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1.
Cancer Cell ; 10(6): 459-72, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17157787

RESUMEN

Oncogene-induced senescence functions to limit tumor development. However, a complete understanding of the signals that trigger this type of senescence is currently lacking. We found that mutations affecting NF1, Raf, and Ras induce a global negative feedback response that potently suppresses Ras and/or its effectors. Moreover, these signals promote senescence by inhibiting the Ras/PI3K pathway, which can impact the senescence machinery through HDM2 and FOXO. This negative feedback program is regulated in part by RasGEFs, Sprouty proteins, RasGAPs, and MKPs. Moreover, these signals function in vivo in benign human tumors. Thus, the ultimate response to the aberrant activation of the Ras pathway is a multifaceted negative feedback signaling network that terminates the oncogenic signal and participates in the senescence response.


Asunto(s)
Senescencia Celular , Genes ras/fisiología , Transducción de Señal/fisiología , Animales , Células Cultivadas , Retroalimentación , Genes de Neurofibromatosis 1/fisiología , Genes de Retinoblastoma/fisiología , Genes p53/fisiología , Humanos , Ratones , Neoplasias/genética , Neoplasias/patología , Fosfatidilinositol 3-Quinasas/fisiología , Células Madre/patología , Quinasas raf/fisiología
2.
Science ; 380(6642): eabj5559, 2023 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-37079666

RESUMEN

Cells respond to mitochondrial poisons with rapid activation of the adenosine monophosphate-activated protein kinase (AMPK), causing acute metabolic changes through phosphorylation and prolonged adaptation of metabolism through transcriptional effects. Transcription factor EB (TFEB) is a major effector of AMPK that increases expression of lysosome genes in response to energetic stress, but how AMPK activates TFEB remains unresolved. We demonstrate that AMPK directly phosphorylates five conserved serine residues in folliculin-interacting protein 1 (FNIP1), suppressing the function of the folliculin (FLCN)-FNIP1 complex. FNIP1 phosphorylation is required for AMPK to induce nuclear translocation of TFEB and TFEB-dependent increases of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) and estrogen-related receptor alpha (ERRα) messenger RNAs. Thus, mitochondrial damage triggers AMPK-FNIP1-dependent nuclear translocation of TFEB, inducing sequential waves of lysosomal and mitochondrial biogenesis.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Lisosomas , Mitocondrias , Biogénesis de Organelos , Proteínas Quinasas Activadas por AMP/metabolismo , Lisosomas/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Fosforilación , Procesamiento Proteico-Postraduccional , Humanos
3.
Cancer Discov ; 13(4): 1002-1025, 2023 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-36715544

RESUMEN

KRAS is the most frequently mutated oncogene in human lung adenocarcinomas (hLUAD), and activating mutations frequently co-occur with loss-of-function mutations in TP53 or STK11/LKB1. However, mutation of all three genes is rarely observed in hLUAD, even though engineered comutation is highly aggressive in mouse lung adenocarcinoma (mLUAD). Here, we provide a mechanistic explanation for this difference by uncovering an evolutionary divergence in the regulation of triosephosphate isomerase (TPI1). In hLUAD, TPI1 activity is regulated via phosphorylation at Ser21 by the salt inducible kinases (SIK) in an LKB1-dependent manner, modulating flux between the completion of glycolysis and production of glycerol lipids. In mice, Ser21 of TPI1 is a Cys residue that can be oxidized to alter TPI1 activity without a need for SIKs or LKB1. Our findings suggest this metabolic flexibility is critical in rapidly growing cells with KRAS and TP53 mutations, explaining why the loss of LKB1 creates a liability in these tumors. SIGNIFICANCE: Utilizing phosphoproteomics and metabolomics in genetically engineered human cell lines and genetically engineered mouse models (GEMM), we uncover an evolutionary divergence in metabolic regulation within a clinically relevant genotype of human LUAD with therapeutic implications. Our data provide a cautionary example of the limits of GEMMs as tools to study human diseases such as cancers. This article is highlighted in the In This Issue feature, p. 799.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Triosa-Fosfato Isomerasa , Animales , Humanos , Ratones , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Mutación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Triosa-Fosfato Isomerasa/genética , Triosa-Fosfato Isomerasa/metabolismo
4.
Cancer Discov ; 9(11): 1606-1627, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31350328

RESUMEN

Mutations in the LKB1 (also known as STK11) tumor suppressor are the third most frequent genetic alteration in non-small cell lung cancer (NSCLC). LKB1 encodes a serine/threonine kinase that directly phosphorylates and activates 14 AMPK family kinases ("AMPKRs"). The function of many of the AMPKRs remains obscure, and which are most critical to the tumor-suppressive function of LKB1 remains unknown. Here, we combine CRISPR and genetic analysis of the AMPKR family in NSCLC cell lines and mouse models, revealing a surprising critical role for the SIK subfamily. Conditional genetic loss of Sik1 revealed increased tumor growth in mouse models of Kras-dependent lung cancer, which was further enhanced by loss of the related kinase Sik3. As most known substrates of the SIKs control transcription, gene-expression analysis was performed, revealing upregulation of AP1 and IL6 signaling in common between LKB1- and SIK1/3-deficient tumors. The SIK substrate CRTC2 was required for this effect, as well as for proliferation benefits from SIK loss. SIGNIFICANCE: The tumor suppressor LKB1/STK11 encodes a serine/threonine kinase frequently inactivated in NSCLC. LKB1 activates 14 downstream kinases in the AMPK family controlling growth and metabolism, although which kinases are critical for LKB1 tumor-suppressor function has remained an enigma. Here we unexpectedly found that two understudied kinases, SIK1 and SIK3, are critical targets in lung cancer.This article is highlighted in the In This Issue feature, p. 1469.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Células A549 , Quinasas de la Proteína-Quinasa Activada por el AMP , Proteínas Quinasas Activadas por AMP , Animales , Sistemas CRISPR-Cas , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Edición Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Ratones , Trasplante de Neoplasias , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Transducción de Señal , Carga Tumoral
5.
Diabetes ; 53(4): 1141-9, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15047633

RESUMEN

The Finland-United States Investigation Of NIDDM Genetics (FUSION) study aims to identify genetic variants that predispose to type 2 diabetes by studying affected sibling pair families from Finland. Chromosome 20 showed our strongest initial evidence for linkage. It currently has a maximum logarithm of odds (LOD) score of 2.48 at 70 cM in a set of 495 families. In this study, we searched for diabetes susceptibility variant(s) at 20q13 by genotyping single nucleotide polymorphism (SNP) markers in case and control DNA pools. Of 291 SNPs successfully typed in a 7.5-Mb interval, the strongest association confirmed by individual genotyping was with SNP rs2144908, located 1.3 kb downstream of the primary beta-cell promoter P2 of hepatocyte nuclear factor-4 alpha (HNF4A). This SNP showed association with diabetes disease status (odds ratio [OR] 1.33, 95% CI 1.06-1.65, P = 0.011) and with several diabetes-related traits. Most of the evidence for linkage at 20q13 could be attributed to the families carrying the risk allele. We subsequently found nine additional associated SNPs spanning a 64-kb region, including the P2 and P1 promoters and exons 1-3. Our results and the independent observation of association of SNPs near the P2 promoter with diabetes in a separate study population of Ashkenazi Jewish origin suggests that variant(s) located near or within HNF4A increases susceptibility to type 2 diabetes.


Asunto(s)
Cromosomas Humanos Par 20/genética , Proteínas de Unión al ADN , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad/genética , Variación Genética , Fosfoproteínas/genética , Polimorfismo de Nucleótido Simple/genética , Factores de Transcripción/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Mapeo Cromosómico , ADN/sangre , ADN/genética , Diabetes Mellitus Tipo 2/sangre , Familia , Finlandia , Marcadores Genéticos , Genotipo , Factor Nuclear 4 del Hepatocito , Humanos , Escala de Lod , Oportunidad Relativa , Valor Predictivo de las Pruebas , Medición de Riesgo , Estados Unidos
6.
Diabetes ; 53(3): 821-9, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14988269

RESUMEN

The aim of the Finland-United States Investigation of NIDDM Genetics (FUSION) study is to identify genes that predispose to type 2 diabetes or are responsible for variability in diabetes-related traits via a positional cloning and positional candidate gene approach. In a previously published genome-wide scan of 478 Finnish affected sibling pair (ASP) families (FUSION 1), the strongest linkage results were on chromosomes 20 and 11. We now report a second genome-wide scan using an independent set of 242 Finnish ASP families (FUSION 2), a detailed analysis of the combined set of 737 FUSION 1 + 2 families (495 updated FUSION 1 families), and fine mapping of the regions of chromosomes 11 and 20. The strongest FUSION 2 linkage results were on chromosomes 6 (maximum logarithm of odds score [MLS] = 2.30 at 95 cM) and 14 (MLS = 1.80 at 57 cM). For the combined FUSION 1 + 2 families, three results were particularly notable: chromosome 11 (MLS = 2.98 at 82 cM), chromosome 14 (MLS = 2.74 at 58 cM), and chromosome 6 (MLS = 2.66 at 96 cM). We obtained smaller FUSION 1 + 2 MLSs on chromosomes X (MLS = 1.27 at 152 cM) and 20p (MLS = 1.21 at 20 cM). Among the 10 regions that showed nominally significant evidence for linkage in FUSION 1, four (on chromosomes 6, 11, 14, and X) also showed evidence for linkage in FUSION 2 and stronger evidence for linkage in the combined FUSION 1 + 2 sample.


Asunto(s)
Cromosomas Humanos Par 11/genética , Cromosomas Humanos Par 14/genética , Cromosomas Humanos Par 6/genética , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad/genética , Edad de Inicio , Anciano , Secuencia de Bases , Constitución Corporal , Cartilla de ADN , Familia , Femenino , Finlandia , Marcadores Genéticos , Genoma Humano , Humanos , Masculino , Persona de Mediana Edad , Hermanos
7.
Cell Metab ; 22(5): 907-21, 2015 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-26456332

RESUMEN

AMP-activated protein kinase (AMPK) is a central energy gauge that regulates metabolism and has been increasingly involved in non-metabolic processes and diseases. However, AMPK's direct substrates in non-metabolic contexts are largely unknown. To better understand the AMPK network, we use a chemical genetics screen coupled to a peptide capture approach in whole cells, resulting in identification of direct AMPK phosphorylation sites. Interestingly, the high-confidence AMPK substrates contain many proteins involved in cell motility, adhesion, and invasion. AMPK phosphorylation of the RHOA guanine nucleotide exchange factor NET1A inhibits extracellular matrix degradation, an early step in cell invasion. The identification of direct AMPK phosphorylation sites also facilitates large-scale prediction of AMPK substrates. We provide an AMPK motif matrix and a pipeline to predict additional AMPK substrates from quantitative phosphoproteomics datasets. As AMPK is emerging as a critical node in aging and pathological processes, our study identifies potential targets for therapeutic strategies.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Adhesión Celular/genética , Proteínas Oncogénicas/genética , Mapas de Interacción de Proteínas/genética , Proteínas Quinasas Activadas por AMP/química , Proteínas Quinasas Activadas por AMP/genética , Animales , Movimiento Celular/genética , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Humanos , Proteínas Oncogénicas/metabolismo , Péptidos/metabolismo , Fosforilación , Análisis de la Célula Individual , Especificidad por Sustrato
8.
Cancer Discov ; 3(8): 880-93, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23661552

RESUMEN

The NF1 tumor suppressor protein neurofibromin is a negative regulator of Ras. Neurofibromin is dynamically regulated by the proteasome, and its degradation and reexpression are essential for maintaining appropriate levels of Ras-GTP. Like p53, NF1/neurofibromin can be inactivated in cancer by both mutations and excessive proteasomal destruction; however, little is known about the mechanisms that underlie this latter process. Here, we show that a Cullin 3 (Cul3)/kelch repeat and BTB domain-containing 7 complex controls both the regulated proteasomal degradation of neurofibromin and the pathogenic destabilization of neurofibromin in glioblastomas. Importantly, RNAi-mediated Cul3 ablation and a dominant-negative Cul3 directly stabilize neurofibromin, suppress Ras and extracellular signal-regulated kinase, and inhibit proliferation in an NF1-dependent manner. Moreover, in glioblastomas where neurofibromin is chronically destabilized, Cul3 inhibition restabilizes the protein and suppresses tumor development. Collectively, these studies show a previously unrecognized role for Cul3 in regulating Ras and provide a molecular framework that can be exploited to develop potential cancer therapies.


Asunto(s)
Glioblastoma/metabolismo , Neurofibromina 1/metabolismo , Complejos de Ubiquitina-Proteína Ligasa/metabolismo , Proteínas ras/metabolismo , Animales , Transformación Celular Neoplásica , Células Cultivadas , Proteínas Cullin/metabolismo , Genes Supresores de Tumor , Glioblastoma/genética , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Sistema de Señalización de MAP Quinasas , Ratones , Células 3T3 NIH , Neurofibromina 1/genética , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Estabilidad Proteica , Transactivadores/metabolismo , Ubiquitinación , Proteínas ras/genética
10.
Nat Cell Biol ; 20(7): 740-741, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29941928
11.
Cancer Discov ; 3(3): 338-49, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23171796

RESUMEN

BRAF mutations play a well-established role in melanomagenesis; however, without additional genetic alterations, tumor development is restricted by oncogene-induced senescence (OIS). Here, we show that mutations in the NF1 tumor suppressor gene cooperate with BRAF mutations in melanomagenesis by preventing OIS. In a genetically engineered mouse model, Nf1 mutations suppress Braf-induced senescence, promote melanocyte hyperproliferation, and enhance melanoma development. Nf1 mutations function by deregulating both phosphoinositide 3-kinase and extracellular signal-regulated kinase pathways. As such, Nf1/Braf-mutant tumors are resistant to BRAF inhibitors but are sensitive to combined inhibition of mitogen-activated protein/extracellular signal-regulated kinase kinase and mTOR. Importantly, NF1 is mutated or suppressed in human melanomas that harbor concurrent BRAF mutations, NF1 ablation decreases the sensitivity of melanoma cell lines to BRAF inhibitors, and NF1 is lost in tumors from patients following treatment with these agents. Collectively, these studies provide mechanistic insight into how NF1 cooperates with BRAF mutations in melanoma and show that NF1/neurofibromin inactivation may have an impact on responses to targeted therapies.


Asunto(s)
Carcinogénesis/genética , Genes de Neurofibromatosis 1 , Melanoma/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Animales , Procesos de Crecimiento Celular/genética , Línea Celular Tumoral , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos , Genotipo , Humanos , Indoles/farmacología , Melanocitos/patología , Melanocitos/fisiología , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Ratones , Ratones Desnudos , Neurofibromina 1/deficiencia , Neurofibromina 1/genética , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/metabolismo , Transducción de Señal , Sulfonamidas/farmacología , Vemurafenib , Ensayos Antitumor por Modelo de Xenoinjerto
12.
Cancer Cell ; 16(1): 44-54, 2009 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-19573811

RESUMEN

Loss-of-function mutations in the NF1 tumor suppressor result in deregulated Ras signaling and drive tumorigenesis in the familial cancer syndrome neurofibromatosis type I. However, the extent to which NF1 inactivation promotes sporadic tumorigenesis is unknown. Here we report that NF1 is inactivated in sporadic gliomas via two mechanisms: excessive proteasomal degradation and genetic loss. NF1 protein destabilization is triggered by the hyperactivation of protein kinase C (PKC) and confers sensitivity to PKC inhibitors. However, complete genetic loss, which only occurs when p53 is inactivated, mediates sensitivity to mTOR inhibitors. These studies reveal an expanding role for NF1 inactivation in sporadic gliomagenesis and illustrate how different mechanisms of inactivation are utilized in genetically distinct tumors, which consequently impacts therapeutic sensitivity.


Asunto(s)
Genes Supresores de Tumor , Glioblastoma/genética , Glioma/genética , Mutación , Neurofibromatosis 1/genética , Neurofibromina 1/antagonistas & inhibidores , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Complejo de la Endopetidasa Proteasomal/genética , Células 3T3 , Animales , Regulación hacia Abajo , Genes p53 , Genes ras , Glioblastoma/enzimología , Glioma/enzimología , Ratones , Neurofibromatosis 1/metabolismo , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
13.
Proc Natl Acad Sci U S A ; 99(26): 16928-33, 2002 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-12482934

RESUMEN

To facilitate positional cloning of complex trait susceptibility loci, we are investigating methods to reduce the effort required to identify trait-associated alleles. We examined primer extension analysis by matrix-assisted laser desorptionionization time-of-flight mass spectrometry to screen single-nucleotide polymorphisms (SNPs) for association by using DNA pools. We tested whether this method can accurately estimate allele frequency differences between pools while maintaining the high-throughput nature of assay design, sample handling, and scoring. We follow up interesting allele frequency differences in pools by genotyping individuals. We tested DNA pools of 182, 228, and 499 individuals using 16 SNPs with minor allele frequencies 0.026-0.486 and allele frequency differences 0.001-0.108 that we had genotyped previously on individuals and 381 SNPs that we had not. Precision, as measured by the average standard deviation among 16 semidependent replicates, was 0.021 +/- 0.011 for the 16 SNPs and 0.018 +/- 0.008 for the 291381 SNPs used in further analysis. For the 16 SNPs, the average absolute error in predicting allele frequency differences between pools was 0.009; the largest errors were 0.031, 0.028, and 0.027. We determined that compensating for unequal peak heights in heterozygotes improved precision of allele frequency estimates but had only a very minor effect on accuracy of allele frequency differences between pools. Based on these data and assuming pools of 500 individuals, we conclude that at significance level 0.05 we would have 95% (82%) power to detect population allele frequency differences of 0.07 for control allele frequencies of 0.10 (0.50).


Asunto(s)
ADN/análisis , Pool de Genes , Polimorfismo de Nucleótido Simple , Alelos , Frecuencia de los Genes , Genotipo , Reacción en Cadena de la Polimerasa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
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