Uma série de três complexos de cobre(II) dinucleares, contendo ligantes nitrogenados e grupos aromáticos (compostos 2, 4 e 6), foi sintetizada e caracterizada por diversas técnicas espectroscópicas (UV/Vis, IV e EPR). Esses compostos tiveram sua atividade tirosinase avaliada à temperatura ambiente, através da oxidação de L-di-hidroxifenilalanina (L-dopa), e sua citotoxicidade investigada frente a células melanomas, comparada às de complexos análogos de cobre(II) mononucleares (compostos 1, 3 e 5). A influência da luz UVB, que estimula a melanogênese, também foi verificada. A exposição das células à radiação de intensidade (13 ± 2) mJ/cm2 aumentou os danos causados, principalmente em presença das espécies dinucleares. A citotoxicidade dos diferentes complexos foi determinada frente a duas linhagens de melanomas humanos (SKMEL-05 e SKMEL-147), após 24 e 48h de incubação. Células com maior teor de melanina foram mais sensíveis aos efeitos dos complexos. Verificou-se um aumento na porcentagem de células na fase sub-G1 do ciclo celular após tratamento por 24 ou 48h com estes complexos, ao contrário do verificado frente a queratinócitos não tumorais. Testes clonogênicos também indicaram maior atividade do composto (2) contendo dois centros de cobre em sua estrutura, com diminuição significativa no número de células sobreviventes após tratamento. Ensaios complementares mostraram a redução dos íons de cobre(II) nos compostos (1) e (2) em presença de melanina e a formação de espécies reativas de oxigênio (radicais hidroxil e ânions superóxido), através de espectroscopia EPR ou do uso de sondas fluorescentes. Adicionalmente, foi constatado um aumento no nível de vacúolos citoplasmáticos após tratamento com o complexo (2), indicando indução à autofagia, corroborada pelo monitoramento das proteínas LC3 e tubulina, implicadas neste processo de morte celular. Os resultados apontam para a ocorrência de pelo menos dois mecanismos de ação dos complexos frente aos melanomas, por processo apoptótico e autofágico. Indicam ainda que esta reatividade frente a melanomas é fortemente dependente da estrutura dos complexos de cobre, sendo mais significativa para os dinucleares / A series of dinuclear copper(II) complexes containing nitrogen ligands and aromatic groups (compounds 2, 4 and 6), were synthesized and characterized by various spectroscopic methods (UV/Vis, IR and EPR). These complexes had their tyrosinase activity evaluated at room temperature, through the oxidation of L-di-hidroxyphenylalanine (L-dopa), and its cytotoxicity toward melanoma cells investigated, in comparison with the toxicity of the corresponding mononuclear complexes (compounds 1, 3 and 5). The influence of UVB light, that stimulates melanogenesis, was also verified. The exposition of the cells to radiation of intensity (13 ± 2) mJ/cm2, increased the caused damage, especially in the presence of dinuclear species. The cytotoxicity of the different complexes was determined toward two cell lines of human melanomas (SKMEL-05 e SKMEL-147), after 24 and 48h incubation. Cells containing higher leveis of melanin were more sensitive to the effects of the complexes. An increasing in the percentage of cells in the sub-G1 phase of cellular cycle was verified after treatment for 24 or 48h with these complexes. On the contrary, this effect was not observed with non-tumor keratinocytes. Clonogenic tests also indicated higher activity of compound 2 containing two copper centers in its structure, with a significant decrease in the number of survival cells after the treatment. Complementary assays show the reduction of copper(II) ions in complexes (1) and (2), in the presence of melanin, as well as the formation of reactive oxygen species (hydroxyl radicais and superoxide anions) via EPR spectroscopy or the use of fluorescent labels. Further, an increase in the levei of cytoplasmatic vacuoles was verified after treatment with complex (2), indicating induction to autophagy, which was corroborated by monitoring the proteins LC3 and tubulin, implicated in this process of cell death. The results pointed to the occurrence of at least two mechanisms of action of these complexes toward melanomas, apoptotic and autophagic processes. Also, they indicated that the reactivity of the studied compounds is strongly dependent on its structural features, being more remarkable to the dinuclear ones.

L'autophagie est un processus d'autodigestion qui se produit dans toutes les cellules eucaryotes et conduit à la dégradation d'éléments du cytoplasme (organites, macromolécules) par le lysosome. Ce mécanisme, qui se produit de manière basale, permet le renouvellement du contenu cytoplasmique mais également la survie cellulaire lorsqu'il est induit par différents stress (carence nutritionnelle, hypoxie…). L'autophagie est alors impliquée dans diverses pathologies comme les maladies neurodégénératives et le cancer car sa dérégulation peut grandement perturber l'homéostasie cellulaire. Le but de ma thèse est de déterminer le rôle de la protéine nucléaire et cytoplasmique BAT3 dans l'autophagie et d'étudier son mécanisme de régulation. Cette protéine de 150 kDa, également appelée BAG6 ou Scythe, est composée de nombreux domaines protéiques (UBL, Prolin-rich, NLS, BAG) qui lui permettent d'interagir avec de multiples partenaires. Sa fonction majeure réside dans le contrôle qualité du cytoplasme mais BAT3 est aussi impliquée dans l'immunité ou l'apoptose. Ce travail identifie la protéine BAT3 comme essentiel pour l'autophagie basale et induite. Nous montrons que son mécanisme d'action passe par la régulation de la localisation de l'acétyltransférase p300 et l'acétylation de ces substrats : p53 et une protéine de la machinerie de l'autophagie : ATG7. En effet, BAT3 (i) limite la présence de p300 dans le cytosol en (ii) maintenant un faible et régulable niveau d'acétylation d'ATG7 et (iii) permet l'acétylation de p53 dans le noyau au cours de la carence nutritionnelle, événement indispensable à l'induction de l'autophagie. / Autophagy, literally meaning self-eating, is a highly evolutionary conserved process in eukaryotes in which parts of the cytoplasm (organelles, macromolecules) are degraded by lysosomes. Basal autophagy is a quality control mechanism allowing the renewal of the cytoplasm but autophagy is also induced by cellular stress (starvation, hypoxia…) to improve cell survival. Autophagy has been implicated in several physiopathologies such as cancer or neurodegenerative diseases. Deregulations of autophagy may profoundly affect homeostasis.The purpose of my thesis is to explore the role of the nucleo-cytoplasmic shuttling protein BAT3 in autophagy and the mechanism of BAT3-dependent autophagy.Also known as BAG6 or Scythe, this 150 kDa protein is composed of various domain (UBL, Prolin-Rich, NLS, BAG) by which BAT3 interacts with multiple partners. The major of role BAT3 seems to be the protein quality control but BAT3 is also implicated in immunity and apoptosis. Our work demonstrates that the protein BAT3 is essential for basal and starvation-induced autophagy. We show that BAT3 regulation of autophagy is mediated by the modulation of p300 acetyltransferase intracellular localization and acetylation of two subtrates: p53 and the autophagy-related protein ATG7. Indeed, Bat3 allows: (i) the limitation of p300 into cytosol resulting in (ii) the maintenance of a low level of ATG7 acetylation and (iii) the increase of the starvation-induced p53 autophagy leading to the induction of autophagy.

Fan, Dahua. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 117-155). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Vesicle trafficking provides the solution to the 'sorting problem' - how the eukaryotic cell maintains the distinct identities, and thus functional properties, of its membrane-bound organelles. During vesicle trafficking, proteins are selectively sorted into membrane bound transport intermediates by vesicle adaptors, which include those of the highly conserved adaptor protein (AP) complex family. Each AP complex has a distinct subcellular localisation and functions in the sorting of a specific subset of transmembrane cargo proteins. Adaptor protein complex 4 (AP-4) is one of the more recently identified AP complexes, whose function has largely remained elusive. In humans, AP-4 deficiency causes a severe neurological disorder, suggesting an important role in neuronal development and homeostasis. However, the pathomechanisms that underly the neuronal pathology in AP-4 deficiency are currently unknown. AP-4 is proposed to function in protein sorting at the trans-Golgi network (TGN), so AP-4 deficiency can be thought of as a disease of missorting. The aim of this study was to apply unbiased global proteomic approaches to define the composition of AP-4 vesicles and to identify physiological cargo proteins of the AP-4 pathway. Using 'Dynamic Organellar Maps' and comparative analysis of vesicle-enriched fractions from wild-type and AP-4-depleted cells, three ubiquitously expressed transmembrane cargo proteins, ATG9A, SERINC1 and SERINC3, were found to be mislocalised in AP-4-deficient cells. Two novel cytosolic AP-4 accessory proteins, RUSC1 and RUSC2, were also identified. Further proteomic analyses confirmed the interactions between these proteins. AP-4 deficiency was found to cause missorting of ATG9A in diverse cell types, including patient derived cells, as well as dysregulation of autophagy. RUSC2 facilitates the transport of AP-4-derived, ATG9A and SERINC-positive vesicles from the TGN to the cell periphery. These vesicles cluster in close association with autophagosomes, suggesting they are the 'ATG9 reservoir' required for autophagosome biogenesis. This study uncovers ATG9A trafficking as a ubiquitous function of the AP-4 pathway. Furthermore, it provides a potential molecular pathomechanism of AP-4 deficiency, through dysregulated spatial control of autophagy.

The important role of the central intermediary metabolite acetyl-coenzyme A (AcCoA)for several anabolic and catabolic pathways is well characterised. However, the role of AcCoA as the only known donor of acetyl groups for protein acetylation in regulation of enzyme activities, protein complex stability as well as epigenetic status off chromatin, is only recently emerging. Among multiple other pathways, the autophagy pathway has now been shown to be directly regulated by protein acetylation and deacetylation. Therefore, it was reasoned that the availability of AcCoA, via the modulation of AcCoA generating enzymes, may regulate autophagy. This study has focussed on the role of the acetate-mediated route to nuclear-cytosolic AcCoA synthesis, catalysed by AcCoA synthetase 2 (ACSS2), in the regulation of autophagy.

Introdução: As síndromes de Li-Fraumeni (LFS) e Li-Fraumeni Like (LFL) são síndromes hereditárias de predisposição a câncer frequentemente associadas à mutações germinativas no gene TP53. Devido à importância de p53 e diversidade de processos celulares que ela regula, várias vias de sinalização podem ser afetadas pela doença. Nesse estudo discutimos o impacto da mutação p.R337H na proliferação, senescência, autofagia, população e funcionalidade mitocondrial. Métodos: As taxas de proliferação foram avaliadas pelo ensaio de Population Doubling. Os experimentos de senescência, autofagia, massa total e funcionalidade mitocondrial foram realizados por citometria de fluxo. Resultados: As células contendo a mutação proliferaram mais do que as células controle. Além disso, as células mutadas não ativaram autofagia sob tratamento de Rapamicina nem senescência sob tratamento de Doxorubicina ou Cisplatina e exibiram maior população mitocondrial, mas com funcionalidade inalterada após os tratamentos. Conclusão: os dados sugerem que a mutação p.R337H em TP53 afeta a indução de senescência realizada por p53 e suas funções pró-autofágicas, bem como seu controle. As células mutadas proliferam mais do que células sem mutação em TP53 e exibiram maior massa mitocondrial sem perda de funcionalidade após o tratamento com Doxorubicina. / Background: Li-Fraumeni (LFS) and Li-Fraumeni Like (LFL) syndromes are hereditary cancer predisposition syndromes frequently associated with germline mutation in TP53. Due to the importance of the protein p53 and its regulation of several important cellular processes, impairment in some pathways can be implicated. Here we discuss the impact of p.R337H TP53 mutation on proliferation, senescence, autophagy, mitochondrial population and functionality. Methods: Growth rates were assayed with Population Doubling assay. Senescence and autophagy were assessed through flow cytometry and functionality and total population of mitochondria were also analyzed through flow cytometry. Results: mutated cells proliferated more than control cells. TP53 mutated cells didn’t build up autophagy under Rapamycin treatmend nor senescence under Doxorubicin or Cisplatin treatments and showed more mitochondrial mass, but no alterations in mitochondrial functionality after Doxorubicin treatment. Conclusion:data suggests that p.R337H TP53 mutation affect senescence induction by p53 and pro-autophagic actions of p53. Mutated cells proliferate more than control cells and exhibited larger mitochondrial mass without effects in their functionality in response to Doxorubicin treatment.

L’autophagie est un mécanisme vacuolaire de dégradation de matériel cytoplasmique permettant le maintien de l’homéostasie cellulaire, mais elle peut être également activée par de nombreux stress, comme l’infection virale. Le virus de l’Herpès Simplex de type 1 (HSV 1) est capable de contrecarrer ce mécanisme de défense antivirale. HSV-1 possède une protéine ICP34.5 capable d’inhiber l’autophagie en se liant à Beclin 1, une protéine de la machinerie autophagique. Nous avons mis en évidence une deuxième protéine d’HSV-1 capable d’inhiber l’autophagie, la protéine tardive Us11, qui pourrait avoir un rôle complémentaire à celui d’ICP34.5 dans le contrôle de l’autophagie par le virus.Nous montrons que l’expression ectopique d’Us11 permet de bloquer l’autophagie induite par différents stimuli, et ce de manière similaire à ICP34.5. De plus, dans un contexte viral, l’expression précoce d’Us11 dans des cellules infectées par un virusICP34.5 permet un contrôle de l’autophagie comparable à celui d’un virus sauvage. Nous avons ensuite recherché le mécanisme d’action d’Us11. La protéine Us11 a été décrite comme pouvant interagir avec la kinase dépendante de l’ARN double brin PKR, empêchant ainsi la phosphorylation de son substrat eIF2, un facteur d’initiation de la traduction. Nous avons observé qu’en l’absence de PKR, Us11 n’est plus capable d’inhiber l’autophagie. Nous avons pu confirmer qu’Us11 a besoin de se lier à PKR pour exercer son activité inhibitrice par la construction de formes tronquées d’Us11, permettant de montrer l’importance de son domaine d’interaction avec PKR dans l’inhibition de l’autophagie. L’étude des formes tronquées d’Us11 a soulevé le fait que le domaine N-terminal était également nécessaire. Aucune interaction de ce domaine avec une protéine cellulaire n’a été identifiée à ce jour, mais il pourrait permettre l’interaction d’Us11 avec une autre protéine de la machinerie autophagique. Cependant, nous avons montré qu’Us11 n’interagissait pas avec Beclin 1 et n’avait pas d’effet sur la kinase mTOR, une autre voie importante de l’autophagie. Enfin, nous avons étudié la modulation de la voie PKR/eIF2 lors de la stimulation de l’autophagie par la carence, et nos résultats suggèrent que cette voie joue un rôle sous-estimé dans la réponse à la carence.Le mécanisme d’action de la protéine Us11, qui consiste en un blocage de l’autophagie en inhibant PKR, n’avait jamais été décrit auparavant. Ce travail ouvre de nombreuses perspectives dans l’étude de la voie PKR/eIF2 vis à vis de la régulation de l’autophagie, ainsi que dans la compréhension de l’implication de l’autophagie dans la neurovirulence d’HSV-1. / Autophagy is an evolutionary conserved vacuolar mechanism allowing to degrade cytoplasmic components and to maintaining cellular homeostasis, but it can also be triggered by a variety of stress-related conditions, including viral infection. The herpes simplex virus 1 (HSV-1) is able to counteract this antiviral mechanism. Notably, HSV-1 encodes a protein, IPC34.5, which inhibits autophagy through its interaction with the autophagy machinery protein Beclin 1. In the present work, we uncovered a second anti-autophagic protein from HSV-1, the late protein Us11, which likely plays a complementary role to ICP34.5 regarding the inhibition of autophagy by the virus. We demonstrated that ectopic expression of Us11 inhibited autophagy triggered by different stimuli, as observed for ICP34.5. Moreover, during viral infection, early expression of Us11 was sufficient to block autophagy in cells infected with a ICP34.5 virus, similarly to the wild-type virus. We then explored the mechanism of action of Us11. Us11 has been described as capable of interacting with the dsRNA-dependent kinase PKR, therefore preventing it to phosphorylate its substrate eIF2, a translation initiation factor. We demonstrated that Us11 was no longer able to inhibit autophagy when expressed in PKR-deficient cells. We confirmed that Us11 binding to PKR was necessary for its function by constructing various truncated forms of Us11 that showed that the PKR-binding domain was crucial. We also unveiled the importance of a domain located within the N-terminal part of Us11. This domain has no cellular molecular partner known, but it can allow Us11 to interact with another protein of the autophagy machinery. However, we further showed that Us11 did not interact with Beclin 1 nor affected the kinase activity of mTOR, another important pathway regulating autophagy. In our work, we also gained insights into regulatory mechanisms of starvation-induced autophagy.The inhibition of autophagy through the specific blockade of PKR by Us11 had never been previously described. This work thus paves the way for studying the involvement of PKR/eIF2 pathway in the regulation of autophagy and for exploring the role of autophagy in HSV-1 neurovirulence.

Plus de 80% des cancers colorectaux sont initiés par la perte de fonction du gène Apc. Afin d’identifier de nouvelles cibles thérapeutiques, nous avons utilisé des modèles murins présentant des mutations du gène Apc et recherché par des analyses de puces à ADN de nouveaux événements moléculaires impliqués au cours de la carcinogenèse intestinale.Cette approche nous a permis d’identifier une activation de la signalisation Notch tout au long du processus tumoral. Toutefois, cette activation n’est pas un élément clé de la progression tumorale puisque son inhibition n’empêche pas le phénotype tumoral induit par la perte du gène Apc. En parallèle, nos travaux ont permis d’identifier une induction de l’autophagie tout au long de la carcinogenèse intestinale. L’activation de ce processus biologique ouvre, quant à lui, de nouvelles perspectives thérapeutiques dans le traitement du CCR. / Over 80% of colorectal cancers are linked to an Apc mutation. To identify new therapeutic targets, we used mouse models with Apc mutations and performed microarray experiments to identify key molecular events involved in intestinal carcinogenesis. This approach allowed usto identify an activation of the Notch signaling all along tumor progression. However, this induction is dispensable for tumor development since its inhibition did not prevent the Apc phenotype. In addition, we have identified an induction of autophagy throughout intestinal carcinogenesis which appears to be an attractive therapeutic target in the treatment of CRC patients.

La voie TORC1 joue un rôle majeur dans le contrôle de la croissance cellulaire et de la réponse à divers stress. Le dérèglement de cette voie est constaté dans de nombreux cancers et autres maladies. Au cours de ma thèse, j’ai montré que le complexe SEA émerge comme un régulateur central des différentes activités de TORC1. Durant la carence azotée, les délétions des gènes du complexe SEA dans l’organisme modèle S.cerevisiae mènent à la délocalisation de la kinase Tor1 vers le cytoplasme, à des défauts d’autophagie et à la fragmentation de la vacuole. L’inactivation de TORC1 par le traitement avec la rapamycine ou pendant la carence azotée change le niveau d’expression des membres du complexe SEA. De plus, le complexe SEA interagit avec la mitochondrie, joue un rôle dans la réponse au stress oxydatif et peut servir de lien moléculaire entre les fonctions mitochondriales et la voie TORC1. Enfin, j’ai pu observer que le complexe SEA est impliqué dans les mécanismes de résistance à une drogue souvent utilisée en chimiothérapie, la doxorubicine. Je présente dans mes travaux la première carte d’interconnectivité des protéines composant le complexe SEA. Nos données suggèrent que le complexe SEA émerge comme une plateforme qui peut coordonner les activités structurales et enzymatiques nécessaires pour le fonctionnement efficace de la voie de signalisation TORC1. / The TORC1 pathway plays a major role in controlling cell growth and response to various stresses. Deregulation of this pathway is found in many cancers and other diseases. In my thesis, I have shown that the SEA complex emerges as a central regulator of the various activities of TORC1. During the nitrogen deficiency, deletions of SEA complex genes in the model organism S.cerevisiae lead to the relocation of Tor1 kinase to the cytoplasm, to defects in autophagy and the fragmentation of the vacuole. Inactivation of TORC1 by treatment with rapamycin or nitrogen starvation changes the level of expression of SEA complex members. Moreover, the SEA complex interacts with mitochondrion, plays a role in oxidative stress response and can serve as a molecular link between mitochondrial functions and TORC1 pathway. Finally, I observed that the SEA complex is involved in the mechanisms of resistance to a drug often used in chemotherapy, the doxorubicin. I present in my work the first interconnectivity map protein of the SEA complex component. Our data suggest that the SEA complex emerges as a platform that can coordinate structural and enzymatic activities necessary for the efficient function of the TORC1 signalling pathway.

Considéré comme un cancer de l'âge mûr, l'incidence du cancer colorectal ne cesse d'augmenter avec l'allongement de la vie. Dans la majorité des cas, le cancer colique est associé à une mutation du gène suppresseur de tumeur Apc, contrôlant l’activation de la signalisation Wnt/β-caténine. Afin, d'identifier de nouveaux acteurs de la tumorigenèse colique, notre laboratoire a développé des modèles murins de mutation du gène Apc qui ont pour avantage de mimer la pathologie humaine (Colnot et al, 2004 ; Andreu et al, 2005). La création de ces modèles a permis à l’équipe de démontrer i) qu’une activation physiologique de cette voie contrôle la prolifération des cellules souches et des progéniteurs ainsi que leur différenciation et ii) qu’une activation aigüe est suffisante pour déclencher l’initiation tumorale intestinale (Andreu et al, 2005; Andreu et al, 2008). Les travaux antérieurs à mon arrivée ont permis d’identifier différents évènements moléculaires et cellulaires induits en cascade suite à l’activation pathologique de la voie Wnt/β-caténine. Parmi ceux-ci, une induction transcriptionnelle de gènes impliqués dans l'autophagie a été mise en évidence. Ce processus d'auto-cannibalisme cellulaire est associé à de nombreuses pathologies telles que les maladies neurodégénératives ou infectieuses. Cependant, le rôle de l'autophagie dans le cancer reste ambivalent et son implication dans le cancer colique demeure inconnue.Dans ce contexte, mon travail de doctorat a consisté à répondre aux questions suivantes :L’induction transcriptionnelle de gène Atg s’accompagne-t-elle d’une activation du processus d’autophagie à tous les stades de la progression tumorale intestinale murine et humaine?Des études de transcriptomique à haut débit nous ont permis d’identifier une induction transcriptionnelle de gènes clés du processus d’autophagie tels qu’Atg7. Cependant, l’activation fonctionnelle de l’autophagie n’est pas toujours associée à une augmentation de la transcription des acteurs de ce processus. Nous nous sommes donc intéressés aux marqueurs couramment décris dans la littérature et permettant d’établir l’état d’activation du flux autophagique. Ainsi, nous avons étudié le niveau d’expression de ces marqueurs par des expériences de western-blot et d’immuno-marquages sur des échantillons tumoraux humains et murins à différents stades de la progression du CRC. L’inhibition de l’autophagie impacte-t-elle la carcinogénèse colorectale?Dans ce contexte, nous avons généré un modèle murin de délétion conditionnelle et simultanée d'un allèle du gène Apc et des deux allèles du gène Atg7 (gène clé de l'autophagie) spécifiquement dans les cellules épithéliales intestinales. Afin de suivre l'apparition et l'évolution des tumeurs au cours du temps, nous avons mis au point une nouvelle méthode non-invasive de reconstruction tridimensionnelle de côlons de souris, issue d'imagerie échographique à haute résolution. Dans le but de caractériser l’impact de l’inhibition de l’autophagie, les modifications propres à la cellule déficiente en autophagie ont été explorées, notamment le statut énergétique ainsi que les changements dans l’environnement immunitaire et microbien de l’épithélium intestinal. Finalement, l’inhibition génétique de l’autophagie dans notre modèle murin, prédisposé au développement de tumeurs intestinales, nous a permis de caractériser l’implication de l’autophagie dans la carcinogénèse colique, ainsi que les mécanismes moléculaires et cellulaires liant l’auto-cannibalisme cellulaire à la pathologie tumorale. / Colorectal cancer is one of the major causes of cancer-related deaths. We took advantage of Apc mutant mice that mimic the adenomatous polyps that affect humans with an inactivated Apc gene, to gain insight into the critical events that affect the development of colorectal cancer. We show that autophagy, a catabolic pathway involved in the degradation of intracellular proteins and organelles, is activated in intestinal murine and human cancer and its inhibition has a crucial role in controlling tumorigenesis. We report that the in vivo conditional deletion of the essential autophagy gene Atg7 in intestinal epithelial cells inhibits the formation of pre-cancerous lesions resulting from Apc loss by enhancing immunosurveillance. The antibody-mediated depletion of CD8+ T cells demonstrated a critical role for CD8+ T cells in antitumoral responses resulting from the inhibition of autophagy. We used a broad-spectrum antibiotics treatment to show that the expansion of IFN-producing CD8+ T cells following the deletion of Atg7 is dependent on the intestinal microbiota and is associated with Paneth and goblet cell defects. In addition, the inhibition of autophagy affected tumor cell growth and restrained cancer growth for extended time periods. We demonstrate that the inhibition of autophagy in Apc tumor cells results in a stress response accompanied by metabolic defects, characterized by AMPK activation and p53 cell cycle arrest. This study suggests that autophagy inhibitors may suppress tumorigenesis in patients at high risk of developing colorectal cancer.