responses vary from patient to patient, highlighting the need for individually tailored treatments. To make this possible, biomarkers predicting treatment outcome are needed to better guide treatment decisions. The aim of this thesis was to evaluate the expression of certain proteins and the frequency of certain SNPs (Single nucleotide polymorphisms) in tumor biopsies and cell cultures of head and neck squamous cell carcinomas (HNSCC), and to explore their potential as biomarkers for treatment outcome. Furthermore, we aimed to study the impact of hypoxia on treatment response, epithelial-tomesenchymal transition (EMT), and induction of cancer stem cells (CSC). In papers I and II, we investigated two proteins, survivin and WRAP53β, using immunohistochemistry (IHC) in tumor biopsies from 40 patients categorized as Non-responders or Responders to radiotherapy. High expression of survivin and nuclear expression of WRAP53β were significantly more prevalent in the Responder group. The combination of these two factors correlated strongest to overall survival, but not to a significantly higher extent compared to survivin alone. Moreover, when examined separately, a high percentage of p53-stained cells and the presence of the SNP FGFR4 Gln388Arg correlated to improved overall survival, whereas the SNP XPD Lys751Gln was associated with worse overall survival. The latter three showed no significant correlations to radiotherapy response. In paper III, the two most promising proteins identified in papers I and II were analyzed in a study cohort of 149 tumor biopsies of glottic laryngeal SCC, categorized as T2N0-T3N0. In this patient group, no significant associations between survivin expression and survival could be found. However, expression of cytoplasmic WRAP53β was significantly linked to worse disease-free-survival (DSF) compared to nuclear WRAP53β or negative staining for WRAP53β. Positive expression of p16INK4a was found in 7% of the tumors. The prevalence of p16 INK4a was higher in younger patients (<60) and associated with absence of recurrence and longer DSF. In paper IV, five HNSCC cell lines were cultured in normoxic (20% O2) and hypoxic (1% O2) conditions and changes in treatment response, EMT profile, and expression of CSC markers were examined. As expected, hypoxia induced EMT and to a certain extent expression of CSC markers. Silencing of the hypoxia-inducible-factor-1α (HIF-1α) only partly reversed these effects, suggesting that other mechanisms are involved. Whereas most cell lines became more resistant to treatment in hypoxia, one cell line (LK0412) became more sensitive to cetuximab-treatment in hypoxia, an effect that was revoked by depletion of HIF-1α, suggesting a possible sensitizing effect of HIF-1α to cetuximab-treatment. Taken together, WRAP53β appears to be a promising biomarker candidate for treatment outcome in HNSCC, but further evaluation especially on the subcellular localization of WRAP53β is required. Even though the role of survivin in radiotherapy response in glottic SCC seems to be insignificant, it might have a more important role in other HNSCC subsites. As far as the effects of hypoxia, it appears that hypoxia might have a sensitizing effect on cetuximab-treatment in certain cases, which seems to be HIF1-α –dependent. Further studies are required to clarify the importance of this observation.

Impact of Lysosomal Function in Cancer and Apoptosis

Nilsson, Cathrine January 2008 (has links)
Lysosomes, the recycling units of the cell, participate in the signaling pathway to apoptosis, which has stimulated the search for anti-cancer drugs targeting the lysosomal compartment. Lysosomes are, however, often altered in cancer cells. The aim of this thesis was to investigate the involvement of lysosomes during apoptosis in normal and cancer cells. We developed and used flow cytometric methods to measure cytosolic and lysosomal pH in cells. The cytosolic pH of U937 cells decreased, in a caspase-independent way, by 1.4 pH-units during apoptosis. Concomitantly, the lysosomal pH increased from 4.3 to 5.2, suggesting that proton release from lysosomes might be responsible for cytosolic acidification. When studying the lysosomal pH of head and neck squamous cell carcinoma (HNSCC) cell lines and normal oral keratinocytes (NOKs), the pH was significantly increased in three of five HNSCC cell lines, as compared to NOKs. Moreover, high lysosomal pH correlated to low expression of the B subunit of the vacuolar V0/V1-ATPase, a necessary component of the proton pump responsible for lysosomal acidification, and to reduced intrinsic cisplatin sensitivity. Cisplatin-induced apoptosis was, at least partly, dependent on lysosomal cathepsins. When investigating the colony formation ability of the two HNSCC cell lines LK0412 and SqCC/Y1, both were found to give rise to holoclones, indicating the presence of cells with cancer stem cell properties. Holoclone cells from the LK0412 cell line were less sensitive to cisplatin compared to more differentiated paraclone cells. Moreover, we detected differences in intracellular localization of the lysosomal compartment and expression of cathepsins between holo- and paraclone cells. This thesis shows that changes found in the lysosomal compartment of cancer cells, such as alteration of lysosomal pH, might influence the outcome of a drug treatment. In addition, differences in drug sensitivity between subpopulations of tumor cells may affect the outcome of an anticancer therapy. / Programmerad celldöd eller apoptos är en viktig mekanism för att upprätthålla balans mellan kroppens celler. Vid exempelvis cancer fungerar inte styrningen av denna process, vilket leder till att för få celler dör och en tumör kan växa ohämmat. Denna avhandling fokuserar på lysosomen, en mycket sur organell i cellen som är ansvarig för nedbrytning av cellmaterial. Hos cancerceller är lysosomerna ofta förändrade. Vi har undersökt lysosomernas roll under apoptos hos normala celler och hos cancerceller. För att kunna undersöka pH-förändringar under apoptos har vi utvecklat metoder att mäta cytosoliskt och lysosomalt pH med hjälp av en teknik som kallas flödescytometri. I apoptotiska celler ser vi att det cytosoliska pH:t sjunker med 1.4 pH-enheter till pH 5.7 samtidigt som det lysosomala pH:t ökar från 4.3 till 5.5. Detta tyder på att läckage av vätejoner från lysosomerna kan orsaka en försurning av cytosolen under apoptos. Genom att studera normala orala keratinocyter och jämföra dessa mot fem olika cellinjer eeablerade från skivepitelcancer från munhåla har vi också funnit ett samband mellan det lysosomala pH:t och känsligheten för cellgiftet cisplatin. Cisplatinbehandling leder till apoptos hos alla celler men en högre dos krävs hos celler som har ett högt lysosomalt pH. Tumörer tros innehålla ett litet antal sk cancerstamceller, som har förmåga att kontinuerligt kopiera sig själva utan att åldras. Överlevnad av dessa celler tros vara orsaken till att en tumör återkommer efter en behandling. Vi visar i denna avhandling att cellinjer från skivepitelcancer innehåller celler som har cancerstamcellsegenskaper, och att dessa celler kan ha en lägre känslighet mot cisplatin jämfört med mer utvecklade cancerceller. Lysosomerna utgör ett intressant framtida mål för nya cancerläkemedel. I denna avhandling visar vi att förändringar i det lysosomala systemet kan påverka effekten av ett läkemedel och att skillnader mellan olika sub-populationer av celler från samma tumör kan påverka resultatet av en behandling.

Genomic Alterations in Experimental Endometrial Adenocarcinoma

Falck, Eva January 2012 (has links)
No description available.

Meta-analysis of whether mammilla tumor metastasis can be mitigated by mass-testing

Sabbag, Shafir January 2020 (has links)
Tumors are mutated abnormal groups of cells that develop at any stage of life in any part of the body. Mammilla tumors appear in chest tissue that contain malignant cells in the terminal ductal-lobular unit, where the risk of the development of a mammilla tumor increases with age with a probability of 14.7%. Previous reviews have only focused on radiotherapy and digital mammography, while this review is, to the best of the author´s knowledge, the first review that encompasses the tomosynthesis and presumptive magnetic resonance using digital mammography. The aim of the meta-analysis was to determine the extent in which mass-testing of mammilla tumor metastasis can lead to its mitigation in adult females of all age-groups. The research question was the following: To what extent can mammilla tumor metastasis be mitigated by mass-testing of adult females of all age-groups? As part of the meta-analysis, a literature review was conducted using a selection of keywords in search queries on Pubmed, Libsearch and Academic Search Elite. In conclusion, mass-testing of mammilla tumor metastasis does not lead to a mitigation in adult females of all age-groups, since there was not a statistical significance of pooled value as indicated by the forest plot and the funnel plot indicated that the publication bias had some effect and the Mann-Whitney U-test also indicated that there was not a significance difference. Future research may consist of whether adult females within the age-range of 60-80 benefit from the test.

Sexuell hälsa efter färdigbehandlad gynekologisk cancer : En litteraturöversikt

Elffors, Malin, Norberg, Alexandra January 2022 (has links)

När bröstcancern tog över livet : En litteraturöversikt om kvinnors upplevelser i vardagen

Grenedal, Felicia, Lingesten, Saga January 2022 (has links)

IL13R⍺2-CAR T cells for Immunotherapy of Glioblastoma

Zhu, Xu January 2021 (has links)
Glioblastoma is the most malignant form of gliomas and is a highly infiltrative while non-metastatic tumor of the central nervous system. Patients with glioblastoma have a poor prognosis of 15 months median survival after diagnosis. Promising results were reported in recent clinical trial regarding glioblastoma treatment with chimeric antigen receptor (CAR) T therapy. The lab has previously developed five novel scFvs targeting IL13R⍺2, a tumor-associated antigen in glioblastoma, and integrated them into the second-generation CAR. We named them, 10CAR, 27CAR, 55CAR, 75CAR and 117CAR. The ex vivo cytotoxicity and proliferation assay demonstrated that the 117CAR T construct has the best functionality, while 27CAR T construct has a poor functionality compared to the rest of the constructs. FACS analysis was performed to check the CAR expression in different constructs. 27CAR T cells showed the lowest surface CAR expression and 117CAR T cells displayed the highest out of five constructs. 27CAR T cells were also activated more without stimulation compared to other constructs. We selected out 27CAR and 117CAR T cells for the further investigation to understand the attribution of the discrepancy between 27CAR and 117CAR T cells.   We observed a larger cellular size for 27CAR T cells compared to the rest constructs in flowcytometry analysis, which is usually associated with activation. IFN-γ production of all constructs without target cells stimulation were detected to examine the activation state of different constructs. We observed the highest IFN-γ production in 27CAR T cells without stimulation. These results together indicate that a potent antigen-independent activation or, in other words, tonic signaling is present in 27CAR T cell. The tonic signaling further leads to an early exhaustive phenotype of 27CAR T cells, that is not present in 117CAR T cells. Removing the endodomain of CAR rescued the antigen-independent activation and early exhaustion of 27CAR T cells. The surface and total CAR expression of 27CAR and 117CAR T cells were determined by flowcytometry. 27CAR T cells presented a lower expression of both surface and total CAR. A significantly lower percentage of total CAR on the surface indicates the internalization of CARs in 27CAR T cells. Removing the intracellular domain of 27CAR did not restore the surface expression of CAR. 27CAR and 117CAR differ in four CDRs of scFv, CDR1, 2,3 in the heavy chain and CDR3 in the light chain. We replaced all the amino acids differing between these two constructs with alanine in a CDR-by-CDR manner and obtained five alanine substitution constructs. We then analyzed the CAR expression in Jurkat cells, and we found that the trafficking of CAR to the surface was significantly improved by mutating the CDR2 in the heavy chain or CDR3 in the light chain. Moreover, when the two CDRs were replaced simultaneously, almost all transduced cells expressed CAR, as was the case of cells transduced with 117CAR.   To summarize, the tonic signaling induced by higher tendency of clustering of 27scFv results in the antigen-independent activation and early exhaustion of 27CAR T cells. By removing the endodomain of 27CAR, we abrogated the phenomenon. Further, CDR2 in heavy and CDR3 in light chain in 27scFv are responsible for the impaired trafficking of CAR to the surface.

Costimulation of T cells and its role in T cell recognition of malignant colorectal cells in vitro

Murray, Nicholas January 1998 (has links)
No description available.

The development of a proton grid therapy

Henry, Thomas January 2017 (has links)
No description available.

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