RESUMO
The function of biomolecular condensates is often restricted by condensate dissolution. Whether condensates can be suppressed without condensate dissolution is unclear. Here, we show that upstream regulators of the Hippo signaling pathway form functionally antagonizing condensates, and their coalescence into a common phase provides a mode of counteracting the function of biomolecular condensates without condensate dissolution. Specifically, the negative regulator SLMAP forms Hippo-inactivating condensates to facilitate pathway inhibition by the STRIPAK complex. In response to cell-cell contact or osmotic stress, the positive regulators AMOT and KIBRA form Hippo-activating condensates to facilitate pathway activation. The functionally antagonizing SLMAP and AMOT/KIBRA condensates further coalesce into a common phase to inhibit STRIPAK function. These findings provide a paradigm for restricting the activity of biomolecular condensates without condensate dissolution, shed light on the molecular principles of multiphase organization, and offer a conceptual framework for understanding upstream regulation of the Hippo signaling pathway.
Assuntos
Via de Sinalização Hippo , Proteínas Serina-Treonina Quinases , Transdução de SinaisRESUMO
The Hippo pathway was initially discovered in Drosophila melanogaster as a key regulator of tissue growth. It is an evolutionarily conserved signaling cascade regulating numerous biological processes, including cell growth and fate decision, organ size control, and regeneration. The core of the Hippo pathway in mammals consists of a kinase cascade, MST1/2 and LATS1/2, as well as downstream effectors, transcriptional coactivators YAP and TAZ. These core components of the Hippo pathway control transcriptional programs involved in cell proliferation, survival, mobility, stemness, and differentiation. The Hippo pathway is tightly regulated by both intrinsic and extrinsic signals, such as mechanical force, cell-cell contact, polarity, energy status, stress, and many diffusible hormonal factors, the majority of which act through G protein-coupled receptors. Here, we review the current understanding of molecular mechanisms by which signals regulate the Hippo pathway with an emphasis on mechanotransduction and the effects of this pathway on basic biology and human diseases.
Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Animais , Via de Sinalização Hippo , Humanos , Mecanotransdução Celular , Proteínas Serina-Treonina Quinases/fisiologia , Serina-Treonina Quinase 3 , Proteínas Supressoras de Tumor/metabolismoRESUMO
Cell fate specification by lateral inhibition typically involves contact signaling through the Delta-Notch signaling pathway. However, whether this is the only signaling mode mediating lateral inhibition remains unclear. Here we show that in zebrafish oogenesis, a group of cells within the granulosa cell layer at the oocyte animal pole acquire elevated levels of the transcriptional coactivator TAZ in their nuclei. One of these cells, the future micropyle precursor cell (MPC), accumulates increasingly high levels of nuclear TAZ and grows faster than its surrounding cells, mechanically compressing those cells, which ultimately lose TAZ from their nuclei. Strikingly, relieving neighbor-cell compression by MPC ablation or aspiration restores nuclear TAZ accumulation in neighboring cells, eventually leading to MPC re-specification from these cells. Conversely, MPC specification is defective in taz-/- follicles. These findings uncover a novel mode of lateral inhibition in cell fate specification based on mechanical signals controlling TAZ activity.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Oogênese/fisiologia , Proteínas de Peixe-Zebra/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Comunicação Celular/fisiologia , Diferenciação Celular/fisiologia , Linhagem da Célula , Núcleo Celular/metabolismo , Feminino , Células da Granulosa/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Oócitos/metabolismo , Oócitos/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ativação Transcricional/fisiologia , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/antagonistas & inibidoresRESUMO
The periodic segmentation of the vertebrate body axis into somites, and later vertebrae, relies on a genetic oscillator (the segmentation clock) driving the rhythmic activity of signaling pathways in the presomitic mesoderm (PSM). To understand whether oscillations are an intrinsic property of individual cells or represent a population-level phenomenon, we established culture conditions for stable oscillations at the cellular level. This system was used to demonstrate that oscillations are a collective property of PSM cells that can be actively triggered in vitro by a dynamical quorum sensing signal involving Yap and Notch signaling. Manipulation of Yap-dependent mechanical cues is sufficient to predictably switch isolated PSM cells from a quiescent to an oscillatory state in vitro, a behavior reminiscent of excitability in other systems. Together, our work argues that the segmentation clock behaves as an excitable system, introducing a broader paradigm to study such dynamics in vertebrate morphogenesis.
Assuntos
Relógios Biológicos , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular , Embrião de Galinha , Embrião de Mamíferos/metabolismo , Embrião não Mamífero/metabolismo , Mesoderma/metabolismo , Camundongos , Morfogênese , Fosfoproteínas/metabolismo , Percepção de Quorum , Somitos/metabolismo , Proteínas de Sinalização YAPRESUMO
Poorly immunogenic tumor cells evade host immunity and grow even in the presence of an intact immune system, but the complex mechanisms regulating tumor immunogenicity have not been elucidated. Here, we discovered an unexpected role of the Hippo pathway in suppressing anti-tumor immunity. We demonstrate that, in three different murine syngeneic tumor models (B16, SCC7, and 4T1), loss of the Hippo pathway kinases LATS1/2 (large tumor suppressor 1 and 2) in tumor cells inhibits tumor growth. Tumor regression by LATS1/2 deletion requires adaptive immune responses, and LATS1/2 deficiency enhances tumor vaccine efficacy. Mechanistically, LATS1/2-null tumor cells secrete nucleic-acid-rich extracellular vesicles, which induce a type I interferon response via the Toll-like receptors-MYD88/TRIF pathway. LATS1/2 deletion in tumors thus improves tumor immunogenicity, leading to tumor destruction by enhancing anti-tumor immune responses. Our observations uncover a key role of the Hippo pathway in modulating tumor immunogenicity and demonstrate a proof of concept for targeting LATS1/2 in cancer immunotherapy.
Assuntos
Tolerância Imunológica , Neoplasias/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Vacinas Anticâncer/imunologia , Deleção de Genes , Imunoterapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Receptores Toll-Like/metabolismo , Proteínas Supressoras de Tumor/genéticaRESUMO
YAP and TAZ (YAP/TAZ), two major effectors of the Hippo signaling pathway, are frequently activated in human cancers. The activity of YAP/TAZ is strictly repressed upon phosphorylation by LATS1/2 tumor suppressors. However, it is unclear how LATS1/2 are precisely regulated by upstream factors such as Hippo kinases MST1/2. Here, we show that WWC proteins (WWC1/2/3) directly interact with LATS1/2 and SAV1, and SAV1, in turn, brings in MST1/2 to phosphorylate and activate LATS1/2. Hence, WWC1/2/3 play an organizer role in a signaling module that mediates LATS1/2 activation by MST1/2. Moreover, we have defined a minimum protein interaction interface on WWC1/2/3 that is sufficient to activate LATS1/2 in a robust and specific manner. The corresponding minigene, dubbed as SuperHippo, can effectively suppress tumorigenesis in multiple tumor models. Our study has uncovered a molecular mechanism underlying LATS1/2 regulation and provides a strategy for treating diverse malignancies related to Hippo pathway dysregulation.
Assuntos
Proteínas Serina-Treonina Quinases , Transdução de Sinais , Carcinogênese , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/fisiologia , Proteínas Supressoras de Tumor/metabolismoRESUMO
Loss of the NF2 tumor suppressor gene is a common finding in meningiomas, and more recently YAP1 fusions have been found in a subset of pediatric NF2 wild-type meningiomas. In the previous issue of Genes & Development, Szulzewsky and colleagues (pp. 857-870) showed that TEAD-dependent YAP1 activity by either the loss of the NF2 gene or YAP1-MAML2 fusion is an oncogenic process promoting meningioma tumorigenesis. Furthermore, pharmacological inhibition of YAP1-TEAD resulted in antitumor activity in both YAP1 fusion-positive and NF2 mutant meningiomas. Together, these data indicate that disruption of the YAP1-TEAD interaction raises a potential therapeutic option for these tumors that requires future investigation.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Neoplasias Meníngeas , Meningioma , Fatores de Transcrição/metabolismo , Carcinogênese/genética , Criança , Humanos , Neoplasias Meníngeas/genética , Meningioma/genética , Meningioma/patologia , Oncogenes , Fatores de Transcrição/genéticaRESUMO
YAP1 is a transcriptional coactivator regulated by the Hippo signaling pathway, including NF2. Meningiomas are the most common primary brain tumors; a large percentage exhibit heterozygous loss of chromosome 22 (harboring the NF2 gene) and functional inactivation of the remaining NF2 copy, implicating oncogenic YAP activity in these tumors. Recently, fusions between YAP1 and MAML2 have been identified in a subset of pediatric NF2 wild-type meningiomas. Here, we show that human YAP1-MAML2-positive meningiomas resemble NF2 mutant meningiomas by global and YAP-related gene expression signatures. We then show that expression of YAP1-MAML2 in mice induces tumors that resemble human YAP1 fusion-positive and NF2 mutant meningiomas by gene expression. We demonstrate that YAP1-MAML2 primarily functions by exerting TEAD-dependent YAP activity that is resistant to Hippo signaling. Treatment with YAP-TEAD inhibitors is sufficient to inhibit the viability of YAP1-MAML2-driven mouse tumors ex vivo. Finally, we show that expression of constitutively active YAP1 (S127/397A-YAP1) is sufficient to induce similar tumors, suggesting that the YAP component of the gene fusion is the critical driver of these tumors. In summary, our results implicate YAP1-MAML2 as a causal oncogenic driver and highlight TEAD-dependent YAP activity as an oncogenic driver in YAP1-MAML2 fusion meningioma as well as NF2 mutant meningioma in general.
RESUMO
The Hippo-YAP signaling pathway plays a critical role in development, homeostasis, regeneration, and tumorigenesis by converging on YAP, a coactivator for the TEAD family DNA-binding transcription factors, to regulate downstream transcription programs. Given its pivotal role as the nuclear effector of the Hippo pathway, YAP is indispensable in multiple developmental and tissue contexts. Here we report that the essentiality of YAP in liver and lung development can be genetically bypassed by simultaneous inactivation of the TEAD corepressor VGLL4. This striking antagonistic epistasis suggests that the major physiological function of YAP is to antagonize VGLL4. We further show that the YAP-VGLL4 antagonism plays a widespread role in regulating Hippo pathway output beyond normal development, as inactivation of Vgll4 dramatically enhanced intrahepatic cholangiocarcinoma formation in Nf2-deficient livers and ameliorated CCl4-induced damage in normal livers. Interestingly, Vgll4 expression is temporally regulated in development and regeneration and, in certain contexts, provides a better indication of overall Hippo pathway output than YAP phosphorylation. Together, these findings highlight the central importance of VGLL4-mediated transcriptional repression in Hippo pathway regulation and inform potential strategies to modulate Hippo signaling in cancer and regenerative medicine.
Assuntos
Via de Sinalização Hippo , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Sinalização YAP , Fatores de Transcrição de Domínio TEARESUMO
Cytosolic DNA acts as a universal danger-associated molecular pattern (DAMP) signal; however, the mechanisms of self-DNA release into the cytosol and its role in inflammatory tissue injury are not well understood. We found that the internalized bacterial endotoxin lipopolysaccharide (LPS) activated the pore-forming protein Gasdermin D, which formed mitochondrial pores and induced mitochondrial DNA (mtDNA) release into the cytosol of endothelial cells. mtDNA was recognized by the DNA sensor cGAS and generated the second messenger cGAMP, which suppressed endothelial cell proliferation by downregulating YAP1 signaling. This indicated that the surviving endothelial cells in the penumbrium of the inflammatory injury were compromised in their regenerative capacity. In an experimental model of inflammatory lung injury, deletion of cGas in mice restored endothelial regeneration. The results suggest that targeting the endothelial Gasdermin D activated cGAS-YAP signaling pathway could serve as a potential strategy for restoring endothelial function after inflammatory injury.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Ciclo Celular/genética , Proliferação de Células/genética , DNA Mitocondrial/genética , Células Endoteliais/metabolismo , Inflamação/genética , Nucleotidiltransferases/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Citosol/metabolismo , DNA Mitocondrial/metabolismo , Células Endoteliais/citologia , Células HEK293 , Humanos , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nucleotídeos Cíclicos/metabolismo , Nucleotidiltransferases/metabolismo , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/metabolismo , Transdução de Sinais , Proteínas de Sinalização YAPRESUMO
Cholesterol metabolism is tightly associated with colorectal cancer (CRC). Nevertheless, the clinical benefit of statins, the inhibitor of cholesterol biogenesis mevalonate (MVA) pathway, is inconclusive, possibly because of a lack of patient stratification criteria. Here, we describe that YAP-mediated zinc finger MYND-type containing 8 (ZMYND8) expression sensitizes intestinal tumors to the inhibition of the MVA pathway. We show that the oncogenic activity of YAP relies largely on ZMYND8 to enhance intracellular de novo cholesterol biogenesis. Disruption of the ZMYND8-dependent MVA pathway greatly restricts the self-renewal capacity of Lgr5+ intestinal stem cells (ISCs) and intestinal tumorigenesis. Mechanistically, ZMYND8 and SREBP2 drive the enhancer-promoter interaction to facilitate the recruitment of Mediator complex, thus upregulating MVA pathway genes. Together, our results establish that the epigenetic reader ZMYND8 endows YAP-high intestinal cancer with metabolic vulnerability.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias Colorretais/metabolismo , Ácido Mevalônico/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Camundongos , Camundongos Transgênicos , Proteínas Supressoras de Tumor/genética , Proteínas de Sinalização YAPRESUMO
Interferon-γ (IFN-γ)-mediated adaptive resistance is one major barrier to improving immunotherapy in solid tumors. However, the mechanisms are not completely understood. Here, we report that IFN-γ promotes nuclear translocation and phase separation of YAP after anti-PD-1 therapy in tumor cells. Hydrophobic interactions of the YAP coiled-coil domain mediate droplet initiation, and weak interactions of the intrinsically disordered region in the C terminus promote droplet formation. YAP partitions with the transcription factor TEAD4, the histone acetyltransferase EP300, and Mediator1 and forms transcriptional hubs for maximizing target gene transcriptions, independent of the canonical STAT1-IRF1 transcription program. Disruption of YAP phase separation reduced tumor growth, enhanced immune response, and sensitized tumor cells to anti-PD-1 therapy. YAP activity is negatively correlated with patient outcome. Our study indicates that YAP mediates the IFN-γ pro-tumor effect through its nuclear phase separation and suggests that YAP can be used as a predictive biomarker and target of anti-PD-1 combination therapy.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Resistencia a Medicamentos Antineoplásicos , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia , Interferon gama/metabolismo , Neoplasias Experimentais , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Células HEK293 , Humanos , Interferon gama/genética , Camundongos , Camundongos Knockout , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAPRESUMO
Mammalian SWI/SNF (BAF) chromatin remodelers play dosage-sensitive roles in many human malignancies and neurologic disorders. The gene encoding the BAF subunit actin-like 6a (ACTL6A) is amplified early in the development of many squamous cell carcinomas (SCCs), but its oncogenic role remains unclear. Here we demonstrate that ACTL6A overexpression leads to its stoichiometric assembly into BAF complexes and drives their interaction and engagement with specific regulatory regions in the genome. In normal epithelial cells, ACTL6A was substoichiometric to other BAF subunits. However, increased ACTL6A levels by ectopic expression or in SCC cells led to near saturation of ACTL6A within BAF complexes. Increased ACTL6A occupancy enhanced polycomb opposition genome-wide to activate SCC genes and facilitated the co-dependent loading of BAF and TEAD-YAP complexes on chromatin. Both mechanisms appeared to be critical and function as a molecular AND gate for SCC initiation and maintenance, thereby explaining the specificity of the role of ACTL6A amplification in SCCs.
Assuntos
Actinas/metabolismo , Carcinoma de Células Escamosas/metabolismo , Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Actinas/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Epigênese Genética , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Proteínas do Grupo Polycomb/genética , Ligação Proteica , Fatores de Transcrição de Domínio TEA/genética , Fatores de Transcrição de Domínio TEA/metabolismo , Proteínas de Sinalização YAP/genética , Proteínas de Sinalização YAP/metabolismoRESUMO
Missense mutations of the tumor suppressor Neurofibromin 2 (NF2/Merlin/schwannomin) result in sporadic to frequent occurrences of tumorigenesis in multiple organs. However, the underlying pathogenicity of NF2-related tumorigenesis remains mostly unknown. Here we found that NF2 facilitated innate immunity by regulating YAP/TAZ-mediated TBK1 inhibition. Unexpectedly, patient-derived individual mutations in the FERM domain of NF2 (NF2m) converted NF2 into a potent suppressor of cGAS-STING signaling. Mechanistically, NF2m gained extreme associations with IRF3 and TBK1 and, upon innate nucleic acid sensing, was directly induced by the activated IRF3 to form cellular condensates, which contained the PP2A complex, to eliminate TBK1 activation. Accordingly, NF2m robustly suppressed STING-initiated antitumor immunity in cancer cell-autonomous and -nonautonomous murine models, and NF2m-IRF3 condensates were evident in human vestibular schwannomas. Our study reports phase separation-mediated quiescence of cGAS-STING signaling by a mutant tumor suppressor and reveals gain-of-function pathogenesis for NF2-related tumors by regulating antitumor immunity.
Assuntos
Imunidade Inata , Proteínas de Membrana/metabolismo , Mutação de Sentido Incorreto , Neoplasias/metabolismo , Neurofibromina 2/metabolismo , Nucleotidiltransferases/metabolismo , Evasão Tumoral , Animais , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Masculino , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/patologia , Neurofibromina 2/genética , Nucleotidiltransferases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de SinaisRESUMO
Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers worldwide and evolves often to lung metastasis. P53R175H (homologous to Trp53R172H in mice) is a common hot spot mutation. How metastasis is regulated by p53R175H in ESCC remains to be investigated. To investigate p53R175H-mediated molecular mechanisms, we used a carcinogen-induced approach in Trp53R172H/- mice to model ESCC. In the primary Trp53R172H/- tumor cell lines, we depleted Trp53R172H (shTrp53) and observed a marked reduction in cell invasion in vitro and lung metastasis burden in a tail-vein injection model in comparing isogenic cells (shCtrl). Furthermore, we performed bulk RNA-seq to compare gene expression profiles of metastatic and primary shCtrl and shTrp53 cells. We identified the YAP-BIRC5 axis as a potential mediator of Trp53R172H -mediated metastasis. We demonstrate that expression of Survivin, an antiapoptotic protein encoded by BIRC5, increases in the presence of Trp53R172H Furthermore, depletion of Survivin specifically decreases Trp53R172H-driven lung metastasis. Mechanistically, Trp53R172H but not wild-type Trp53, binds with YAP in ESCC cells, suggesting their cooperation to induce Survivin expression. Furthermore, Survivin high expression level is associated with increased metastasis in several GI cancers. Taken together, this study unravels new insights into how mutant p53 mediates metastasis.
Assuntos
Neoplasias Pulmonares/fisiopatologia , Survivina/genética , Survivina/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/genética , Camundongos , Mutação , Metástase Neoplásica , Transcriptoma , Proteína Supressora de Tumor p53/metabolismoRESUMO
Epithelioid hemangioendothelioma (EHE) is a genetically homogenous vascular sarcoma that is a paradigm for TAZ dysregulation in cancer. EHE harbors a WWTR1(TAZ)-CAMTA1 gene fusion in >90% of cases, 45% of which have no other genetic alterations. In this study, we used a first of its kind approach to target the Wwtr1-Camta1 gene fusion to the Wwtr1 locus, to develop a conditional EHE mouse model whereby Wwtr1-Camta1 is controlled by the endogenous transcriptional regulators upon Cre activation. These mice develop EHE tumors that are indistinguishable from human EHE clinically, histologically, immunohistochemically, and genetically. Overall, these results demonstrate unequivocally that TAZ-CAMTA1 is sufficient to drive EHE formation with exquisite specificity, as no other tumor types were observed. Furthermore, we fully credential this unique EHE mouse model as a valid preclinical model for understanding the role of TAZ dysregulation in cancer formation and for testing therapies directed at TAZ-CAMTA1, TAZ, and YAP/TAZ signaling.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Carcinogênese/genética , Modelos Animais de Doenças , Fusão Gênica , Hemangioendotelioma Epitelioide/genética , Hemangioendotelioma Epitelioide/patologia , Transativadores/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas de Ligação ao Cálcio/genética , Humanos , Camundongos , Transdução de Sinais/genética , Transativadores/genéticaRESUMO
Epithelioid hemangioendothelioma (EHE) is a poorly understood and devastating vascular cancer. Sequencing of EHE has revealed a unique gene fusion between the Hippo pathway nuclear effector TAZ (WWTR1) and the brain-enriched transcription factor CAMTA1 in â¼90% of cases. However, it remains unclear whether the TAZ-CAMTA1 gene fusion is a driver of EHE, and potential targeted therapies are unknown. Here, we show that TAZ-CAMTA1 expression in endothelial cells is sufficient to drive the formation of vascular tumors with the distinctive features of EHE, and inhibition of TAZ-CAMTA1 results in the regression of these vascular tumors. We further show that activated TAZ resembles TAZ-CAMTA1 in driving the formation of EHE-like vascular tumors, suggesting that constitutive activation of TAZ underlies the pathological features of EHE. We show that TAZ-CAMTA1 initiates an angiogenic and regenerative-like transcriptional program in endothelial cells, and disruption of the TAZ-CAMTA1-TEAD interaction or ectopic expression of a dominant negative TEAD in vivo inhibits TAZ-CAMTA1-mediated transformation. Our study provides the first genetic model of a TAZ fusion oncoprotein driving its associated human cancer, pinpointing TAZ-CAMTA1 as the key driver and a valid therapeutic target of EHE.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Carcinogênese/genética , Células Endoteliais/patologia , Regulação Neoplásica da Expressão Gênica , Hemangioendotelioma Epitelioide/genética , Hemangioendotelioma Epitelioide/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Transativadores/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular Tumoral , Fusão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Transativadores/genética , Proteínas com Motivo de Ligação a PDZ com Coativador TranscricionalRESUMO
The Hippo pathway effectors Yes-associated protein 1 (YAP) and its homolog TAZ are transcriptional coactivators that control gene expression by binding to TEA domain (TEAD) family transcription factors. The YAP/TAZ-TEAD complex is a key regulator of cancer-specific transcriptional programs, which promote tumor progression in diverse types of cancer, including breast cancer. Despite intensive efforts, the YAP/TAZ-TEAD complex in cancer has remained largely undruggable due to an incomplete mechanistic understanding. Here, we report that nuclear phosphoinositides function as cofactors that mediate the binding of YAP/TAZ to TEADs. The enzymatic products of phosphoinositide kinases PIPKIα and IPMK, including phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4,5-trisphosphate (P(I3,4,5)P3), bridge the binding of YAP/TAZ to TEAD. Inhibiting these kinases or the association of YAP/TAZ with PI(4,5)P2 and PI(3,4,5)P3 attenuates YAP/TAZ interaction with the TEADs, the expression of YAP/TAZ target genes, and breast cancer cell motility. Although we could not conclusively exclude the possibility that other enzymatic products of IPMK such as inositol phosphates play a role in the mechanism, our results point to a previously unrecognized role of nuclear phosphoinositide signaling in control of YAP/TAZ activity and implicate this pathway as a potential therapeutic target in YAP/TAZ-driven breast cancer.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias da Mama , Transdução de Sinais , Transativadores , Fatores de Transcrição , Proteínas de Sinalização YAP , Humanos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAP/metabolismo , Proteínas de Sinalização YAP/genética , Feminino , Transativadores/metabolismo , Transativadores/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/metabolismo , Linhagem Celular Tumoral , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatidilinositóis/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Núcleo Celular/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genéticaRESUMO
The uptake of macromolecules and cellular debris through macropinocytosis has emerged as an important nutrient acquisition strategy of cancer cells. Genetic alterations commonly found in human cancers (e.g. mutations in KRAS or loss of PTEN) have been shown to increase macropinocytosis. To identify additional effectors that enable cell growth dependent on the uptake of extracellular proteins, pancreatic ductal adenocarcinoma (PDA) cells were selected for growth in medium where extracellular albumin was the obligate source of the essential amino acid leucine. Analysis of global changes in chromatin availability and gene expression revealed that PDA cells selected under these conditions exhibited elevated activity of the transcriptional activators Yap/Taz. Knockout of Yap/Taz prevented growth of PDA cells in leucine-deficient medium, but not in complete medium. Furthermore, constitutively active forms of Yap or Taz were sufficient to stimulate macropinocytosis of extracellular protein. In addition to promoting the uptake of plasma proteins, Yap/Taz also promoted the scavenging of apoptotic cell bodies and necrotic debris by PDA cells. The Yap/Taz transcriptional target Axl was found to be essential for cell growth dependent on the uptake of dead cells and cell debris. Together, these studies suggest that the Hippo pathway effectors Yap and Taz are important transcriptional regulators of endocytic nutrient uptake.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Nutrientes/metabolismo , Pinocitose/fisiologia , Fatores de Transcrição/metabolismo , Aciltransferases , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Espaço Extracelular/metabolismo , Humanos , Camundongos , Proteínas de Sinalização YAPRESUMO
Cancer cells must adapt metabolism to thrive despite nutrient limitations in the tumor microenvironment. In this issue of Genes & Development, King and colleagues (pp. 1345-1358) report a role for transcriptional regulators of the Hippo pathway to facilitate protein scavenging and support proliferation under some nutrient-deprived conditions.