Neste trabalho foi desenvolvido um estudo sobre o desvio lateral do feixe utilizado em protonterapia. Por meio de softwares, como o SRIM2012 e GEANT4, que permitem simulações de passagem de partículas pesadas pela matéria, foi possível a obtenção de resultados para estudos específicos nessa área. A importância dessas simulações vem de sua simplicidade de uso frente ao alto custo dos aceleradores de hádrons e a enorme variedade de possibilidades para análises de métodos. A protonterapia vem apresentando resultados promissores frente ao tratamento convencional por fótons, e a análise dos parâmetros calculados por simulações e seus níveis de incerteza na região do pico de Bragg será essencial para o futuro aprimoramento de planos de tratamento em protonterapia. Foram utilizados alvos compostos de água e também de materiais substitutos aos tecidos humanos para a análise do espalhamento do feixe de prótons, e os resultados obtidos apresentam a tendência do aumento do desvio lateral na região de máximo alcance dos prótons com o aumento da energia inicial do feixe, sendo esta incerteza lateral da mesma ordem de grandeza da incerteza em profundidade encontrada na literatura atual. / This work developed a study of the lateral deviation of the beam used in proton therapy. Through software, such as SRIM2012 and GEANT4, which allow simulations of heavy particles passing through matter, it was possible to obtain results for specific studies in this area. The importance of these simulations comes from its simplicity of use mainly due to the high cost of hadron accelerators and the huge variety of possibilities for methods analysis. The proton therapy has shown promising results compared to conventional treatment by photons, the analysis of the parameters calculated by simulations and their levels of uncertainty in the region of the Bragg peak will be essential for future improvements of treatment plans in proton therapy. Targets used were composed of water and also of human tissue substitute materials for scattering analysis of the proton beam, and the results show the trend of increased lateral deviation with initial energy of the beam increasing in the region of maximum range of protons, where we find the Bragg peak, and this lateral uncertainty has the same order of magnitude than the uncertainty in depth found in the current literature.

Neste trabalho foi desenvolvido um estudo sobre o desvio lateral do feixe utilizado em protonterapia. Por meio de softwares, como o SRIM2012 e GEANT4, que permitem simulações de passagem de partículas pesadas pela matéria, foi possível a obtenção de resultados para estudos específicos nessa área. A importância dessas simulações vem de sua simplicidade de uso frente ao alto custo dos aceleradores de hádrons e a enorme variedade de possibilidades para análises de métodos. A protonterapia vem apresentando resultados promissores frente ao tratamento convencional por fótons, e a análise dos parâmetros calculados por simulações e seus níveis de incerteza na região do pico de Bragg será essencial para o futuro aprimoramento de planos de tratamento em protonterapia. Foram utilizados alvos compostos de água e também de materiais substitutos aos tecidos humanos para a análise do espalhamento do feixe de prótons, e os resultados obtidos apresentam a tendência do aumento do desvio lateral na região de máximo alcance dos prótons com o aumento da energia inicial do feixe, sendo esta incerteza lateral da mesma ordem de grandeza da incerteza em profundidade encontrada na literatura atual. / This work developed a study of the lateral deviation of the beam used in proton therapy. Through software, such as SRIM2012 and GEANT4, which allow simulations of heavy particles passing through matter, it was possible to obtain results for specific studies in this area. The importance of these simulations comes from its simplicity of use mainly due to the high cost of hadron accelerators and the huge variety of possibilities for methods analysis. The proton therapy has shown promising results compared to conventional treatment by photons, the analysis of the parameters calculated by simulations and their levels of uncertainty in the region of the Bragg peak will be essential for future improvements of treatment plans in proton therapy. Targets used were composed of water and also of human tissue substitute materials for scattering analysis of the proton beam, and the results show the trend of increased lateral deviation with initial energy of the beam increasing in the region of maximum range of protons, where we find the Bragg peak, and this lateral uncertainty has the same order of magnitude than the uncertainty in depth found in the current literature.

Objetivo: Avaliar as vitaminas e as enzimas envolvidas na defesa antioxidante e os marcadores de peroxidação lipídica durante o tratamento oncológico de pacientes com neoplasia de estômago ou de esôfago Casuística: O estudo prospectivo longitudinal foi conduzido com 14 pacientes com neoplasia de estômago ou de esôfago [62,1 anos (IC95% 55,6-68,6)], sob tratamento oncológico em unidade especializada. O estudo incluiu também 15 voluntários saudáveis [61,3 anos (IC95% 57,3-65,3)]. Métodos: Foram aplicados os questionários de ingestão alimentar (Recordatórios de 24h), de qualidade de vida (FACT G), de fadiga (FACIT Fatigue) e inquéritos relacionados com efeitos adversos e de toxicidade (CTCAE) que potencialmente interferem na ingestão alimentar e no estado nutricional. Foram feitas as medidas antropométricas, a impedância bioelétrica e coleta de sangue para os exames laboratoriais. Foram dosadas as vitaminas antioxidantes C e E, as enzimas superóxido dismutase (SOD) e glutationa peroxidase (GPx), além dos marcadores de peroxidação lipídica, malondialdeído (MDA) e 8-isoprostano. No Grupo Câncer, os procedimentos foram feitos antes do início, na metade e ao término do tratamento oncológico; o Grupo Controle foi submetido às mesmas avaliações em apenas uma ocasião. A análise estatística foi feita por meio do software Statistica 8.0, usando testes estatísticos não paramétricos. Resultados: Não foram observadas diferenças nos escores de qualidade e de fadiga. As reações adversas relacionadas ao tratamento oncológico foram redução da ingestão de alimentos, saliva espessa com alteração no paladar e náuseas. Antes do início do tratamento, os pacientes com câncer já haviam perdido 17% do peso em relação ao usual; o peso corporal e o IMC reduziram entre a primeira e a terceira avaliação, mas não houve alteração na composição de massa corporal magra e gorda, na ingestão energética e da maioria dos macronutrientes no decorrer do estudo. Quando comparados ao Grupo Controle, o Grupo Câncer apresentou menores valores de vitamina C [10,8 (IC95%4,5-17,0) vs. 25,5 (IC95%19,9-30,7) mol/L], maiores valores da SOD [2056 (IC95%1933-2178) vs. 1595 (IC95%1430-1761) USOD/gHb] e MDA [0,73 (IC95%0,50-0,88) vs. 0,29 (IC95%0,25-0,33) mol/]. No decorrer do estudo, houve diminuição nos níveis de SOD entre a primeira e a segunda [2056 (IC95%1933-2178) vs. 1973 (IC95%1826-2120) USOD/gHb] e entre a primeira e a terceira avaliação [2056 (IC95%1933-2178) vs. 1827 (IC95%1687-1967) USOD/gHb]. A concentração da vitamina C permaneceu baixa e os valores da GPx, vitamina E, MDA e 8-isoprostano permaneceram inalterados durante o estudo. Conclusões: O tratamento oncológico reduziu o peso, mas não alterou os escores de qualidade de vida e de fadiga. No início do estudo, a baixa concentração da vitamina C e os valores aumentados da SOD e do MDA sugerem que o processo tumoral induz o estresse oxidativo e a peroxidação lipídica. A redução da atividade da SOD e os valores inalterados da GPx, vitamina C, vitamina E, MDA e isoprostano ao longo do estudo, sugerem que o tratamento oncológico não intensifica o estresse oxidativo. / Objective: To evaluate the vitamins and the enzymes involved in antioxidant defense and lipid peroxidation markers for cancer treatment of patients with gastric or esophageal cancer. Subjects: The prospective longitudinal study was conducted with 14 patients with gastric or esophageal cancer [62,1 years (IC95% 55,6-68,6)], under cancer treatment in a specialized unit. The study also included 15 healthy volunteers [61,3 years (IC95% 57,3-65,3)]. Methods: The questionnaires about dietary intake (24-hour Dietary Recall), quality of life (FACT-G), fatigue (FACIT-Fatigue) and inquiries related adverse effects and toxicity (CTCAE) that potentially interfere with food intake and nutritional status were applied. The anthropometric measurements, the bioelectrical impedance and blood collection for laboratory tests were made. The antioxidant vitamins C and E, the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) were dosed, beyond the markers of lipid peroxidation, malondialdehyde (MDA) and 8-isoprostane. In the Cancer Group, the procedures were done before the start, in the middle and at the end of cancer treatment; the Control Group underwent the same evaluations on only one occasion. The statistical analysis was performed using Statistica 8.0 software, using non-parametric statistical tests. Results: There were no differences in the quality and fatigue scores. The adverse reactions related to cancer treatment were the reduction of dietary intake, thick saliva with altered taste and nausea. Before the treatment, the patients with cancer had already lost 17% of weight with respect to the usual; the body weight and IMC reduced between the first and the third evaluation, but there was no change in the composition of lean and fat mass, energy intake and most micronutrient during the study. When compared to the Control Group, the Cancer Group had lower vitamin C [10,8 (IC95% 4,5-17,0) vs. 25.5 (IC95% 19,9-30,7) mol/L], higher values of SOD [2056 (IC95% 1933-2178) vs. 1595 (IC95% 1430-1761) USOD/gHb] and MDA [0,73 (IC95% 0,50-0,88) vs. 0,29 (IC95% 0,25-0,33) mol/L]. During the study, there was a decrease in the levels of SOD between the first and the second [2056 (IC95% 1933-2178) vs. 1973 (IC95% 1826-2120) USOD/gHb] and between the first and the third evaluation [2056 (IC95% 1933-2178) vs. 1827 (IC95% 1687-1967) USOD/gHb]. The concentration of vitamin C remained low and values of GPx, vitamin E, MDA and 8-isoprostane were unchanged during the study. Conclusions: The cancer treatment reduced the weight but did not change the quality of life scores and fatigue. At the beginning of the study, the low concentration of vitamin C and increased levels of SOD and MDA suggest that the tumor process induced oxidative stress and lipid peroxidation. The reduction of the SOD activity and the unchanged values GPx, vitamin C, vitamin E, MDA and isoprostane throughout the study suggest that the cancer treatment does not enhance oxidative stress.

Orientador: Marcelo Brocchi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T04:43:16Z (GMT). No. of bitstreams: 1 Damiani_IgorAlexandreCampos_M.pdf: 2676549 bytes, checksum: 95c7715f3b322149e80749501a5500a2 (MD5) Previous issue date: 2011 / Resumo: Salmonella enterica Typhimurium é uma bactéria anaeróbica facultativa que apresenta tropismo por áreas tumorais. Esta interessante propriedade abre novas perspectivas em relação à pesquisa contra o câncer, pois há muito tempo buscam-se veículos seletivos para a eliminação de neoplasias. A inibição do crescimento tumoral e até mesmo seu total retrocesso foram observados em modelos murinos de câncer tratados com linhagens atenuadas de S. enterica. Além disso, seu potencial como veículo de moléculas antitumorais exógenas (vacina de DNA, RNAi, citocinas e enzimas, por exemplo) também foi descrito. No entanto, as linhagens testadas em humanos até o presente não induziram os mesmos efeitos observados nos modelos animais. Isto indica que estudos adicionais são necessários para otimização desta terapia, incluindo o teste de novas linhagens mutantes atenuadas de S. enterica....Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Salmonella enterica Typhimurium, a facultative anaerobic bacterium, presents tropism for tumor areas. This interesting property creates new perspectives in cancer research, in which great efforts have been done to seek a drug carrier that could selectively target and destroy malignant cells. Inhibition of tumor growth and even its total elimination were observed in murine cancer models infected by attenuated strains of S. enterica. Besides, its potential as a carrier of exogenous antitumor molecules (DNA vaccine, iRNA, cytokines and enzymes, for example) is also described. Nevertheless, when these strains were tested in humans, they did not induce the same effects observed in murine models. Thus, additional studies are needed to optimize this therapy, including the test of novel S. enterica attenuated strains...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Microbiologia / Mestre em Genética e Biologia Molecular

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Despite the advances in therapies such as chemotherapy and radiotherapy, tumours have been shown to be resistant to the treatments. Gold nanoparticles (AuNPs) have been recognized as effective radiosensitizers of low energy (e.g. 200–500 kV) X-rays, leading to the emission of Auger electrons that cause highly localised ionizing damage to cells. Spherical AuNPs were synthesised via the reduction of the chloroaurate ions by sodium citrate. Characterisation of AuNPs involved UV-visible spectrophotometry, zeta (Z) potential, dynamic light scattering (DLS) and polydispersity index (PDI) measurements for determination of surface plasmon resonance (SPR), surface charge and stability, as well as transmission electron microscopy (TEM) for hydrodynamic core sizes, size distribution width and shape of AuNPs. Both the 5 and 10 nm AuNPs were found to be anionic with λmax absorbance of 525 nm and uniform size distribution. DLS measurement at 38.12 nm and 48.50 nm, respectively for 5 nm and 10 nm AuNPs, points to aggregation of the AuNPs. However, TEM measurements confirmed the core size of the 10 nm AuNPs. Non-malignant Chinese hamster ovary (CHO-K1), brain endothelial (BEnd5), breast (MCF-10A), isolated human lymphocytes and malignant breast (MCF-7) cell lines were treated with 50 μg/ml of AuNPs, and irradiated with either 1, 2 or 4 Gy X-rays or 1 or 2 Gy p(66)/Be neutron radiation. The γ-H2AX foci assay, cytokinesis-block micronucleus assay, MTT assay and fluorescence-activated cell sorting (FACS) was used to determine that amount of double stranded breaks (DSBs) in isolated lymphocytes, the presence and number of micronuclei (MNi) within binucleated cells (BNCs), cell viability and cell cycle progression, respectively. Preliminary experiments that established the reliability of the study regarding the induction of DNA damage after the bombardment of AuNPs by scattered low kV X-rays, were carried out on lymphocytes. Combined treatment (AuNPs and radiation) resulted in more endogenous foci in comparison to lymphocytes that were treated with AuNPs only. The CHO-K1 and MCF-7 cells showed higher MNi frequencies after the combination treatment of AuNPs and radiation compared to the number of MNi in samples exposed to AuNPs and radiation separately. The AuNPs alone influenced the cellular kinetics of all cell types. Interaction indices, which is the enhancement factor of AuNPs in combination with radiation, for AuNPs and 6 MV 2 Gy X-rays of 1.6 to 1.7 and 1.3 to 1.4 have respectively been determined for CHO-K1 and MCF-7 cells, whilst that for the other cell types used in the study were not different from Unity. As expected, the interaction indices between AuNPs and p(66)/Be neutrons was lower than the interaction indices after 2 Gy X-rays, as p(66)/Be neutrons interact only with the nuclei of the AuNP's atoms and the X-ray photons interact with the orbital electrons of the atoms of the AuNPs leading to Auger electron emission. The cell viability assay showed that 50 μg/ml of AuNPs had an inhibitory effect on cellular proliferation, in all four cell linnes whereas the lower concentrations (2.5, 5 and 10 μg/ml) had no effect. Results in this study, revealed an increase in the accumulation of CHO-K1 an MCF-7 cells in the G₂/M phase of the cell cycle after being treated with AuNPs followed by X-ray radiation, suggesting that the cells have possibly been sensitised to the damaging effects of radiation. Further studies are required to quantify internalised AuNPs and to then link the possible concentration differences of the AuNPs to differences in radiation damage effects observed for the different cell types.

Magister Scientiae (Nutrition Management) - MSc(NM) / Acute lymphocytic leukemia (ALL) is the most common type of childhood cancer accounting for approximately 25% of cancers diagnosed in children less than 20 years of age. It originates in the bone marrow and prevents the normal manufacture of red blood cells, white blood cells and platelets. A poor nutritional status is frequently observed in children with ALL at the time of diagnosis and during treatment which may result in protein energy malnutrition if nutrition intervention is delayed. This retrospective study aims to assess the nutritional status of children newly diagnosed with Acute Lymphoblastic Leukemia (ALL) using 20 case studies between 1 January 2013 and 31 December 2014 from Sheikh Khalifa Medical City (Abu Dhabi, UAE), in order to develop an appropriate nutritional support protocol for pediatric ALL patients treated at this institution. Study Design: A retrospective descriptive case study design was used. The study population consisted of 20 electronic medical records of patients aged between 1-14 years who were newly diagnosed with Acute Lymphoblastic Leukemia (ALL) and admitted to Sheikh Khalifa Medical City for treatment during the period 1 January 2012 and 31 Dec 2014. Data Collection: Identification of suitable participants began through a review of each potential study participant`s electronic medical record. Data was collected and recorded on a data collection form (Appendix III) from the electronic medical record for each suitable participant for the following at admission and during the full duration of all phases of cancer treatment namely induction, consolidation, interim maintenance, delayed intensification and maintenance. The data collected comprised of the following: age, gender, date of diagnosis, symptoms on diagnosis, the cancer diagnosis (type and subtype), anthropometric measurements (weight, length/ height, head circumference), biochemical values (visceral proteins, blood glucose levels, hemoglobin, hematocrit, lymphocyte count), clinical assessment (stomatitis, anemia, mucositis), diet history (home feeding regimes; consumption of daily requirements; food preferences – types, textures; food allergies, food intolerances; food aversions; use of oral nutritional supplements; treatment-related side-effects; systemic related side-effects (nausea; vomiting; diarrhea; anorexia; appetite changes; taste changes; physical activity level; depression), dietary requirements (age and gender related nutritional requirements for energy, protein, fat and fluids) and indications for nutritional support (oral feeding; enteral feeding; parenteral feeding). Analysis of Results: The weights and length/ heights of participants recorded in the electronic medical records were converted to z-scores on the World Health Organization growth charts. The diet prescription of nutritional intervention was interpreted in comparison to the biochemical indices, anthropometric status and dietary intake of each participant. All the data involving changes in anthropometrics, biochemistry, diet history and nutritional interventions from each case study (from diagnosis and through all stages of treatment) was screened and compared with reference values in the context of the age and sex of the child. Evidence based nutritional guidelines were used to document the outcomes of the medical nutrition treatment provided in order to develop a nutrition support protocol for children with Acute Lymphoblastic Leukemia at Sheikh Khalifa Medical City. Results: The results showed that weight loss expressed as a percentage of body weight provided a more accurate estimate of the true significance of weight loss in subjects undergoing cancer treatment (chemotherapy) for ALL. A weight loss of greater than 5% of body weight over a period of one month is considered a sign of nutritional deprivation even if the subject is not classified as undernourished by anthropometric parameters. Subjects experienced the highest weight loss during the consolidation phase and interim maintenance phases of treatment. Conclusion: It can therefore be concluded that pediatric subjects on cancer treatment for ALL at SKMC and receiving nutritional support underwent changes in nutritional status as manifest by a reduction in more than 5% of their body weight during three phases of treatment namely induction, consolidation and interim maintenance. An appropriate nutrition support protocol was developed based on the results and experience obtained from this study for pediatric ALL patients treated at SKMC.

Bakgrund: Bröstcancer är den vanligaste cancerformen att drabbas av som kvinna. Många kvinnor upplever biverkningar från bröstcancerbehandlingen. En av de vanligaste biverkningarna är fatigue som kan upplevas i olika dimensioner. Sjuksköterskan har en viktig roll att informera, stödja och motivera patienten till att utföra egenvård före, under och efter bröstcancerbehandling. Syfte: Belysa olika former av fysisk aktivitet och dess påverkan på fatigue hos kvinnor vid behandling av bröstcancer.  Metod: En litteraturöversikt genomfördes där elva kvantitativa studier valdes ut. Databaserna som användes var PubMed, MEDLINE with Full Text och ProQuest Nursing & Allied Health Database. Artiklarna har granskats, diskuterats och sammanfattats för att sedan kunnat urskilja likheter och skillnader. Resultat: Det framkom att utförandet av fysisk aktivitet i olika former hade en påverkbar effekt för att minska fatigue hos kvinnor vid behandling av bröstcancer. Resultatet ledde fram till en huvudrubrik: Fysisk aktivitet som bidrar till minskad fatigue med tre underrubriker: Aerob fysisk aktivitet, Kombination av aerob och muskelstärkande fysisk aktivitet samt Promenader som fysisk aktivitet. Diskussion: Utgår från fyra rubriker: Den fysiska aktivitetens upplägg och struktur, Hinder för att utföra fysisk aktivitet, Känslan av att utföra fysisk aktivitet och Sjuksköterskans stödjande funktion. Innehållet har diskuterats tillsammans med Dorothea E. Orems teori om egenvård, samt ny tillförd kvalitativ data. / Background: Breast cancer is the most common form of cancer that affects women. Many women experience side effects from breast cancer treatments. One of the most common side effects is fatigue that can be perceived in different dimensions. The nurse has an important role by informing, supporting and motivating the patient to perform self-care activities before, during and after breast cancer treatment. Aim: Illustrate different forms of physical activity and its effect on fatigue in women undergoing breast cancer treatment. Method: A literature review has been conducted where eleven quantitative studies were selected. The databases used were PubMed, MEDLINE with Full Text and ProQuest Nursing & Allied Health Database. The articles have been reviewed, discussed and summarized in order to distinguish between similarities and differences. Results: It was found that physical activity, in various forms, had an effect to reduce fatigue. The result led to a main heading: Physical activity’s effect on fatigue with three subheadings: Aerobic physical activity, Combination of aerobic and muscle strengthening physical activity and Walking as physical activity. Discussion: Four parts emerged from the result: The physical activity’s planning and structure, Barriers to perform physical activity, Positive experiences of physical activity and Nurse’s supportive function. The content has been discussed in conjunction with Dorothea E. Orem’s self-care theory and new applied qualitative data.

M.Sc. / Statistics provided by the World Health Organization state that cancer accounted for 7.9 million deaths worldwide in 2007, with numbers expected to increase to over 12 million by the year 2030. The transformation of a normal cell to a malignant tumour is known to be the result of a set of several key mutations in the genome of a normal cell, resulting in several unique properties including the evasion of programmed cell death, or apoptosis. Exacerbation of this cell death evasion can occur by overexpression of cell survival effectors such as heat shock proteins (Hsps), which are a family of highly conserved proteins that are rapidly induced in response to a variety of stresses in order to protect the cell from death. These proteins perform this function both by assisting in protein folding and therefore acting as molecular chaperones and also by directly interacting with the apoptotic machinery to prevent the initiation of cellular death. Various Hsps interfere at a range of sites in the intrinsic apoptotic pathway, both upstream of the mitochondria, and downstream at the sites of caspase activation. Similarly, Hsps also interfere at various sites in the extrinsic pathway, the caspase-independent pathways, and also function to promote the activity of survival pathways. Nonsteroidal anti-inflammatory drugs (NSAIDs) are well known for their anti-inflammatory properties via inhibition of cyclooxygenase (COX) enzymes. These drugs have also been shown to induce apoptosis in a variety of cancer cell lines as well as decrease the risk of the development of various cancers. Interestingly, NSAIDs have additionally been shown to have the curious property of activating the heat shock transcription factor (HSF1) at concentrations much higher than that required for inhibition of COX activity. The combination of NSAIDs and hyperthermia has resulted in seemingly contradictory evidence, where some studies show that this combination leads to thermotolerance and resistance to further treatments, whilst other studies have shown that this combination directly leads to cell death or indirectly sensitizes cells to subsequent stress.

M.Sc. / Established therapies currently in use for the treatment of breast cancer are high risk, since their employment harbors multiple undesirable and detrimental side effects. In many cases these are associated with poor therapeutic outcome managing only to briefly extend patient lifespan. As a result, many newly designed treatments have surfaced that aim to effectively remove cancerous tissue and improve survival rates while minimizing the aggressive onsets to the patient. Photodynamic Therapy (PDT) has, for a long time, been targeted as a combatant for cancer. Its therapeutic mechanism is based on the tumor-specific intracellular localization of a photosynthetic compound, i.e: photosensitizer, prior to its irradiation-mediated excitation thereby generating high levels of reactive oxygen species (ROS). At the molecular level, this causes irreversible photodamage to vital intracellular targets resulting in cell death. The plasma membrane-, mitochondrial-, lysosomal-, and endoplasmic reticulum systems are all prime targets of PDT and vary in susceptibility depending on both the type of cancer being treated and the photosensitizer administered. Newly designed photosensitizers are governed by their enhanced structural properties to localize and therefore target certain areas of a cell. Since each cancer type has a unique set of susceptible and resistant characteristics, knowledge of each new photosensitizers’ range, efficiency, and mechanism of cell death is required. This enables pairing of these drugs to appropriate cancer types for maximal PDT effect. Here, two newly designed metallo-phthalocyanine photosensitizers, AlPcSmix and GePcSmix, were analyzed for their photodynamic effect on the estrogen-positive, breast cancer cell line, MCF-7. Being one of the most reliable cell lines, it is a prominent research model because it mimics the problems encountered with tumor resistance to therapy induced cell death via pathway restrictions. Photosensitizer administration and excitation by light irradiation to this cell culture system was therefore referred to as in vitro Photodynamic Treatment (in vitro PDT) and not Therapy. ii Initial dosage and time responsive studies confirmed that 35 μM AlPcSmix and 115 μM GePcSmix both excited using 15 J/cm2 at 680 nm proved most effective in reducing viability, whilst individually contributing little adverse influence to cellular homeostasis. Using these dosages, in vitro PDT analysis on several cellular parameters indicated a complex mode of cell death was induced. Morphology revealed typical markers consistent with apoptotic, autophagic and necrotic cell death while variations in proliferation and cytotoxicity levels were inconsistent with stress responses observed. This correlated with the detection for four common apoptotic markers which also revealed discrepancies within the death pathway as possible mutational deficiencies may have rendered MCF-7 cellular systems incomplete. Taken together, the wide range of cellular parameters studied suggests cells undergo a mixture of death modes interchanging via a complex system of molecular switches over time that concludes in secondary necrosis. This was attributed to the assortment of sulphonated phthalocyanine species enabling a broad intracellular distribution range coupled with the non-specific targeting action typical of the ROS generated, in addition to the absence of a phagocytic conclusion to the death process. In vitro PDT with AlPcSmix was shown to harbor a greater toxicity to GePcSmix as cells completed the death response within a shorter time period however, both promoted MCF-7 population cell death sufficient enough to warrant further study for their use as potential agents in the PDT of breast cancer.

M.Sc. / Breast cancer is the most commonly diagnosed cancer and cause of death in women world wide as well as in South Africa. Cancer is characterized by over-proliferation of cells or the inhibition of programmed cell death known as apoptosis, a well coordinated process that results in the activation of several proteases and other hydrolytic enzymes. Apoptosis is regulated by enhancers and inhibitors, such as heat shock proteins (Hsps) that modulate the apoptotic process according to the demands of specific cells. Hsps can regulate the release of pro-apoptotic factors from the mitochondria as well as inhibit key steps in the apoptotic cascade such as activation of caspases. The Hsp70 family constitutes the most conserved and best studied class of Hsps and the stress-induced Hsp70 also blocks the apoptotic pathway at different levels. Hsp70 is furthermore overexpressed in several tumor cells and can effectively inhibit cell death induced by a wide range of stimuli including several cancer related stresses such as hyperthermia, chemotherapeutic agents and nonsteroidal anti-inflammatory drugs (NSAIDs) i.a. aspirin (acetylated salicylic acid) In addition to their potent analgesic, antipyretic and anti-inflammatory activity, NSAIDs can inhibit cell proliferation and induce apoptosis in many cancer cell lines. However, NSAIDs can also lower the temperature threshold for Hsp70 induction and induce a transcriptionally inert intermediate of Hsp70 that can be converted to a transcriptionally active state by a subsequent exposure to heat shock. This suggests that NSAIDs act differently under heat stress, possibly increasing cellular protection through the heat shock response in cancer cells with already elevated levels of Hsps. It is therefore hypothesized that the synergistic use of heat shock with salicylic acid (SA) treatment will increase Hsp70 expression and protein accumulation and further enhance the resistance of breast cancer cells to apoptosis. The effects of SA on its own or in combination with HS on the viability of MCF-7 breast cancer cells as well as Hsp70 protein levels and gene expression were therefore investigated. SA treatments were found to induce cell death in a dose-dependent manner with the most significant decrease in viability observed after treatment with 20 mM SA.