RESUMO
How cancer-associated chromatin abnormalities shape tumor-immune interaction remains incompletely understood. Recent studies have linked DNA hypomethylation and de-repression of retrotransposons to anti-tumor immunity through the induction of interferon response. Here, we report that inactivation of the histone H3K36 methyltransferase NSD1, which is frequently found in squamous cell carcinomas (SCCs) and induces DNA hypomethylation, unexpectedly results in diminished tumor immune infiltration. In syngeneic and genetically engineered mouse models of head and neck SCCs, NSD1-deficient tumors exhibit immune exclusion and reduced interferon response despite high retrotransposon expression. Mechanistically, NSD1 loss results in silencing of innate immunity genes, including the type III interferon receptor IFNLR1, through depletion of H3K36 di-methylation (H3K36me2) and gain of H3K27 tri-methylation (H3K27me3). Inhibition of EZH2 restores immune infiltration and impairs the growth of Nsd1-mutant tumors. Thus, our work uncovers a druggable chromatin cross talk that regulates the viral mimicry response and enables immune evasion of DNA hypomethylated tumors.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Histona Metiltransferases , Evasão Tumoral , Animais , Camundongos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Cromatina , Metilação de DNA , Neoplasias de Cabeça e Pescoço/genética , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histonas/genética , Histonas/metabolismo , Interferons/genética , Proteínas Nucleares/metabolismo , Receptores de Interferon/genética , Retroelementos , Evasão Tumoral/genéticaRESUMO
The urothelium of the bladder functions as a waterproof barrier between tissue and outflowing urine. Largely quiescent during homeostasis, this unique epithelium rapidly regenerates in response to bacterial or chemical injury. The specification of the proper cell types during development and injury repair is crucial for tissue function. This Review surveys the current understanding of urothelial progenitor populations in the contexts of organogenesis, regeneration and tumorigenesis. Furthermore, we discuss pathways and signaling mechanisms involved in urothelial differentiation, and consider the relevance of this knowledge to stem cell biology and tissue regeneration.
Assuntos
Transformação Celular Neoplásica , Urotélio , Diferenciação Celular/fisiologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Humanos , Células-Tronco , Bexiga Urinária , Urotélio/fisiologiaRESUMO
Retinoic acid (RA) signaling is essential for multiple developmental processes, including appropriate pancreas formation from the foregut endoderm. RA is also required to generate pancreatic progenitors from human pluripotent stem cells. However, the role of RA signaling during endocrine specification has not been fully explored. In this study, we demonstrate that the disruption of RA signaling within the NEUROG3-expressing endocrine progenitor population impairs mouse ß cell differentiation and induces ectopic expression of crucial δ cell genes, including somatostatin. In addition, the inhibition of the RA pathway in hESC-derived pancreatic progenitors downstream of NEUROG3 induction impairs insulin expression. We further determine that RA-mediated regulation of endocrine cell differentiation occurs through Wnt pathway components. Together, these data demonstrate the importance of RA signaling in endocrine specification and identify conserved mechanisms by which RA signaling directs pancreatic endocrine cell fate.
Assuntos
Células Secretoras de Insulina/metabolismo , Pâncreas/metabolismo , Transdução de Sinais , Tretinoína/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Embrião de Mamíferos/metabolismo , Proteínas de Homeodomínio/genética , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Pâncreas/citologia , Receptores do Ácido Retinoico/deficiência , Receptores do Ácido Retinoico/genética , Somatostatina/genética , Somatostatina/metabolismo , Células Secretoras de Somatostatina/citologia , Células Secretoras de Somatostatina/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Transativadores/deficiência , Transativadores/genética , Proteínas Wnt/metabolismoRESUMO
PURPOSE: Previous work identified rare variants in DSTYK associated with human congenital anomalies of the kidney and urinary tract (CAKUT). Here, we present a series of mouse and human studies to clarify the association, penetrance, and expressivity of DSTYK variants. METHODS: We phenotypically characterized Dstyk knockout mice of 3 separate inbred backgrounds and re-analyzed the original family segregating the DSTYK c.654+1G>A splice-site variant (referred to as "SSV" below). DSTYK loss of function (LOF) and SSVs were annotated in individuals with CAKUT, epilepsy, or amyotrophic lateral sclerosis vs controls. A phenome-wide association study analysis was also performed using United Kingdom Biobank (UKBB) data. RESULTS: Results demonstrate â¼20% to 25% penetrance of obstructive uropathy, at least, in C57BL/6J and FVB/NJ Dstyk-/- mice. Phenotypic penetrance increased to â¼40% in C3H/HeJ mutants, with mild-to-moderate severity. Re-analysis of the original family segregating the rare SSV showed low penetrance (43.8%) and no alternative genetic causes for CAKUT. LOF DSTYK variants burden showed significant excess for CAKUT and epilepsy vs controls and an exploratory phenome-wide association study supported association with neurological disorders. CONCLUSION: These data support causality for DSTYK LOF variants and highlights the need for large-scale sequencing studies (here >200,000 cases) to accurately assess causality for genes and variants to lowly penetrant traits with common population prevalence.
Assuntos
Epilepsia , Sistema Urinário , Anormalidades Urogenitais , Animais , Camundongos , Humanos , Penetrância , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Anormalidades Urogenitais/genética , Rim/anormalidades , Fatores de Risco , Epilepsia/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genéticaRESUMO
The bladder's remarkable regenerative capacity had been thought to derive exclusively from its own progenitors. While examining consequences of DNA methyltransferase 1 (Dnmt1) inactivation in mouse embryonic bladder epithelium, we made the surprising discovery that Wolffian duct epithelial cells can support bladder regeneration. Conditional Dnmt1 inactivation in mouse urethral and bladder epithelium triggers widespread apoptosis, depletes basal and intermediate bladder cells, and disrupts uroplakin protein expression. These events coincide with Wolffian duct epithelial cell recruitment into Dnmt1 mutant urethra and bladder where they are reprogrammed to express bladder markers, including FOXA1, keratin 5, P63, and uroplakin. This is evidence that Wolffian duct epithelial cells are summoned in vivo to replace damaged bladder epithelium and function as a reservoir of cells for bladder regeneration.
Assuntos
Bexiga Urinária/fisiologia , Urotélio/fisiologia , Ductos Mesonéfricos/fisiologia , Animais , Animais Recém-Nascidos , Apoptose , Linhagem da Célula , DNA (Citosina-5-)-Metiltransferase 1/fisiologia , Dano ao DNA , Metilação de DNA , Células Epiteliais/fisiologia , Camundongos , RegeneraçãoRESUMO
Renal agenesis and hypodysplasia (RHD) are major causes of pediatric chronic kidney disease and are highly genetically heterogeneous. We conducted whole-exome sequencing in 202 case subjects with RHD and identified diagnostic mutations in genes known to be associated with RHD in 7/202 case subjects. In an additional affected individual with RHD and a congenital heart defect, we found a homozygous loss-of-function (LOF) variant in SLIT3, recapitulating phenotypes reported with Slit3 inactivation in the mouse. To identify genes associated with RHD, we performed an exome-wide association study with 195 unresolved case subjects and 6,905 control subjects. The top signal resided in GREB1L, a gene implicated previously in Hoxb1 and Shha signaling in zebrafish. The significance of the association, which was p = 2.0 × 10-5 for novel LOF, increased to p = 4.1 × 10-6 for LOF and deleterious missense variants combined, and augmented further after accounting for segregation and de novo inheritance of rare variants (joint p = 2.3 × 10-7). Finally, CRISPR/Cas9 disruption or knockdown of greb1l in zebrafish caused specific pronephric defects, which were rescued by wild-type human GREB1L mRNA, but not mRNA containing alleles identified in case subjects. Together, our study provides insight into the genetic landscape of kidney malformations in humans, presents multiple candidates, and identifies SLIT3 and GREB1L as genes implicated in the pathogenesis of RHD.
Assuntos
Anormalidades Congênitas/genética , Exoma/genética , Nefropatias/congênito , Rim/anormalidades , Mutação/genética , Proteínas de Neoplasias/genética , Alelos , Animais , Estudos de Casos e Controles , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Feminino , Heterogeneidade Genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Hereditariedade/genética , Homozigoto , Humanos , Nefropatias/genética , Masculino , Proteínas de Membrana/genética , Camundongos , Fenótipo , RNA Longo não Codificante/genética , Sistema Urinário/anormalidades , Anormalidades Urogenitais/genética , Peixe-ZebraRESUMO
Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation.
Assuntos
Sistema Urogenital/anatomia & histologia , Sistema Urogenital/embriologia , Animais , Camundongos , Modelos Animais , Uretra/anatomia & histologia , Uretra/embriologia , Bexiga Urinária/anatomia & histologia , Bexiga Urinária/embriologia , Sistema Urinário/anatomia & histologia , Sistema Urinário/embriologiaRESUMO
Danforth's short tail mutant (Sd) mouse, first described in 1930, is a classic spontaneous mutant exhibiting defects of the axial skeleton, hindgut, and urogenital system. We used meiotic mapping in 1,497 segregants to localize the mutation to a 42.8-kb intergenic segment on chromosome 2. Resequencing of this region identified an 8.5-kb early retrotransposon (ETn) insertion within the highly conserved regulatory sequences upstream of Pancreas Specific Transcription Factor, 1a (Ptf1a). This mutation resulted in up to tenfold increased expression of Ptf1a as compared to wild-type embryos at E9.5 but no detectable changes in the expression levels of other neighboring genes. At E9.5, Sd mutants exhibit ectopic Ptf1a expression in embryonic progenitors of every organ that will manifest a developmental defect: the notochord, the hindgut, and the mesonephric ducts. Moreover, at E 8.5, Sd mutant mice exhibit ectopic Ptf1a expression in the lateral plate mesoderm, tail bud mesenchyme, and in the notochord, preceding the onset of visible defects such as notochord degeneration. The Sd heterozygote phenotype was not ameliorated by Ptf1a haploinsufficiency, further suggesting that the developmental defects result from ectopic expression of Ptf1a. These data identify disruption of the spatio-temporal pattern of Ptf1a expression as the unifying mechanism underlying the multiple congenital defects in Danforth's short tail mouse. This striking example of an enhancer mutation resulting in profound developmental defects suggests that disruption of conserved regulatory elements may also contribute to human malformation syndromes.
Assuntos
Desenvolvimento Embrionário/genética , Mutagênese Insercional/genética , Retroelementos/genética , Fatores de Transcrição , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Mesoderma/anormalidades , Mesoderma/crescimento & desenvolvimento , Camundongos , Pâncreas/anormalidades , Pâncreas/crescimento & desenvolvimento , Medula Espinal/anormalidades , Medula Espinal/crescimento & desenvolvimento , Cauda/anatomia & histologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Mutations in the receptor tyrosine kinase RET are associated with congenital anomalies of kidneys or urinary tract (CAKUT). RET tyrosine Y1015 is the docking site for PLCγ, a major regulator of RET signaling. Abrogating signaling via Y1015 causes CAKUT that are markedly different than renal agenesis in Ret-null or RetY1062F mutant mice. We performed analysis of Y1015F mutant upper and lower urinary tracts in mice to delineate its molecular and developmental roles during early urinary tract formation. We found that the degeneration of the common nephric ducts (CND), the caudal-most Wolffian duct (WD) segment, depends on Y1015 signals. The CNDs in Y1015F mutants persist owing to increased proliferation and reduced apoptosis, and showed abundance of phospho-ERK-positive cells. In the upper urinary tract, the Y1015 signals are required for proper patterning of the mesonephros and metanephros. Timely regression of mesonephric mesenchyme and proper demarcation of mesonephric and metanephric mesenchyme from the WD depends on RetY1015 signaling. We show that the mechanism of de novo ectopic budding is via increased ERK activity due to abnormal mesenchymal GDNF expression. Although reduction in GDNF dosage improved CAKUT it did not affect delayed mesenchyme regression. Experiments using whole-mount immunofluorescence confocal microscopy and explants cultures of early embryos with ERK-specific inhibitors suggest an imbalance between increased proliferation, decreased apoptosis and increased ERK activity as a mechanism for WD defects in RetY1015F mice. Our work demonstrates novel inhibitory roles of RetY1015 and provides a possible mechanistic explanation for some of the confounding broad range phenotypes in individuals with CAKUT.
Assuntos
Padronização Corporal , Proteínas Proto-Oncogênicas c-ret/metabolismo , Tirosina/metabolismo , Sistema Urinário/embriologia , Animais , Apoptose , Sítios de Ligação , Proliferação de Células , Desenvolvimento Embrionário , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial/biossíntese , Masculino , Mesoderma/metabolismo , Camundongos , Mutação , Técnicas de Cultura de Órgãos , Proteínas Proto-Oncogênicas c-ret/genética , Transdução de Sinais , Sistema Urinário/anormalidadesRESUMO
Urinary tract development depends on a complex series of events in which the ureter moves from its initial branch point on the nephric duct (ND) to its final insertion site in the cloaca (the primitive bladder and urethra). Defects in this maturation process can result in malpositioned ureters and hydronephrosis, a common cause of renal disease in children. Here, we report that insertion of the ND into the cloaca is an unrecognized but crucial step that is required for proper positioning of the ureter and that depends on Ret signaling. Analysis of Ret mutant mice at birth reveals hydronephrosis and defective ureter maturation, abnormalities that our results suggest are caused, at least in part, by delayed insertion of the ND. We find a similar set of malformations in mutants lacking either Gata3 or Raldh2. We show that these factors act in parallel to regulate ND insertion via Ret. Morphological analysis of ND extension in wild-type embryos reveals elaborate cellular protrusions at ND tips that are not detected in Ret, Gata3 or Raldh2 mutant embryos, suggesting that these protrusions may normally be important for fusion with the cloaca. Together, our studies reveal a novel Ret-dependent event, ND insertion, that, when abnormal, can cause obstruction and hydronephrosis at birth; whether ND defects underlie similar types of urinary tract abnormalities in humans is an interesting possibility.
Assuntos
Aldeído Oxirredutases/metabolismo , Fator de Transcrição GATA3/metabolismo , Proteínas Proto-Oncogênicas c-ret/metabolismo , Sistema Urinário/embriologia , Sistema Urinário/metabolismo , Aldeído Oxirredutases/deficiência , Aldeído Oxirredutases/genética , Animais , Sequência de Bases , Extensões da Superfície Celular/metabolismo , Extensões da Superfície Celular/ultraestrutura , Cloaca/anormalidades , Cloaca/embriologia , Cloaca/metabolismo , Primers do DNA/genética , Feminino , Fator de Transcrição GATA3/deficiência , Fator de Transcrição GATA3/genética , Regulação da Expressão Gênica no Desenvolvimento , Hidronefrose/embriologia , Hidronefrose/genética , Hidronefrose/metabolismo , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Morfogênese , Gravidez , Proteínas Proto-Oncogênicas c-ret/deficiência , Proteínas Proto-Oncogênicas c-ret/genética , Transdução de Sinais , Sistema Urinário/anormalidadesRESUMO
The GenitoUrinary Development Molecular Anatomy Project (GUDMAP) is an international consortium working to generate gene expression data and transgenic mice. GUDMAP includes data from large-scale in situ hybridisation screens (wholemount and section) and microarray gene expression data of microdissected, laser-captured and FACS-sorted components of the developing mouse genitourinary (GU) system. These expression data are annotated using a high-resolution anatomy ontology specific to the developing murine GU system. GUDMAP data are freely accessible at www.gudmap.org via easy-to-use interfaces. This curated, high-resolution dataset serves as a powerful resource for biologists, clinicians and bioinformaticians interested in the developing urogenital system. This paper gives examples of how the data have been used to address problems in developmental biology and provides a primer for those wishing to use the database in their own research.
Assuntos
Bases de Dados Genéticas , Internet , Sistema Urogenital/metabolismo , Animais , Humanos , Camundongos , Software , Sistema Urogenital/crescimento & desenvolvimentoRESUMO
Removal of toxic substances from the blood depends on patent connections between the kidney, ureters and bladder that are established when the ureter is transposed from its original insertion site in the male genital tract to the bladder. This transposition is thought to occur as the trigone forms from the common nephric duct and incorporates into the bladder. Here we re-examine this model in the context of normal and abnormal development. We show that the common nephric duct does not differentiate into the trigone but instead undergoes apoptosis, a crucial step for ureter transposition controlled by vitamin A-induced signals from the primitive bladder. Ureter abnormalities occur in 1-2% of the human population and can cause obstruction and end-stage renal disease. These studies provide an explanation for ureter defects underlying some forms of obstruction in humans and redefine the current model of ureter maturation.
Assuntos
Apoptose , Néfrons/embriologia , Ureter/embriologia , Bexiga Urinária/embriologia , Vitamina A/fisiologia , Animais , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Transgênicos , Néfrons/citologia , Organogênese/genética , Transdução de SinaisRESUMO
PURPOSE OF REVIEW: This review addresses significant changes in our understanding of urothelial development and regeneration. Understanding urothelial differentiation will be important in the push to find new methods of bladder reconstruction and augmentation, as well as identification of bladder cancer stem cells. RECENT FINDINGS: This review will cover recent findings including the identification of novel progenitor cells in the embryo and adult urothelium, function of the urothelium, and regeneration of the urothelium. Using Cre-lox recombination with cell-type-specific Cre lines, lineage studies from our laboratory have revealed novel urothelial cell types and progenitors that are critical for formation and regeneration of the urothelium. Interestingly, our studies indicate that Keratin-5-expressing basal cells, which have previously been proposed to be urothelial stem cells, are a self-renewing unipotent population, whereas P-cells, a novel urothelial cell type, are progenitors in the embryo, and intermediate cells serve as a progenitor pool in the adult. SUMMARY: These findings could have important implications for our understanding of cancer tumorigenesis and could move the fields of regeneration and reconstruction forward.
Assuntos
Regeneração , Urotélio/fisiologia , Células-Tronco Adultas/citologia , Animais , Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células Epiteliais/citologia , Humanos , Células-Tronco Neoplásicas/patologia , Neoplasias da Bexiga Urinária/patologiaRESUMO
Muscle invasive bladder cancers (BCs) can be divided into 2 major subgroups-basal/squamous (BASQ) tumors and luminal tumors. Since Pparg has low or undetectable expression in BASQ tumors, we tested the effects of rosiglitazone, Pparg agonist, in a mouse model of BASQ BC. We find that rosiglitazone reduces proliferation while treatment with rosiglitazone plus trametinib, a MEK inhibitor, induces apoptosis and reduces tumor volume by 91% after 1 month. Rosiglitazone and trametinib also induce a shift from BASQ to luminal differentiation in tumors, which our analysis suggests is mediated by retinoid signaling, a pathway known to drive the luminal differentiation program. Our data suggest that rosiglitazone, trametinib, and retinoids, which are all FDA approved, may be clinically active in BASQ tumors in patients.
Assuntos
Apoptose , Proliferação de Células , Modelos Animais de Doenças , Piridonas , Pirimidinonas , Rosiglitazona , Neoplasias da Bexiga Urinária , Animais , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Piridonas/farmacologia , Piridonas/uso terapêutico , Pirimidinonas/farmacologia , Pirimidinonas/uso terapêutico , Rosiglitazona/farmacologia , Rosiglitazona/uso terapêutico , Camundongos , Apoptose/efeitos dos fármacos , Humanos , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Invasividade Neoplásica , Feminino , PPAR gama/metabolismo , PPAR gama/agonistas , Tiazolidinedionas/farmacologia , Tiazolidinedionas/uso terapêutico , Diferenciação Celular/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Retinoides/farmacologia , Retinoides/uso terapêuticoRESUMO
Multi-platform mutational, proteomic, and metabolomic spatial mapping was used on the whole-organ scale to identify the molecular evolution of bladder cancer from mucosal field effects. We identified complex proteomic and metabolomic dysregulations in microscopically normal areas of bladder mucosa adjacent to dysplasia and carcinoma in situ. The mutational landscape developed in a background of complex defects of protein homeostasis which included dysregulated nucleocytoplasmic transport, splicesome, ribosome biogenesis, and peroxisome. These changes were combined with altered urothelial differentiation which involved lipid metabolism and protein degradations controlled by PPAR. The complex alterations of proteome were accompanied by dysregulation of gluco-lipid energy-related metabolism. The analysis of mutational landscape identified three types of mutations based on their geographic distribution and variant allele frequencies. The most common were low frequency α mutations restricted to individual mucosal samples. The two other groups of mutations were associated with clonal expansion. The first of this group referred to as ß mutations occurred at low frequencies across the mucosa. The second of this group called γ mutations increased in frequency with disease progression. Modeling of the mutations revealed that carcinogenesis may span nearly 30 years and can be divided into dormant and progressive phases. The α mutations developed gradually in the dormant phase. The progressive phase lasted approximately five years and was signified by the advent of ß mutations, but it was driven by γ mutations which developed during the last 2-3 years of disease progression to invasive cancer. Our study indicates that the understanding of complex alterations involving mucosal microenvironment initiating bladder carcinogenesis can be inferred from the multi-platform whole-organ mapping.
RESUMO
We describe a strategy that combines histologic and molecular mapping that permits interrogation of the chronology of changes associated with cancer development on a whole-organ scale. Using this approach, we present the sequence of alterations around RB1 in the development of bladder cancer. We show that RB1 is not involved in initial expansion of the preneoplastic clone. Instead, we found a set of contiguous genes that we term "forerunner" genes whose silencing is associated with the development of plaque-like field effects initiating carcinogenesis. Specifically, we identified five candidate forerunner genes (ITM2B, LPAR6, MLNR, CAB39L, and ARL11) mapping near RB1. Two of these genes, LPAR6 and CAB39L, are preferentially downregulated in the luminal and basal subtypes of bladder cancer, respectively. Their loss of function dysregulates urothelial differentiation, sensitizing the urothelium to N-butyl-N-(4-hydroxybutyl)nitrosamine-induced cancers, which recapitulate the luminal and basal subtypes of human bladder cancer.
Assuntos
Carcinogênese , Diferenciação Celular , Neoplasias da Bexiga Urinária , Urotélio , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Carcinogênese/patologia , Carcinogênese/genética , Carcinogênese/metabolismo , Regulação Neoplásica da Expressão Gênica , Camundongos Endogâmicos C57BL , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores de Ácidos Lisofosfatídicos/genética , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Urotélio/patologia , Urotélio/metabolismoRESUMO
In humans and mice, mutations in the Ret gene result in Hirschsprung's disease and renal defects. In the embryonic kidney, binding of Ret to its ligand, Gdnf, induces a program of epithelial cell remodeling that controls primary branch formation and branching morphogenesis within the kidney. Our previous studies showed that transcription factors belonging to the retinoic acid (RA) receptor family are crucial for controlling Ret expression in the ureteric bud; however, the mechanism by which retinoid-signaling acts has remained unclear. In the current study, we show that expression of a dominant-negative RA receptor in mouse ureteric bud cells abolishes Ret expression and Ret-dependent functions including ureteric bud formation and branching morphogenesis, indicating that RA-receptor signaling in ureteric bud cells is crucial for renal development. Conversely, we find that RA-receptor signaling in ureteric bud cells depends mainly on RA generated in nearby stromal cells by retinaldehyde dehydrogenase 2, an enzyme required for most fetal RA synthesis. Together, these studies suggest that renal development depends on paracrine RA signaling between stromal mesenchyme and ureteric bud cells that regulates Ret expression both during ureteric bud formation and within the developing collecting duct system.
Assuntos
Rim/embriologia , Retinoides/metabolismo , Transdução de Sinais , Aldeído Oxirredutases/genética , Aldeído Oxirredutases/fisiologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Imunoquímica , Hibridização In Situ , Masculino , Camundongos , Morfogênese/genética , Morfogênese/fisiologia , Técnicas de Cultura de Órgãos , Retinal Desidrogenase/genética , Retinal Desidrogenase/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Almost 1% of human infants are born with urogenital abnormalities, many of which are linked to irregular connections between the distal ureters and the bladder. During development, ureters migrate by an unknown mechanism from their initial integration site in the Wolffian ducts up to the base of the bladder in a process that we call ureter maturation. Rara(-/-) Rarb2(-/-) mice display impaired vitamin A signaling and develop syndromic urogenital malformations similar to those that occur in humans, including renal hypoplasia, hydronephrosis and mega-ureter, abnormalities also seen in mice with mutations in the proto-oncogene Ret. Here we show that ureter maturation depends on formation of the 'trigonal wedge', a newly identified epithelial outgrowth from the base of the Wolffian ducts, and that the distal ureter abnormalities seen in Rara(-/-) Rarb2(-/-) and Ret(-/-) mutant mice are probably caused by a failure of this process. Our studies indicate that formation of the trigonal wedge may be essential for correct insertion of the distal ureters into the bladder, and that these events are mediated by the vitamin A and Ret signaling pathways.
Assuntos
Proteínas de Drosophila , Proteínas Proto-Oncogênicas/fisiologia , Receptores Proteína Tirosina Quinases/fisiologia , Ureter/embriologia , Vitamina A/fisiologia , Animais , Células Epiteliais/citologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Morfogênese , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-ret , Receptores Proteína Tirosina Quinases/genética , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico , Transdução de Sinais , Ureter/metabolismo , Bexiga Urinária/embriologiaRESUMO
Bladder cancers (BCs) can be divided into 2 major subgroups displaying distinct clinical behaviors and mutational profiles: basal/squamous (BASQ) tumors that tend to be muscle invasive, and luminal/papillary (LP) tumors that are exophytic and tend to be non-invasive. Pparg is a likely driver of LP BC and has been suggested to act as a tumor suppressor in BASQ tumors, where it is likely suppressed by MEK-dependent phosphorylation. Here we tested the effects of rosiglitazone, a Pparg agonist, in a mouse model of BBN-induced muscle invasive BC. Rosiglitazone activated Pparg signaling in suprabasal epithelial layers of tumors but not in basal-most layers containing highly proliferative invasive cells, reducing proliferation but not affecting tumor survival. Addition of trametinib, a MEK inhibitor, induced Pparg signaling throughout all tumor layers, and eradicated 91% of tumors within 7-days of treatment. The 2-drug combination also activated a luminal differentiation program, reversing squamous metaplasia in the urothelium of tumor-bearing mice. Paired ATAC-RNA-seq analysis revealed that tumor apoptosis was most likely linked to down-regulation of Bcl-2 and other pro-survival genes, while the shift from BASQ to luminal differentiation was associated with activation of the retinoic acid pathway and upregulation of Kdm6a, a lysine demethylase that facilitates retinoid-signaling. Our data suggest that rosiglitazone, trametinib, and retinoids, which are all FDA approved, may be clinically active in BASQ tumors in patients. That muscle invasive tumors are populated by basal and suprabasal cell types with different responsiveness to PPARG agonists will be an important consideration when designing new treatments.