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In addition to being novel biomarkers for poor cancer prognosis, members of Lymphocyte antigen-6 (Ly6) gene family also play a crucial role in avoiding immune responses to tumors. However, it has not been possible to identify the underlying mechanism of how Ly6 gene regulation operates in human cancers. Transcriptome, epigenome and proteomic data from independent cancer databases were analyzed in silico and validated independently in 334 colorectal cancer tissues (CRC). RNA mediated gene silencing of regulatory genes, and treatment with MEK and p38 MAPK inhibitors were also tested in vitro. We report here that the Lymphocyte antigen 6G6D is universally downregulated in mucinous CRC, while its activation progresses through the classical adenoma-carcinoma sequence. The DNA methylation changes in LY6G6D promoter are intimately related to its transcript regulation, epigenomic and histological subtypes. Depletion of DNA methyltransferase 1 (DNMT1), which maintains DNA methylation, results in the derepression of LY6G6D expression. RNA-mediated gene silencing of p38α MAPK or its selective chemical inhibition, however, reduces LY6G6D expression, reducing trametinib's anti-inflammatory effects. Patients treated with FOLFOX-based first-line therapy experienced decreased survival due to hypermethylation of the LY6G6D promoter and decreased p38α MAPK signaling. We found that cancer-specific immunodominant epitopes are controlled by p38α MAPKs signaling and suppressed by DNA methylation in histological variants with Mucinous differentiation. This work provides a promising prospective for clinical application in diagnosis and personalized therapeutic strategies of colorectal cancer.
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Insulin-like growth factor binding protein 6 (IGFBP6) is a secreted protein with a controversial role in human malignancies, being downregulated in most types of human cancer, but upregulated in selected tumors. Ovarian cancer (OC) is a human malignancy characterized by IGFBP6 downregulation; however, the significance of its low expression during ovarian carcinogenesis is still poorly understood. In the present study, IGFBP6 expression and activation of its associated signaling pathway were evaluated in two matched OC cell lines derived from a high-grade serous OC before and after platinum resistance (PEA1 and PEA2 cells, respectively). A whole genome gene expression analysis was comparatively performed in both cell lines upon IGFBP6 stimulation using Illumina technology. IGFBP6 gene expression data from human OC cases were obtained from public datasets. Gene expression data from public datasets confirmed the downregulation of IGFBP6 in primary and metastatic OC tissues compared with in normal ovarian tissues. The comparative analysis of platinum-sensitive (PEA1) and platinum-resistant (PEA2) cell lines showed quantitative and qualitative differences in the activation of IGFBP6 signaling. Notably, IGFBP6 enhanced ERK1/2 phosphorylation only in PEA1 cells, and induced more evident and significant gene expression reprogramming in PEA1 cells compared with in PEA2 cells. Furthermore, the analysis of selected genes modulated by IGFBP6 (i.e., FOS, JUN, TNF, IL6, IL8 and EGR1) exhibited an inverse regulation in PEA1 versus PEA2 cells. In addition, selected hallmarks (TNFA_signaling_via_NFKB, TGF_beta_signaling, P53_pathway) and IL-6 signaling were positively regulated in PEA1 cells, whereas they were inhibited in PEA2 cells in response to IGFBP6. These data suggested that dysregulation of IGFBP6 signaling may serve a role in the progression of OC, and is likely associated with the development of platinum resistance.
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Metabolic rewiring fuels rapid cancer cell proliferation by promoting adjustments in energetic resources, and increasing glucose uptake and its conversion into lactate, even in the presence of oxygen. Furthermore, solid tumors often contain hypoxic areas and can rapidly adapt to low oxygen conditions by activating hypoxia inducible factor (HIF)1α and several downstream pathways, thus sustaining cell survival and metabolic reprogramming. Since TNF receptorassociated protein 1 (TRAP1) is a HSP90 molecular chaperone upregulated in several human malignancies and is involved in cancer cell adaptation to unfavorable environments and metabolic reprogramming, in the present study, its role was investigated in the adaptive response to hypoxia in human colorectal cancer (CRC) cells and organoids. In the present study, glucose uptake, lactate production and the expression of key metabolic genes were evaluated in TRAP1silenced CRC cell models under conditions of hypoxia/normoxia. Whole genome gene expression profiling was performed in TRAP1silenced HCT116 cells exposed to hypoxia to establish the role of TRAP1 in adaptive responses to oxygen deprivation. The results revealed that TRAP1 was involved in regulating hypoxiainduced HIF1α stabilization and glycolytic metabolism and that glucose transporter 1 expression, glucose uptake and lactate production were partially impaired in TRAP1silenced CRC cells under hypoxic conditions. At the transcriptional level, the gene expression reprogramming of cancer cells driven by HIF1α was partially inhibited in TRAP1silenced CRC cells and organoids exposed to hypoxia. Moreover, Gene Set Enrichment Analysis of TRAP1silenced HCT116 cells exposed to hypoxia demonstrated that TRAP1 was involved in the regulation of ribosome biogenesis and this occurred with the inhibition of the mTOR pathway. Therefore, as demonstrated herein, TRAP1 is a key factor in maintaining HIF1αinduced genetic/metabolic program under hypoxic conditions and may represent a promising target for novel metabolic therapies.
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Neoplasias Colorrectales , Oxígeno , Hipoxia de la Célula , Neoplasias Colorrectales/patología , Glucosa/metabolismo , Glucólisis , Proteínas HSP90 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Lactatos , Oxígeno/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Ribosomas/patología , Factor 1 Asociado a Receptor de TNF/metabolismoRESUMEN
Epigenetics is involved in tumor progression and drug resistance in human colorectal carcinoma (CRC). This study addressed the hypothesis that the DNA methylation profiling may predict the clinical behavior of metastatic CRCs (mCRCs). The global methylation profile of two human mCRC subgroups with significantly different outcome was analyzed and compared with gene expression and methylation data from The Cancer Genome Atlas COlon ADenocarcinoma (TCGA COAD) and the NCBI GENE expression Omnibus repository (GEO) GSE48684 mCRCs datasets to identify a prognostic signature of functionally methylated genes. A novel epigenetic signature of eight hypermethylated genes was characterized that was able to identify mCRCs with poor prognosis, which had a CpG-island methylator phenotype (CIMP)-high and microsatellite instability (MSI)-like phenotype. Interestingly, methylation events were enriched in genes located on the q-arm of chromosomes 13 and 20, two chromosomal regions with gain/loss alterations associated with adenoma-to-carcinoma progression. Finally, the expression of the eight-genes signature and MSI-enriching genes was confirmed in oxaliplatin- and irinotecan-resistant CRC cell lines. These data reveal that the hypermethylation of specific genes may provide prognostic information that is able to identify a subgroup of mCRCs with poor prognosis.
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Wnt/ß-Catenin signaling is involved in embryonic development, regeneration, and cellular differentiation and is responsible for cancer stemness maintenance. The HSP90 molecular chaperone TRAP1 is upregulated in 60-70% of human colorectal carcinomas (CRCs) and favors stem cells maintenance, modulating the Wnt/ß-Catenin pathway and preventing ß-Catenin phosphorylation/degradation. The role of TRAP1 in the regulation of Wnt/ß-Catenin signaling was further investigated in human CRC cell lines, patient-derived spheroids, and CRC specimens. TRAP1 relevance in the activation of Wnt/ß-Catenin signaling was highlighted by a TCF/LEF Cignal Reporter Assay in Wnt-off HEK293T and CRC HCT116 cell lines. Of note, this regulation occurs through the modulation of Wnt ligand receptors LRP5 and LRP6 that are both downregulated in TRAP1-silenced cell lines. However, while LRP5 mRNA is significantly downregulated upon TRAP1 silencing, LRP6 mRNA is unchanged, suggesting independent mechanisms of regulation by TRAP1. Indeed, LRP5 is regulated upon promoter methylation in CRC cell lines and human CRCs, whereas LRP6 is controlled at post-translational level by protein ubiquitination/degradation. Consistently, human CRCs with high TRAP1 expression are characterized by the co-upregulation of active ß-Catenin, LRP5 and LRP6. Altogether, these data suggest that Wnt/ß-Catenin signaling is modulated at multiple levels by TRAP1.
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Neoplasias del Colon/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/metabolismo , Vía de Señalización Wnt , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Células HEK293 , Humanos , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/genética , Masculino , Persona de Mediana Edad , Regiones Promotoras Genéticas , Proteolisis , Células Tumorales Cultivadas , Ubiquitinación , beta Catenina/metabolismoRESUMEN
Metabolic rewiring is a mechanism of adaptation to unfavorable environmental conditions and tumor progression. TRAP1 is an HSP90 molecular chaperone upregulated in human colorectal carcinomas (CRCs) and responsible for downregulation of oxidative phosphorylation (OXPHOS) and adaptation to metabolic stress. The mechanism by which TRAP1 regulates glycolytic metabolism and the relevance of this regulation in resistance to EGFR inhibitors were investigated in patient-derived CRC spheres, human CRC cells, samples, and patients. A linear correlation was observed between TRAP1 levels and 18 F-fluoro-2-deoxy-glucose (18 F-FDG) uptake upon PET scan or GLUT1 expression in human CRCs. Consistently, TRAP1 enhances GLUT1 expression, glucose uptake, and lactate production and downregulates OXPHOS in CRC patient-derived spheroids and cell lines. Mechanistically, TRAP1 maximizes lactate production to balance low OXPHOS through the regulation of the glycolytic enzyme phosphofructokinase-1 (PFK1); this depends on the interaction between TRAP1 and PFK1, which favors PFK1 glycolytic activity and prevents its ubiquitination/degradation. By contrast, TRAP1/PFK1 interaction is lost in conditions of enhanced OXPHOS, which results in loss of TRAP1 regulation of PFK1 activity and lactate production. Notably, TRAP1 regulation of glycolysis is involved in resistance of RAS-wild-type CRCs to EGFR monoclonals. Indeed, either TRAP1 upregulation or high glycolytic metabolism impairs cetuximab activity in vitro, whereas TRAP1 targeting and/or inhibition of glycolytic pathway enhances cell response to cetuximab. Finally, a linear correlation between 18 F-FDG PET uptake and poor response to cetuximab in first-line therapy in human metastatic CRCs was observed. These results suggest that TRAP1 is a key determinant of CRC metabolic rewiring and favors resistance to EGFR inhibitors through regulation of glycolytic metabolism.
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Neoplasias Colorrectales/metabolismo , Resistencia a Antineoplásicos , Proteínas HSP90 de Choque Térmico/metabolismo , Fosfofructoquinasa-1/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Efecto Warburg en Oncología , Línea Celular Tumoral , Respiración de la Célula/efectos de los fármacos , Cetuximab/farmacología , Neoplasias Colorrectales/patología , Resistencia a Antineoplásicos/efectos de los fármacos , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Estabilidad de Enzimas/efectos de los fármacos , Receptores ErbB/metabolismo , Fluorodesoxiglucosa F18/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Oxidación-Reducción , Fenotipo , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas B-raf/metabolismo , Efecto Warburg en Oncología/efectos de los fármacosRESUMEN
Cholangiocarcinoma is a primary malignancy of the biliary tract characterized by late and unspecific symptoms, unfavorable prognosis, and few treatment options. The advent of next-generation sequencing has revealed potential targetable or actionable molecular alterations in biliary tumors. Among several identified genetic alterations, the IDH1 mutation is arousing interest due to its role in epigenetic and metabolic remodeling. Indeed, some IDH1 point mutations induce widespread epigenetic alterations by means of a gain-of-function of the enzyme, which becomes able to produce the oncometabolite 2-hydroxyglutarate, with inhibitory activity on α-ketoglutarate-dependent enzymes, such as DNA and histone demethylases. Thus, its accumulation produces changes in the expression of several key genes involved in cell differentiation and survival. At present, small-molecule inhibitors of IDH1 mutated enzyme are under investigation in preclinical and clinical phases as promising innovative treatments for IDH1-mutated intrahepatic cholangiocarcinomas. This review examines the molecular rationale and the results of preclinical and early-phase studies on novel pharmacological agents targeting mutant IDH1 in cholangiocarcinoma patients. Contextually, it will offer a starting point for discussion on combined therapies with metabolic and epigenetic drugs, to provide molecular support to target the interplay between metabolism and epigenetics, two hallmarks of cancer onset and progression.
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Antineoplásicos/uso terapéutico , Neoplasias de los Conductos Biliares/tratamiento farmacológico , Colangiocarcinoma/tratamiento farmacológico , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Neoplasias de los Conductos Biliares/metabolismo , Neoplasias de los Conductos Biliares/patología , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patología , HumanosRESUMEN
Background: HPV-positive oral squamous cell carcinomas (OSCCs) are specific biological and clinical entities, characterized by a more favorable prognosis compared to HPV-negative OSCCs and occurring generally in non-smoking and non-drinking younger individuals. However, poor information is available on the molecular and the clinical behavior of HPV-positive oral cancers occurring in smoking/drinking subjects. Thus, this study was designed to compare, at molecular level, two OSCC cell lines, both derived from drinking and smoking individuals and differing for presence/absence of HPV infection. Methods: HPV-negative UPCI-SCC-131 and HPV16-positive UPCI-SCC-154 cell lines were compared by whole genome gene expression profiling and subsequently studied for activation of Wnt/ßCatenin signaling pathway by the expression of several Wnt-target genes, ßCatenin intracellular localization, stem cell features and miRNA let-7e. Gene expression data were validated in head and neck squamous cell carcinoma (HNSCC) public datasets. Results: Gene expression analysis identified Wnt/ßCatenin pathway as the unique signaling pathway more active in HPV-negative compared to HPV-positive OSCC cells and this observation was confirmed upon evaluation of several Wnt-target genes (i.e., Cyclin D1, Cdh1, Cdkn2a, Cd44, Axin2, c-Myc and Tcf1). Interestingly, HPV-negative OSCC cells showed higher levels of total ßCatenin and its active form, increase of its nuclear accumulation and more prominent stem cell traits. Furthermore, miRNA let-7e was identified as potential upstream regulator responsible for the downregulation of Wnt/ßCatenin signaling cascade since its silencing in UPCI-SCC-154 cell resulted in upregulation of Wnt-target genes. Finally, the analysis of two independent gene expression public datasets of human HNSCC cell lines and tumors confirmed that Wnt/ßCatenin pathway is more active in HPV-negative compared to HPV-positive tumors derived from individuals with smoking habit. Conclusions: These data suggest that lack of HPV infection is associated with more prominent activation of Wnt/ßCatenin signaling pathway and gain of stem-like traits in tobacco-related OSCCs.
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Papillomavirus Humano 16/genética , Nicotiana/efectos adversos , Infecciones por Papillomavirus/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Anciano , Antígenos CD/genética , Proteína Axina/genética , Cadherinas/genética , Línea Celular Tumoral , Ciclina D1/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Regulación Neoplásica de la Expresión Génica/genética , Factor Nuclear 1-alfa del Hepatocito/genética , Papillomavirus Humano 16/patogenicidad , Humanos , Receptores de Hialuranos/genética , Masculino , MicroARNs/genética , Persona de Mediana Edad , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/virología , Proteínas Proto-Oncogénicas c-myc/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/inducido químicamente , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/virología , Vía de Señalización Wnt/genéticaRESUMEN
Tumor Necrosis Factor Receptor-Associated Protein 1 (TRAP1) is a heat shock protein 90 (HSP90) molecular chaperone overexpressed in 60-70% human colorectal carcinomas (CRCs) and the co-upregulation of TRAP1 and associated 6-related proteins identifies metastatic CRCs with poor prognosis. Since the molecular mechanisms responsible for TRAP1 regulation are still unknown, the significance of TRAP1 gene copy number (CN) and the role of post-transductional protein modifications were addressed. TRAP1 gene aneuploidy accounted for 34.5% of cases in a cohort of 58 human CRCs and TRAP1 CN correlated with its mRNA and protein expression, suggesting that transcriptional mechanisms are responsible for TRAP1 upregulation. Furthermore, the analysis of the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium/The Cancer Genome Atlas (CPTAC/TCGA) CRC database showed that TRAP1 polysomy significantly correlates with lymph node involvement. However, a subgroup of tumors showed TRAP1 protein levels independent from its CN. Of note, a direct correlation was observed between TRAP1 protein levels and the expression of S-nitrosoglutathione reductase (GSNOR), a denitrosylase involved in the regulation of protein S-nitrosylation. Furthermore, CRC cell lines exposed to hypoxia or dichloroacetate treatment showed the downregulation of TRAP1 upon GSNOR silencing and this resulted in increased TRAP1 mono/polyubiquitination. These data suggest that transcriptional and post-transductional mechanisms account for TRAP1 expression in human CRCs and GSNOR protects TRAP1 from S-nitrosylation and consequent proteasome degradation mostly in conditions of stress.
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Dosificación de Gen/genética , Proteínas HSP90 de Choque Térmico/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/fisiología , Proteínas HSP90 de Choque Térmico/genética , Humanos , Masculino , Persona de Mediana Edad , ProteómicaRESUMEN
Cancer has been considered, for a long time, a genetic disease where mutations in keyregulatory genes drive tumor initiation, growth, metastasis, and drug resistance. Instead, theadvent of high-throughput technologies has revolutionized cancer research, allowing to investigatemolecular alterations at multiple levels, including genome, epigenome, transcriptome, proteome,and metabolome and showing the multifaceted aspects of this disease. The multi-omics approachesrevealed an intricate molecular landscape where different cellular functions are interconnected andcooperatively contribute to shaping the malignant phenotype. Recent evidence has brought to lighthow metabolism and epigenetics are highly intertwined, and their aberrant crosstalk can contributeto tumorigenesis. The oncogene-driven metabolic plasticity of tumor cells supports the energeticand anabolic demands of proliferative tumor programs and secondary can alter the epigeneticlandscape via modulating the production and/or the activity of epigenetic metabolites. Conversely,epigenetic mechanisms can regulate the expression of metabolic genes, thereby altering themetabolome, eliciting adaptive responses to rapidly changing environmental conditions, andsustaining malignant cell survival and progression in hostile niches. Thus, cancer cells takeadvantage of the epigenetics-metabolism crosstalk to acquire aggressive traits, promote cellproliferation, metastasis, and pluripotency, and shape tumor microenvironment. Understandingthis bidirectional relationship is crucial to identify potential novel molecular targets for theimplementation of robust anti-cancer therapeutic strategies.
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Epigénesis Genética , Neoplasias/genética , Neoplasias/metabolismo , Supervivencia Celular , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Humanos , Metástasis de la Neoplasia , Metabolismo Secundario , Microambiente TumoralRESUMEN
Heat shock protein 90 (HSP90) molecular chaperones are a family of ubiquitous proteins participating in several cellular functions through the regulation of folding and/or assembly of large multiprotein complexes and client proteins. Thus, HSP90s chaperones are, directly or indirectly, master regulators of a variety of cellular processes, such as adaptation to stress, cell proliferation, motility, angiogenesis, and signal transduction. In recent years, it has been proposed that HSP90s play a crucial role in carcinogenesis as regulators of genotype-to-phenotype interplay. Indeed, HSP90 chaperones control metabolic rewiring, a hallmark of cancer cells, and influence the transcription of several of the key-genes responsible for tumorigenesis and cancer progression, through either direct binding to chromatin or through the quality control of transcription factors and epigenetic effectors. In this review, we will revise evidence suggesting how this interplay between epigenetics and metabolism may affect oncogenesis. We will examine the effect of metabolic rewiring on the accumulation of specific metabolites, and the changes in the availability of epigenetic co-factors and how this process can be controlled by HSP90 molecular chaperones. Understanding deeply the relationship between epigenetic and metabolism could disclose novel therapeutic scenarios that may lead to improvements in cancer treatment.
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Antineoplásicos/uso terapéutico , Progresión de la Enfermedad , Epigénesis Genética , Proteínas HSP90 de Choque Térmico/metabolismo , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/farmacología , Epigénesis Genética/efectos de los fármacos , Humanos , Neoplasias/genética , FenotipoRESUMEN
The unfolded protein response (UPR) is a stress response activated by the accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum (ER) and its uncontrolled activation is mechanistically responsible for several human pathologies, including metabolic, neurodegenerative, and inflammatory diseases, and cancer. Indeed, ER stress and the downstream UPR activation lead to changes in the levels and activities of key regulators of cell survival and autophagy and this is physiologically finalized to restore metabolic homeostasis with the integration of pro-death or/and pro-survival signals. By contrast, the chronic activation of UPR in cancer cells is widely considered a mechanism of tumor progression. In this review, we focus on the relationship between ER stress, apoptosis, and autophagy in human breast cancer and the interplay between the activation of UPR and resistance to anticancer therapies with the aim to disclose novel therapeutic scenarios. The hypothesis that autophagy and UPR may provide novel molecular targets in human malignancies is discussed.
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Autofagia/genética , Neoplasias de la Mama/genética , Estrés del Retículo Endoplásmico/genética , Respuesta de Proteína Desplegada/genética , Apoptosis/genética , Neoplasias de la Mama/patología , Resistencia a Antineoplásicos/genética , Retículo Endoplásmico/genética , Femenino , Humanos , Transducción de Señal/genéticaRESUMEN
Syndesmos (SDOS) is a functionally poorly characterized protein that directly interacts with p53 binding protein 1 (53BP1) and regulates its recruitment to chromatin. We show here that SDOS interacts with another important cancer-linked protein, the chaperone TRAP1, associates with actively translating polyribosomes and represses translation. Moreover, we demonstrate that SDOS directly binds RNA in living cells. Combining individual gene expression profiling, nucleotide crosslinking and immunoprecipitation (iCLIP), and ribosome profiling, we discover several crucial pathways regulated post-transcriptionally by SDOS. Among them, we identify a small subset of mRNAs responsible for the biogenesis of primary cilium that have been linked to developmental and degenerative diseases, known as ciliopathies, and cancer. We discover that SDOS binds and regulates the translation of several of these mRNAs, controlling cilia development.
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Cilios/genética , Proteínas de Unión al ARN/fisiología , Cilios/metabolismo , Ciliopatías/genética , Células HCT116 , Proteínas HSP90 de Choque Térmico/metabolismo , Células HeLa , Humanos , Neoplasias/genética , Polirribosomas/metabolismo , Unión Proteica/genética , Biosíntesis de Proteínas/genética , Dominios y Motivos de Interacción de Proteínas/genética , Estructura Terciaria de Proteína , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genéticaRESUMEN
OBJECTIVES: Preoperative chemoradiation is currently the standard of care in locally advanced rectal carcinoma, even though a subset of rectal tumors does not achieve major clinically meaningful responses upon neoadjuvant chemoradiation. At present, no molecular biomarkers are available to predict response to neoadjuvant chemoradiation and select resistant tumors willing more intense therapeutic strategies. Thus, BRAF mutational status was investigated for its role in favoring resistance to radiation in colorectal carcinoma cell lines and cyclin-dependent kinase 1 as a target to improve radiosensitivity in BRAF V600E colorectal tumor cells. METHODS: Colony-forming assay and apoptotic rates were evaluated to compare the sensitivity of different colon carcinoma cell lines to ionizing radiation and their radiosensitivity upon exposure to BRAF and/or cyclin-dependent kinase 1 inhibitory/silencing strategies. Cyclin-dependent kinase 1 expression/subcellular distribution was studied by immunoblot analysis. RESULTS: Colon carcinoma BRAF V600E HT29 cells exhibited poor response to radiation compared to BRAF wild-type COLO320 and HCT116 cells. Interestingly, neither radiosensitizing doses of 5-fluoruracil nor BRAF inhibition/silencing significantly improved radiosensitivity in HT29 cells. Of note, poor response to radiation correlated with upregulation/relocation of cyclin-dependent kinase 1 in mitochondria. Consistently, cyclin-dependent kinase 1 inhibition/silencing as well as its targeting, through inhibition of HSP90 quality control pathway, significantly inhibited the clonogenic ability and increased apoptotic rates in HT29 cells upon exposure to radiation. CONCLUSION: These data suggest that BRAF V600E colorectal carcinoma cells are poorly responsive to radiation, and cyclin-dependent kinase 1 represents a target to improve radiosensitivity in BRAF V600E colorectal tumor cells.
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Proteína Quinasa CDC2/genética , Neoplasias Colorrectales/radioterapia , Proteínas Proto-Oncogénicas B-raf/genética , Tolerancia a Radiación/genética , Proteína Quinasa CDC2/antagonistas & inhibidores , Proteína Quinasa CDC2/biosíntesis , Línea Celular Tumoral , Quimioradioterapia/métodos , Neoplasias Colorrectales/patología , Fluorouracilo/farmacología , Células HCT116 , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Células HT29 , Humanos , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Tolerancia a Radiación/efectos de los fármacos , Radiación Ionizante , Fármacos Sensibilizantes a Radiaciones/farmacologíaRESUMEN
BACKGROUND: BRAF inhibitors are effective anticancer agents in BRAF-mutated melanomas. By contrast, evidences about sensitivity of thyroid carcinomas to BRAF inhibition are conflicting and it has been proposed that BRAF V600E thyroid carcinoma cells are less sensitive to BRAF inhibitors due to activation of parallel signaling pathways. This study evaluated the hypothesis that feedback activation of EGFR signaling counteracts the cytostatic activity of vemurafenib (PLX4032) in BRAF V600E thyroid carcinoma cells. METHODS: Cell proliferation, cell cycle distribution, induction of apoptosis and EGFR and AKT signaling were evaluated in thyroid carcinoma cell lines bearing the BRAF V600E mutation in response to PLX4032. RESULTS: A partial and transient cytostatic response to PLX4032 was observed in thyroid carcinoma cell lines bearing the BRAF V600E mutation, with lack of full inhibition of ERK pathway. Interestingly, the exposure of thyroid carcinoma cells to PLX4032 resulted in a rapid feedback activation of EGFR signaling with parallel activation of AKT phosphorylation. Consistently, the dual inhibition of EGFR and BRAF, through combination therapy with PLX4032 and gefitinib, resulted in prevention of EGFR phosphorylation and sustained inhibition of ERK and AKT signaling and cell proliferation. Of note, the combined treatment with gefitinib and vemurafenib or the exposure of EGFR-silenced thyroid carcinoma cells to vemurafenib induced synthetic lethality compared to single agents. CONCLUSIONS: These data suggest that the dual EGFR and BRAF blockade represents a strategy to by-pass resistance to BRAF inhibitors in thyroid carcinoma cells.
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Regulation of tumour cell proliferation by molecular chaperones is still a complex issue. Here, the role of the HSP90 molecular chaperone TRAP1 in cell cycle regulation was investigated in a wide range of human breast, colorectal, and lung carcinoma cell lines, and tumour specimens. TRAP1 modulates the expression and/or the ubiquitination of key cell cycle regulators through a dual mechanism: (i) transcriptional regulation of CDK1, CYCLIN B1, and MAD2, as suggested by gene expression profiling of TRAP1-silenced breast carcinoma cells; and (ii) post-transcriptional quality control of CDK1 and MAD2, being the ubiquitination of these two proteins enhanced upon TRAP1 down-regulation. Mechanistically, TRAP1 quality control on CDK1 is crucial for its regulation of mitotic entry, since TRAP1 interacts with CDK1 and prevents CDK1 ubiquitination in cooperation with the proteasome regulatory particle TBP7, this representing the limiting factor in TRAP1 regulation of the G2-M transition. Indeed, TRAP1 silencing results in enhanced CDK1 ubiquitination, lack of nuclear translocation of CDK1/cyclin B1 complex, and increased MAD2 degradation, whereas CDK1 forced up-regulation partially rescues low cyclin B1 and MAD2 levels and G2-M transit in a TRAP1-poor background. Consistently, the CDK1 inhibitor RO-3306 is less active in a TRAP1-high background. Finally, a significant correlation was observed between TRAP1 and Ki67, CDK1 and/or MAD2 expression in breast, colorectal, and lung human tumour specimens. This study represents the first evidence that TRAP1 is relevant in the control of the complex machinery that governs cell cycle progression and mitotic entry and provides a strong rationale to regard TRAP1 as a biomarker to select tumours with deregulated cell cycle progression and thus likely poorly responsive to novel cell cycle inhibitors. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Proliferación Celular , Quinasas Ciclina-Dependientes/metabolismo , Puntos de Control de la Fase G2 del Ciclo Celular , Proteínas HSP90 de Choque Térmico/metabolismo , Proteínas Mad2/metabolismo , Neoplasias/enzimología , ATPasas Asociadas con Actividades Celulares Diversas , Adulto , Anciano , Anciano de 80 o más Años , Proteína Quinasa CDC2 , Línea Celular Tumoral , Ciclina B1/metabolismo , Quinasas Ciclina-Dependientes/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Proteínas HSP90 de Choque Térmico/genética , Humanos , Antígeno Ki-67/metabolismo , Proteínas Mad2/genética , Masculino , Persona de Mediana Edad , Neoplasias/genética , Neoplasias/patología , Complejo de la Endopetidasa Proteasomal/metabolismo , Interferencia de ARN , Transducción de Señal , Factores de Tiempo , Transcripción Genética , Transfección , UbiquitinaciónRESUMEN
INTRODUCTION: HSP90 molecular chaperones (i.e., HSP90α, HSP90ß, GRP94 and TRAP1) are potential therapeutic targets to design novel anticancer agents. However, despite numerous designed HSP90 inhibitors, most of them have failed due to unfavorable toxicity profiles and lack of specificity toward different HSP90 paralogs. Indeed, a major limitation in this field is the high structural homology between different HSP90 chaperones, which significantly limits our capacity to design paralog-specific inhibitors. Area covered: This review examines the relevance of TRAP1 in tumor development and progression, with an emphasis on its oncogenic/oncosuppressive role in specific human malignancies and its multifaceted and context-dependent functions in cancer cells. Herein, we discuss the rationale for considering TRAP1 as a potential molecular target and the strategies used to date, to achieve its compartmentalized inhibition directly in mitochondria. Expert opinion: TRAP1 targeting may represent a promising strategy for cancer therapy, based on the increasing and compelling evidence supporting TRAP1 involvement in human carcinogenesis. However, considering the complexity of TRAP1 biology, future strategies of drug discovery need to improve selectivity and specificity toward TRAP1 respect to other HSP90 paralogs. The characterization of specific human malignancies suitable for TRAP1 targeting is also mandatory.
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Antineoplásicos/farmacología , Proteínas HSP90 de Choque Térmico/metabolismo , Neoplasias/tratamiento farmacológico , Animales , Progresión de la Enfermedad , Diseño de Fármacos , Descubrimiento de Drogas/métodos , Humanos , Mitocondrias/metabolismo , Terapia Molecular Dirigida , Neoplasias/patologíaRESUMEN
Metabolic reprogramming is one of the most frequent stress-adaptive response of cancer cells to survive environmental changes and meet increasing nutrient requirements during their growth. These modifications involve cellular bioenergetics and cross talk with surrounding microenvironment, in a dynamic network that connect different molecular processes, such as energy production, inflammatory response, and drug resistance. Even though the Warburg effect has long been considered the main metabolic feature of cancer cells, recent reports identify mitochondrial oxidative metabolism as a driving force for tumor growth in an increasing number of cellular contexts. In recent years, oxidative phosphorylation has been linked to a remodeling of inflammatory response due to autocrine or paracrine secretion of interleukines that, in turn, induces a regulation of gene expression involving, among others, molecules responsible for the onset of drug resistance. This process is especially relevant in ovarian cancer, characterized by low survival, high frequency of disease relapse and chemoresistance. Recently, the molecular chaperone TRAP1 (tumor necrosis factor-associated protein 1) has been identified as a key junction molecule in these processes in ovarian cancer: in fact, TRAP1 mediates a metabolic switch toward oxidative phosphorylation that, in turn, triggers cytokines secretion, with consequent gene expression remodeling, finally leading to cisplatin resistance and epithelial-to-mesenchymal transition in ovarian cancer models. This review summarizes how metabolism, chemoresistance, inflammation, and epithelial-to-mesenchymal transition are strictly interconnected, and how TRAP1 stays at the crossroads of these processes, thus shedding new lights on molecular networks at the basis of ovarian cancer.
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Resistencia a Antineoplásicos , Proteínas HSP90 de Choque Térmico/metabolismo , Inflamación/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Ovario/efectos de los fármacos , Fosforilación Oxidativa , Animales , Antineoplásicos/farmacología , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Proteínas HSP90 de Choque Térmico/análisis , Proteínas HSP90 de Choque Térmico/inmunología , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Inflamación/patología , Neoplasias Ováricas/inmunología , Neoplasias Ováricas/patología , Ovario/inmunología , Ovario/metabolismo , Ovario/patología , Fosforilación Oxidativa/efectos de los fármacosRESUMEN
TRAP1 is a HSP90 molecular chaperone upregulated in colorectal carcinomas and involved in control of intracellular signaling, cell cycle, apoptosis and drug resistance, stemness and bioenergetics through co-traslational regulation of a network of client proteins. Thus, the clinical significance of TRAP1 protein network was analyzed in human colorectal cancers. TRAP1 and/or its client proteins were quantified, by immunoblot analysis, in 60 surgical specimens of colorectal carcinomas at different stages and, by immunohistochemistry, in 9 colorectal adenomatous polyps, 11 in situ carcinomas and 55 metastatic colorectal tumors. TRAP1 is upregulated at the transition between low- and high-grade adenomas, in in situ carcinomas and in about 60% of human colorectal carcinomas, being downregulated only in a small cohort of tumors. The analysis of TCGA database showed that a subgroup of colorectal tumors is characterized by gain/loss of TRAP1 copy number, this correlating with its mRNA and protein expression. Interestingly, TRAP1 is co-expressed with the majority of its client proteins and hierarchical cluster analysis showed that the upregulation of TRAP1 and associated 6-protein signature (i.e., IF2α, eF1A, TBP7, MAD2, CDK1 and ßCatenin) identifies a cohort of metastatic colorectal carcinomas with a significantly shorter overall survival (HR 5.4; 95% C.I. 1.1-26.6; p=0.037). Consistently, the prognostic relevance of TRAP1 was confirmed in a cohort of 55 metastatic colorectal tumors. Finally, TRAP1 positive expression and its prognostic value are more evident in left colon cancers. These data suggest that TRAP1 protein network may provide a prognostic signature in human metastatic colorectal carcinomas.
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Adenocarcinoma/metabolismo , Biomarcadores de Tumor/análisis , Neoplasias Colorrectales/metabolismo , Proteínas HSP90 de Choque Térmico/biosíntesis , Adenocarcinoma/genética , Adenocarcinoma/mortalidad , Anciano , Anciano de 80 o más Años , Análisis por Conglomerados , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Supervivencia sin Enfermedad , Femenino , Dosificación de Gen , Proteínas HSP90 de Choque Térmico/genética , Humanos , Immunoblotting , Inmunohistoquímica , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Pronóstico , Transcriptoma , Regulación hacia ArribaRESUMEN
Colorectal carcinoma (CRC) is a common cause of cancer-related death worldwide. Indeed, treatment failures are triggered by cancer stem cells (CSCs) that give rise to tumor repopulation upon initial remission. Thus, the role of the heat shock protein TRAP1 in stemness was investigated in CRC cell lines and human specimens, based on its involvement in colorectal carcinogenesis, through regulation of apoptosis, protein homeostasis and bioenergetics. Strikingly, co-expression between TRAP1 and stem cell markers was observed in stem cells located at the bottom of intestinal crypts and in CSCs sorted from CRC cell lines. Noteworthy, TRAP1 knockdown reduced the expression of stem cell markers and impaired colony formation, being the CSC phenotype and the anchorage-independent growth conserved in TRAP1-rich cancer cells. Consistently, the gene expression profiling of HCT116 cells showed that TRAP1 silencing results in the loss of the stem-like signature with acquisition of a more-differentiated phenotype and the downregulation of genes encoding for activating ligands and target proteins of Wnt/ß-catenin pathway. Mechanistically, TRAP1 maintenance of stemness is mediated by the regulation of Wnt/ß-catenin signaling, through the modulation of the expression of frizzled receptor ligands and the control of ß-catenin ubiquitination/phosphorylation. Remarkably, TRAP1 is associated with higher expression of ß-catenin and several Wnt/ß-catenin target genes in human CRCs, thus supporting the relevance of TRAP1 regulation of ß-catenin in human pathology. This study is the first demonstration that TRAP1 regulates stemness and Wnt/ß-catenin pathway in CRC and provides novel landmarks in cancer biology and therapeutics.