HOXA7 belongs to a family of homeobox transcription factors that are master regulators of cell differentiation, morphogenesis during embryonic development and cell proliferation. Dysregulation and non-nuclear localization of these proteins play a role in a large number of solid tumours, with reports of significant upregulation of HOXA7 in oral dysplasia. It is unclear whether HOXA7 induction in solid tumours is causative or if it is a result of oncogenic changes. In this thesis we studied its effect on cell differentiation, growth, stemness, cell migration, EMT and cell senescence. The main hypothesis was that HOXA7 regulated keratinocyte differentiation through the regulation of activator protein 1 (AP-1), a keratinocyte specific activator of differentiation. We also hypothesised that HOXA7 increased the proliferation rate in keratinocytes. In an AP-1 reporter assay in HEK293 cells, HOXA7 was shown to decrease AP-1 activity significantly. The inactivation of AP-1 was not due to inactivation of PKC, as HOXA7 did not interfere with the activation of the kinases in HEK293. More specifically, we reported a very significant repression of c-Jun and JunD promoter activity in the presence of ectopic HOXA7 in HEK293 cells. We further showed that this mechanism might also be applicable in keratinocytes, as HOXA7 inhibited the transcription of AP-1 subunits of both the Jun and Fos family in skin keratinocytes. Furthermore, we showed transcriptional repression of four differentiation markers and a downregulation of K1 and FLG protein in transduced NEB-1 monolayers as well as K1 suppression in HaCaT cells. The organotypic cultures revealed a downregulation of K1, K10, and filaggrin in stratified HaCaT cells by HOXA7. There was however no downregulation in oral keratinocytes. These observations taken together suggested that HOXA7 repressed the synthesis of AP-1 units in skin keratinocytes, which would have resulted in reduced quantities of AP-1 and therefore lower activity. Contrary to previous reports, we observed no positive involvement of HOXA7 in keratinocyte proliferation, EMT or migration. There was however an indication of cell-type specific MET and induced cell senescence. Based on our results we propose a cell-type specific role of HOXA7 as an antagonist of AP-1 transcription in skin keratinocytes, and a possible direct binding of HOXA7 to c-Jun and JunD promoters.

Merlin is a tumour suppressor protein that is frequently mutated or downregulated in cancer. Biallelic Merlin inactivation is causative of tumour formation, including schwannoma, meningioma and ependymoma. These tumours can occur sporadically or as part of the genetic condition Neurofibromatosis type 2 (NF2) and cause significant morbidity. The current treatment options are restricted to surgery and radiotherapy, which are invasive and may cause further tumour development. The activity of both the E3 ubiquitin ligase complex Cullin 4 really interesting new gene (RING) E3 ubiquitin ligase- DNA damage binding protein (DDB1) and Cullin 4 associated factor 1 (CRL4-DCAF1) and Kinase suppressor of RAS 1 (KSR1) have been shown to be upregulated in schwannoma to drive tumour growth. KSR1 has also been shown to interact with components of the CRL4-DCAF1 complex. We investigated the expression, interaction and therapeutic potential of targeting these proteins in Merlin deficient schwannoma and meningioma using a primary human cell model and relevant cell lines. We found that DCAF1 and KSR1 protein were overexpressed in schwannoma and meningioma and confirmed that targeting both DCAF1 and KSR1 in meningioma had additive effects on proliferation. We also identified that CRL4-DCAF1 facilitates KSR1 dependent RAF/Mitogen-activated protein kinase (MAPK)/ Extracellular signal regulated kinase (ERK) kinase (MEK)/ERK pathway activity. We showed MLN3651, a neddylation inhibitor that targets ubiquitin ligase activity, reduced proliferation and activated apoptosis in Merlin-deficient tumours. We also showed that Merlin-positive tumours were less sensitive to MLN3651 than Merlin-deficient tumours; therefore, MLN3651 sensitivity may be CRL4-DCAF1-dependent. Finally, combination of MLN3651 and the MEK1/2 inhibitor AZD6244 had additive effects, particularly in meningioma. Combinatorial therapy activated the Hippo pathway, inhibited RAF/MEK/ERK pathway activity and proliferation demonstrating that targeting the activity and downstream pathways of both DCAF1 and KSR1 represents an attractive novel therapeutic strategy in Merlin-deficient tumours.

Glucocorticoids, key hormonal regulators of the stress response, powerfully influence inflammation and metabolism. Reducing excessive glucocorticoid exposure is beneficial in treating metabolic and cognitive disorders, but manipulating systemic endogenous glucocorticoids risks compromising their beneficial effects. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activates glucocorticoids in target tissues and thus inhibition of this enzyme presents a clinical opportunity to reduce tissue-specific glucocorticoid action. Active glucocorticoids also exert potent angiostatic effects by binding the glucocorticoid receptor (GR), and 11β-HSD1 inhibitors have proven beneficial in models of myocardial infarction by promoting angiogenesis. The possibility that 11β-HSD1 inhibitors may increase pathological angiogenesis, such as that seen in solid tumours, remains unaddressed. This project tested the hypothesis that 11β-HSD1 inhibition promotes tumour growth as a result of increased angiogenesis, using murine models of squamous cell carcinoma (SCC) and pancreatic ductal adenocarcinoma (PDAC). Murine SCC or PDAC cells were injected (1x106 cells/flank) into WT female mice fed either standard diet, or diet containing the 11β-HSD1 inhibitor UE2316 (175 mg/kg, N=6/group), or into 11β-HSD1 knockout (Del1) mice fed standard diet. Developing tumours were measured by callipers over several weeks, before animals were culled and tissues collected. SCC tumours grew more rapidly in UE2316-treated mice to reach a significantly (P < 0.01) larger final volume (0.158 ± 0.037 cm3) than in control mice (0.051 ± 0.007 cm3). PDA tumours were unaffected by 11β-HSD1 inhibition or deletion. Immunofluorescent co-staining of tumour sections for CD31/α-smooth muscle actin revealed no differences in vessel density, and RT-qPCR showed no difference in angiogenic factor expression, after 11β-HSD1 inhibition/deletion in either tumour type. GR and 11β-HSD1 RNA expression were greater in SCC vs PDAC tumours (P < 0.001), as was 11β-HSD1 activity (P < 0.0001). In studies using the aortic ring assay of ex vivo angiogenesis, 11β-HSD1 deletion, but not inhibition with UE2316, was shown to prevent glucocorticoid-mediated angiostasis. The growth/viability of tumour cell lines was not affected by UE2316 or corticosterone, as assessed by live cell imaging using the Incucyte imaging system. RNA-sequencing of SCC tumours revealed that multiple factors involved in the innate immune/inflammatory response were reduced in UE2316-treated tumours, and that extracellular matrix regulation was also altered by UE2316. Imaging of tumour sections using Second Harmonic Generation microscopy confirmed that UE2316 altered Type I collagen deposition in SCC (P < 0.001) but not PDAC. 11β-HSD1 inhibition can increase tumour growth, possibly via suppression of inflammatory/immune cell signalling and alteration of the extracellular matrix, and tumours with higher GR and 11β-HSD1 content, such as SCC, may be more at risk. Interestingly this investigation found no evidence of increased angiogenesis in vivo or ex vivo after UE2316 treatment, suggesting that 11β-HSD1 inhibition does not promote angiogenesis in all ischaemic environments. Future work must focus on the effects of 11β-HSD1 inhibition on the immune and extracellular matrix component of the tumour microenvironment. While promotion of pathological angiogenesis does not appear to pose a major threat, 11β-HSD1 inhibitors may still interact with the immune and inflammatory environment in tumours to the detriment of health.

A proteína Akt modula a função de numerosos substratos envolvidos na regulação da sobrevivência celular, progressão do ciclo celular e crescimento celular. Estudos prévios realizados em nosso laboratório demonstraram a superexpressão de Akt em adenoma pleomórfico, mioepitelioma e carcinoma adenóide cístico. O objetivo deste estudo foi analisar a via da proteína Akt através da avaliação da expressão das proteínas NFkB e PTEN em neoplasias benignas e malignas de glândulas salivares através das técnicas de imunohistoquímica, western blotting e imunofluorescência, e a possível interação protéica direta entre p-Akt/Mdm2 e p-Akt/PTEN em linhagem de carcinoma adenóide cístico. A superexpressão nuclear na proteína PTEN foi encontrada nas duas neoplasias malignas estudadas. Além disso, não foi observada interação direta entre as proteínas p-Akt/Mdm2 e p-Akt/PTEN, as quais apresentam localização nuclear em neoplasias de glândulas salivares. / The Akt protein modulates the function of numerous substrates involved in the regulation of cell survival, cell cycle progression and cell growth. Previous studies from our laboratories showed overexpression of Akt and Mdm2 followed by the lack of p53 expression in pleomorphic adenoma, myoepithelioma and adenoid cystic carcinoma. The aim of this study was to analyze the Akt pathway through evaluation of expression of NFkB and PTEN proteins in pleomorphic adenoma, carcinoma ex pleomophic adenoma and adenoid cystic carcinoma by western blotting, immunofluorescence and immunohistochemical techniques, and we have intended to analyse a possible direct interaction between p-Akt/Mdm2 and p-Akt/ PTEN protein in salivary gland tumours. Overexpression of nuclear PTEN was present in both carcinomas studied. In addition, there was no direct interaction between p-Akt/Mdm2 and p-Akt/ PTEN protein, which presents a nuclear localization in salivary gland tumours.

Linfomas pertencem a um grupo de neoplasias em que há proliferação monoclonal de linfócitos malignos, sendo uma das neoplasias mais frequentemente diagnosticadas em cães. Podem ser classificados quanto à forma anatômica em multicêntrico, mediastinal, digestório e extranodal. Dentre os extranodais, os linfomas cutâneos são classificados histologicamente como epiteliotrópicos e não epiteliotrópicos e são predominantemente de imunfenótipo T, com raros casos do tipo B. A principal característica histopatológica do linfoma epiteliotrópico em cães é o tropismo das células neoplásicas pela epiderme, mucosa ou estruturas anexas, enquanto o linfoma não epiteliotrópico é caracterizado pela infiltração dérmica e subcutânea sem invasão das estruturas anexas. Os linfomas cutâneos caninos têm progressão rápida, são considerados bastante agressivos e com mau prognóstico, com baixa taxa de resposta à quimioterapia. Um dos fatores que podem contribuir para isso é a resistência das células a múltiplas drogas e entre esses mecanismos de resistência estão o efluxo de drogas do meio intracelular para o extracelular por meio dos transportadores da família ABC, como a glicoproteína-P, MRP (multiple resistance protein) e BCRP (breast câncer resistance protein) e da LRP (lung resistance protein), uma proteína vault responsável pelo transporte nucleocitoplasmático. O objetivo deste estudo foi caracterizar imunofenotipicamente os linfomas cutâneos, a proliferação celular por meio do marcador Ki67, a expressão das proteínas de resistência glicoproteína-P, MRP, BCRP e LRP e avaliar a relação dessas proteínas com a sobrevida dos animais. Foi realizado um estudo retrospectivo com 21 casos de cães linfomas cutâneos com diagnóstico histopatológico. A técnica de imunoistoquímica foi utilizada para determinar a imunofenotipagem dos linfomas pelos marcadores CD3 e CD20, a proliferação celular por Ki67 e a expressão de glicoproteína-P, MRP, BCRP e LRP. Dos 21 animais, 38% tiveram diagnóstico histopatológico de linfoma epiteliotrópico, 52% eram linfomas não epiteliotrópicos, 5% dos casos de linfoma não tiveram epiteliotropismo definido e 5% foram classificados como neoplasia de células redondas. O imunofenótipo predominante foi CD3+CD20- (76%), 15% dos casos eram CD3-CD20+ e 9% eram CD3+CD20+. A mediana de células marcadas para Ki67 foi de 31%. Com relação aos marcadores de resistência a múltiplas drogas, a mediana da marcação de glicoproteína-P foi de 40%, a de LRP foi de 65% enquanto para MRP e BCRP, 19% e 23%, respectivamente. Os linfomas cutâneos não epiteliotrópicos foram mais frequentes que os epiteliotrópicos e o imunfenótipo predominante foi o T. A ocorrência de linfócitos CD3-CD20+ e CD3+CD20+ indica a necessidade de mais estudos e um painel mais amplo de anticorpos para subtipagem desses linfomas. A glicoproteína-P teve maior expressão nos linfomas não epiteliotrópicos do que nos epiteliotrópicos e não houve correlação entre as proteínas de resistência e o tempo de sobrevida dos animais, sugerindo que, além da biologia da neoplasia, outros mecanismos de resistência a múltiplas drogas diferente dos estudados possam ter um papel relevante na baixa resposta do linfoma cutâneo à quimioterapia. / Lymphoma is a group of blood cell tumors that develop from monoclonal proliferation of malignant lymphocytes. Lymphoma is the most frequent neoplasia in dogs and can be anatomically classified in multicentric, mediastinal, digestive and extranodal. Cutaneous lymphomas an extranodal type of lymphoma are classified histologically in epitheliotropic and non-epitheliotropic and are predominantly of T-cell immunophenotype, and rare cases of B cell phenotype. The main histopathological characteristic of epitheliotropic lymphoma in dogs is the tropism of neoplastic cells by the epidermis, mucosa or adjacent structures, while non-epitheliotropic lymphoma is characterized by dermal and subcutaneous infiltration without invasion of adjacent structures. Canine cutaneous lymphomas have rapid progression, are considered very aggressive and have poor prognosis. These dogs, usually have a low rate of response to chemotherapy which can be associated to an antineoplastic resistance. Among mechanisms of resistance are efflux of drugs from intracellular to extracellular through ABC family transporters such as P-glycoprotein, MRP (multple resistance protein) and BCRP (breast cancer resistance protein) and LRP (lung resistance protein), a vault protein responsible for nucleocytoplasmic transport. The aim of this study was to characterize immunophenotypically cutaneous lymphomas, measure cell proliferation using the Ki67 marker, the expression of resistance proteins P-glycoprotein, MRP, BCRP and LRP and to evaluate the relationship of these proteins with the survival of the animals. A retrospective study was performed with 21 cases of dogs with cutaneous lymphoma with histopathological diagnosis. Immunohistochemical was used to immunophenotyping of lymphomas by CD3 and CD20 markers, Ki67 cell proliferation, and P-glycoprotein, MRP, BCRP and LRP expression. Of the 21 animals, 38% had histopathological diagnosis of epitheliotropic lymphoma, 52% were non-epitheliotropic lymphomas, 5% of lymphoma cases had no definition and 5% were classified as round cell neoplasia. The predominant immunophenotype was CD3+CD20- (76%), 15% of the cases were CD3-CD20 + and 9% were CD3 + CD20 +. The median of cells labeled for Ki67 was 31%. Regarding the markers of resistance to multiple drugs, the median of the P-glycoprotein label was 40%, which 65% of LRP while for MRP and BCRP, 19% and 23%, respectively. Non-epitheliotropic cutaneous lymphomas were more frequent than epitheliotropic lymphomas and the predominant immunophenotype was T. The occurrence of CD3-CD20+ and CD3+CD20+ lymphocytes indicates the need for further studies and a wider panel of antibodies for subtyping these lymphomas. P-glycoprotein had higher expression in non-epitheliotropic lymphomas than in epitheliotropic lymphomas and there was no correlation between resistance proteins and survival time of the animals, suggesting that in addition to the biology of neoplasia other mechanisms of resistance to multiple drugs different from those studied may play a relevant role in the low response of cutaneous lymphoma to chemotherapy.

G3BP1 and G3BP2 are members of a highly conserved family of multi-functional RNA binding proteins, which appear to co-ordinate signal transduction and post-transcriptional gene regulation. Both proteins are over-expressed in cancer, and G3BP1 promotes cell proliferation and survival. Aberrant expression of various RNA binding proteins is common in cancer, and several of these proteins influence tumorigenesis. Therefore, detailed examination of RNA binding proteins, such as G3BPs, may provide insights into the post-transcriptional mechanisms underlying tumorigenesis. Tumours arise as a consequence of genetic mutation or alteration, which often result from stress-induced DNA damage. Cancer progression is facilitated by various epigenetic stress adaptation mechanisms. Stressful stimuli induce transitory translational shut-off, mediated by phosphorylation of eukaryotic initiation factor alpha;(eIF2alpha;). This phosphorylation event leads to formation of discrete cytoplasmic foci known as stress granules (SGs), which are translationally-silent sites of mRNA sorting. It was initially thought that an RNA-binding protein, T-cell internal antigen 1 (TIA-1), was instrumental in both the formation and functioning of SGs, because over-expression of TIA-1 induces spontaneous SGs and concomitantly causes a decrease in reporter gene expression. It is now clear that SG content can change depending on the type of stress, and that various proteins, including G3BP1, can induce spontaneous SGs. In vitro evidence previously implicated both G3BP1 and G3BP2 as endoribonucleases, so it was suggested that G3BPs act to target mRNA for decay at the SG. This project sought to further investigate this proposal, and in this way gain insight into the specific function of G3BPs in post-transcriptional regulation during tumorigenesis. Characterisation of G3BP1 and G3BP2 expression and localisation patterns in human cells and cancer was necessary before functional analyses in human cell systems could be undertaken. Both proteins were found to be over-expressed in breast cancer, irrespective of cancer stage or grade. G3BP1 and G3BP2 were also expressed in all human cell lines tested, despite previously observed tissue-specific expression. These results support the notion that G3BP expression is switched on in parallel with cell proliferation, and as such, may influence tumorigenesis. The results of further analyses suggested that the diverse functions attributed to G3BP1 and G3BP2 may be facilitated by isoform-specific expression, various post-translational modifications and sub-cellular localisation. Despite the absence of a canonical endoribonuclease domain, it was previously reported that site-specific phosphorylation of G3BP1 enables the protein to degrade a synthetic c-myc RNA substrate in vitro. This finding implicated G3BP in the specific regulation of a proto-oncogene. Tailored reporter assays were thus designed in order to address the in vivo consequences of G3BP's putative endoribonuclease activity. Contrary to expectations, all G3BP family members increased or maintained the expression of a range of reporters, at both the mRNA and protein level, irrespective of the presence of any particular cis-acting element, coding sequence or promoter. These results support the emerging notion that G3BPs positively affect the expression of at least some of their target mRNAs, and may also indirectly promote transcription. In contrast to the theory that G3BPs degrade proto-oncogenic mRNA/s, these findings are consistent with a role for G3BP in promoting cell proliferation and survival. Further analyses showed that G3BP1 and G3BP2 simultaneously increased reporter gene expression and induced SG formation. These findings highlighted the fact that SGs are dynamic sorting stations for mRNAs, and not merely sites of stalled translation. This result also supports the notion that a variety of proteins may be recruited to the SG to facilitate a multitude of mRNA fates. Although the precise role of the SG in stress adapation is not known, it is clear that an appropriate integrated stress response (ISR) is required for cells to survive in sub-optimal conditions. It was found that specific G3BP1 knockdown inhibited SG formation and cell survival, and this appeared to occur downstream of eIF2alpha; phosphorylation. The phosphorylation of eIFalpha; is the only factor known to be necessary for SG formation and cell survival. This data is the first to implicate SG formation itself, downstream of eIF2alpha; phosphorylation, in the survival phase of the ISR. The results also suggest that G3BP1 plays a pivotal role in the post-transcriptional mechanisms underlying stress adaptation. To facilitate future analysis of G3BP roles in the regulation of specific transcripts and in SG biology, a pilot study to identify G3BP RNA ligands was undertaken. Immunoprecipitation of epitope-tagged G3BP1 from stable cell lines facilitated purification and isolation of RNA in association with G3BP1. Specific RNA transcripts were subsequently detected and identified by microarray. Many genes were enriched in the G3BP1 immunoprecipitate. Transcript enrichment in the control immunoprecipitate was comparatively weak and seemingly random, suggesting that several replicates will enable generation of a reliable target list. This work forms a promising basis for further investigations into G3BP functionality, and also provides a platform for broader and more large-scale analyses of the mechanisms of post-transcriptional gene regulation. The work presented in this thesis addressed the potential post-transcriptional mechanisms by which the G3BP family of proteins mediate cell proliferation and survival. Both G3BP1 and G3BP2 were shown to be over-expressed in tumours and each appeared to promote reporter gene expression. G3BP1 was also found to play a pivotal role in stress adaptation. A technique to identify novel RNA ligands was assessed, and it was found that G3BP1 may interact with various mRNA transcripts. It is hypothesised that the G3BP family of proteins, and in particular G3BP1, function to determine the fate of specific RNAs in response to cellular stress and other stimuli. In this way, G3BP proteins may facilitate appropriate responses to extra-cellular stimuli which allow for cell proliferation and survival.

One of the main objectives of combining radiation treatment and chemotherapy is to obtain a therapeutic gain by an improved tumour control with less or no enhancement of normal tissue toxicity. The optimal schedule for the combined treatment of cisplatin-radiation is still under investigation. Neither the optimal time interval, nor the most adequate sequence of administration of cisplatin and radiation are known. The results of the trials are also inconclusive. Some trials showed a supra-additive effect from the administration of cisplatin before radiotherapy, others, on contrary, from the injection of drug after radiotherapy. The present work encompasses the major challenges brought by the combined modality treatment: cisplatin-radiotherapy. The major goal of this work was to investigate the optimal treatment sequencing between cisplatin and radiotherapy and also the optimal schedule for head and neck carcinomas. Therefore, a computer-based tumour model with literature-given biological parameters has been developed which has allowed the simulation of treatment with radiation and chemotherapy. Radiotherapy has been simulated on the virtual tumour and the effects of radiotherapy on tumour regression and regrowth have been analyzed. Also, the mechanisms of cisplatin's action on tumour have been implemented, and the phenomena of drug resistance and tumour repopulation during chemotherapy studied. Finally, the combined modality treatment has been simulated, and the effect of drug-radiation interaction on tumour behaviour evaluated. The current investigation has shown that cisplatin administered immediately before radiation gives similar tumour control to the post-radiation sequencing of the drug. Furthermore, the killing effect of the combined modality treatment on tumour increases with the increase in cell recruitment. The individual cell kill produced by cisplatin and radiation leads to an additive-only tumour response when the treatments are given concurrently, and for a synergistic effect cisplatin must potentiate the effect of radiation. The final conclusion, by which cisplatin administered on a daily basis leads to a better tumour control than cisplatin administered weekly, is in accordance with the latest trial results on head and neck cancers. Therefore, treatment regimens that correlate better with the pharmacokinetics and the radiobiological properties of the therapeutic agents result in better outcomes. / Thesis (Ph.D.)--School of Chemistry and Physics, 2004.

Introduction: Radiofrequency ablation (RFA) is a popular method of treating unresectable liver tumours by the use of a high frequency, alternating electrical current that heats and destroys tumour cells. The size of the ablation is limited by localised charring of adjacent tissue that prevents further conduction of the radiofrequency current. In the clinical setting, this results in increased rates of local recurrence in tumours that are greater than 3 cm in diameter as multiple, overlapping ablations need to be performed to treat the one tumour. To overcome this problem, a modified form of RFA called Bimodal Electric Tissue Ablation (BETA) has been created. BETA adds a direct electrical current to the alternating radiofrequency current, thus establishing its bimodal character. When direct currents are used in biological tissues, water is transferred from anode to cathode by a process called electro-osmosis. By attaching the cathode to the radiofrequency electrode, water is attracted to the area thus preventing tissue desiccation and charring. The BETA circuit has been constructed and tested using a porcine model. The aims of the studies are to confirm that larger ablations can be produced with the BETA system and that it is safe to use in an animal model. Three studies have been performed to test these aims in porcine liver. Methods: The first study was designed to compare sizes of the ablation produced between standard RFA and the BETA circuit. This was followed by a long-term study to assess associated changes to liver function and pathological changes within the liver as well as identifying any other treatment related morbidity. The third study assessed the difference in ablation size and safety aspects when the positive electrode of the direct current circuitry was moved from small surface area under the skin to a large surface area on the skin. Results: Ablations with significantly larger diameters are created with the BETA circuit using a multi-tine needle (49.55 mm versus 27.78 mm, p<0.001). This finding was confirmed in the third experiment using a straight needle (25 mm versus 15.33 mm, p<0.001). Ablations produced by the BETA circuit induce coagulative necrosis within the treated liver and the injury heals by fibrosis in a manner similar to other thermal therapies. Significant rises in some serum liver enzymes are seen within 24 hours of treatment but these return to normal within 4 days. An electrolytic type injury can be produced at the site of the positive electrode. By increasing the surface area of this electrode, the risk of tissue damage is decreased but ablations are significantly smaller (18 mm versus 25 mm, p<0.001). Conclusions: The BETA circuit consistently produces significantly larger ablations than RFA. The treatment appears safe but positioning of the positive electrode of the direct current requires careful consideration. Injuries produced behave like other thermal therapies with coagulative necrosis followed by fibrotic healing. As larger ablations are consistently produced, it is hypothesised that with further refinements, tumours greater than 3 cm in diameter could be treated with lower rates of recurrence. / Thesis (M.S.) -- University of Adelaide, School of Medicine, 2008

Laser thermal ablation (LTA) is an in situ ablative technique that induces heat destruction of liver tumours. Despite increasing clinical use of LTA, reports of long-term outcomes and limitation of treatment in specific cohorts of patients with liver tumours are lacking. In addition, the mechanisms of action of therapy have not been fully elucidated. This study highlights the long-term clinical results and limitations of LTA in the treatment of a cohort of patients with unresectable colorectal liver metastases and examines the mechanisms of action of thermal ablative injury in a murine model.

The main aims were to: explore whether there is a relation between doctors’ ability to identify patients’ worry and wish for information and self-efficacy with regard to communicating with patients about difficult matters; describe which cues doctors consider when estimating patients’ worry and wish for information, and investigate whether there is a relation between patients’ satisfaction with doctors’ care and patients’ psychosocial function. Eleven doctors and 69 patients (of which 36 patients participated in the longitudinal study) with carcinoid tumours participated. Doctors’ self-efficacy, and ability to identify patients’ worry/wish for information were investigated at patients’ first admission. Doctors were interviewed about which cues they considered when estimating patients worry/wish for information. Patients’ satisfaction with care (CASC SF 4.0) and psychosocial function (EORTC QLQ-C30, HADS) were measured longitudinally, during the first year after diagnosis. Doctors reported higher self-efficacy when showing good ability to identify patients’ wish for information, than when showing less good ability, overestimated patients’ worry and underestimated patients’ wish for information. Doctors considered patients’ verbal behaviour and body language together with knowledge and experience when estimating patients worry and wish for information. Patients who met doctors showing good ability to identify their wish for information, reported a higher cognitive function than patients who met doctors showing less good ability. At all assessments patients expressed high satisfaction with doctor’ care and patients’ satisfaction did not change over time. Patients’ satisfaction with doctors’ care were related to their psychosocial function shortly after the first three admissions to specialist care. Patients with carcinoid tumours in some respects reported a worse HRQoL than the general Swedish population. Fatigue, diarrhoea, limited possibilities to work/pursue daily activities, and worry that the illness will get worse were among the most prevalent, and worst, aspects of disease- and treatment related distress.