RESUMO
Cancer stem cells (CSCs) have been hypothesized to represent the driving force behind tumour progression and metastasis, making them attractive cancer targets. However, conclusive experimental evidence for their functional relevance is still lacking for most malignancies. Here we show that the leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) identifies intestinal CSCs in mouse tumours engineered to recapitulate the clinical progression of human colorectal cancer. We demonstrate that selective Lgr5+ cell ablation restricts primary tumour growth, but does not result in tumour regression. Instead, tumours are maintained by proliferative Lgr5- cells that continuously attempt to replenish the Lgr5+ CSC pool, leading to rapid re-initiation of tumour growth upon treatment cessation. Notably, CSCs are critical for the formation and maintenance of liver metastasis derived from colorectal cancers. Together, our data highlight distinct CSC dependencies for primary versus metastasic tumour growth, and suggest that targeting CSCs may represent a therapeutic opportunity for managing metastatic disease.
Assuntos
Neoplasias Colorretais/patologia , Metástase Neoplásica/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Receptores Acoplados a Proteínas G/metabolismo , Animais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Separação Celular , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Injeções Subcutâneas , Intestinos/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Camundongos , Metástase Neoplásica/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Organoides/patologia , Organoides/transplante , Receptores Acoplados a Proteínas G/análiseRESUMO
Mutations of WD repeat domain 62 (WDR62) lead to autosomal recessive primary microcephaly (MCPH), and down-regulation of WDR62 expression causes the loss of neural progenitor cells (NPCs). However, how WDR62 is regulated and hence controls neurogenesis and brain size remains elusive. Here, we demonstrate that mitogen-activated protein kinase kinase kinase 3 (MEKK3) forms a complex with WDR62 to promote c-Jun N-terminal kinase (JNK) signaling synergistically in the control of neurogenesis. The deletion of Mekk3, Wdr62, or Jnk1 resulted in phenocopied defects, including premature NPC differentiation. We further showed that WDR62 protein is positively regulated by MEKK3 and JNK1 in the developing brain and that the defects of wdr62 deficiency can be rescued by the transgenic expression of JNK1. Meanwhile, WDR62 is also negatively regulated by T1053 phosphorylation, leading to the recruitment of F-box and WD repeat domain-containing protein 7 (FBW7) and proteasomal degradation. Our findings demonstrate that the coordinated reciprocal and bidirectional regulation among MEKK3, FBW7, WDR62, and JNK1, is required for fine-tuned JNK signaling for the control of balanced NPC self-renewal and differentiation during cortical development.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteína 7 com Repetições F-Box-WD/fisiologia , MAP Quinase Quinase Quinase 3/fisiologia , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Diferenciação Celular , Proteína 7 com Repetições F-Box-WD/genética , Feminino , Células HEK293 , Humanos , MAP Quinase Quinase Quinase 3/genética , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microcefalia/genética , Microcefalia/fisiopatologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese/fisiologia , Fosforilação , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
Aging is accompanied by disrupted information flow, resulting from accumulation of molecular mistakes. These mistakes ultimately give rise to debilitating disorders including skeletal muscle wasting, or sarcopenia. To derive a global metric of growing 'disorderliness' of aging muscle, we employed a statistical physics approach to estimate the state parameter, entropy, as a function of genes associated with hallmarks of aging. Escalating network entropy reached an inflection point at old age, while structural and functional alterations progressed into oldest-old age. To probe the potential for restoration of molecular 'order' and reversal of the sarcopenic phenotype, we systemically overexpressed the longevity protein, Klotho, via AAV. Klotho overexpression modulated genes representing all hallmarks of aging in old and oldest-old mice, but pathway enrichment revealed directions of changes were, for many genes, age-dependent. Functional improvements were also age-dependent. Klotho improved strength in old mice, but failed to induce benefits beyond the entropic tipping point.
Assuntos
Envelhecimento/metabolismo , Glucuronidase/metabolismo , Músculo Esquelético/metabolismo , Sarcopenia/metabolismo , Fatores Etários , Envelhecimento/genética , Envelhecimento/patologia , Animais , Dependovirus/genética , Dependovirus/metabolismo , Feminino , Regulação da Expressão Gênica , Terapia Genética , Vetores Genéticos , Glucuronidase/genética , Células HEK293 , Humanos , Proteínas Klotho , Masculino , Camundongos Endogâmicos C57BL , Força Muscular , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Recuperação de Função Fisiológica , Sarcopenia/genética , Sarcopenia/fisiopatologia , Sarcopenia/terapia , TranscriptomaRESUMO
The AP-1 transcription factor c-Jun is required for Ras-driven tumorigenesis in many tissues and is considered as a classical proto-oncogene. To determine the requirement for c-Jun in a mouse model of K-RasG12D-induced lung adenocarcinoma, we inducibly deleted c-Jun in the adult lung. Surprisingly, we found that inactivation of c-Jun, or mutation of its JNK phosphorylation sites, actually increased lung tumor burden. Mechanistically, we found that protein levels of the Jun family member JunD were increased in the absence of c-Jun. In c-Jun-deficient cells, JunD phosphorylation was increased, and expression of a dominant-active JNKK2-JNK1 transgene further increased lung tumor formation. Strikingly, deletion of JunD completely abolished Ras-driven lung tumorigenesis. This work identifies JunD, not c-Jun, as the crucial substrate of JNK signaling and oncogene required for Ras-induced lung cancer.
Assuntos
Adenocarcinoma de Pulmão , Carcinogênese , Neoplasias Pulmonares , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas ras/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica , Genes jun/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , MAP Quinase Quinase 7/genética , MAP Quinase Quinase 7/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-jun/genética , Fator de Transcrição AP-1/metabolismoRESUMO
OBJECTIVES: The streptozotocin (STZ) model is widely used in diabetes research. However, the cellular and molecular states of pancreatic endocrine cells in this model remain unclear. This study explored the molecular characteristics of islet cells treated with STZ and re-evaluated ß-cell dysfunction and regeneration in the STZ model. METHODS: We performed single-cell RNA sequencing of pancreatic endocrine cells from STZ-treated mice. High-quality sequencing data from 2,999 cells were used to identify clusters via Louvain clustering analysis. Principal component analysis (PCA), t-distributed stochastic neighbor embedding (t-SNE), uniform manifold approximation and projection (UMAP), force-directed layout (FDL), and differential expression analysis were used to define the heterogeneity and transcriptomic changes in islet cells. In addition, qPCR and immunofluorescence staining were used to confirm findings from the sequencing data. RESULTS: Untreated ß-cells were divided into two populations at the transcriptomic level, a large high-Glut2 expression (Glut2high) population and a small low-Glut2 expression (Glut2low) population. At the transcriptomic level, Glut2low ß-cells in adult mice did not represent a developmentally immature state, although a fraction of genes associated with ß-cell maturation and function were downregulated in Glut2low cells. After a single high-dose STZ treatment, most Glut2high cells were killed, but Glut2low cells survived and over time changed to a distinct cell state. We did not observe conversion of Glut2low to Glut2high ß-cells up to 9 months after STZ treatment. In addition, we did not detect transcriptomic changes in the non-ß endocrine cells or a direct trans-differentiation pathway from the α-cell lineage to the ß-cell lineage in the STZ model. CONCLUSIONS: We identified the heterogeneity of ß-cells in both physiological and pathological conditions. However, we did not observe conversion of Glut2low to Glut2high ß-cells, transcriptomic changes in the non-ß endocrine cells, or direct trans-differentiation from the α-cell lineage to the ß-cell lineage in the STZ model. Our results clearly define the states of islet cells treated with STZ and allow us to re-evaluate the STZ model widely used in diabetes studies.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Células Secretoras de Insulina/fisiologia , Ilhotas Pancreáticas/metabolismo , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/fisiopatologia , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Células Secretoras de Glucagon/metabolismo , Glucose/metabolismo , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Análise de Célula Única/métodos , Estreptozocina/farmacologia , Transcriptoma/genéticaRESUMO
The year 2017 marked the 20th anniversary of the first publication describing Klotho. This single protein was and is remarkable in that its absence in mice conferred an accelerated aging, or progeroid, phenotype with a dramatically shortened life span. On the other hand, genetic overexpression extended both health span and life span by an impressive 30%. Not only has Klotho deficiency been linked to a number of debilitating age-related illnesses but many subsequent reports have lent credence to the idea that Klotho can compress the period of morbidity and extend the life span of both model organisms and humans. This suggests that Klotho functions as an integrator of organ systems, making it both a promising tool for advancing our understanding of the biology of aging and an intriguing target for interventional studies. In this review, we highlight advances in our understanding of Klotho as well as key challenges that have somewhat limited our view, and thus translational potential, of this potent protein.
Assuntos
Envelhecimento/genética , Glucuronidase , Longevidade/fisiologia , Animais , Senescência Celular/fisiologia , Glucuronidase/genética , Glucuronidase/metabolismo , Humanos , Proteínas Klotho , Camundongos , Pesquisa Translacional BiomédicaRESUMO
In the original version of this article [1], there was 1 error in the affiliation of the European Institute of Oncology (affiliation 3). In this correction article the updated affiliation is shown for clarification.
RESUMO
Squamous cell carcinomas (SCCs) account for the majority of cancer mortalities. Although TP63 is an established lineage-survival oncogene in SCCs, therapeutic strategies have not been developed to target TP63 or it's downstream effectors. In this study we demonstrate that TP63 directly regulates NRG1 expression in human SCC cell lines and that NRG1 is a critical component of the TP63 transcriptional program. Notably, we show that squamous tumors are dependent NRG1 signaling in vivo, in both genetically engineered mouse models and human xenograft models, and demonstrate that inhibition of NRG1 induces keratinization and terminal squamous differentiation of tumor cells, blocking proliferation and inhibiting tumor growth. Together, our findings identify a lineage-specific function of NRG1 in SCCs of diverse anatomic origin.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Diferenciação Celular , Neuregulina-1/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos Nus , Receptor ErbB-3/metabolismoRESUMO
Choroid plexus tumours (CPTs) account for 2-5% of brain tumours in children. They can spread along the neuraxis and can recur after treatment. Little is known about the molecular mechanisms underlying their formation and only few high fidelity mouse models of p53-deficient malignant CPTs are available.We show here that c-MYC overexpression in the choroid plexus epithelium induces T-cell inflammation-dependent choroid plexus papillomas in a mouse model. We demonstrate that c-MYC is expressed in a substantial proportion of human choroid plexus tumours and that this subgroup of tumours is characterised by an inflammatory transcriptome and significant inflammatory infiltrates. In compound mutant mice, overexpression of c-MYC in an immunodeficient background led to a decreased incidence of CPP and reduced tumour bulk. Finally, reduced tumour size was also observed upon T-cell depletion in CPP-bearing mice. Our data raise the possibility that benign choroid plexus tumours expressing c-MYC could be amenable to medical therapy with anti-inflammatory drugs.
Assuntos
Encefalite/metabolismo , Papiloma do Plexo Corióideo/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Linfócitos T/metabolismo , Animais , Encéfalo/patologia , Modelos Animais de Doenças , Encefalite/complicações , Humanos , Camundongos Transgênicos , Papiloma do Plexo Corióideo/etiologia , Papiloma do Plexo Corióideo/patologia , TranscriptomaRESUMO
Under injury conditions, dedicated stem cell populations govern tissue regeneration. However, the molecular mechanisms that induce stem cell regeneration and enable plasticity are poorly understood. Here, we investigate stem cell recovery in the context of the hair follicle to understand how two molecularly distinct stem cell populations are integrated. Utilizing diphtheria-toxin-mediated cell ablation of Lgr5+ (leucine-rich repeat-containing G-protein-coupled receptor 5) stem cells, we show that killing of Lgr5+ cells in mice abrogates hair regeneration but this is reversible. During recovery, CD34+ (CD34 antigen) stem cells activate inflammatory response programs and start dividing. Pharmacological attenuation of inflammation inhibits CD34+ cell proliferation. Subsequently, the Wnt pathway controls the recovery of Lgr5+ cells and inhibition of Wnt signalling prevents Lgr5+ cell and hair germ recovery. Thus, our study uncovers a compensatory relationship between two stem cell populations and the underlying molecular mechanisms that enable hair follicle regeneration.
Assuntos
Alopecia/metabolismo , Plasticidade Celular , Proliferação de Células , Folículo Piloso/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Regeneração , Células-Tronco/metabolismo , Alopecia/genética , Alopecia/fisiopatologia , Animais , Anti-Inflamatórios/farmacologia , Antígenos CD34/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Plasticidade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Predisposição Genética para Doença , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/crescimento & desenvolvimento , Folículo Piloso/patologia , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Knockout , Fenótipo , Receptores Acoplados a Proteínas G/deficiência , Receptores Acoplados a Proteínas G/genética , Regeneração/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/patologia , Via de Sinalização WntRESUMO
Neural stem and progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes and oligodendrocytes. However, the mechanisms underlying the decision of a stem cell to either self-renew or differentiate are incompletely understood. We demonstrate here that Fbw7 (F-box and WD repeat domain containing-7), the substrate recognition component of an SCF (complex of SKP1, CUL1 and F-box protein)-type E3 ubiquitin ligase, is a key regulator of NSC/NPC viability and differentiation. The absence of Fbw7 in the mouse brain caused severely impaired stem cell differentiation and increased progenitor cell death. Fbw7 deficiency resulted in accumulation of two SCF(Fbw7) substrates, the transcription factors active Notch1 and N-terminally phosphorylated c-Jun. Genetic and pharmacological rescue experiments identified c-Jun as a key substrate of Fbw7 in controlling progenitor cell viability, whereas inhibition of Notch signaling alleviated the block in stem cell differentiation. Thus Fbw7 controls neurogenesis by antagonizing Notch and c-Jun N-terminal kinase (JNK)/c-Jun signaling.