RESUMO
Cancer cells exhibit distinct metabolic activities and nutritional dependencies compared to normal cells. Thus, characterization of nutrient demands by individual tumor types may identify specific vulnerabilities that can be manipulated to target the destruction of cancer cells. We find that MYC-driven liver tumors rely on augmented tryptophan (Trp) uptake, yet Trp utilization to generate metabolites in the kynurenine (Kyn) pathway is reduced. Depriving MYC-driven tumors of Trp through a No-Trp diet not only prevents tumor growth but also restores the transcriptional profile of normal liver cells. Despite Trp starvation, protein synthesis remains unhindered in liver cancer cells. We define a crucial role for the Trp-derived metabolite indole 3-pyruvate (I3P) in liver tumor growth. I3P supplementation effectively restores the growth of liver cancer cells starved of Trp. These findings suggest that I3P is a potential therapeutic target in MYC-driven cancers. Developing methods to target this metabolite represents a potential avenue for liver cancer treatment.
Assuntos
Carcinogênese , Indóis , Neoplasias Hepáticas , Proteínas Proto-Oncogênicas c-myc , Triptofano , Triptofano/metabolismo , Animais , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Indóis/metabolismo , Indóis/farmacologia , Humanos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Camundongos , Carcinogênese/metabolismo , Carcinogênese/genética , Linhagem Celular Tumoral , Cinurenina/metabolismo , Camundongos Endogâmicos C57BL , Fígado/metabolismo , Fígado/patologia , MasculinoRESUMO
The actin filament (F-actin) bundling protein fascin-1 is highly enriched in many metastatic cancers. Fascin's contribution to metastasis have been ascribed to its enhancement of cell migration and invasion. However, mouse genetic studies clearly point to functions also in tumorigenesis, yet without mechanistic underpinnings. Here, we show that fascin expression promotes the formation of a non-canonical signaling complex that enables anchorage-independent proliferation. This complex shares similarities to focal adhesions and we refer to them as pseudo-adhesion signaling scaffolds (PASS). PASS are enriched with tyrosine phosphorylated proteins and require fascin's F-actin-bundling activity for its assembly. PASS serve as hubs for the Rac1/PAK/JNK proliferation signaling axis, driven by PASS-associated Rac-specific GEFs. Experimental disruption of either fascin or RacGEF function abrogates sustained proliferation of aggressive cancers in vitro and in vivo . These results add a new molecular element to the growing arsenal of metabolic and oncogenic signaling programs regulated by the cytoskeleton architecture.
RESUMO
Increased nucleolar size and activity correlate with aberrant ribosome biogenesis and enhanced translation in cancer cells. One of the first and rate-limiting steps in translation is the interaction of the 40S small ribosome subunit with mRNAs. Here, we report the identification of the zinc finger protein 692 (ZNF692), a MYC-induced nucleolar scaffold that coordinates the final steps in the biogenesis of the small ribosome subunit. ZNF692 forms a hub containing the exosome complex and ribosome biogenesis factors specialized in the final steps of 18S rRNA processing and 40S ribosome maturation in the granular component of the nucleolus. Highly proliferative cells are more reliant on ZNF692 than normal cells; thus, we conclude that effective production of small ribosome subunits is critical for translation efficiency in cancer cells.
Assuntos
Proteínas de Ligação a DNA , Biossíntese de Proteínas , Proteínas Ribossômicas , Subunidades Ribossômicas Menores de Eucariotos , Fatores de Transcrição , Nucléolo Celular/metabolismo , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas Menores de Eucariotos/metabolismo , Ribossomos/metabolismo , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/metabolismo , Humanos , Animais , Ratos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
A select group of patients with hepatocellular carcinomas (HCC) benefit from surgical, radiologic, and systemic therapies that include a combination of anti-angiogenic and immune-checkpoint inhibitors. However, because HCC is generally asymptomatic in its early stages, this not only leads to late diagnosis, but also to therapy resistance. The nucleoside analogue 6-thio-dG (THIO) is a first-in-class telomerase-mediated telomere-targeting anticancer agent. In telomerase expressing cancer cells, THIO is converted into the corresponding 5'-triphosphate, which is efficiently incorporated into telomeres by telomerase, activating telomere damage responses and apoptotic pathways. Here, we show how THIO is effective in controlling tumor growth and, when combined with immune checkpoint inhibitors, is even more effective in a T-cell-dependent manner. We also show telomere stress induced by THIO increases both innate sensing and adaptive antitumor immunity in HCC. Importantly, the extracellular high-mobility group box 1 protein acts as a prototypical endogenous DAMP (Damage Associated Molecular Pattern) in eliciting adaptive immunity by THIO. These results provide a strong rationale for combining telomere-targeted therapy with immunotherapy.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Telomerase , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Telomerase/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Telômero/genética , Imunidade AdaptativaRESUMO
Within the growing field of amino acid metabolism, tryptophan (Trp) catabolism is an area of increasing interest. Trp is essential for protein synthesis, and its metabolism gives rise to biologically active catabolites including serotonin and numerous metabolites in the kynurenine (Kyn) pathway. In normal tissues, the production of Trp metabolites is directly regulated by the tissue-specific expression of Trp-metabolizing enzymes. Alterations of these enzymes in cancers can shift the balance and lead to an increased production of specific byproducts that can function as oncometabolites. For example, increased expression of the enzyme indoleamine 2,3-dioxygenase, which converts Trp into Kyn, leads to an increase in Kyn levels in numerous cancers. Kyn functions as an oncometabolite in cancer cells by promoting the activity of the transcription factor aryl hydrocarbon receptor, which regulates progrowth genes. Moreover, Kyn also inhibits T-cell activity and thus allows cancer cells to evade clearance by the immune system. Therefore, targeting the Kyn pathway has become a therapeutic focus as a novel means to abrogate tumor growth and immune resistance. This review summarizes the biological role and regulation of Trp metabolism and its catabolites with an emphasis on tumor cell growth and immune evasion and outlines areas for future research focus.
Assuntos
Neoplasias , Triptofano , Humanos , Triptofano/metabolismo , Cinurenina/metabolismo , Neoplasias/genética , Neoplasias/terapia , Triptofano Oxigenase/genética , Linfócitos T/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismoRESUMO
The ligand-activated transcription factor aryl hydrocarbon receptor (AHR) regulates cellular detoxification, proliferation and immune evasion in a range of cell types and tissues, including cancer cells. In this study, we used RNA-sequencing to identify the signature of the AHR target genes regulated by the pollutant 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and the endogenous ligand kynurenine (Kyn), a tryptophan-derived metabolite. This approach identified a signature of six genes (CYP1A1, ALDH1A3, ABCG2, ADGRF1 and SCIN) as commonly activated by endogenous or exogenous ligands of AHR in multiple colon cancer cell lines. Among these, the actin-severing protein scinderin (SCIN) was necessary for cell proliferation; SCIN downregulation limited cell proliferation and its expression increased it. SCIN expression was elevated in a subset of colon cancer patient samples, which also contained elevated ß-catenin levels. Remarkably, SCIN expression promoted nuclear translocation of ß-catenin and activates the WNT pathway. Our study identifies a new mechanism for adhesion-mediated signaling in which SCIN, likely via its ability to alter the actin cytoskeleton, facilitates the nuclear translocation of ß-catenin. This article has an associated First Person interview with the first authors of the paper.
Assuntos
Neoplasias do Colo , Poluentes Ambientais , Dibenzodioxinas Policloradas , Humanos , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , beta Catenina/genética , beta Catenina/metabolismo , Via de Sinalização Wnt/genética , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Ligantes , Cinurenina , Triptofano , Actinas/metabolismo , Neoplasias do Colo/genética , RNARESUMO
Glioblastoma is the most common and aggressive type of cancer in the brain; its poor prognosis is often marked by reoccurrence due to resistance to the chemotherapeutic agent temozolomide, which is triggered by an increase in the expression of DNA repair enzymes such as MGMT. The poor prognosis and limited therapeutic options led to studies targeted at understanding specific vulnerabilities of glioblastoma cells. Metabolic adaptations leading to increased synthesis of nucleotides by de novo biosynthesis pathways are emerging as key alterations driving glioblastoma growth. In this study, we show that enzymes necessary for the de novo biosynthesis of pyrimidines, DHODH and UMPS, are elevated in high grade gliomas and in glioblastoma cell lines. We demonstrate that DHODH's activity is necessary to maintain ribosomal DNA transcription (rDNA). Pharmacological inhibition of DHODH with the specific inhibitors brequinar or ML390 effectively depleted the pool of pyrimidines in glioblastoma cells grown in vitro and in vivo and impaired rDNA transcription, leading to nucleolar stress. Nucleolar stress was visualized by the aberrant redistribution of the transcription factor UBF and the nucleolar organizer nucleophosmin 1 (NPM1), as well as the stabilization of the transcription factor p53. Moreover, DHODH inhibition decreased the proliferation of glioblastoma cells, including temozolomide-resistant cells. Importantly, the addition of exogenous uridine, which reconstitutes the cellular pool of pyrimidine by the salvage pathway, to the culture media recovered the impaired rDNA transcription, nucleolar morphology, p53 levels, and proliferation of glioblastoma cells caused by the DHODH inhibitors. Our in vivo data indicate that while inhibition of DHODH caused a dramatic reduction in pyrimidines in tumor cells, it did not affect the overall pyrimidine levels in normal brain and liver tissues, suggesting that pyrimidine production by the salvage pathway may play an important role in maintaining these nucleotides in normal cells. Our study demonstrates that glioblastoma cells heavily rely on the de novo pyrimidine biosynthesis pathway to generate ribosomal RNA (rRNA) and thus, we identified an approach to inhibit ribosome production and consequently the proliferation of glioblastoma cells through the specific inhibition of the de novo pyrimidine biosynthesis pathway.
Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Nucléolo Celular/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Pirimidinas/biossíntese , Animais , Antineoplásicos/uso terapêutico , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/uso terapêutico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Nucléolo Celular/metabolismo , Di-Hidro-Orotato Desidrogenase , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Glioblastoma/patologia , Humanos , Camundongos , Complexos Multienzimáticos/antagonistas & inibidores , Complexos Multienzimáticos/metabolismo , Nucleofosmina , Orotato Fosforribosiltransferase/antagonistas & inibidores , Orotato Fosforribosiltransferase/metabolismo , Orotidina-5'-Fosfato Descarboxilase/antagonistas & inibidores , Orotidina-5'-Fosfato Descarboxilase/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , RNA Ribossômico/biossíntese , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Tryptophan is one of the eight essential amino acids that must be obtained from the diet. Interestingly, tryptophan is the least abundant amino acid in most proteins, a large portion of cellular tryptophan is converted into metabolites of the serotonin and kynurenine pathways. In a recent study, (Venkateswaran, Lafita-Navarro et al., 2019, Genes Dev), we discovered that colon cancer cells display greater uptake and processing of tryptophan than normal colonic cells and tissues. This process is mediated by the oncogenic transcription factor MYC that promotes the expression of the tryptophan importers SLC1A5 and SLC7A5 and the tryptophan metabolizing enzyme AFMID. The metabolism of tryptophan in colon cancer cells generates kynurenine, a biologically active metabolite necessary to maintain continuous cell proliferation. Our results indicate that kynurenine functions as an oncometabolite, at least in part, by activating the transcription factor AHR, which then regulates growth promoting genes in cancer cells. We propose that blocking kynurenine production or activity can be an efficient approach to specifically limit the growth of colon cancer cells. Here, we describe our findings and new questions for future studies targeted at understanding AHR-independent function of kynurenine, as well as interfering with the enzyme AFMID as a new strategy to target the kynurenine pathway.
RESUMO
Members of the MYC family of proto-oncogenes are the most commonly deregulated genes in all human cancers. MYC proteins drive an increase in cellular proliferation and facilitate multiple aspects of tumor initiation and progression, thereby controlling all hallmarks of cancer. MYC's ability to drive metabolic reprogramming of tumor cells leading to biomass accumulation and cellular proliferation is the most studied function of these oncogenes. MYC also regulates tumor progression and is often implicated in resistance to chemotherapy and in metastasis. While most oncogenic functions of MYC are attributed to its role as a transcription factor, more recently, new roles of MYC as a pro-survival factor in the cytoplasm suggest a previously unappreciated diversity in MYC's roles in cancer progression. This review will focus on the role of MYC in invasion and will discuss the canonical functions of MYC in Epithelial to Mesenchymal Transition and the cytoplasmic functions of MYC-nick in collective migration.
Assuntos
Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Movimento Celular , Transição Epitelial-Mesenquimal , Humanos , Invasividade Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Transcrição GênicaRESUMO
Tumors display increased uptake and processing of nutrients to fulfill the demands of rapidly proliferating cancer cells. Seminal studies have shown that the proto-oncogene MYC promotes metabolic reprogramming by altering glutamine uptake and metabolism in cancer cells. How MYC regulates the metabolism of other amino acids in cancer is not fully understood. Using high-performance liquid chromatography (HPLC)-tandem mass spectrometry (LC-MS/MS), we found that MYC increased intracellular levels of tryptophan and tryptophan metabolites in the kynurenine pathway. MYC induced the expression of the tryptophan transporters SLC7A5 and SLC1A5 and the enzyme arylformamidase (AFMID), involved in the conversion of tryptophan into kynurenine. SLC7A5, SLC1A5, and AFMID were elevated in colon cancer cells and tissues, and kynurenine was significantly greater in tumor samples than in the respective adjacent normal tissue from patients with colon cancer. Compared with normal human colonic epithelial cells, colon cancer cells were more sensitive to the depletion of tryptophan. Blocking enzymes in the kynurenine pathway caused preferential death of established colon cancer cells and transformed colonic organoids. We found that only kynurenine and no other tryptophan metabolite promotes the nuclear translocation of the transcription factor aryl hydrocarbon receptor (AHR). Blocking the interaction between AHR and kynurenine with CH223191 reduced the proliferation of colon cancer cells. Therefore, we propose that limiting cellular kynurenine or its downstream targets could present a new strategy to reduce the proliferation of MYC-dependent cancer cells.
Assuntos
Neoplasias do Colo/fisiopatologia , Cinurenina/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Triptofano/metabolismo , Sistema ASC de Transporte de Aminoácidos/genética , Antineoplásicos/farmacologia , Arilformamidase/genética , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Indóis/farmacologia , Cinurenina/genética , Transportador 1 de Aminoácidos Neutros Grandes/genética , Antígenos de Histocompatibilidade Menor/genética , Oximas/farmacologia , Proto-Oncogene Mas , Sulfonamidas/farmacologiaRESUMO
MYC enhances protein synthesis by regulating genes involved in ribosome biogenesis and protein translation. Here, we show that MYC-induced protein translation is mediated by the transcription factor aryl hydrocarbon receptor (AHR), which is induced by MYC in colonic cells. AHR promotes protein synthesis by activating the transcription of genes required for ribosome biogenesis and protein translation, including OGFOD1 and NOLC1. Using surface sensing of translation (SUnSET) to measure global protein translation, we found that silencing AHR or its targets diminishes protein synthesis. Therefore, targeting AHR or its downstream pathways could provide a novel approach to limit biomass production in MYC-driven tumors.
Assuntos
Nucléolo Celular/metabolismo , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores de Hidrocarboneto Arílico/fisiologia , Animais , Linhagem Celular , Nucléolo Celular/genética , Células Cultivadas , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-myc/genética , Ratos , Receptores de Hidrocarboneto Arílico/biossíntese , Receptores de Hidrocarboneto Arílico/genética , Ativação TranscricionalRESUMO
The common participation of oncogenic KRAS proteins in many of the most lethal human cancers, together with the ease of detecting somatic KRAS mutant alleles in patient samples, has spurred persistent and intensive efforts to develop drugs that inhibit KRAS activity. However, advances have been hindered by the pervasive inter- and intra-lineage diversity in the targetable mechanisms that underlie KRAS-driven cancers, limited pharmacological accessibility of many candidate synthetic-lethal interactions and the swift emergence of unanticipated resistance mechanisms to otherwise effective targeted therapies. Here we demonstrate the acute and specific cell-autonomous addiction of KRAS-mutant non-small-cell lung cancer cells to receptor-dependent nuclear export. A multi-genomic, data-driven approach, utilizing 106 human non-small-cell lung cancer cell lines, was used to interrogate 4,725 biological processes with 39,760 short interfering RNA pools for those selectively required for the survival of KRAS-mutant cells that harbour a broad spectrum of phenotypic variation. Nuclear transport machinery was the sole process-level discriminator of statistical significance. Chemical perturbation of the nuclear export receptor XPO1 (also known as CRM1), with a clinically available drug, revealed a robust synthetic-lethal interaction with native or engineered oncogenic KRAS both in vitro and in vivo. The primary mechanism underpinning XPO1 inhibitor sensitivity was intolerance to the accumulation of nuclear IκBα (also known as NFKBIA), with consequent inhibition of NFκB transcription factor activity. Intrinsic resistance associated with concurrent FSTL5 mutations was detected and determined to be a consequence of YAP1 activation via a previously unappreciated FSTL5-Hippo pathway regulatory axis. This occurs in approximately 17% of KRAS-mutant lung cancers, and can be overcome with the co-administration of a YAP1-TEAD inhibitor. These findings indicate that clinically available XPO1 inhibitors are a promising therapeutic strategy for a considerable cohort of patients with lung cancer when coupled to genomics-guided patient selection and observation.
Assuntos
Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Carioferinas/antagonistas & inibidores , Carioferinas/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Feminino , Proteínas Relacionadas à Folistatina/genética , Genes Letais/genética , Via de Sinalização Hippo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/metabolismo , Porfirinas/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Verteporfina , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas de Sinalização YAP , Proteína Exportina 1RESUMO
KRAS is one of the most commonly mutated oncogenes in human cancer. Mutant KRAS aberrantly regulates metabolic networks. However, the contribution of cellular metabolism to mutant KRAS tumorigenesis is not completely understood. We report that mutant KRAS regulates intracellular fatty acid metabolism through Acyl-coenzyme A (CoA) synthetase long-chain family member 3 (ACSL3), which converts fatty acids into fatty Acyl-CoA esters, the substrates for lipid synthesis and ß-oxidation. ACSL3 suppression is associated with depletion of cellular ATP and causes the death of lung cancer cells. Furthermore, mutant KRAS promotes the cellular uptake, retention, accumulation, and ß-oxidation of fatty acids in lung cancer cells in an ACSL3-dependent manner. Finally, ACSL3 is essential for mutant KRAS lung cancer tumorigenesis in vivo and is highly expressed in human lung cancer. Our data demonstrate that mutant KRAS reprograms lipid homeostasis, establishing a metabolic requirement that could be exploited for therapeutic gain.
Assuntos
Acil Coenzima A/metabolismo , Coenzima A Ligases/genética , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Carcinogênese/metabolismo , Transformação Celular Neoplásica/metabolismo , Coenzima A Ligases/metabolismo , Ácidos Graxos/metabolismo , Humanos , Ligases/metabolismo , Metabolismo dos Lipídeos/genética , Lipogênese/fisiologia , Neoplasias Pulmonares/metabolismo , Camundongos Knockout , OxirreduçãoRESUMO
PURPOSE: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide due to the limited availability of effective therapeutic options. For instance, there are no effective strategies for NSCLCs that harbor mutant KRAS, the most commonly mutated oncogene in NSCLC. Thus, our purpose was to make progress toward the generation of a novel therapeutic strategy for NSCLC. EXPERIMENTAL DESIGN: We characterized the effects of suppressing focal adhesion kinase (FAK) by RNA interference (RNAi), CRISPR/CAS9 gene editing or pharmacologic approaches in NSCLC cells and in tumor xenografts. In addition, we tested the effects of suppressing FAK in association with ionizing radiation (IR), a standard-of-care treatment modality. RESULTS: FAK is a critical requirement of mutant KRAS NSCLC cells. With functional experiments, we also found that, in mutant KRAS NSCLC cells, FAK inhibition resulted in persistent DNA damage and susceptibility to exposure to IR. Accordingly, administration of IR to FAK-null tumor xenografts causes a profound antitumor effect in vivo CONCLUSIONS: FAK is a novel regulator of DNA damage repair in mutant KRAS NSCLC and its pharmacologic inhibition leads to radiosensitizing effects that could be beneficial in cancer therapy. Our results provide a framework for the rationale clinical testing of FAK inhibitors in NSCLC patients. Clin Cancer Res; 22(23); 5851-63. ©2016 AACR.
Assuntos
Dano ao DNA/genética , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Mutação/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Radiossensibilizantes/metabolismo , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Camundongos Nus , Mutação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Interferência de RNA/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Dietary effects on tumor biology can be exploited to unravel cancer vulnerabilities. Here, we present surprising evidence for anti-proliferative action of high-calorie-diet (HCD) feeding on KRAS-driven lung tumors. Tumors of mice that commenced HCD feeding before tumor onset displayed defective unfolded protein response (UPR) and unresolved endoplasmic reticulum (ER) stress. Unresolved ER stress and reduced proliferation are reversed by chemical chaperone treatment. Whole-genome transcriptional analyses revealed FKBP10 as one of the most downregulated chaperones in tumors of the HCD-pre-tumor-onset group. FKBP10 downregulation dampens tumor growth in vitro and in vivo. Providing translational value to these results, we report that FKBP10 is expressed in human KRAS-positive and -negative lung cancers, but not in healthy parenchyma. Collectively, our data shed light on an unexpected anti-tumor action of HCD imposed before tumor onset and identify FKBP10 as a putative therapeutic target to selectively hinder lung cancer.
Assuntos
Dieta , Neoplasias Pulmonares/patologia , Fenilbutiratos/toxicidade , Proteínas ras/metabolismo , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica/efeitos dos fármacos , Regulação para Baixo , Doxiciclina/toxicidade , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Camundongos SCID , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a Tacrolimo/antagonistas & inibidores , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/metabolismo , Transplante Heterólogo , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Proteínas ras/genéticaRESUMO
UNLABELLED: Lung cancer commonly displays a number of recurrent genetic abnormalities, and about 30% of lung adenocarcinomas carry activating mutations in the Kras gene, often concomitantly with inactivation of tumor suppressor genes p16(INK4A) and p14(ARF) of the CDKN2AB locus. However, little is known regarding the function of p15INK4B translated from the same locus. To determine the frequency of CDKN2AB loss in human mutant KRAS lung cancer, The Cancer Genome Atlas (TCGA) database was interrogated. Two-hit inactivation of CDKN2A and CDKN2B occurs frequently in patients with mutant KRAS lung adenocarcinoma. Moreover, p15INK4B loss occurs in the presence of biallelic inactivation of p16(INK4A) and p14(ARF), suggesting that p15INK4B loss confers a selective advantage to mutant KRAS lung cancers that are p16(INK4A) and p14(ARF) deficient. To determine the significance of CDKN2AB loss in vivo, genetically engineered lung cancer mouse models that express mutant Kras in the respiratory epithelium were utilized. Importantly, complete loss of CDKN2AB strikingly accelerated mutant Kras-driven lung tumorigenesis, leading to loss of differentiation, increased metastatic disease, and decreased overall survival. Primary mutant Kras lung epithelial cells lacking Cdkn2ab had increased clonogenic potential. Furthermore, comparative analysis of mutant Kras;Cdkn2a null with Kras;Cdkn2ab null mice and experiments with mutant KRAS;CDKN2AB-deficient human lung cancer cells indicated that p15INK4B is a critical tumor suppressor. Thus, the loss of CDKN2AB is of biologic significance in mutant KRAS lung tumorigenesis by fostering cellular proliferation, cancer cell differentiation, and metastatic behavior. IMPLICATIONS: These findings indicate that mutant Kras;Cdkn2ab null mice provide a platform for accurately modeling aggressive lung adenocarcinoma and testing therapeutic modalities.