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1.
Cell Rep ; 40(3): 111125, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858546

RESUMO

PTEN and LKB1 are intimately associated with gastrointestinal tumorigenesis. Mutations of PTEN or LKB1 lead to Cowden syndrome and Peutz-Jeghers syndrome characterized by development of gastrointestinal polyps. However, the cells of origin of these polyps and underlying mechanism remain unclear. Here, we reveal that PTEN or LKB1 deficiency in Gli1+ gut mesenchymal cells, but not intestinal epithelium, drives polyp formation histologically resembling polyposis in human patients. Mechanistically, although PTEN and LKB1 converge to regulate mTOR/AKT signaling in various tumor contexts, we find that mTOR is essential for PTEN-deletion-induced polyp formation but is largely dispensable for polyposis induced by mesenchymal LKB1 deficiency. Altogether, our studies identify Gli1-expressing mesenchymal cells as a common cell of origin for polyposis associated with PTEN and LKB1 and reveal their engagement of different downstream pathways in gut mesenchyme to suppress gastrointestinal tumorigenesis.


Assuntos
Quinases Proteína-Quinases Ativadas por AMP/metabolismo , Neoplasias Colorretais , Síndrome de Peutz-Jeghers , Transformação Celular Neoplásica , Neoplasias Colorretais/genética , Humanos , PTEN Fosfo-Hidrolase/genética , Síndrome de Peutz-Jeghers/genética , Síndrome de Peutz-Jeghers/patologia , Proteínas Serina-Treonina Quinases/genética , Serina-Treonina Quinases TOR , Proteína GLI1 em Dedos de Zinco/genética
2.
Cancer Discov ; 12(6): 1462-1481, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35320348

RESUMO

Altered RNA expression of repetitive sequences and retrotransposition are frequently seen in colorectal cancer, implicating a functional importance of repeat activity in cancer progression. We show the nucleoside reverse transcriptase inhibitor 3TC targets activities of these repeat elements in colorectal cancer preclinical models with a preferential effect in p53-mutant cell lines linked with direct binding of p53 to repeat elements. We translate these findings to a human phase II trial of single-agent 3TC treatment in metastatic colorectal cancer with demonstration of clinical benefit in 9 of 32 patients. Analysis of 3TC effects on colorectal cancer tumorspheres demonstrates accumulation of immunogenic RNA:DNA hybrids linked with induction of interferon response genes and DNA damage response. Epigenetic and DNA-damaging agents induce repeat RNAs and have enhanced cytotoxicity with 3TC. These findings identify a vulnerability in colorectal cancer by targeting the viral mimicry of repeat elements. SIGNIFICANCE: Colorectal cancers express abundant repeat elements that have a viral-like life cycle that can be therapeutically targeted with nucleoside reverse transcriptase inhibitors (NRTI) commonly used for viral diseases. NRTIs induce DNA damage and interferon response that provide a new anticancer therapeutic strategy. This article is highlighted in the In This Issue feature, p. 1397.


Assuntos
Neoplasias Colorretais , DNA Polimerase Dirigida por RNA , Animais , Antivirais , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , DNA , Humanos , Interferons/metabolismo , Lamivudina , Estágios do Ciclo de Vida , RNA , DNA Polimerase Dirigida por RNA/metabolismo , Proteína Supressora de Tumor p53/genética
3.
Cell ; 178(1): 160-175.e27, 2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31155233

RESUMO

Single-cell technologies have described heterogeneity across tissues, but the spatial distribution and forces that drive single-cell phenotypes have not been well defined. Combining single-cell RNA and protein analytics in studying the role of stromal cancer-associated fibroblasts (CAFs) in modulating heterogeneity in pancreatic cancer (pancreatic ductal adenocarcinoma [PDAC]) model systems, we have identified significant single-cell population shifts toward invasive epithelial-to-mesenchymal transition (EMT) and proliferative (PRO) phenotypes linked with mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling. Using high-content digital imaging of RNA in situ hybridization in 195 PDAC tumors, we quantified these EMT and PRO subpopulations in 319,626 individual cancer cells that can be classified within the context of distinct tumor gland "units." Tumor gland typing provided an additional layer of intratumoral heterogeneity that was associated with differences in stromal abundance and clinical outcomes. This demonstrates the impact of the stroma in shaping tumor architecture by altering inherent patterns of tumor glands in human PDAC.


Assuntos
Fibroblastos Associados a Câncer/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Microambiente Tumoral , Animais , Proliferação de Células , Técnicas de Cocultura , Transição Epitelial-Mesenquimal , Feminino , Células HEK293 , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas Quinases Ativadas por Mitógeno/metabolismo , RNA-Seq , Fator de Transcrição STAT3/metabolismo , Células Estromais/metabolismo , Transfecção
4.
JCI Insight ; 2(3): e91078, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28194445

RESUMO

There is tremendous excitement for the potential of epigenetic therapies in cancer, but the ability to predict and monitor response to these drugs remains elusive. This is in part due to the inability to differentiate the direct cytotoxic and the immunomodulatory effects of these drugs. The DNA-hypomethylating agent 5-azacitidine (AZA) has shown these distinct effects in colon cancer and appears to be linked to the derepression of repeat RNAs. LINE and HERV are two of the largest classes of repeats in the genome, and despite many commonalities, we found that there is heterogeneity in behavior among repeat subtypes. Specifically, the LINE-1 and HERV-H subtypes detected by RNA sequencing and RNA in situ hybridization in colon cancers had distinct expression patterns, which suggested that these repeats are correlated to transcriptional programs marking different biological states. We found that low LINE-1 expression correlates with global DNA hypermethylation, wild-type TP53 status, and responsiveness to AZA. HERV-H repeats were not concordant with LINE-1 expression but were found to be linked with differences in FOXP3+ Treg tumor infiltrates. Together, distinct repeat RNA expression patterns define new molecular classifications of colon cancer and provide biomarkers that better distinguish cytotoxic from immunomodulatory effects by epigenetic drugs.


Assuntos
Azacitidina/farmacologia , Neoplasias do Colo/genética , Metilação de DNA , Sequências Repetitivas de Ácido Nucleico , Idoso , Linhagem Celular Tumoral , Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Sequências Repetitivas de Ácido Nucleico/efeitos dos fármacos , Análise de Sequência de RNA/métodos
5.
Cancer Res ; 77(2): 320-329, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-28069799

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies lacking effective therapeutic strategies. Here, we show that the noncanonical IκB-related kinase, IKBKE, is a critical oncogenic effector during KRAS-induced pancreatic transformation. Loss of IKBKE inhibits the initiation and progression of pancreatic tumors in mice carrying pancreatic-specific KRAS activation. Mechanistically, we demonstrate that this protumoral effect of IKBKE involves the activation of GLI1 and AKT signaling and is independent of the levels of activity of the NF-κB pathway. Further analysis reveals that IKBKE regulates GLI1 nuclear translocation and promotes the reactivation of AKT post-inhibition of mTOR in PDAC cells. Interestingly, combined inhibition of IKBKE and mTOR synergistically blocks pancreatic tumor growth. Together, our findings highlight the functional importance of IKBKE in pancreatic cancer, support the evaluation of IKBKE as a therapeutic target in PDAC, and suggest IKBKE inhibition as a strategy to improve efficacy of mTOR inhibitors in the clinic. Cancer Res; 77(2); 320-9. ©2017 AACR.


Assuntos
Carcinogênese/patologia , Carcinoma Ductal Pancreático/patologia , Quinase I-kappa B/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Animais , Carcinogênese/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Xenoenxertos , Humanos , Immunoblotting , Imuno-Histoquímica , Camundongos , Neoplasias Pancreáticas/metabolismo , Transdução de Sinais/fisiologia
6.
Cell Rep ; 14(5): 1169-1180, 2016 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-26832411

RESUMO

The Tead family transcription factors are the major intracellular mediators of the Hippo-Yap pathway. Despite the importance of Hippo signaling in tumorigenesis, Tead-dependent downstream oncogenic programs and target genes in cancer cells remain poorly understood. Here, we characterize Tead4-mediated transcriptional networks in a diverse range of cancer cells, including neuroblastoma, colorectal, lung, and endometrial carcinomas. By intersecting genome-wide chromatin occupancy analyses of Tead4, JunD, and Fra1/2, we find that Tead4 cooperates with AP1 transcription factors to coordinate target gene transcription. We find that Tead-AP1 interaction is JNK independent but engages the SRC1-3 co-activators to promote downstream transcription. Furthermore, we show that Tead-AP1 cooperation regulates the activity of the Dock-Rac/CDC42 module and drives the expression of a unique core set of target genes, thereby directing cell migration and invasion. Together, our data unveil a critical regulatory mechanism underlying Tead- and AP1-controlled transcriptional and functional outputs in cancer cells.


Assuntos
Movimento Celular , Proteínas de Ligação a DNA/metabolismo , Proteínas Musculares/metabolismo , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sequência de Bases , Linhagem Celular Tumoral , Análise por Conglomerados , Genoma Humano , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Invasividade Neoplásica , Neoplasias/genética , Neoplasias/patologia , Ligação Proteica , Sequências Reguladoras de Ácido Nucleico/genética , Fatores de Transcrição de Domínio TEA
7.
Mol Cell ; 51(2): 211-25, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-23769673

RESUMO

Dysregulation of Wnt signaling is closely associated with human liver tumorigenesis. However, liver cancer-specific Wnt transcriptional programs and downstream effectors remain poorly understood. Here, we identify tribbles homolog 2 (TRIB2) as a direct target of Wnt/TCF in liver cancer and demonstrate that transcription of Wnt target genes, including TRIB2, is coordinated by the TCF and FoxA transcription factors in liver cancer cells. We show that Wnt-TRIB2 activation is critical for cancer cell survival and transformation. Mechanistically, TRIB2 promotes protein stabilization of the YAP transcription coactivator through interaction with the ßTrCP ubiquitin ligase. Furthermore, we find that TRIB2 relieves the liver tumor suppressor protein C/EBPα-mediated inhibition of YAP/TEAD transcriptional activation in liver cancer cells. Altogether, our study uncovers a regulatory mechanism underlying liver cancer-specific Wnt transcriptional output, and suggests that TRIB2 functions as a signaling nexus to integrate the Wnt/ß-catenin, Hippo/YAP, and C/EBPα pathways in cancer cells.


Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Nucleares/metabolismo , Fator 1 de Transcrição de Linfócitos T/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Western Blotting , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular , Diferenciação Celular , Proliferação de Células , Imunofluorescência , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator 1 de Transcrição de Linfócitos T/genética , Fatores de Transcrição/genética , Proteínas Wnt/genética , beta Catenina/genética
8.
J Biol Chem ; 288(24): 17589-96, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23645682

RESUMO

Hedgehog (Hh) signaling is involved in multiple aspects of embryonic gut development, including mesenchymal growth and smooth muscle differentiation. The Gli family transcription factors is thought to collectively mediate Hh signaling in mammals. However, the function of different Gli proteins in gut development remains uncharacterized. Here, we genetically dissect the contribution of Gli transcriptional activation and de-repression in intestinal growth and patterning. We find that removal of the Gli3 repressor is dispensable for intestinal development and does not play a major role in Hh-controlled gut development. However, Gli2 activation is able to fully rescue the Smoothened (Smo)-null intestinal phenotype, suggesting that the Gli2 transcription factor is the main effector for Hh signaling in the intestine. To understand further the molecular mechanism underlying Hh/Gli function in the developing gut, we identify a subset of small leucine-rich glycoproteins (SLRPs) that may function downstream of Hh signaling in the mesenchyme. We show that osteoglycin, a SLRP, inhibits Hh-induced differentiation toward the smooth muscle lineage in C3H10T1/2 pluripotent mesenchymal cells. Taken together, our study reveals, for the first time, the distinct roles of Gli proteins in intestine development and suggests SLRPs as novel regulators of smooth muscle cell differentiation.


Assuntos
Intestinos/embriologia , Fatores de Transcrição Kruppel-Like/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Intestinos/citologia , Mesoderma/embriologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Transgênicos , Miócitos de Músculo Liso/fisiologia , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais , Receptor Smoothened , Proteína Gli2 com Dedos de Zinco , Proteína Gli3 com Dedos de Zinco
9.
Proc Natl Acad Sci U S A ; 109(17): E1038-47, 2012 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-22493246

RESUMO

Pancreatic ductal adenocarcinoma (PDAC), one of the most aggressive human malignancies, is thought to be initiated by KRAS activation. Here we find that transcriptional activation mediated by the Gli family of transcription factors, although dispensable for pancreatic development, is required for Kras-induced proliferation and survival in primary pancreatic epithelial cells in culture and for Kras-driven pancreatic intraepithelial neoplasia and PDAC formation in vivo. Further, ectopic Gli1 activation in the mouse pancreas accelerates Kras-driven tumor formation, underscoring the importance of Gli transcription factors in pancreatic tumorigenesis. Interestingly, we demonstrate Gli-regulated I-kappa-B kinase epsilon (IKBKE) and NF-κB activity in pancreatic cancer cells and show that this activity is a critical downstream mediator for Gli-dependent PDAC cell transformation and survival. Together, these studies demonstrate the requirement for Gli in Kras-dependent pancreatic epithelial transformation, suggest a mechanism of Gli-NF-κB oncogenic activation, and provide genetic evidence supporting the therapeutic targeting of Gli activity in pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático/genética , Genes ras , Neoplasias Pancreáticas/genética , Fatores de Transcrição/metabolismo , Animais , Carcinoma Ductal Pancreático/patologia , Proliferação de Células , Proteínas I-kappa B/metabolismo , Camundongos , NF-kappa B/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas/metabolismo
10.
Proc Natl Acad Sci U S A ; 108(27): 11127-32, 2011 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21690388

RESUMO

The level of TGF-ß/bone morphogenetic protein (BMP) signaling through Smad is tightly regulated to ensure proper embryonic patterning and homeostasis. Here we show that Smad activation by TGF-ß/BMP is blocked by a highly conserved phosphorylation event in the α-helix 1 region of Smad [T312 in Drosophila Smad1 (MAD)]. α-helix 1 phosphorylation reduces Smad interaction with TGF-ß/BMP receptor kinase and affects all receptor-activated Smads except Smad3. Tissue culture and transgenic studies in Drosophila further demonstrate that the biological activity of MAD is repressed by T312 phosphorylation in vivo. Through RNAi screening of the kinome, we have identified Misshapen (Msn) and the mammalian orthologs TNIK, MINK1, and MAP4K4 as the kinases responsible for α-helix 1 phosphorylation. Targeted expression of an active form of Msn in the wing imaginal disk disrupted activation of endogenous MAD by Dpp and expression of the Dpp/MAD target gene. Msn kinases belong to the Ste20 kinase family that has been shown to act as MAP kinase kinase kinase kinase (MAP4K). Our findings thus reveal a function of Msn independent of its impact on MAP kinase cascades. This Smad inhibition mechanism by Msn likely has important implications for development and disease.


Assuntos
Proteínas de Drosophila/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Smad/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Sítios de Ligação , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Genes de Insetos , Humanos , Dados de Sequência Molecular , Fosforilação , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Estrutura Secundária de Proteína , Interferência de RNA , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Proteínas Smad/química , Proteínas Smad/genética , Proteínas Smad/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/metabolismo
11.
Development ; 137(10): 1721-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20430747

RESUMO

Homeostasis of the vertebrate digestive tract requires interactions between an endodermal epithelium and mesenchymal cells derived from the splanchnic mesoderm. Signaling between these two tissue layers is also crucial for patterning and growth of the developing gut. From early developmental stages, sonic hedgehog (Shh) and indian hedgehog (Ihh) are secreted by the endoderm of the mammalian gut, indicative of a developmental role. Further, misregulated hedgehog (Hh) signaling is implicated in both congenital defects and cancers arising from the gastrointestinal tract. In the mouse, only limited gastrointestinal anomalies arise following removal of either Shh or Ihh. However, given the considerable overlap in their endodermal expression domains, a functional redundancy between these signals might mask a more extensive role for Hh signaling in development of the mammalian gut. To address this possibility, we adopted a conditional approach to remove both Shh and Ihh functions from early mouse gut endoderm. Analysis of compound mutants indicates that continuous Hh signaling is dispensable for regional patterning of the gut tube, but is essential for growth of the underlying mesenchyme. Additional in vitro analysis, together with genetic gain-of-function studies, further demonstrate that Hh proteins act as paracrine mitogens to promote the expansion of adjacent mesenchymal progenitors, including those of the smooth muscle compartment. Together, these studies provide new insights into tissue interactions underlying mammalian gastrointestinal organogenesis and disease.


Assuntos
Trato Gastrointestinal/embriologia , Proteínas Hedgehog/fisiologia , Mamíferos/embriologia , Mesoderma/embriologia , Anormalidades Múltiplas/genética , Animais , Técnicas de Cultura de Células , Células Cultivadas , Embrião de Mamíferos , Feminino , Trato Gastrointestinal/metabolismo , Gástrula/anormalidades , Gástrula/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Masculino , Mamíferos/genética , Mesoderma/metabolismo , Camundongos , Camundongos Transgênicos , Músculo Liso/embriologia , Músculo Liso/metabolismo , Organogênese/genética , Comunicação Parácrina/genética , Comunicação Parácrina/fisiologia , Transdução de Sinais/fisiologia
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