RESUMO
Protection against oxidative damage caused by excessive reactive oxygen species (ROS) by an antioxidant network is essential for the health of tissues, especially in the cardiovascular system. Here, we identified a gene with important antioxidant features by analyzing a null allele of zebrafish ubiad1, called barolo (bar). bar mutants show specific cardiovascular failure due to oxidative stress and ROS-mediated cellular damage. Human UBIAD1 is a nonmitochondrial prenyltransferase that synthesizes CoQ10 in the Golgi membrane compartment. Loss of UBIAD1 reduces the cytosolic pool of the antioxidant CoQ10 and leads to ROS-mediated lipid peroxidation in vascular cells. Surprisingly, inhibition of eNOS prevents Ubiad1-dependent cardiovascular oxidative damage, suggesting a crucial role for this enzyme and nonmitochondrial CoQ10 in NO signaling. These findings identify UBIAD1 as a nonmitochondrial CoQ10-forming enzyme with specific cardiovascular protective function via the modulation of eNOS activity.
Assuntos
Dimetilaliltranstransferase/metabolismo , Células Endoteliais/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ubiquinona/análogos & derivados , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Dimetilaliltranstransferase/genética , Complexo de Golgi/metabolismo , Coração/embriologia , Humanos , Miocárdio/citologia , Espécies Reativas de Oxigênio/metabolismo , Ubiquinona/genética , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genéticaRESUMO
Smooth muscle cells (SMCs) represent a major structural and functional component of many organs during embryonic development and adulthood. These cells are a crucial component of vertebrate structure and physiology, and an updated overview of the developmental and functional process of smooth muscle during organogenesis is desirable. Here, we describe the developmental origin of SMCs within different tissues by comparing their specification and differentiation with other organs, including the cardiovascular, respiratory and intestinal systems. We then discuss the instructive roles of smooth muscle in the development of such organs through signaling and mechanical feedback mechanisms. By understanding SMC development, we hope to advance therapeutic approaches related to tissue regeneration and other smooth muscle-related diseases.
Assuntos
Desenvolvimento Embrionário , Músculo Liso/crescimento & desenvolvimento , Miócitos de Músculo Liso/fisiologia , Vertebrados/crescimento & desenvolvimento , Animais , Animais Geneticamente Modificados , Sistema Cardiovascular , Diferenciação Celular/fisiologia , Trato Gastrointestinal , Pulmão , Mesoderma , Músculo Liso/citologia , Músculo Liso/embriologia , Músculo Liso Vascular/embriologia , Músculo Liso Vascular/crescimento & desenvolvimento , Miócitos de Músculo Liso/citologia , Organogênese/fisiologia , Sistema Respiratório , Vertebrados/embriologiaRESUMO
Congenital or neonatal cardiomyopathies are commonly associated with a poor prognosis and have multiple etiologies. In two siblings, a male and female, we identified an undescribed type of lethal congenital restrictive cardiomyopathy affecting the right ventricle. We hypothesized a novel autosomal recessive condition. To identify the cause, we performed genetic, in vitro and in vivo studies. Genome-wide SNP typing and parametric linkage analysis was done in a recessive model to identify candidate regions. Exome sequencing analysis was done in unaffected and affected siblings. In the linkage regions, we selected candidate genes that harbor two rare variants with predicted functional effects in the patients and for which the unaffected sibling is either heterozygous or homozygous reference. We identified two compound heterozygous variants in KIF20A; a maternal missense variant (c.544C>T: p.R182W) and a paternal frameshift mutation (c.1905delT: p.S635Tfs*15). Functional studies confirmed that the R182W mutation creates an ATPase defective form of KIF20A which is not able to support efficient transport of Aurora B as part of the chromosomal passenger complex. Due to this, Aurora B remains trapped on chromatin in dividing cells and fails to translocate to the spindle midzone during cytokinesis. Translational blocking of KIF20A in a zebrafish model resulted in a cardiomyopathy phenotype. We identified a novel autosomal recessive congenital restrictive cardiomyopathy, caused by a near complete loss-of-function of KIF20A. This finding further illustrates the relationship of cytokinesis and congenital cardiomyopathy.
Assuntos
Cardiomiopatias/congênito , Cardiomiopatias/genética , Cinesinas/genética , Mutação de Sentido Incorreto , Feminino , Genes Letais , Heterozigoto , Humanos , Lactente , Morte do Lactente , Masculino , Linhagem , Gravidez , Recidiva , IrmãosRESUMO
Intestinal smooth muscle cells (iSMCs) are a crucial component of the adult gastrointestinal tract and support intestinal differentiation, peristalsis and epithelial homeostasis during development. Despite these crucial roles, the origin of iSMCs and the mechanisms responsible for their differentiation and function remain largely unknown in vertebrates. Here, we demonstrate that iSMCs arise from the lateral plate mesoderm (LPM) in a stepwise process. Combining pharmacological and genetic approaches, we show that TGFß/Alk5 signaling drives the LPM ventral migration and commitment to an iSMC fate. The Alk5-dependent induction of zeb1a and foxo1a is required for this morphogenetic process: zeb1a is responsible for driving LPM migration around the gut, whereas foxo1a regulates LPM predisposition to iSMC differentiation. We further show that TGFß, zeb1a and foxo1a are tightly linked together by miR-145 In iSMC-committed cells, TGFß induces the expression of miR-145, which in turn is able to downregulate zeb1a and foxo1a The absence of miR-145 results in only a slight reduction in the number of iSMCs, which still express mesenchymal genes but fail to contract. Together, our data uncover a cascade of molecular events that govern distinct morphogenetic steps during the emergence and differentiation of vertebrate iSMCs.
Assuntos
Intestinos/citologia , Miócitos de Músculo Liso/citologia , Animais , Animais Geneticamente Modificados , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Mucosa Intestinal/metabolismo , Intestinos/embriologia , Mesoderma/citologia , Mesoderma/embriologia , Mesoderma/metabolismo , Modelos Biológicos , Morfogênese , Miócitos de Músculo Liso/metabolismo , Regiões Promotoras Genéticas , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismoRESUMO
E3 ligases mediate the covalent attachment of ubiquitin to target proteins thereby enabling ubiquitin-dependent signaling. Unraveling how E3 ligases are regulated is important because miscontrolled ubiquitylation can lead to disease. Cellular inhibitor of apoptosis (cIAP) proteins are E3 ligases that modulate diverse biological processes such as cell survival, proliferation, and migration. Here, we have solved the structure of the caspase recruitment domain (CARD) of cIAP1 and identified that it is required for cIAP1 autoregulation. We demonstrate that the CARD inhibits activation of cIAP1's E3 activity by preventing RING dimerization, E2 binding, and E2 activation. Moreover, we show that the CARD is required to suppress cell proliferation and migration. Further, CARD-mediated autoregulation is also necessary to maximally suppress caspase-8-dependent apoptosis and vascular tree degeneration in vivo. Taken together, our data reveal mechanisms by which the E3 ligase activity of cIAP1 is controlled, and how its deregulation impacts on cell proliferation, migration and cell survival.
Assuntos
Proteínas Inibidoras de Apoptose/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , Sequência de Aminoácidos , Animais , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Humanos , Proteínas Inibidoras de Apoptose/química , Proteínas Inibidoras de Apoptose/genética , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Estrutura Terciária de Proteína/fisiologia , Alinhamento de Sequência , Eletricidade Estática , Ubiquitina-Proteína Ligases/química , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
The purpose of this review is to provide an overview of redox mechanisms, sources and antioxidants that control signaling events in ECs. In particular, we describe which molecules are involved in redox signaling and how they influence the relationship between ECs and other vascular component with regard to angiogenesis. Recent and new tools to investigate physiological ROS signaling will be also discussed. Such findings are providing an overview of the ROS biology relevant for endothelial cells in the context of normal and pathological angiogenic conditions.
Assuntos
Células Endoteliais/metabolismo , Mitocôndrias/metabolismo , NADPH Oxidases/metabolismo , Neovascularização Fisiológica/fisiologia , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/fisiologia , Animais , Humanos , Proteínas Tirosina Fosfatases/metabolismoRESUMO
During neuronal development and maturation, microRNAs (miRs) play diverse functions ranging from early patterning, proliferation and commitment to differentiation, survival, homeostasis, activity and plasticity of more mature and adult neurons. The role of miRs in the differentiation of olfactory receptor neurons (ORNs) is emerging from the conditional inactivation of Dicer in immature ORN, and the depletion of all mature miRs in this system. Here, we identify specific miRs involved in olfactory development, by focusing on mice null for Dlx5, a homeogene essential for both ORN differentiation and axon guidance and connectivity. Analysis of miR expression in Dlx5(-/-) olfactory epithelium pointed to reduced levels of miR-9, miR-376a and four miRs of the -200 class in the absence of Dlx5. To functionally examine the role of these miRs, we depleted miR-9 and miR-200 class in reporter zebrafish embryos and observed delayed ORN differentiation, altered axonal trajectory/targeting, and altered genesis and position of olfactory-associated GnRH neurons, i.e. a phenotype known as Kallmann syndrome in humans. miR-9 and miR-200-class negatively control Foxg1 mRNA, a fork-head transcription factor essential for development of the olfactory epithelium and of the forebrain, known to maintain progenitors in a stem state. Increased levels of z-foxg1 mRNA resulted in delayed ORN differentiation and altered axon trajectory, in zebrafish embryos. This work describes for the first time the role of specific miR (-9 and -200) in olfactory/GnRH development, and uncovers a Dlx5-Foxg1 regulation whose alteration affects receptor neuron differentiation, axonal targeting, GnRH neuron development, the hallmarks of the Kallmann syndrome.
Assuntos
Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Hormônio Liberador de Gonadotropina/metabolismo , Proteínas de Homeodomínio/metabolismo , MicroRNAs/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/fisiologia , Condutos Olfatórios/fisiologia , Animais , Animais Geneticamente Modificados , Diferenciação Celular/genética , Células Cultivadas , Embrião de Mamíferos , Feminino , Fatores de Transcrição Forkhead/genética , Hormônio Liberador de Gonadotropina/genética , Proteínas de Homeodomínio/genética , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Mutação/genética , Proteínas do Tecido Nervoso/genética , Mucosa Olfatória/citologia , Mucosa Olfatória/embriologia , Condutos Olfatórios/citologia , Gravidez , Peixe-ZebraRESUMO
The process of de novo vessel formation, called angiogenesis, is essential for tumor progression and spreading. Targeting of molecular pathways involved in such tumor angiogenetic processes by using specific drugs or inhibitors is important for developing new anticancer therapies. Drug discovery remains to be the main focus for biomedical research and represents the essence of antiangiogenesis cancer research. To pursue these molecular and pharmacological goals, researchers need to use animal models that facilitate the elucidation of tumor angiogenesis mechanisms and the testing of antiangiogenic therapies. The past few years have seen the zebrafish system emerge as a valid model organism to study developmental angiogenesis and, more recently, as an alternative vertebrate model for cancer research. In this review, we will discuss why the zebrafish model system has the advantage of being a vertebrate model equipped with easy and powerful transgenesis as well as imaging tools to investigate not only physiological angiogenesis but also tumor angiogenesis. We will also highlight the potential of zebrafish for identifying antitumor angiogenesis drugs to block tumor development and progression. We foresee the zebrafish model as an important system that can possibly complement well-established mouse models in cancer research to generate novel insights into the molecular mechanism of the tumor angiogenesis.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neovascularização Fisiológica/efeitos dos fármacos , Peixe-Zebra , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Técnicas de Transferência de Genes , Genes Reporter , Ensaios de Triagem em Larga Escala , Microscopia Confocal , Terapia de Alvo Molecular , Transplante de Neoplasias , Neovascularização Patológica/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Especificidade da Espécie , Relação Estrutura-Atividade , Peixe-Zebra/embriologiaRESUMO
microRNAs (miRNAs) have a pivotal role during the formation and function of the cardiovascular system. More than 300 miRNAs have been currently found within the mammalian genome, however only few specific miRNAs, named endomiRNAs, showed conseved endothelial cell expression and function. In this review we present an overview of the currently known endomiRNAs, focusing on their genome localization, processing and target gene repression during vasculogenesis and angiogenesis.
Assuntos
Células Endoteliais/fisiologia , MicroRNAs/genética , Neovascularização Fisiológica/genética , Transdução de Sinais , Animais , Vasos Sanguíneos/citologia , Vasos Sanguíneos/crescimento & desenvolvimento , Vasos Sanguíneos/metabolismo , Humanos , MicroRNAs/metabolismo , MicroRNAs/fisiologia , Família Multigênica , Interferência de RNARESUMO
Metastasis has a major part in the severity of disease and lethality of cancer. Circulating tumour cells (CTCs) represent a reservoir of metastatic precursors in circulation, most of which cannot survive due to hostile conditions in the bloodstream. Surviving cells colonise a secondary site based on a combination of physical, metabolic, and oxidative stress protection states required for that environment. Recent advances in CTC isolation methods and high-resolution 'omics technologies are revealing specific metabolic pathways that support this selection of CTCs. In this review, we discuss recent advances in our understanding of CTC biology and discoveries of adaptations in metabolic pathways during their selection. Understanding these traits and delineating mechanisms by which they confer acquired resistance or vulnerability in CTCs is crucial for developing successful prognostic and therapeutic strategies in cancer.
Assuntos
Neoplasias , Células Neoplásicas Circulantes , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Humanos , Neoplasias/patologia , Neoplasias/metabolismo , Neoplasias/genética , Redes e Vias Metabólicas , Estresse Oxidativo , Metástase Neoplásica , PrognósticoRESUMO
The metabolic mechanisms supporting the process of endothelial-to-mesenchymal transition (EndMT) remain largely unknown. Here, Zhu et al. describe a novel role for acetate and ACC2 in regulating EndMT and atherosclerosis via modulation of the TGF-ß signaling. This study sheds light on the role of glucose-derived metabolites that drive endothelial pathophysiology.
Assuntos
Acetatos , Aterosclerose , Glucose , Fator de Crescimento Transformador beta , Humanos , Acetatos/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
The use of transgenic animals carrying exogenous DNA integrated in their genome is a routine in modern-day laboratories. Nowadays, the zebrafish system represents the most useful tool for transgenesis studies mainly due to easy accessibility and manipulation of the eggs, which are produced in high numbers and over a relatively short generation time. The zebrafish transgenic technology is very straightforward when coupled with angiogenesis studies allowing easy in vivo observation of the vertebrate embryonic vasculature. Here, we describe the most common technique to generate vascular-labelled transgenic zebrafish embryos and their applications to study tumor angiogenesis and visualize tumor extravasation.
Assuntos
Neoplasias , Peixe-Zebra , Animais , Animais Geneticamente Modificados , DNA , Neoplasias/irrigação sanguínea , Neoplasias/genética , Neovascularização Patológica/genética , Peixe-Zebra/genéticaRESUMO
AIMS: The circadian clock is an internal biological timer that co-ordinates physiology and gene expression with the 24-h solar day. Circadian clock perturbations have been associated to vascular dysfunctions in mammals, and a function of the circadian clock in angiogenesis has been suggested. However, the functional role of the circadian clock in endothelial cells (ECs) and in the regulation of angiogenesis is widely unexplored. METHODS AND RESULTS: Here, we used both in vivo and in vitro approaches to demonstrate that ECs possess an endogenous molecular clock and show robust circadian oscillations of core clock genes. By impairing the EC-specific function of the circadian clock transcriptional activator basic helix-loop-helix ARNT like 1 (BMAL1) in vivo, we detect angiogenesis defects in mouse neonatal vascular tissues, as well as in adult tumour angiogenic settings. We then investigate the function of circadian clock machinery in cultured EC and show evidence that BMAL and circadian locomotor output cycles protein kaput knock-down impair EC cell cycle progression. By using an RNA- and chromatin immunoprecipitation sequencing genome-wide approaches, we identified that BMAL1 binds the promoters of CCNA1 and CDK1 genes and controls their expression in ECs. CONCLUSION(S): Our findings show that EC display a robust circadian clock and that BMAL1 regulates EC physiology in both developmental and pathological contexts. Genetic alteration of BMAL1 can affect angiogenesis in vivo and in vitro settings.
Assuntos
Fatores de Transcrição ARNTL , Ritmo Circadiano , Animais , Camundongos , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Ritmo Circadiano/genética , Células Endoteliais/metabolismo , Regiões Promotoras Genéticas , Ciclo Celular , Mamíferos/genética , Mamíferos/metabolismoRESUMO
Cancer is a leading cause of death worldwide. If left untreated, tumors tend to grow and spread uncontrolled until the patient dies. To support this growth, cancer cells need large amounts of nutrients and growth factors that are supplied and distributed to the tumor tissue by the vascular system. The aberrant tumor vasculature shows deep morphological, molecular, and metabolic differences compared to the blood vessels belonging to the non-malignant tissues (also referred as normal). A better understanding of the metabolic mechanisms driving the differences between normal and tumor vasculature will allow the designing of new drugs with a higher specificity of action and fewer side effects to target tumors and improve a patient's life expectancy. In this review, we aim to summarize the main features of tumor endothelial cells (TECs) and shed light on the critical metabolic pathways that characterize these cells. A better understanding of such mechanisms will help to design innovative therapeutic strategies in healthy and diseased angiogenesis.
RESUMO
Cutaneous melanoma is the deadliest type of skin cancer, although it accounts for a minority of all skin cancers. Oxidative stress is involved in all stages of melanomagenesis and cutaneous melanoma can sustain a much higher load of Reactive Oxygen Species (ROS) than normal tissues. Melanoma cells exploit specific antioxidant machinery to support redox homeostasis. The enzyme UBIA prenyltransferase domain-containing protein 1 (UBIAD1) is responsible for the biosynthesis of non-mitochondrial CoQ10 and plays an important role as antioxidant enzyme. Whether UBIAD1 is involved in melanoma progression has not been addressed, yet. Here, we provide evidence that UBIAD1 expression is associated with poor overall survival (OS) in human melanoma patients. Furthermore, UBIAD1 and CoQ10 levels are upregulated in melanoma cells with respect to melanocytes. We show that UBIAD1 and plasma membrane CoQ10 sustain melanoma cell survival and proliferation by preventing lipid peroxidation and cell death. Additionally, we show that the NAD(P)H Quinone Dehydrogenase 1 (NQO1), responsible for the 2-electron reduction of CoQ10 on plasma membranes, acts downstream of UBIAD1 to support melanoma survival. By showing that the CoQ10-producing enzyme UBIAD1 counteracts oxidative stress and lipid peroxidation events in cutaneous melanoma, this work may open to new therapeutic investigations based on UBIAD1/CoQ10 loss to cure melanoma.
Assuntos
Dimetilaliltranstransferase/metabolismo , Melanoma , Neoplasias Cutâneas , Antioxidantes/metabolismo , Morte Celular , Humanos , Peroxidação de Lipídeos , Melanoma/genética , Ubiquinona/análogos & derivados , Ubiquinona/metabolismo , Ubiquinona/farmacologia , Melanoma Maligno CutâneoRESUMO
Vascular mural cells (vMCs) play an essential role in the development and maturation of the vasculature by promoting vessel stabilization through their interactions with endothelial cells. Whether endothelial metabolism influences mural cell recruitment and differentiation is unknown. Here, we show that the oxidative pentose phosphate pathway (oxPPP) in endothelial cells is required for establishing vMC coverage of the dorsal aorta during early vertebrate development in zebrafish and mice. We demonstrate that laminar shear stress and blood flow maintain oxPPP activity, which in turn, promotes elastin expression in blood vessels through production of ribose-5-phosphate. Elastin is both necessary and sufficient to drive vMC recruitment and maintenance when the oxPPP is active. In summary, our work demonstrates that endothelial cell metabolism regulates blood vessel maturation by controlling vascular matrix composition and vMC recruitment.
Assuntos
Vasos Sanguíneos/citologia , Vasos Sanguíneos/metabolismo , Matriz Extracelular/metabolismo , Fosforilação Oxidativa , Via de Pentose Fosfato , Animais , Biomarcadores , Elastina/biossíntese , Elastina/genética , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Expressão Gênica , Genes Reporter , Glucose/metabolismo , Hemodinâmica , Camundongos , Camundongos Knockout , Modelos Biológicos , Estresse Oxidativo , Pentosefosfatos/metabolismo , Peixe-ZebraRESUMO
Angiogenesis, the active formation of new blood vessels from pre-existing ones, is a complex and demanding biological process that plays an important role in physiological as well as pathological settings. Recent evidence supports cell metabolism as a critical regulator of angiogenesis. However, whether and how cell metabolism regulates endothelial growth factor receptor levels and nucleotide synthesis remains elusive. We here shown in both human cell lines and mouse models that during developmental and pathological angiogenesis, endothelial cells (ECs) use glutaminolysis-derived glutamate to produce aspartate (Asp) via aspartate aminotransferase (AST/GOT). Asp leads to mTORC1 activation which, in turn, regulates endothelial translation machinery for VEGFR2 and FGFR1 synthesis. Asp-dependent mTORC1 pathway activation also regulates de novo pyrimidine synthesis in angiogenic ECs. These findings identify glutaminolysis-derived Asp as a regulator of mTORC1-dependent endothelial translation and pyrimidine synthesis. Our studies may help overcome anti-VEGF therapy resistance by targeting endothelial growth factor receptor translation.
Assuntos
Ácido Aspártico , Células Endoteliais , Alvo Mecanístico do Complexo 1 de Rapamicina , Neovascularização Patológica , Neovascularização Fisiológica , Animais , Ácido Aspártico/metabolismo , Linhagem Celular , Células Endoteliais/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Neovascularização Patológica/metabolismo , Neovascularização Fisiológica/fisiologia , Biossíntese de Proteínas/fisiologia , Pirimidinas , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
The circadian clock regulates a wide range of molecular pathways and biological processes. The expression of clock genes is often altered in cancer, fostering tumor initiation and progression. Inhibition and activation of core circadian clock genes, as well as treatments that restore circadian rhythmicity, have been successful in counteracting tumor growth in different experimental models. Here, we provide an up-to-date overview of studies that show the therapeutic effects of targeting the clock molecular machinery in cancer, both genetically and pharmacologically. We also highlight future areas for progress that offer a promising path towards innovative anticancer strategies. Substantial limitations in the current understanding of the complex interplay between the circadian clock and cancer in vivo need to be addressed in order to allow clock-targeting therapies in cancer.