A Doxorrubicina (DOX) é um dos antineoplásicos mais utilizados no tratamento de tumores sólidos, como os de pele. Sua baixa penetração cutânea e instabilidade frente aos tecidos biológicos impedem, no entanto, sua aplicação tópica e localizada. Dentro deste contexto, o objetivo deste trabalho foi direcionar e aumentar a penetração cutânea da DOX, além de protegê-la contra eventuais degradações na pele, através do desenvolvimento de nanopartículas lipídicas sólidas (NLS) contendo DOX e da aplicação da iontoforese. As NLS foram obtidas pelo método da Microemulsão (ME), vertendo-as em excesso de água gelada e agitando o sistema vigorosamente. Foram obtidas NLS com cargas superficiais negativas (NLS-N) e NLS com cargas superficiais positivas (NLS-P). As NLS-N eram compostas por ácido esteárico, lecitina de soja, taurodeoxicolato de sódio e água. E as NLS-P por um derivado do colesterol e/ou ácido esteárico, poloxamer, cloreto de cetilpiridínio e água. As NLS com tamanho de partícula, polidispersividade e potencial zeta adequados para os estudos de permeação cutânea e celular foram definidas a partir de um planejamento fatorial completo (32). NLS-N e NLS-P selecionadas foram incorporadas com 8% de DOX e utilizadas nos estudos de permeação e citotoxicidade. O tamanho médio da NLS-N foi de 175 nm (PdI 0,278) e da NLS-P 278 nm (PdI 0,357). A eficiência de encapsulação foi de 90 e 61% para as NLS-N e NLS-P, respectivamente. Estudos de localização celular foram realizados e observou-se que as NLS-N permitiram a penetração da DOX tanto no citoplasma quanto no núcleo das células, assim como as NLS-P que também permitiram a penetração da DOX em um maior número de células tumorais. Estudos de estabilidade mostraram que a DOX encapsulada nas NLS foi estável a 4º C por até 48 h, sendo que as NLS liofilizadas foram estáveis por pelo menos 30 dias. Nos estudos de liberação da DOX das NLS observou-se que estas sustentaram a liberação da DOX. Porém, as NLS-P liberaram a DOX mais rapidamente do que as NLS-N, 40 e 25% em 72 horas, respectivamente. Nos estudos de permeação cutânea, observou-se que as NLS aumentaram significativamente a quantidade de DOX na solução receptora e na epiderme viável quando comparada com soluções de DOX. As NLS parecem penetrar/fundir na pele carregando o fármaco para camadas profundas da pele, diminuindo sua interação com o estrato córneo. A aplicação da corrente elétrica na dispersão de NLS aumentou a penetração das partículas na pele e, conseqüentemente, a penetração da DOX. As cargas superficiais das NLS positivas e negativas não influenciaram na sua penetração por iontoforese. Estudos de determinação do fluxo eletrosmótico com paracetamol mostraram que o principal mecanismo para a entrada das partículas na pele é o eletrosmótico e não o eletrorrepulsivo (proveniente das cargas). As NLS-P diminuíram o fluxo eletrosmótico significativamente, neutralizando as cargas negativas da pele e evidenciando a penetração das partículas neste tecido. Foram realizados estudos de citotoxicidade da DOX em diferentes formulações, em células B16F10 e em A431, e foi observado que a DOX encapsulada nas NLS-N é significativamente mais citotóxica do que as outras formulações, atingindo uma citotoxicidade de 100% quando em contato com as células de melanoma após apenas 6 h de incubação em concentrações superiores a 20 ng/mL. A aplicação de corrente elétrica em cultura de células aumentou também a penetração do fármaco nas células tumorais e, conseqüentemente, sua citotoxicidade. A indução dos tumores in vivo não se mostrou viável para o modelo de camundongos sem pêlo utilizado, porém o tratamento iontoforético demonstrou-se viável. / Doxorubicin (DOX) is one of the most used antineoplastic drug to treat solid tumors, such as skin cancer. Its low penetration into the skin and its instability in biological tissues, however, difficult topical and localized application. Within this context, the aim of this work was to increase DOX penetration into the skin, and to protect the drug against possible skin degradation, through the development of solid lipid nanoparticles (SLN) and the application of iontophoresis. The standardization and validation of two methodologies for the DOX quantification was performed: one of them using an UV/Vis spectrophotometer and the other using the HPLC. Both methods showed suitable linearity, sensibility, selectively, precision and accuracy, according to the in vigor specifications. SLN was obtained by microemulsion (ME) method spilling them into an excess of water with vigorously shaking. SLN were obtained with negative surface charge (SLN-N) and SLN with positive surface charge (SLN-P). SLN-N contained stearic acid, soy lecithin, sodium taurodeoxicolate, water and SLN-P containing compritol and / or stearic acid, poloxamer, sodium chloride, water. Particle size, polydispersity and zeta potential suitable for studies of skin permeation and cell were defined from a complete factorial design (32). The average size of the SLN-N was 175 nm (PdI 0.278) and the SLN-P 278 nm (PdI 0.357). The encapsulation efficiency was 90, and 61% for SLN-N and SLN -P, respectively. Studies of cellular location were made and showed that the SLN -N allowed the penetration of DOX in the cytoplasm and the nucleus of cells, as well as SLN -P that also allowed the penetration of DOX in a larger number of tumor cells. Encapsulated DOX in the SLN was stable at 4° C for 48 hours, and freeze-dried SLN are stable for at least 30 days. In release studies with DOX-SLN was observed that they control DOX release. However, SLN-P DOX release more quickly than SLN-N, 40 and 25% in 72 hours, respectively. In skin permeation studies, it is observed that SLN significantly increase the amount of DOX in the receiver compartment and in the epidermis. It seems that SLN penetrate / merge the skin carrying the drug to the deep skin layers, reducing its interaction with the stratum corneum. The application of an electrical current increased DOX permeation into the skin, and consequently, DOX penetration. SLN superficial charges do not influence DOX permeatation with iontophoresis. Electrosmotic flow studies showed DOX permeates into the skin mostly for eletrosmose mechanism. Cytotoxicity studies were performed with DOX in different formulations in B16F10 and A431 cells, and it was observed that DOX encapsulated in the SLN-N is significantly more cytotoxic than the other formulations, achieving 100% of cytotoxicity when in contact with the melanoma cells after 6 hours of incubation at concentrations above 20 ng/mL. The application of an electrical current in cell culture also increased the penetration of the drug in tumor cells and, consequently, its cytotoxicity. The induction of tumors in vivo was not feasible for hairless mice, but the iontophoretic treatment demonstrated to be feasible.

Os agentes antineoplásicos são considerados drogas de risco, ou seja, aquelas que podem ocasionar efeitos como genotoxicidade, carcinogenicidade , teratogenicidade ou alteração na fertilidade e a exposição dos profissionais de saúde constitui-se em grande preocupação do ponto de vista de saúde ocupacional. Precedendo o seu emprego na terapia oncológica, estes medicamentos devem ser submetidos a análises físicas, químicas e biológicas para avaliação da qualidade, sendo que estes testes geram considerável volume de resíduos que também requerem tratamento. O objetivo deste trabalho foi avaliar a eficácia de diferentes métodos de inativação para as moléculas de cisplatina, doxorrubicina e paclitaxel em solução injetável, utilizando cromatografia líquida de alta eficiência (avaliação química) e teste de citotoxicidade in vitro (avaliação biológica). Foram avaliados os inativantes Asepto 75® (solução a 0,5%), hipoclorito de sódio (solução a 10%) e tiossulfato de sódio (solução a 10%). Os ativos ficaram expostos aos inativantes por períodos que variaram de 0 a 6 horas. Os resultados demonstraram que o asepto 75 é eficiente para a inativação química e biológica dos três ativos, sendo o tempo de exposição fator determinante para a degradação química da cisplatina. Os graus de citotoxicidade variaram de nenhum a leve (IZ= 0 a 1). O hipoclorito de sódio possui um grau de citotoxicidade por si só, porém foi eficaz na inativação química dos três ativos. Já o inativante tiossulfato de sódio se mostrou eficaz na in ativação química da cisplatina, não tendo efeito sobre a doxorrubicina ou sobre o paclitaxel. Os resultados da avaliação in vitro mostraram-se compatíveis com os da avaliação química. Conclui-se que a inativação dos princípios ativos previamente ao descarte é eficaz para reduzir os riscos ocupacionais e ambientais das drogas citotóxicas. / The anti-neoplastic agents are considered risk drugs, that is, the ones that can cause effects, such as genotoxicity, carcinogenicity, teratogenicity or change in fertility. Because of these factors, the exposure of the health care professionals are a great concern of occupational health. Before the use of the oncological therapy, these drugs should be undergone to the physical, chemical and biological tests for the quality evaluation, considering that these test also produce a considerable amount of waste which also demand treatment. The aim of this work is to evaluate the efficacy oh the different methods of inactivation for the cisplatine molecules, doxorubicine and paclitaxel in injection solutions. Using high performance liquid chromatography (chemical evalution) and in vitro citotoxity test (biological evaluation). It has been evaluated Asepto 75 degradant (aqueous solution at 0,5%), sodium hypochlorite (aqueous solution at 10%) and sodium thyosulfate (aqueous solution at 10%). The drugs were exposed to the degradants in periods that ranged from 0 to 6 hours. The results have been demonstrated that asepto 75 is efficient for the chemical and biological inativation of the drugs, and the time of exposition is determinant for the chemical degradation of cisplatin. The citotoxicity grades have ranged from \"none\" to \"slight\". The sodium hypochlorite has a toxicity grade for itself, although it was effective in the chemical degradation of the three drugs. Yet the sodium thiosulfate degradant has demonstrated to be effective in the chemical inativation of cisplatin, not having effects over doxorubicin or paclitaxel. The results of in vitro evaluation have been compatible with the chemical evaluation. It concludes that the inactivation of the drugs before the waste is effective to reduce the occupational and environmental risks of citotoxic drugs.

Várias evidências sugerem que a dieta é um fator relevante na modificação dos riscos de desenvolvimento de câncer e que a interação nutriente-genoma tem uma influência significativa para a manutenção da saúde. A nutrigênomica estabelece uma relação entre dieta e a investigação das alterações epigenéticas do DNA, que podem ter um papel importante na etiologia de várias doenças degenerativas. A metilação do DNA é um evento epigenético importante na modificação da expressão gênica e já existem relatos de cânceres associados com a metilação da região promotora de genes supressores tumorais, como o gene p16. A metionina (Met) é um aminoácido essencial e necessário para a manutenção do ciclo de metionina, um importante mecanismo nas reações de metilação. Outro fator que pode alterar o padrão de metilação do DNA são os quimioterápicos. A alteração da metilação do DNA, também pode modificar a estrutura dos cromossomos e levar a instabilidade genômica, relacionada com o desenvolvimento de neoplasia. O objetivo deste trabalho foi avaliar o efeito da suplementação de metionina sobre as alterações no padrão de metilação da região promotora do gene p16 no fígado e rins de ratos e as possíveis modificações induzidas pela interação com o antitumoral doxorrubicina (DXR), além da possível instabilidade genômica em células da medula óssea. Para isso, seis grupos de ratos Wistar machos (n=60) foram tratados durante seis semanas com ração comercial normal ou suplementada com 2% de Met, sendo que na 3º semana e 24 horas antes da eutanásia administrou-se salina ou DXR (1 ou 10 mg/Kg p.c.), intraperitonealmente. Os rins e o fígado foram utilizados para extração do DNA e para o estudo do padrão de metilação pelo método COBRA, após a modificação do DNA com bissulfito de sódio e amplificação por PCR. As enzimas EcoRI, TaqI e HphI foram utilizadas para verificar o padrão de metilação da região promotora do gene p16 e a enzima TasI para avaliar a modificação do DNA pelo bissulfito. Em todos os animais houve a restrição do fragmento de estudo pelas enzimas TasI e HphI, porém nenhuma restrição com as enzimas EcoRI e TaqI. O padrão de metilação da região promotora do gene p16 nos rins e no fígado não foi alterado pela suplementação de Met ou pela administração de DXR, quando se comparou os grupos controles e os tratados. A justificativa é que o gene p16 é importante na regulação do ciclo celular, apoptose e senescência e sua regulação segue um mecanismo bem controlado. Para estudar o efeito da suplementação de Met na instabilidade genômica, realizou-se o teste do micronúcleo (MN) na medula óssea dos ratos. Pela a análise do MN, a suplementação com Met não alterou a frequência de MN, mas o tratamento com a DXR (1 e 10mg/Kg) induziu a formação de MN quando comparado com o grupo Controle. A associação de Met+DXR não reduziu a freqüência de MN induzida pela DXR. Conclui-se que a Met na dieta ou a administração do quimioterápico DXR não alterou o padrão de metilação da região promotora do gene p16. O excesso de Met não apresentou ação mutagênica no teste do MN. Não houve efeito antimutagênico da Met quando associada com a DXR. / Several evidences suggest that to diet is a relevant factor in modifying the risks of developing cancer and the nutrient-genome interaction has a significant influence for the maintenance of a good health condition. Nutrigenomic establishes a relation between to diet and the investigation of epigenetic DNA modifications, which may play an important role in the etiology of various degenerative diseases. DNA methylation is an important epigenetic event modification of gene expression and there been reports of cancers associated with promoter methylation region of tumor suppressor genes such as p16 gene. Methionine (Met) is an essential aminoacid to maintain methionine cycle, very important mechanism in methylation reactions. Another factor that can change the methylation pattern is the chemotherapeutic drugs. DNA methylation alteration can also modify chromosome structure and lead to a genomic instability related to the development of neoplasia. The aim of this study was to analyze the effect of methionine supplementation on changes in the methylation pattern of the promoter region of the p16 gene in the liver and kidneys of rats and the possible changes induced by interaction with the antitumoral doxorubicin (DXR), besides the possible genomic instability in bone marrow cells. Six Wistar rats groups (n=60) received commercial diet or commercial diet plus Met 2% for six weeks. At third week and 24 hours before euthanasia they received saline or DXR (1 or 10 mg/Kg) intraperitoneally. DNA extraction of the kidneys and liver was used for the study of the methylation pattern of promoter region on the p16 gene by COBRA method, after DNA sodium bisulfite modification and PCR amplification. EcoRI, TaqI and HphI enzymes were used to determine the methylation pattern of promoter region of the p16 gene and TasI enzyme was used to validate bisulfite conversion. All animals had digestion with TasI and HphI enzymes, however no restriction with EcoRI and TaqI enzymes. Kidneys and liver DNA methylation pattern promoter region of p16 gene did not change by Met supplementation or DXR administration, when comparing the controled and the treated groups. The justification is that the p16 gene is very important in cycle cellular regulation, apoptosis and senescence and its regulation follows a well controlled mechanism. To study Met supplementation in genomic instability the micronucleus (MN) test was realized in the rat bone marrow. By Micronuclei analysis, met supplementation did not alter MN frequency, but DXR treatment (1 or 10 mg/Kg) induced MN formation when compared to Control group. The association of Met+DXR did not decrease MN frequency by induced DXR. In conclusion, Met on the diet or DXR administration did not change methylation pattern of promoter region of the p16 gene. The supplemented Met did not show mutagenic effect in MN test. There was no antimutagenic effect of Met when associated to DXR.

O carcinoma da bexiga urinária (CB) é a segunda doença maligna mais frequente do trato urinário. Devido a baixa eficácia dos tratamentos intravesicais atuais (imunoterapia com BCG e quimioterapia), seja pelo baixo tempo de residência do fármaco na bexiga ou pela baixa permeabilidade no urotélio, novas estratégias que aumentem esse tempo de residência do fármaco e sua penetração na bexiga têm sido investigadas. Dentre estas estratégias pode-se citar os sistemas de liberação sustentada nanoestruturados, que liberam o fármaco gradativamente, protegem o fármaco encapsulado, aumenta a biodisponibilidade, aumentando a eficácia da terapia e diminuindo os efeitos adversos. Nesta linha, o objetivo desse trabalho foi produzir e utilizar carreadores lipídicos nanoestruturados (CLN) como sistema de carreamento de doxorrubicina (DOXO) e a sua avaliação biológica em células de câncer de bexiga. Os CLN, compostos por manteiga de Illipê (lipídeo sólido), ácido oleico (óleo) e o estabilizante Pluronic F68, foram preparados pelo método de emulsão a quente e sonicação. A caracterização físico-química do CLN foi realizada determinando o diâmetro hidrodinâmico médio e potencial zeta (carga superficial) por espalhamento de luz dinâmico (DLS), cristalinidade por calorimetria exploratória diferencial (DSC), eficiência de encapsulamento por espectrofotometria UV-vis, ensaio de citotoxicidade em células RT4 e análise de permeação ex vivo e in vivo das formulações aplicadas em bexiga de porco por microscopia confocal. O diâmetro hidrodinâmico médio dos CLN sem o fármaco foi de 103 nm e seu PdI (índice de polidispersão) igual a 0,2. O encapsulamento da DOXO aumentou o diâmetro dos CLN para 112 nm e o valor de PdI foi de 0,2. O baixo valor de PdI indica formulações com baixa polidispersão. Os valores de potencial zeta dos CLN sem e com DOXO foram ambos negativos, variando de -5 mV a -25 mV. Nos termogramas das amostras de CLN-DOXO não foi observado o pico referente a fusão da DOXO em 197,93ºC, indicando que o fármaco provavelmente está molecularmente disperso na matriz lipídica. Nos ensaios de citotoxicidade, a formulação CLN-DOXO mostrou-se mais citotóxica do que a DOXO livre em baixas concentrações (31-250 ng/mL). O valor de IC50 reduziu 2,1 vezes quando a DOXO foi encapsulada. Essa maior atividade antitumoral in vitro pode estar relacionada ao aumento do uptake celular como confirmado pelos ensaios de citometria de fluxo. No estudo de permeação ex vivo em bexiga de porco foram observadas permeações muito semelhantes das formulações de DOXO livre e encapsulada em CLN. Porém no ensaio in vivo a DOXO encapsulada permeou mais que a DOXO livre. Os resultados obtidos apontam para um promissor sistema de liberação de doxorrubicina para a terapia do câncer de bexiga. / Urinary bladder carcinoma (BC) is the second most common malignant disease of the urinary tract. Due to the low efficacy of current intravesical treatments (BCG immunotherapy and chemotherapy), either because of the low residence time of the drug in the bladder or due to low permeability in the urothelium, new strategies that increase the residence time of the drug and its penetration into the bladder have been investigated. These strategies include nanostructured sustained release systems, which release the drug gradually, protect the encapsulated drug, increase the bioavailability; increasing the effectiveness of the therapy and reducing side effects. In this line, the aim of this work was to produce and apply nanostructured lipid carriers (NLC) as a doxorubicin delivery system (DOXO) and its biological evaluation in bladder cancer cells. The NLC, composed by Illipe butter (solid lipid), oleic acid (oil) and Pluronic F68 stabilizer, were prepared by the hot emulsion and sonication method. The physical-chemical characterization of these NLC was performed by measured the mean hydrodynamic diameter and zeta potential (surface charge) by dynamic light scattering (DLS), crystallinity by differential scanning calorimetry (DSC), encapsulation efficiency by UV-vis spectrophotometry, cytotoxicity assay in RT4 cells and ex vivo and in vivo permeation assay of formulations applied to pig bladder by confocal microscopy. The mean hydrodynamic diameter of NLC without the drug was 103 nm and its PdI (polydispersity index) was 0.2. The encapsulation of DOXO increased the NLC diameter to 112 nm and the PdI value was 0.2. The low value of PdI indicates formulations with low polydispersion. The zeta potential values of the NLC without and with DOXO were both negative (-5 mV to -25 mV). In the thermograms of the NLC-DOXO sample the fusion peak of DOXO at 197.93 was not observed, indicating that the drug is molecularly dispersed in the lipid matrix. In the cytotoxicity assays, the NLC-DOXO formulation was more cytotoxic than free DOXO at low concentrations (31-250 ng/mL). The IC50 value was reduced 2.1 fold when DOXO was encapsulated. This increased in vitro antitumor activity may be related to increased cell uptake as confirmed by flow cytometry analysis. In the ex vivo permeation study in the pig bladder, a very similar permeation was observed between free and encapsulated DOXO. However, in the in vivo assay the encapsulated DOXO permeated more than free DOXO. The results indicates a promising release system of doxorubicin to bladder cancer therapy.

O uso da elevação da temperatura local como recurso adjuvante no combate ao câncer tem sido explorado intensamente nas últimas décadas. A hipertermia, como é chamada essa elevação de temperatura local, apresenta seu maior potencial clínico quando combinada com a quimioterapia e/ou radioterapia, sendo capaz de promover benefícios terap êuticos significativos. Apesar dos resultados positivos, a hipertermia, até o momento, não se estabeleceu como terapia padrão, devido a limitações no controle da deposição de energia e no monitoramento da distribuição de temperatura em tempo real. Neste trabalho, discutem-se características fundamentais da eficiência da hipertermia no tratamento de tumores cerebrais e de bexiga. O projeto foi todo ele desenvolvido em colaboração com o grupo de hipertermia do Department of Radiation Oncology da Duke University. Com relação à hipertermia aplicada ao cérebro, primeiramente apresenta-se o procedimento de desenvolvimento e teste de eficiência de um mini-aplicador de micro-onda dedicado ao aquecimento do cérebro de camundongos. Após estes, avaliou-se a capacidade de disponibilização termo-estimulada da doxorrubicina a modelos tumorais de glioblastoma. O método utilizado para monitoramento da liberação e distribuição da doxorrubicina foi a microscopia confocal de fluorescência intravital. O estudo do impacto da hipertermia sob a distribuição da formulação de doxorrubicina encapsulada em lipossomos termosensíveis demonstrou que a elevação moderada de temperatura promove alterações significativas na permeabilidade da barreira hematoencefálica, além de promover aumento do acúmulo total de droga e aumento no grau de penetração. Para a hipertermia aplicada à bexiga, apresenta-se um estudo de viabilidade de aquecimento para uma metodologia alternativa ao dispositivo de uso clínico padrão (_Synergo_), denominada magneto-hipertermia. Os ensaios com a magneto-hipertermia apontam que o uso de nanopartículas magnéticas sob influência de um campo magnético alternado (40 kHz) é capaz de elevar a temperatura do lúmen da bexiga a 42_C de forma localizada, não promovendo efeitos significativos de aquecimento a tecidos do entorno. / The use of local heating to achieve adjuvant response in cancer treatment has been widely explored in the last decades. The thermal therapy has a well-known clinical bene_t when combined to chemotherapy and/or radiotherapy. Despite all positive results, the use of thermal therapy has not yet been established as standard treatment, mainly due to the limitation on the control of energy deposition and real-time temperature mapping. This thesis discuss some of the fundamentals of the application of hyperthermia to treat bladder and brain tumors. All experiments were performed in collaboration with the Department of Radiation Oncology of Duke University. As regards brain experiments, we developed and built a microwave antenna dedicated to locally heating the mouse brain. After that, we assessed the ability of thermo release and thermo delivery of doxorubicin to glioblastoma tumor models. Intravital confocal fluorescence microscopy was used to monitor the drug release and distribution into brain tissue as a whole. Our findings indicated that a mild elevation in brain temperature (42_C) modulates the permeability of the blood-brain barrier and promotes an increase on both total drug accumulation and drug penetration. Concerning bladder hyperthermia, we investigated the feasibility of magnetic-hyperthermia as an alternative heating source to the standard clinical device (_Synergo_). The magnetic-hyperthermia results indicate that the amount of heat dissipation by the magnetic nanoparticles, under the influence of alternating magnetic field (40KHz), was able to raise the temperature in the bladder lumen to 42_C and did not promote any significant heating effects on surrounding tissues.

Introdução: A doxorrubicina (DOX) é um quimioterápico que gera efeitos tóxicos no tecido adiposo (T.A.) e reduz a qualidade de vida dos pacientes. Objetivos: Investigar os efeitos metabólicos do tratamento com DOX no T.A. branco e propor terapia adjuvante que atenue efeitos deletérios. Métodos: Procedimento experimental 1: ratos Wistar foram tratados com dose única de DOX (15mg/kg). Cultura de células: 3T3L1 foram incubadas por 24h, 96h e 12 dias com DOX. Procedimento experimental 2: animais C57/BL6 receberam doses fracionadas de DOX associado ao uso de metformina (MET) (300mg/kg, diário) ou não. Conclusão: A DOX gera um alto impacto sobre a homeostasia do T.A. branco tanto no tratamento agudo com dose única, como no tratamento crônico com doses mais baixas. Os processos fisiológicos do tecido adiposo sofreram profundas alterações, o que resultou em menor tamanho do adipócito, maior fibrose, diminuição das vias metabólicas e redução da adiponectina e leptina circulantes, e o tratamento com MET não reverteu esses efeitos, só prevenindo o processo de fibrose do TA. / Introduction: Doxorubicin (DOX) is a chemotherapy that generates toxic effects on adipose tissue (AT) and reduces the quality of life of patients. Objectives: To investigate the metabolic effects of treatment with DOX on AT white and to propose adjuvant therapy to mitigate deleterious effects. Methods: Experimental Procedure 1: Wistar rats were treated with a single dose of doxorubicin (15mg/ kg). Cell Culture: 3T3-L1 were incubated for 24h, 96h and 12 days with doxorubicin. Experimental procedure 2: C57/BL6 mice received fractionated doses of DOX associated with the use of metformin (MET) (300 mg/kg daily) or not. Conclusion: DOX generates a high impact on the homeostasis of white AT in both acute single dose treatment, such as in chronic treatment with lower doses. The physiological processes of AT have undergone major changes, resulting in a smaller of adipocytes, increased fibrosis, reduction in metabolic pathways and decreased circulating adiponectin and leptin, and the treatment with MET did not reverse these effects, only prevent the fibrosis process on AT.

O carcinoma da bexiga urinária (CB) é a segunda doença maligna mais frequente do trato urinário. Devido a baixa eficácia dos tratamentos intravesicais atuais (imunoterapia com BCG e quimioterapia), seja pelo baixo tempo de residência do fármaco na bexiga ou pela baixa permeabilidade no urotélio, novas estratégias que aumentem esse tempo de residência do fármaco e sua penetração na bexiga têm sido investigadas. Dentre estas estratégias pode-se citar os sistemas de liberação sustentada nanoestruturados, que liberam o fármaco gradativamente, protegem o fármaco encapsulado, aumenta a biodisponibilidade, aumentando a eficácia da terapia e diminuindo os efeitos adversos. Nesta linha, o objetivo desse trabalho foi produzir e utilizar carreadores lipídicos nanoestruturados (CLN) como sistema de carreamento de doxorrubicina (DOXO) e a sua avaliação biológica em células de câncer de bexiga. Os CLN, compostos por manteiga de Illipê (lipídeo sólido), ácido oleico (óleo) e o estabilizante Pluronic F68, foram preparados pelo método de emulsão a quente e sonicação. A caracterização físico-química do CLN foi realizada determinando o diâmetro hidrodinâmico médio e potencial zeta (carga superficial) por espalhamento de luz dinâmico (DLS), cristalinidade por calorimetria exploratória diferencial (DSC), eficiência de encapsulamento por espectrofotometria UV-vis, ensaio de citotoxicidade em células RT4 e análise de permeação ex vivo e in vivo das formulações aplicadas em bexiga de porco por microscopia confocal. O diâmetro hidrodinâmico médio dos CLN sem o fármaco foi de 103 nm e seu PdI (índice de polidispersão) igual a 0,2. O encapsulamento da DOXO aumentou o diâmetro dos CLN para 112 nm e o valor de PdI foi de 0,2. O baixo valor de PdI indica formulações com baixa polidispersão. Os valores de potencial zeta dos CLN sem e com DOXO foram ambos negativos, variando de -5 mV a -25 mV. Nos termogramas das amostras de CLN-DOXO não foi observado o pico referente a fusão da DOXO em 197,93ºC, indicando que o fármaco provavelmente está molecularmente disperso na matriz lipídica. Nos ensaios de citotoxicidade, a formulação CLN-DOXO mostrou-se mais citotóxica do que a DOXO livre em baixas concentrações (31-250 ng/mL). O valor de IC50 reduziu 2,1 vezes quando a DOXO foi encapsulada. Essa maior atividade antitumoral in vitro pode estar relacionada ao aumento do uptake celular como confirmado pelos ensaios de citometria de fluxo. No estudo de permeação ex vivo em bexiga de porco foram observadas permeações muito semelhantes das formulações de DOXO livre e encapsulada em CLN. Porém no ensaio in vivo a DOXO encapsulada permeou mais que a DOXO livre. Os resultados obtidos apontam para um promissor sistema de liberação de doxorrubicina para a terapia do câncer de bexiga. / Urinary bladder carcinoma (BC) is the second most common malignant disease of the urinary tract. Due to the low efficacy of current intravesical treatments (BCG immunotherapy and chemotherapy), either because of the low residence time of the drug in the bladder or due to low permeability in the urothelium, new strategies that increase the residence time of the drug and its penetration into the bladder have been investigated. These strategies include nanostructured sustained release systems, which release the drug gradually, protect the encapsulated drug, increase the bioavailability; increasing the effectiveness of the therapy and reducing side effects. In this line, the aim of this work was to produce and apply nanostructured lipid carriers (NLC) as a doxorubicin delivery system (DOXO) and its biological evaluation in bladder cancer cells. The NLC, composed by Illipe butter (solid lipid), oleic acid (oil) and Pluronic F68 stabilizer, were prepared by the hot emulsion and sonication method. The physical-chemical characterization of these NLC was performed by measured the mean hydrodynamic diameter and zeta potential (surface charge) by dynamic light scattering (DLS), crystallinity by differential scanning calorimetry (DSC), encapsulation efficiency by UV-vis spectrophotometry, cytotoxicity assay in RT4 cells and ex vivo and in vivo permeation assay of formulations applied to pig bladder by confocal microscopy. The mean hydrodynamic diameter of NLC without the drug was 103 nm and its PdI (polydispersity index) was 0.2. The encapsulation of DOXO increased the NLC diameter to 112 nm and the PdI value was 0.2. The low value of PdI indicates formulations with low polydispersion. The zeta potential values of the NLC without and with DOXO were both negative (-5 mV to -25 mV). In the thermograms of the NLC-DOXO sample the fusion peak of DOXO at 197.93 was not observed, indicating that the drug is molecularly dispersed in the lipid matrix. In the cytotoxicity assays, the NLC-DOXO formulation was more cytotoxic than free DOXO at low concentrations (31-250 ng/mL). The IC50 value was reduced 2.1 fold when DOXO was encapsulated. This increased in vitro antitumor activity may be related to increased cell uptake as confirmed by flow cytometry analysis. In the ex vivo permeation study in the pig bladder, a very similar permeation was observed between free and encapsulated DOXO. However, in the in vivo assay the encapsulated DOXO permeated more than free DOXO. The results indicates a promising release system of doxorubicin to bladder cancer therapy.

by To Siu Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 84-92). / Abstract also in Chinese. / Declaration --- p.i / Abstract --- p.ii / Acknowledgement --- p.vi / Abbreviations --- p.vii / List of Figures --- p.viii / List of Tables --- p.xii / Content --- p.xiv / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1. --- Osteosarcoma --- p.1 / Chapter 1.1.1. --- Incidence / Chapter 1.1.2. --- Age and Sex Distribution / Chapter 1.1.3. --- Clinical Features / Chapter 1.1.4. --- Treatment / Chapter 1.2. --- Adriamycin --- p.9 / Chapter 1.2.1. --- Drug Action / Chapter 1.2.2. --- Pharmacology / Chapter 1.3. --- Multidrug Resistance --- p.11 / Chapter 1.4. --- P-glycoprotein --- p.13 / Chapter 1.4.1. --- Nature / Chapter 1.4.2. --- Tissue Distribution / Chapter 1.4.3. --- Relation with MDR / Chapter 1.5 --- Multidrug Resistance Protein --- p.16 / Chapter 1.6. --- Reactive Oxygen Species --- p.17 / Chapter 1.6.1. --- Problems Arising from ROS / Chapter 1.6.2. --- Oxidative Stress and Diseases / Chapter 1.6.3. --- Defense System / Chapter 1.6.4. --- Antioxidative Enzymes / Chapter 1.6.5. --- Relation with MDR / Chapter 1.7. --- Topoisomerase II --- p.22 / Chapter 1.8. --- Methods to Detect MDR --- p.24 / Chapter 1.8.1. --- P-glycoprotein Immunohistochemistry / Chapter 1.8.2. --- Adriamycin Binding Assay / Chapter 1.9. --- Aims of Study --- p.25 / Chapter 2. --- MATERIALS AND METHODS --- p.27 / Chapter 2.1. --- Clinical Study --- p.27 / Chapter 2.1.1. --- Patients Recruitment / Chapter 2.1.2. --- Adriamycin Binding Assay / Chapter 2.1.3. --- P-glycoprotein Immunohistochemistry / Chapter 2.1.3.1. --- Sample and Control Preparation / Chapter 2.1.3.2. --- Immunohistochemical Procedure / Chapter 2.1.4. --- Tumour Necrosis Assessment / Chapter 2.2. --- Effect of Adriamycin on Osteosarcoma Cells --- p.32 / Chapter 2.2.1. --- Establishment of Adriamycin Adapted Osteosarcoma Cells / Chapter 2.2.1.1. --- Maintenance and Subculture of SaOS-2 Cell Line / Chapter 2.2.1.2. --- Storage of Cell Line / Chapter 2.2.1.3. --- Adriamycin Treatment / Chapter 2.2.2. --- KB-V1 Cell Culture / Chapter 2.2.3. --- Adriamycin Binding Assay / Chapter 2.2.4. --- P-glycoprotein Immunohistochemistry / Chapter 2.2.4.1. --- Sample and Control Preparation / Chapter 2.2.4.2. --- Immunohistochemical Procedures / Chapter 2.2.5. --- Thymidine Incorporation Assay / Chapter 2.2.5.1. --- Assay Procedures / Chapter 2.2.6. --- Catalase Assay / Chapter 2.2.6.1. --- Assay Procedures / Chapter 2.2.6.2. --- Unit Calculation / Chapter 2.2.7. --- Glutathione Peroxidase Assay / Chapter 2.2.7.1. --- Assay Procedures / Chapter 2.2.7.2. --- Unit Calculation / Chapter 2.2.8. --- Protein Determination / Chapter 2.3. --- Statistical Analysis --- p.45 / Chapter 3. --- RESULTS --- p.46 / Chapter 3.1. --- Clinical Study --- p.46 / Chapter 3.1.1. --- Patients Recruitment / Chapter 3.1.2. --- Correlation of Adriamycin Sensitivity to Tumour Necrosis / Chapter 3.1.3. --- Correlation of P-glycoprotein Expression to Tumour Necrosis / Chapter 3.1.4. --- Correlation of P-glycoprotein Expression to Adriamycin Sensitivity / Chapter 3.2. --- Effect of Adriamycin on Osteosarcoma Cells --- p.63 / Chapter 3.2.1. --- Adriamycin Sensitivity and P-glycoprotein Expression / Chapter 3.2.2. --- Thymidine Incorporation Rate / Chapter 3.2.3. --- Intracellular Concentration of Catalase / Chapter 3.2.4. --- Intracellular Concentration of Glutathione Peroxidase / Chapter 4. --- DISCUSSIONS --- p.71 / Chapter 4.1. --- Clinical Study --- p.71 / Chapter 4.1.1. --- Patients Recruitment / Chapter 4.1.2. --- Correlation between Adriamycin Sensitivity and Tumour Necrosis / Chapter 4.1.3. --- Correlation between P-glycoprotein Expression and Tumour Necrosis / Chapter 4.1.3.1. --- P-glycoprotein Is Induced During Chemotherapy / Chapter 4.1.3.2. --- P-glycoprotein Cannot Serve As a Prognostic Factor / Chapter 4.1.4. --- Correlation Between Adriamycin Sensitivity and P-glycoprotein Expression / Chapter 4.2. --- Effect of Adriamycin on Osteosarcoma Cells --- p.76 / Chapter 4.2.1. --- Adriamycin Sensitivity and P-glycoprotein Expression / Chapter 4.2.2. --- Proliferation Rate / Chapter 4.2.3. --- Antioxidative Enzymes Activities / Chapter 5. --- CONCLUSION --- p.82 / Chapter 6. --- FURTHER STUDY --- p.83 / Chapter 7. --- BIBLIOGRAPHY --- p.84 / Chapter 8. --- APPENDIX - SOLUTIONS PREPARATION --- p.93

by Lo Hoi Ka Elka. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 172-181). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / LIST OF TABLES AND FIGURES --- p.viii / ABBREVIATIONS --- p.xiv / Chapter CHAPTER 1 : --- INTRODUCTION / Chapter 1.1. --- DIFFERENT TREATMENTS OF THE CANCER THERAPY --- p.1 / Chapter 1.2. --- THE SIDE EFFECTS OF CANCER TREATMENT / Chapter 1.2.1. --- Surgery --- p.1 / Chapter 1.2.2. --- Radiotherapy --- p.2 / Chapter 1.2.3. --- Chemotherapy --- p.2 / Chapter 1.3. --- THE CHARACTERISTICS OF DOXORUBICIN (DOX) / Chapter 1.3.1. --- The structure of Dox --- p.6 / Chapter 1.3.2. --- The actions of Dox --- p.8 / Chapter 1.3.3. --- The adverse side effect of Dox --- p.8 / Chapter 1.4. --- THE RATIONALE OF USING LOW DENSITY LIPOPROTEIN (LDL) AS A TARGET CARRIER IN CANCER THERAPY / Chapter 1.4.1. --- The correlation between cholesterol and cancer --- p.9 / Chapter 1.4.2. --- Low density lipoprotein (LDL) as a target carrier --- p.11 / Chapter 1.4.3. --- The down and up regulation of LDL receptors --- p.14 / Chapter 1.4.4. --- The characteristics of Fuctus Craegus (FC) --- p.15 / Chapter 1.5. --- DIFFERENT METHODS OF THE PREPARATION OF THE LOW DENSITY LIPOPROTEIN-DRUG (LDL- DRUG) --- p.18 / Chapter 1.6. --- THE CHARACTERISTICS OF LOW DENSITY LIPOPROTEIN (LDL) / Chapter 1.6.1. --- The structure of LDL --- p.20 / Chapter 1.6.2. --- The metabolic pathway of LDL in human bodies --- p.23 / Chapter 1.7. --- THE MULTIDRUGS RESISTANCE IN TUMOR CELLS --- p.25 / Chapter 1.7.1. --- The mechanism of multidrug resistance --- p.27 / Chapter 1.7.2. --- The structure of P-glycoprotein --- p.27 / Chapter 1.7.3. --- The mechanism of P-glycoprotein --- p.30 / Chapter 1.8. --- COMBINED TREATMENT WITH HYPERTHERMIA --- p.31 / Chapter 1.9. --- AIM OF THE STUDY --- p.33 / Chapter CHAPTER 2 : --- MATERIALS AND METHODS / Chapter 2.1. --- MATERIALS / Chapter 2.1.1. --- Animals --- p.34 / Chapter 2.1.2. --- Buffers --- p.34 / Chapter 2.1.3. --- Cell culture reagents --- p.36 / Chapter 2.1.4. --- Chemicals --- p.38 / Chapter 2.1.5. --- Culture of cells --- p.40 / Chapter 2.2. --- METHODS / Chapter 2.2.1. --- In vitro studies / Chapter 2.2.1.1. --- "LDL, doxorubicin complex formation" --- p.41 / Chapter 2.2.1.2. --- Determination of the concentration of LDL-Dox --- p.42 / Chapter 2.2.1.3. --- In vitro cytotoxicity --- p.43 / Chapter 2.2.1.4. --- The cytotoxicity of the combined treatment with anticancer drugs --- p.44 / Chapter 2.2.1.5. --- The preparation of Fructus Crataegus (FC) --- p.46 / Chapter 2.2.1.6. --- Western blot --- p.47 / Chapter 2.2.1.7. --- Flow cytometry --- p.49 / Chapter 2.2.1.8. --- Confocal laser scanning microscopy --- p.52 / Chapter 2.2.2. --- In vivo studies / Chapter 2.2.2.1. --- Subcutaneous injection of R-HepG2 cells in nude mouse --- p.55 / Chapter 2.2.2.2. --- Treatment schedules --- p.55 / Chapter 2.2.2.3. --- Assay of investigating of the myocardial injury --- p.56 / Chapter 2.2.2.4. --- Tissue preparation procedure for light microscope (LM) --- p.57 / Chapter 2.2.3. --- Statistical analysis in our research --- p.59 / Chapter CHAPTER 3 : --- RESULTS / Chapter 3.1. --- in vitro STUDIES / Chapter 3.1.1. --- The preparation of low density lipoprotein-doxorubicin (LDL-Dox) --- p.60 / Chapter 3.1.2. --- Studies on human hepatoma cells line (HepG2 cells) / Chapter 3.1.2.1. --- The comparison of Dox and LDL-Dox accumulated in HepG2 cells --- p.63 / Chapter 3.1.2.2. --- Confocal laser scanning microscopic (CLSM) studies on the accumulation of Dox and LDL-Dox in HepG2 cells --- p.65 / Chapter 3.1.2.3. --- The comparsion of the cytotoxicity of Dox and LDL-Dox on HepG2 cells --- p.67 / Chapter 3.1.2.4. --- The comparison of the cytotoxicty of Dox and LDL-Dox with and without hyperthermia on HepG2 cells --- p.73 / Chapter 3.1.2.5. --- The comparison of accumulation of Dox and LDL-Dox in HepG2 cells treated with and without combination of with hyperthermia --- p.77 / Chapter 3.1.2.6. --- Confocal laser scanning microscopic (CLSM) studies on the accumulation of Dox and LDL-Dox in HepG2 treated cells with and without hyperthermia --- p.80 / Chapter 3.1.2.7. --- Modulation of LDL receptors on HepG2 cells------Up- regulation of LDL receptors by Fructus Craegtus (FC) / Chapter 3.1.2.7.1. --- The comparsion of LDL receptor expression on HepG2 cells after Fructus Craegtus (FC) pre-treatment --- p.83 / Chapter 3.1.2.7.2. --- The comparison of accumulation of LDL-Dox accumulated in HepG2 cells pre-treated with and without Fructus Craegtus (FC) --- p.85 / Chapter 3.1.2.7.3. --- Confocal laser scanning microscopic (CLSM) studies on the accumulation of LDL-Doxin HepG2 cells after Fructus Craegtus (FC) pre- treatment --- p.88 / Chapter 3.1.2.7.4. --- Cytotoxicity of combined treatment with LDL-Dox and Fructus Craegtus (FC) --- p.91 / Chapter 3.1.3. --- Studies on multidrug human resistant hepatoma cell line (R-HepG2 cells) / Chapter 3.1.3.1. --- The overexpression level of P-glycoprotein in resistant cell line R-HepG2 --- p.93 / Chapter 3.1.3.2. --- The comparison of Dox and LDL-Dox accumulated in R- HepG2 cells --- p.95 / Chapter 3.1.3.3. --- Confocal laser scanning microscopic (CLSM) studies on the accumulation of Dox and LDL-Dox in R-HepG2 cells --- p.97 / Chapter 3.1.3.4. --- The comparsion of the cytotoxicity of Dox and LDL-Dox on R-HepG2 cells --- p.99 / Chapter 3.1.3.5. --- The comparison of the cytotoxicty of Dox and LDL-Dox with and without hyperthermia on R-HepG2 cells --- p.109 / Chapter 3.1.3.6. --- The comparison of the accumulation of Dox and LDL- Dox in R-HepG2 cells treated in combination with hyperthermia --- p.113 / Chapter 3.1.3.7. --- Confocal laser scanning microscopic (CLSM) studies on the accumulation of Dox and LDL-Dox in R-HepG2 cells with and without hyperthermia --- p.117 / Chapter 3.1.3.8. --- Modulation of LDL receptors on R-HepG2 cells ------ Up-regulation of LDL receptors by Fructus Craegtus (FC) / Chapter 3.1.3.8.1. --- The comparsion of LDL receptor expression on R-HepG2 cells after Fructus Craegtus (FC) pre-treatment --- p.120 / Chapter 3.1.3.8.2. --- The comparsion of the accumulation of LDL- Dox in R-HepG2 cells after Fructus Craegtus (FC) pre-treatment --- p.122 / Chapter 3.1.3.8.3. --- Confocal laser scanning microscopic (CLSM) studies in the accumulation of LDL-Dox by Fructus Craegtus pre-treatment in R-HepG2 cells --- p.125 / Chapter 3.1.3.8.4. --- The comparison of cytotoxicity of combined treatment with LDL-Dox and Fructus Craegtus (FC) in R-HepG2 cells --- p.128 / Chapter 3.2. --- in vivo STUDIES / Chapter 3.2.1. --- The comparison of Dox and LDL-Dox on reducing the tumor sizes and weight in nude mice bearing R-HepG2 cells / Chapter 3.2.1.1. --- The comparison of Dox and LDL-Dox on reducing the tumor size in nude mice bearing R-HepG2 cells --- p.130 / Chapter 3.2.1.2. --- The comparison of Dox and LDL-Dox on reducing the tumor weight in nude mice bearing R-HepG2 cells --- p.138 / Chapter 3.2.2. --- Myocardial injury measured by Lactate dehydrogenase (LDH) activity in nude mice bearing R-HepG2 cells treated with Dox and LDL-Dox --- p.140 / Chapter 3.2.3. --- Myocardial injury measured by Creatine kinase (CK) activity in nude mice bearing R-HepG2 cells treated with Dox and LDL-Dox --- p.143 / Chapter 3.2.4. --- Histological studies of heart of nude mice bearing R-HepG2 cells treated with Dox and LDL-Dox / Chapter 3.2.4.1. --- Heart section of nude mice --- p.146 / Chapter 3.2.4.2. --- Heart section of nude mice bearing R-HepG2 cells --- p.148 / Chapter 3.2.4.3. --- Heart section of lmg/kg Dox treated nude mice bearing R- HepG2 cells --- p.150 / Chapter 3.2.4.4. --- Heart section of 2mg/kg Dox treated nude mice bearing R- HepG2 cells --- p.152 / Chapter 3.2.4.5. --- Heart section of lmg/kg LDL-Dox treated nude mice bearing R-HepG2 cells --- p.154 / Chapter CHAPTER 4 --- : DISCUSSION / Chapter 4.1. --- in vitro STUDIES / Chapter 4.1.1. --- The cytotoxicity of Dox and LDL-Dox on HepG2 cells and R- HepG2 cells --- p.156 / Chapter 4.1.2. --- The combined treatment on HepG2 cells and R-HepG2 cells --- p.157 / Chapter 4.1.3. --- The modulation of LDL-R expression --- p.159 / Chapter 4.2. --- in vivo STUDIES --- p.162 / Chapter CHAPTER 5 --- : CONCLUSION / Chapter 5.1. --- CONCLUSION / Chapter 5.1.1. --- In vitro studies --- p.167 / Chapter 5.1.2. --- In vivo studies --- p.169 / Chapter 5.2. --- FUTURE PROSPECTIVE --- p.170 / REFERENCES --- p.172

La doxorubicine (DXR) est l’un des médicaments les plus efficaces en chimiothérapie, mais sonapplication clinique est limitée par ses effets cardiotoxiques. Malgré des décennies de recherche, sesmécanismes pathogéniques ne sont toujours pas entièrement compris. Il s’ensuit qu’aucun traitementsatisfaisant, curatif ou préventif, n’existe. Dans cette étude, nous recherchons les mécanismes designalisation cellulaire impliqués. Deux modèles expérimentaux de toxicités, aigue d’une part (coeurisolé et perfusé de rat avec la DXR), et chronique d’autre part (rat traité à la DXR), ont permis deréaliser une étude ciblée (sur les voies de signalisation énergétiques) et deux études systémiques(phosphoprotéomique et transcriptomique). Les résultats combinés de ces travaux ont montré que laDXR modifiait le niveau de phosphorylation (activation) ou l’expression génique de protéinesimpliquées dans trois domaines fonctionnels distincts : métabolisme énergétique, réponses au stress,et structure/fonction du sarcomère. (i) Métabolisme énergétique : nous avons confirmé la surprenanteinhibition de l’AMPK, probablement provoquée par un contrôle négatif exercé par des partenaires designalisation (Akt et ERK), plutôt que par une modification des kinases activatrices en amont. Nousavons également montré l’augmentation du niveau de phosphorylation de la PDH, ce qui, en inhibantl’enzyme, ralentit le cycle de Krebs. Cependant, nous avons également observé un phénomènecompensatoire de surexpression de gènes codant pour des enzymes de la glycolyse et du cycle deKrebs ; (ii) Réponses au stress : dans nos modèles, la DXR génère des stress énergétique,génotoxique et oxydatif. Cependant, seuls quelques mécanismes compensatoires sont activés (lesvoies de signalisation de DNA-PK–Akt–GSK3, diverses chaperonnes). Les autres semblent êtreinhibées suggérant que l’amoindricement des réponses au stress serait un des mécanismes de lacardiotoxicité de la DXR; (iii) Structure/fonction du sarcomère: L’augmentation de la phosphorylationde la desmine ainsi que la réduction du nombre de transcrits codant pour des protéines essentiellesau développement cardiaque normal pourraient être la cause de la désorganisation du réseaumyofibrillaire. En conclusion, ces résultats révèlent potentiellement de nouveaux mécanismes de lacardiotoxicité induite par la DXR et permettent d’envisager de nouvelles cibles moléculaires pour ledéveloppement de stratégies protectrices. / Doxorubicin (DXR) is an efficient anticancer drug, the use of which is limited by seriouscardiotoxicity. Despite decades of research, its pathogenic mechanisms are not fully understood, andefficient preventive or curative strategies are not available. Here we address the question whethermechanisms in cardiac cell signaling contribute to the toxicity phenotype. Using experimental modelsfor acute (DXR-perfused, isolated rat hearts) or chronic toxicity (rats injected with DXR), we conducteda targeted study (focusing on energy signaling pathways) and two non-biased studies(phosphoproteomics and transcriptomics). The combined data reveal DXR-induced alterations inphosphorylation (activation) status or gene expression of proteins in mainly three functional domains:energy metabolism, stress responses, and sarcomere structure. (i) Energy metabolism: We confirm aparadox inhibition of AMPK signaling, that is rather due to inhibitory cross-talk with related signalingpartners (Akt, ERK) than impaired AMPK upstream signaling. We also show, among others, theincrease of inhibitory phosphorylation of pyruvate dehydrogenase, slowing down Krebs cycle, but alsoa compensating upregulation of glycolysis and Krebs cycle enzyme transcripts. (ii) Stress-responses:In our models, DXR generates energetic, oxidative and genotoxic stress, but only some compensatorystress responses are activated (DNA-PK–Akt–GSK3 pathway, chaperones). Many others seem to beinhibited, suggesting a blunted response to stress as component of DXR toxicity. (iii) Sarcomerestructure/function: We detect increased phosphorylation of desmin and reduced transcripts essentialfor e.g. normal heart development as potential causes for a disorganized myofibrillar network. Inconclusion, these results reveal some novel potential mechanisms of DXR-induced cardiotoxicity andsuggest new targets for protective strategies.