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<p>In the recent years considerable progress has been made to understand how the protein Bcl-2 regulates apoptosis at the mitochondria. By comparison, the cell death mechanisms at the endoplasmic reticulum remain unclear. In response to the agents that cause endoplasmic reticulum stress in breast cancer cells, the cell-cell adhesion molecule E-cadherin is modified by two independent modifications comprising pro-region retention and O-glycosylation. Both the modifications on E-cadherin inhibit its cell surface transport and the resultant loss of E-cadherin on the plasma membrane sensitizes cells to apoptosis. During this process binding of E-cadherin to type I gamma phosphatidylinositol phosphate kinase (PIPKIγ), a protein required for E-cadherin trafficking to the plasma membrane is prevented by O-glycosylation. E-cadherin deletion mutants that cannot be O-GlcNAcylated continue to bind PIPKIγ, traffick to the cell surface and delay apoptosis, confirming the biological significance of the modifications and PIPKIγ binding in the cell death regulation. These results also led me to determine whether there is a cell death pathway in which commitment to cell death is mediated by proteins primarily located at the endoplasmic reticulum. The studies show that the growth of estrogen receptor-positive breast cancer cells in charcoal stripped bovine serum leads to a form of programmed cell death which is protected by Bcl-2 exclusively localized at the endoplasmic reticulum instead of the mitochondria. Interestingly, the BH3 mimetic ABT-737 can abolish the protection mediated by Bcl-2 localized at the endoplasmic reticulum. Taken together, these studies suggest the novel role of the endoplasmic reticulum in programmed cell death through the identification and elucidation of the mechanisms that regulate the cell death pathway at this organelle.</p> / Doctor of Philosophy (PhD)

Biological systems carry inherent complexity, which pose difficulties observing behavioural properties, such as diffusion coefficients, kinetic constants and state switching occurrences. With constantly improving computing power and microscopy technologies, single molecule methods have become a viable alternative when probing the behaviour of proteins, enzymes, lipids and other molecules. Processed microscopy images and videos provide information such as particle intensities and trajectories, avoiding ensemble averaging and therefore allowing for a detailed breakdown of particle mobility and interactions. A single particle tracking (SPT) algorithm was developed which implements detection, localization and position linking on image stacks. Sub-pixel precise detection is done via either centroid determination, Gaussian fit, or radial symmetry centres, while tracking makes use of distance based global cost optimization. The detection algorithm is also used for single particle spectroscopy, where intensity information is used to determine the size of oligomers, as well as their interaction with other molecules through channel intensity cross-correlation. The algorithm underwent benchmarking with simulated videos and was applied to three different biological systems with comparison to other established methods of analysis. The first system studied was the diffusion of the fluorescent lipophilic dye DiD in a five-component mitochondria-like solid-supported lipid bilayer. Comparing line-scanning fluorescence correlation spectroscopy (FCS) and single particle tracking, the measured diffusion coefficients were found to be statistically different, with DFCS = 3 μm2s-1 and DSPT = 2 μm2s-1, indicating different operational ranges for the two methods. FCS outperforms SPT when the diffusion coefficient exceeds 1 μm2s-1, making it ideal for lipid diffusion in fluid membranes and proteins in solution with weak membrane interaction. SPT is best suited for mobile and immobile membrane inserted proteins, as well as lipid diffusion in viscous membranes. The second system studied was the interaction between the two proteins Bax and Bid when inserted in a membrane. Bax and Bid are both members of the Bcl-2 family of proteins, which plays a vital role in the apoptosis mechanism, by inducing mitochondrial outer membrane permeabilization. To study this system with single particle spectroscopy, fluorescently labelled Bax and truncated Bid (tBid) were imaged when interacting with a mitochondria-like supported lipid bilayer with confocal microscopy. Immobile and mobile particles were detected and distinguished based on the eccentricity of the observed fluorescence spot. The intensity of the particle signal was used to determine oligomer type (homo-oligomerization) while the interaction with the particles' counterpart (hetero-oligomerization) was determined by channel cross-correlation. This allowed the measurement of the 2D-KD values for mobile (0.6 μm-2) and immobile (0.08 μm-2) Bax/tBid complexes, showing that the degree of insertion of the proteins in the membrane greatly affect their affinity for each other. The third and final system studied was the motion of cellulases on cellulose fibers. Enzymatic hydrolysis of crystalline cellulose is a costly step in the generation of fermentable sugars for biofuel production. Due to the complex structure and many possible interaction states of the enzymes with cellulose, single particle tracking is a well-adapted technique to the gathering of information on the enzyme dynamics, which is essential for process optimization. The movement of cellulases on cellulose substrate was observed via labelled Thermobifidia fusca Cel5A, Cel6B and Cel9A on bacterial micro-crystalline cellulose substrate. The detected trajectories were analyzed using multiple diffusion models. A simple one-state diffusion model was insufficient to describe the observed radial displacement distributions and so a two-state model was introduced and confronted with the data using conventional least-squares fits , as well as a hidden Markov approach. The diffusion coefficients of the two states are found to be on the order of Dfast = 10-3 μm2s-1 and Dslow = 10-4 μm2s-1, with the slow state being more stable and therefore more likely to occur. Single particle tracking can give us better insight into complex interactions, such as synergistic binding of proteins existing in several different states and processive enzymatic behaviour, where ensemble averaging techniques can fall short. The uses of single molecule methods are plentiful and with the current rise of machine learning, higher levels of abstraction will provide us with more detailed insights into biological processes, driving promising developments in the medical field, as well as new technologies in many sectors of industry. / Thesis / Doctor of Science (PhD) / Proteins are the motors that drive most cellular processes, for example steering a cell’s life cycle, or decomposing sources of nutrients. Being able to observe the motion of individual proteins is key to understanding their behaviour. In this work a single particle tracking (SPT) program was developed to extract protein trajectories from fluorescence microscopy experiments. With this tool-set we investigated the following two systems. The first system of interest is the Bcl-2 protein family, which is vital during the pro- grammed cell death at the end of each cell’s life span. The failure of a controlled cell death can have dire consequences, such as necrosis and cancer. The Bcl-2 family proteins Bid and Bax are active on the outer membrane of the mitochondria, where they initiate the process of terminating the cell’s functions by forming pores. For our experiments we ar- tificially mimicked the outer membrane of the mitochondria, introduced Bid and Bax and observed their preferential groupings on the membrane surface. This provided indications of the mechanisms involved during binding and pore formation. The motivation behind the investigation of the second system is the improvement of biofuel generation from a renewable source: plant-based biomass. Cellulases are enzymes from bacteria or fungi that break down cellulose – one of the main building blocks of all plant cell walls – into fermentable sugars. In fluorescence microscopy experiments a purified cellulose substrate was used to monitor the motion of three types of cellulases. The insight which we gained into the cellulase behaviour may allow the optimization of the process of cellulose decomposition.

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La protéine tyrosine kinase c-Src est surexprimée et activée dans de nombreux cancers. De manière remarquable, Src est activé dans plus de 80% des adénocarcinomes coliques où il joue un rôle dans la carcinogenèse et la progression vers un phénotype métastatique. c-Src et son homologue viral v-Src activent un grand nombre de voies cellulaires permettant à la tumeur de proliférer, de résister à la mort cellulaire et d’acquérir des capacités accrues de migration et d’angiogenèse. Au cours de ma thèse nous avons mis en évidence un mécanisme inattendu d’échappement à l’apoptose de fibroblastes murins surexprimant de manière stable v-Src et de plusieurs lignées tumorales humaines (coliques en particulier) présentant une activité c-Src dérégulée. Nous avons montré que Src stimule la dégradation protéasomedépendantede la protéine Bik, un membre pro-apoptotique de la famille Bcl-2, connu pour être un suppresseur de tumeurs. Cette régulation post-traductionnelle du niveau d’expression de Bik est à l’origine d’une forte résistance de la voie mitochondriale de l’apoptose. L’inhibition de l’activité kinase de Src ou le blocage de la dégradation de Bik par le protéasome permettent de restaurer des concentrations normales de la protéine Bik dans les cellules transformées et de les restaurer efficacement l’apoptose. En revanche, l’inhibition des protéines anti-apoptotiques de la famille Bcl-2 par l’ABT-737 semble moins efficace. Par ailleurs, nous avons également contribué à mettre en évidence le rôle anti-migratoire et anti-invasif du lithium sur des cellules transformées par Src. Le mécanisme moléculaire mis en jeu implique l’activation redox des protéines tyrosine phosphatases cellulaires. Enfin, nous avons participé à l’étude de peptides mimant les hélices centrales d’insertion de Bax, Bcl-xL et Bid, représentant les trois sous-groupes de protéines de la famille Bcl-2. Nous avons comparé leur comportement vis-à-vis d’une monocouche lipidique mimant la membrane mitochondriale externe ainsi que leur capacité à perméabiliser des mitochondries isolées. Nos résultats nous ont permis de proposer que les fragments centraux d’insertion membranaire des protéines Bcl-2 seraient directement impliqués dans la divergence fonctionnelle des différents sous groupes qui composent la famille / C-Src tyrosine kinase is overexpressed and activated in a number of cancers. Remarkably, Src is deregulated in more than 80% of colorectal adenocarcinoma, playing a role in carcinogenesis and progression toward a metastatic phenotype. c-Src and v-Src activate a large number of intracellular pathways which allow the tumor to proliferate, to evade the cell death machinery and to acquired enhanced migratory and angiogenic abilities. During my PhD, we discovered an unknown mechanism to evade apoptosis developed by murine fibroblasts stably overexpressing v-Src and by some human tumor cell lines with c-Srcb deregulation. We have shown that Src stimulate the proteasomal degradation of the Bik protein, a proapoptotic member of the Bcl-2 family proteins known to act as a tumor suppressor. This post-translationnal regulation of the Bik protein expression level leads to a strong resistance of the mitochondrial pathway of apoptosis. Inhibition of the Src kinase activity or of the Bik proteasome-dependent degradation restore normal levels of the Bik protein and efficiently resensitize these cells to apoptosis. Inhibition of the antiapoptotic Bcl-2 proteins by ABT737 seems to be less efficient in these cells. We also contribute to show that lithium suppresses motility and invasivity of v-Src transformed cells. The molecular mechanism involve a redox activation of the protein tyrosine phosphatases. Finally, we compared the membrane behavior and the ability to permeabilize mitochondria of synthetic peptides derived from the central helical hairpin of Bax,Bcl-xL and Bid. We showed that these structurally analogous domains have distinct membrane behavior which could account for the functional divergence between the Bcl-2 family members

Introdução: O linfoma difuso de grandes células B é o mais freqüente grupo de linfoma não- Hodgkin, perfazendo quase 50% dos casos no serviço de hematologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e Instituto do Câncer do Estado de São Paulo. Possui heterogeneidade clínica e biológica traduzida em mais de vinte subtipos na Organização Mundial da Saúde. Sua terapêutica se baseia na associação do anticorpo monoclonal anti-CD20 e quimioterapia com antracíclico, esquema que resulta em 43,5% de sobrevida global em 10 anos. Determinantes de prognóstico clínico como o Índice Internacional de Prognóstico e o Índice Internacional de Prognóstico Revisado carecem de acurácia, pois até 20% dos pacientes de baixo risco falecerão da doença e 60% dos pacientes de alto risco estarão vivos em quatro anos. Essas discrepâncias podem, em parte, ser atribuídas a fatores genéticos. A assinatura gênica do linfoma difuso de grandes células B tipo centro germinativo apresenta sobrevida global superior ao tipo células B ativadas (76% versus 16%, p=0,01), contudo o perfil de expressão gênica por microarray ainda não está disponível na prática clínica. Entretanto, o escore preditivo de mortalidade para linfoma difuso de grandes células B baseado no valor prognóstico da expressão dos genes BCL2, BCL6, CCND2, FN1, LMO2 e SCYA3 por PCR em tempo real quantitativa mostrou-se independente do Índice Internacional de Prognóstico na era pré-rituximabe. Mas não foi significante em pacientes de alto risco clínico tratados com R-CHOP. Os genes BCL2, CCND2 e SCYA3 integram a assinatura de células B ativadas, BCL6 e LMO2 a do centro germinativo e FN1 a linfonodal. Objetivo: Avaliar o impacto da expressão absoluta dos genes BCL2, BCL6, CCND2, FN1, LMO2 e SCYA3 em população brasileira com linfoma difuso de grandes células B tratada com R-CHOP em relação à resposta global, sobrevida livre de doença, sobrevida livre de progressão e sobrevida global. Métodos: A expressão gênica foi analisada por PCR em tempo real quantitativa de RNA extraído de amostras parafinadas de 63 pacientes, porém foi avaliável em 42. Seus valores foram normatizados pelo gene endógeno ABL e transformados em escala logarítmica na base 2 para posterior correlação com variáveis clínicas e de desfecho. Resultados: Com mediana de seguimento de 29 meses, as sobrevidas global, livre de doença e livre de progressão foram, respectivamente, 82,8%, 97,14% e 87,53%, enquanto a resposta completa foi 82,5%. A expressão de LMO2>3logs e BCL6>3,5logs definiu um grupo de maior sobrevida global (91% versus 64,3%, p=0,040) e sobrevida livre de doença (95,5% versus 70,7%, p=0,03), independentemente do Índice Internacional de Prognóstico (p=0,010 e p=0,042) e com significativa hiperexpressão do SCYA3 (p=0,046). Não se observou associação entre escore preditivo de mortalidade baseado nos seis genes e prognóstico. Assim, foi criado novo escore genético prognóstico baseado no poder da expressão concomitante de LMO2 e CCND2, definindo-se grupos de baixo risco (<2,5) e alto risco (>=2,5) com distintas sobrevidas global (92,4% versus 57,1%, p=0,011) e livre de progressão (96,2% versus 66,7%, p=0,013), independentes do IPI. Conclusão: Em pacientes com linfoma difuso de grandes células B tratados com R-CHOP, a hiperexpressão de BCL6, LMO2 e SCYA3 correlacionou-se com melhor prognóstico. O novo escore genético prognóstico definido por LMO2 e CCND2 estratificou grupos de risco de prognósticos distintos independentes do Índice Internacional de Prognóstico / Introduction: Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma; which accounts for almost 50% of the cases at the Hematology Department of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo. Its clinical and biological heterogeneity results in more than twenty subtypes according to the World Health Organization classification. Its treatment is based on a combination of anti-CD20 monoclonal antibody and antracycline-based chemotherapy, with a 10-year overall survival of 43.5%. Clinical prognostic determinants such as the International Prognostic Index and the Revised International Prognostic Index lack accuracy, since up to 20% of low-risk patients will die from the disease and up to 60% of high-risk patients will be alive within four years. Such discrepancies can partially be attributed to genetic factors. Diffuse large B-cell lymphoma germinal center gene signature shows superior overall survival compared to activated B-cell signature (76% versus 16%, p=0.01), however microarray gene expression profile is not yet available in clinical practice. Nonetheless, the Mortality Predictor Score for diffuse large B-cell lymphoma based on the prognostic value of BCL2, BCL6, CCND2, FN1, LMO2 and SCYA3 gene expression by quantitative real-time PCR has proved to be independent from the International Prognostic Index in the pre-rituximab era. But it was not significant in high clinical risk patients treated with R-CHOP. The genes BCL2, CCND2 and SCYA3 compose activated B-cell signature, whereas BCL6 and LMO2 compose the germinal center signature and FN1 the lymph-node signature. Objective: Evaluate the impact of BCL2, BCL6, CCND2, FN1, LMO2 and SCYA3 absolute gene expression in Brazilian population diagnosed with diffuse large B-cell lymphoma and treated with R-CHOP, with respect to overall response, disease free survival, progression free survival and overall survival. Methods: Gene expression was analyzed by quantitative real-time PCR of RNA extracted from paraffin-embedded samples of 63 patients, although evaluable in 42. Their values were normalized by endogenous gene ABL and log- transformed on a base 2 scale for subsequent correlation with clinical and outcome variables. Results: With a median follow-up of 29 months, overall survival, disease free survival and progression free survival accounted for 82.8%, 97.14% and 87.53% respectively, while complete response was 82.5%. The expression of LMO2>3logs and BCL6>3.5logs defined a group with higher overall survival (91% versus 64.3%, p=0.040) and progression free survival (95.5% versus 70.7%, p=0.03), independent of International Prognostic Index (p=0.010 and p=0.042) and with significant overexpression of SCYA3 (p=0.046). It was not identified any association between six gene Mortality Predictor Score and prognosis. As a result, we developed the New Genetic Prognostic Score based on the power of concomitant expression of LMO2 and CCND2, defining low-risk (<2.5) and high-risk (>=2.5) groups with distinct overall survival (92.4% versus 57.1%, p=0.011) and progression free survival (96.2% versus 66.7%, p=0.013), independent of International Prognostic Index. Conclusion: In patients with diffuse large B-cell lymphoma treated with R-CHOP, hyperexpression of BCL6, LMO2 and SCYA3 was correlated with a better prognosis. The New Genetic Prognostic Score, defined by LMO2 and CCND2, stratified risk groups with different prognosis, independent of International Prognostic Index

Avaliou-se os efeitos dos ácidos oleanólico (AO) e ursólico (AU), triterpenóides presentes em alimentos vegetais e especiarias, quando administrados a ratos F344 durante as etapas de iniciação e seleção/promoção do modelo de hepatocarcinogênese do \"hepatócito resistente\" (RH). Os ratos receberam durante 8 semanas, por entubação gástrica e dissolvido em óleo de milho (OM): AO ou AU (8 mg/100 g de peso corpóreo [p.c.]). Os grupos controle receberam apenas OM (0,25 mL/100 g de p.c; grupo OM), ou água (0,25 mL/100 g de p.c.; grupo Água). O grupo Normal não recebeu qualquer tratamento. O agente iniciante foi uma dose de dietilnitrosamina (DEN, 20 mg/100 g de p.c.). Após 2 semanas de entubação, aplicou-se 3 doses diárias consecutivas de 2-acetilaminofluoreno (2-AAF) (2 mg/100 g de p.c.) e fez-se uma hepatectomia parcial a 70%, acrescida de 1 dose de 2-AAF (0,5 mg/100 g de p.c.) 4 dias após a cirurgia. Em 6 semanas após a iniciação, os animais foram sacrificados. Resultados: A análise macroscópica demonstrou que AO não determinou alterações e AU tendeu a aumentar o número de nódulos de hepatócitos, comparados ao grupo OM. A análise morfométrica das lesões pré-neoplásicas (LPN) hepáticas positivas para glutationa S-transferase forma placentária (GST-p), demonstrou que AO e AU não determinaram alterações no número médio de LPN persistentes, porém reduziram o número médio de LPN em remodelação, comparados ao grupo OM (p < 0,05). AO e AU não determinaram alterações na área média das LPN persistentes, mas diminuíram a área média das LPN em remodelação, comparados ao grupo OM (p < 0,05). AO e AU não determinaram alterações na área do corte ocupada por LPN persistentes, mas diminuíram a área do corte ocupada por LPN em remodelação, comparados ao grupo OM (p < 0,05). Os grupos Água, OM e AU apresentaram aumento na concentração plasmática de colesterol, comparados ao grupo Normal. AO promoveu aumento da expressão do gene que codifica para a enzima HMG-CoA redutase, comparado ao grupo Normal (p < 0,05), e AU promoveu aumento de expressão quando comparado aos grupos Normal, Água, OM e AU (p < 0,05). AO e AU não determinaram alterações nos índices de proliferação celular (imunoistoquímica para bromodeoxiuridina [BrdU]) nas LPN persistentes. AU promoveu aumento (p < 0,05) na proliferação celular nas LPN em remodelação quando comparado ao grupo OM. AO e AU não determinaram alterações na apoptose em LPN persistentes, mas aumentaram o número médio de corpúsculos apoptóticos nas LPN em remodelação (p < 0,05). O índice de Crescimento Ajustado (apoptose/proliferação celular) dos grupos demonstrou que, nas LPN persistentes, a proliferação celular tem predominância sobre a apoptose. Nas LPN em remodelação, a apoptose tem preponderância sobre a proliferação celular. Os danos no DNA hepático (método do \"cometa\") foram maiores no grupo AO (p < 0,05) e AU (p = 0,061), comparados ao grupo OM. A análise por \"imunoblot\" revelou que o modelo do \"RH\" aumentou a expressão e a ativação do fator de transcrição NF-&#954;B (p < 0,05). AO e AU aumentaram a expressão e a ativação de NF-&#954;B, comparados ao grupo OM (p > 0,05). Observou-se que a proteína supressora de tumor p53 está acumulada no citoplasma dos hepatócitos de 77,2% (Água), 66,5% (OM), 69,6% (AO) e 69,7% (AU) das LPN persistentes, e de 22,8% (Água), 33,5% (OM), 30,4% (AO) e 30,3% (AU) das LPN em remodelação marcadas para p53. A proteína anti-apoptótica bcl-2 apresentou aumento de expressão em 78,4% (Água), 72,6% (OM), 73,0% (AO) e 70,4% (AU) das LPN persistentes, e de 21,6% (Água), 27,4% (OM), 27,0% (AO) e 29,6% (AU) das LPN em remodelação marcadas para bcl-2. Conclusões: AO e AU não apresentaram atividade quimiopreventiva nas condições de estudo, mas diminuíram as LPN em remodelação. O aumento da apoptose e diminuição da proliferação celular estão envolvidos com a remodelação. O fator de transcrição NF-&#954;B está envolvido com a hepatocarcinogênese. AO e AU aumentaram a expressão e a ativação de NF-&#954;B. O acúmulo de p53 no citoplasma, bem como a expressão aumentada de bcl-2 estão relacionados ao fenótipo das LPN persistentes. / It was evaluated the effects of the oleanólico acid (OA) and ursolic acid (UA), triterpenoids present in vegetable foods and spices, when administered to rat F344 during the initiation and selection/promotion stages of the resistant hepatocyte model of hepatocarcinogenesis RH. The rat received for 8 weeks, by gavage and dissolved in com oil (CO): OA or UA (8 mg/100 g of body weight [b.w.]). The control groups just received CO (0,25 mL/100 g b.w.; CO group), or water (0,25 mL/100 g b.w.; group Water). Normal group did not receive any treatment type. The initiation agent was dietilnitrosamine (DEN, 20 mg/100 g b.w.). 2 weeks after gavage, it was applied 3 consecutive doses of 2-acetilaminofluoreno (2-AAF) (2 mg/100 g of b.w.) and it was made a 70% partial hepatectomy, added of 1 dose of 2-AAF (0,5 mg/100 9 b.w.) 4 days after the surgery. In 6 weeks after the initiation, the animals were sacrificed. Results: the macroscopic analysis demonstrated that OA did not alter and UA tended to increase the number of hepatocytes nodules, compared to the CO group. The morphometric analysis of the pre-neoplastic lesions (PNL) positive for glutatione S-transferase placentary form (GST-p), demonstrated that OA and UA did not alter the medium number of persistent LPN, however they reduced the medium number of remodeling LPN, compared to the OM group (p <0,05). OA and UA did not alter the medium area of persistent LPN, but they reduced the medium area of remodeling LPN, compared to the CO group (p <0,05). The triterpenoids did not alter the occupied area of the section for persistent LPN, but they reduced the occupied area cut for remodeling LPN, compared to the CO group (p <0,05). The Water, OM and AU groups showed increase in the plasmatic concentration of cholesterol, compared to the Normal group. OA promoted increase of the expression of the gene that codifies for the HMG-CoA reductase enzyme, compared to the Normal group (p <0,05), and AU promoted increase expression when compared to the Normal, Water, OM and AU groups (p <0,05). OA and UA did not alter the indexes of cellular proliferation (imunoistochemistry for bromodeoxiuridine [BrdU)) in persistent LPN. AU promoted increase (p <0,05) in the cellular proliferation in remodeling LPN when compared to the CO group. OA and UA did not alter the apoptosis in persistent LPN, but they increased the medium number of apoptotics bodies in remodeling LPN (p <0,05). The Adjusted Index Growth (cellular apoptosis/proliferation) of the groups demonstrated that, in persistent LPN, the cellular proliferation has predominance on the apoptosis. In remodeling LPN, the apoptosis has preponderance over the cellular proliferation. The damages in hepatic DNA (method of the \"comet\") were larger in the group OA (p <0,05) and AU (p <0,061), compared to the CO group. The analysis for imunoblot revealed that the RH model increased the expression and the activation of the NF-&#954;B transcription factor (p <0,05). OA and UA increased the expression and the activation of NF-&#954;B, compared to the CO group (p> 0,05). It was observed that the p53 tumor suppresser protein is accumulated in the hepatocytes cytoplasm of 77,2% (Water), 66,5% (CO), 69,6% (OA) and 69,7% (UA) of persistent LPN, and of 22,8% (Water), 33,5% (CO), 30,4% (OA) and 30,3% (UA) of remodeling LPN marked for p53. The bcl-2 anti-apoptotic protein presented increase expression in 78,4% (Water), 72,6% (CO), 73,0% (OA) and 70,4% (UA) of persistent LPN, and of 21,6% (Water), 27,4% (CO), 27,0% (OA) and 29,6% (UA) of remodeling LPN marked for bcl-2. Conclusions: AO and AU did not present chemopreventive activity in the study conditions, but they reduced remodeling PNL. The apoptosis increase and cellular proliferation decrease are involved with the remodeling. The transcription factor NF-&#954;B is involved with the hepatocarcinogenesis. AO and AU increased the expression and the activation of NF-&#954;B. The p53 accumulation in the cytoplasm, as well as the increased expression of bcl-2 is related to the phenotype of persistent PNL.