Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Dis Colon Rectum ; 65(1): 40-45, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34882627

RESUMO

BACKGROUND: Approximately 5% to 10% of patients with Lynch syndrome develop urothelial carcinoma. Current screening recommendations vary and are based on expert opinion. Practices need to be evaluated for clinical effectiveness. Our program utilizes urinalysis as a screening test, followed by additional evaluation of microscopic hematuria. OBJECTIVE: This study aimed to determine the clinical utility of a urinalysis-based screening approach for urothelial cancers in patients with Lynch syndrome. DESIGN: This is a retrospective review of a prospectively maintained cohort. SETTING: Patients with Lynch syndrome were managed at a tertiary referral center. PATIENTS: All patients with a Lynch syndrome diagnosis who had a screening urinalysis done as part of our institutional screening protocol (N = 204) were included. MAIN OUTCOME MEASURES: A single-institution hereditary colorectal cancer syndrome registry was queried for patients with Lynch syndrome who had been screened for urothelial carcinomas by urinalysis. Demographics, genotype, family history of urothelial carcinoma, urinalysis results, and subsequent screenings and final diagnosis were gathered for patients between 2008 and 2017. RESULTS: Two hundred four asymptomatic patients underwent screening by urinalysis. Nineteen patients (9.3%) had microscopic hematuria and were further evaluated with urine cytology, imaging, cystoscopy, and/or Urology consultation. None of the 19 patients with microscopic hematuria had urothelial carcinoma. During the same study period, 5 of 204 (2.4%) patients with Lynch syndrome were diagnosed with urothelial cancer, and all presented with symptoms between screening intervals. LIMITATIONS: This is a retrospective study, and not all patients underwent the same secondary evaluation. CONCLUSIONS: No urothelial carcinomas were detected by screening urinalysis in our cohort of asymptomatic patients with Lynch syndrome. False-positive testing led to extensive, mostly uninformative, workups. If urothelial cancer screening is to continue, more effective screening approaches need to be identified. See Video Abstract at http://links.lww.com/DCR/B702. EVALUACIN DEL CRIBADO BASADO EN ANLISIS DE ORINA PARA CARCINOMA UROTELIAL EN PACIENTES CON SNDROME DE LYNCH: ANTECEDENTES:Aproximadamente el 5-10% de los pacientes con síndrome de Lynch desarrollan carcinoma urotelial. Las recomendaciones actuales de detección varían y se basan en la opinión de expertos. Las prácticas deben evaluarse para determinar su eficacia clínica. Nuestro programa utiliza el análisis de orina como prueba de detección, seguido de una evaluación adicional con hematuria microscópica.OBJETIVO:Determinar la utilidad clínica desde un enfoque de cribado basado en análisis de orina, para cánceres uroteliales en pacientes con síndrome de Lynch.DISEÑO:Revisión retrospectiva de una cohorte mantenida prospectivamente.ENTORNO CLINICO:Pacientes con síndrome de Lynch atendidos en un centro de referencia terciario.PACIENTES:Criterios de inclusión fueron todos los pacientes con diagnóstico de síndrome de Lynch realizándoles un análisis de orina de detección como parte de nuestro protocolo de detección institucional (N = 204).PRINCIPALES MEDIDAS DE VALORACION:Solicitando un registro de síndrome de cáncer colorrectal hereditario de una sola institución para pacientes con síndrome de Lynch previamente evaluados para carcinomas uroteliales mediante análisis de orina. Se recopilaron para los pacientes entre 2008 y 2017, datos demográficos, genotipo, antecedentes familiares de carcinoma urotelial, resultados del análisis de orina, posteriores exámenes de detección posteriores y diagnóstico final.RESULTADOS:Doscientos cuatro pacientes asintomáticos fueron sometidos a cribado mediante análisis de orina. Diecinueve pacientes (9,3%) tenían hematuria microscópica y fueron investigados más a fondo con citología de orina, imágenes, cistoscopia y / o consulta de urología. Ninguno de los 19 pacientes con hematuria microscópica tenían carcinoma urotelial. Durante el mismo período de estudio, 5 de 204 (2,4%) pacientes con síndrome de Lynch fueron diagnosticados con cáncer urotelial y todos presentaron presentando síntomas entre los intervalos de detección.LIMITACIONES:Estudio retrospectivo y no todos los pacientes sometidos a la misma evaluación secundaria.CONCLUSIONES:No se detectaron carcinomas uroteliales mediante análisis de orina de detección en nuestra cohorte de pacientes asintomáticos con síndrome de Lynch. Las pruebas de falsos positivos. Condujeron a estudios exhaustivos y en su mayoría poco informativos. Si se desea continuar con la detección del cáncer de urotelio, es necesario identificar enfoques de detección más efectivos. Consulte Video Resumen en http://links.lww.com/DCR/B702.


Assuntos
Carcinoma de Células de Transição/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Urinálise/métodos , Urotélio/patologia , Adulto , Idoso , Carcinoma de Células de Transição/urina , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Eficiência Organizacional , Reações Falso-Positivas , Feminino , Hematúria/diagnóstico , Hematúria/etiologia , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Estudos Retrospectivos , Urinálise/estatística & dados numéricos , Neoplasias Urológicas/patologia
2.
Cancer Res ; 81(17): 4485-4498, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34162680

RESUMO

Emerging research has revealed regulation of colorectal cancer metabolism by bacteria. Fusobacterium nucleatum (Fn) plays a crucial role in the development of colorectal cancer, however, whether Fn infection modifies metabolism in patients with colorectal cancer remains unknown. Here, LC-MS/MS-based lipidomics identified the upregulation of cytochrome P450 monooxygenases, primarily CYP2J2, and their mediated product 12,13-EpOME in patients with colorectal cancer tumors and mouse models, which increased the invasive and migratory ability of colorectal cancer cells in vivo and in vitro by regulating the epithelial-mesenchymal transition (EMT). Metagenomic sequencing indicated a positive correlation between increased levels of fecal Fn and serum 12,13-EpOME in patients with colorectal cancer. High levels of CYP2J2 in tumor tissues also correlated with high Fn levels and worse overall survival in patients with stage III/IV colorectal cancer. Moreover, Fn was found to activate TLR4/AKT signaling, downregulating Keap1 and increasing NRF2 to promote transcription of CYP2J2. Collectively, these data identify that Fn promotes EMT and metastasis in colorectal cancer by activating a TLR4/Keap1/NRF2 axis to increase CYP2J2 and 12,13-EpOME, which could serve as clinical biomarkers and therapeutic targets for Fn-infected patients with colorectal cancer. SIGNIFICANCE: This study uncovers a mechanism by which Fusobacterium nucleatum regulates colorectal cancer metabolism to drive metastasis, suggesting the potential biomarker and therapeutic utility of the CYP2J2/12,13-EpOME axis in Fn-infected patients.


Assuntos
Neoplasias Colorretais/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Infecções por Fusobacterium/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Ácidos Oleicos/metabolismo , Receptor 4 Toll-Like/metabolismo , Idoso , Animais , Carcinogênese , Linhagem Celular Tumoral , Movimento Celular , Neoplasias Colorretais/complicações , Neoplasias Colorretais/microbiologia , Citocromo P-450 CYP2J2/genética , Transição Epitelial-Mesenquimal , Feminino , Infecções por Fusobacterium/complicações , Infecções por Fusobacterium/microbiologia , Fusobacterium nucleatum/metabolismo , Células HCT116 , Células HEK293 , Humanos , Masculino , Metabolômica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Metástase Neoplásica , Transdução de Sinais
3.
Nat Commun ; 12(1): 262, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431859

RESUMO

The pathogenesis of ulcerative colitis (UC), a major type of inflammatory bowel disease, remains unknown. No model exists that adequately recapitulates the complexity of clinical UC. Here, we take advantage of induced pluripotent stem cells (iPSCs) to develop an induced human UC-derived organoid (iHUCO) model and compared it with the induced human normal organoid model (iHNO). Notably, iHUCOs recapitulated histological and functional features of primary colitic tissues, including the absence of acidic mucus secretion and aberrant adherens junctions in the epithelial barrier both in vitro and in vivo. We demonstrate that the CXCL8/CXCR1 axis was overexpressed in iHUCO but not in iHNO. As proof-of-principle, we show that inhibition of CXCL8 receptor by the small-molecule non-competitive inhibitor repertaxin attenuated the progression of UC phenotypes in vitro and in vivo. This patient-derived organoid model, containing both epithelial and stromal compartments, will generate new insights into the underlying pathogenesis of UC while offering opportunities to tailor interventions to the individual patient.


Assuntos
Colite Ulcerativa/patologia , Organoides/patologia , Junções Aderentes/metabolismo , Caderinas/metabolismo , Progressão da Doença , Epitélio/patologia , Fibroblastos/patologia , Humanos , Inflamação/patologia , Omento/transplante , Fenótipo , Análise de Componente Principal , Análise de Sequência de RNA , Sulfonamidas/farmacologia , Transcriptoma/genética , beta Catenina/metabolismo
4.
Oncoscience ; 7(5-6): 36-37, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32676515
5.
Cancer Res ; 80(2): 334-346, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31704889

RESUMO

Neoadjuvant radiation is standard of care for locally advanced rectal cancer. Response to radiation is highly variable and directly linked with survival. However, there currently are no validated biomarkers or molecular targets to predict or improve radiation response, which would help develop personalized treatment and ideally targeted therapies. Here, we identified a novel biomarker, coenzyme A synthase (COASY), whose mRNA expression was consistently elevated in radioresistant human rectal cancers. This observation was validated in independent patient cohorts and further confirmed in colorectal cancer cell lines. Importantly, genetic overexpression and knockdown yielded radioresistant and sensitive phenotypes, respectively, in vitro and in vivo. COASY-knockdown xenografts were more vulnerable to radiation, showing delayed tumor growth, decreased proliferation, and increased apoptosis. Mechanistically, COASY protein directly interacted with the PI3K regulatory subunit PI3K-P85α, which increased AKT and mTOR phosphorylation, enhancing cell survival. Furthermore, shRNA COASY knockdown disrupted downstream PI3K pathway activation and also hindered DNA double-strand break repair, which both led to improved radiosensitivity. Collectively, this work reveals for the first time the biological relevance of COASY as a predictive rectal cancer biomarker for radiation response and offers mechanistic evidence to support COASY as a potential therapeutic target. SIGNIFICANCE: COASY is a novel radiotherapy response modulator in rectal cancer that regulates PI3K activation and DNA repair. Furthermore, COASY levels directly correlate with radiation response and serve as a predictive biomarker.


Assuntos
Adenocarcinoma/terapia , Biomarcadores Tumorais/genética , Tolerância a Radiação/genética , Neoplasias Retais/terapia , Transferases/genética , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Animais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Biópsia , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Reparo do DNA/efeitos da radiação , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Fosforilação , Protectomia , Estudos Prospectivos , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Neoplasias Retais/genética , Neoplasias Retais/mortalidade , Neoplasias Retais/patologia , Reto/patologia , Reto/cirurgia , Transdução de Sinais/genética , Análise de Sobrevida , Transferases/análise , Transferases/metabolismo , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Dis Colon Rectum ; 62(1): 21-26, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30394984

RESUMO

BACKGROUND: The methylator pathway of colorectal carcinogenesis, characterized by CpG island hypermethylation and BRAF mutations, accounts for ≈25% of colorectal cancers. Because these cancers tend to be right sided and because DNA methylation in the right colon increases with age, we expect an increasing proportion of right-sided cancer over time. Conversely, we expect young patients (age <50 y) to have less methylated and fewer right-sided cancers OBJECTIVE:: The purpose of this study was to analyze the distribution and genetic traits of colorectal cancer from different age groups. DESIGN: This was a retrospective cohort study. SETTING: The study was conducted at a high-volume tertiary referral center. PATIENTS: Patient samples included those from our colorectal cancer biobank of resected colorectal cancer specimens. MAIN OUTCOME MEASURES: Tumor CpG island hypermethylation, microsatellite instability, and mutations in KRAS and BRAF oncogenes were analyzed in resected specimens and stratified by age and tumor location. Comparisons included age >50 or <50 years and decade of diagnosis (≤50, 51-60, 61-70, 71-80, and >81 y). Patients with IBD or hereditary syndromes were excluded. RESULTS: A total of 497 colorectal cancers were analyzed (266 men and 231 women); 57 patients (11.5%) were ≤50 years of age. No young cancers (0/57) were hypermethylated compared with 97 (22%) of 440 cancers of patients aged >50 years (p < 0.001). An increasing percentage of tumors were CpG island phenotype high with each decade of age at diagnosis. No cancers in patients <50 years of age were microsatellite unstable compared with 91 (23.6%) of 346 for those >50 years of age. No young cancers contained a BRAF mutation compared with 46 (10.6%) of 434 in older cancers (p < 0.001). KRAS mutations were less common in young cancers compared with older cancers (13/57 (22.8%) vs 126/410 (30.7%); p < 0.01). Eleven (19.3%) of 57 young cancers were proximal compared with 228 (51.8%) of 440 (p < 0.001) older cancers. LIMITATIONS: This study was limited by its retrospective design. CONCLUSIONS: The lack of CpG island methylator phenotype tumors in young patients is consistent with the dominant left-sided cancer distribution seen in the young and focuses efforts to understand and prevent cancer in this age group on causes of chromosomal instability. See Video Abstract at http://links.lww.com/DCR/A709.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Ilhas de CpG , Metilação de DNA , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Estudos Retrospectivos
7.
Stem Cells ; 37(1): 42-53, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30353615

RESUMO

Colorectal cancer (CRC) remains a leading killer in the U.S. with resistance to treatment as the largest hurdle to cure. Colorectal cancer-initiating cells (CICs) are a self-renewing tumor population that contribute to tumor relapse. Here, we report that patient-derived CICs display relative chemoresistance compared with differentiated progeny. In contrast, conventional cell lines failed model therapeutic resistance. CICs preferentially repaired chemotherapy-induced DNA breaks, prompting us to interrogate DNA damage pathways against which pharmacologic inhibitors have been developed. We found that CICs critically depended on the key single-strand break repair mediator, poly(ADP-ribose) polymerase (PARP), to survive treatment with standard-of-care chemotherapy. Small molecule PARP inhibitors (PARPi) sensitized CICs to chemotherapy and reduced chemotherapy-treated CIC viability, self-renewal, and DNA damage repair. Although PARPi monotherapy failed to kill CICs, combined PARPi therapy with chemotherapy attenuated tumor growth in vivo. Clinical significance of PARPi for CRC patients was supported by elevated PARP levels in colorectal tumors compared with normal colon, with further increases in metastases. Collectively, our results suggest that PARP inhibition serves as a point of fragility for CICs by augmenting therapeutic efficacy of chemotherapy. Stem Cells 2019;37:42-53.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Reparo do DNA/genética , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Microambiente Tumoral/genética , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Humanos , Camundongos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia
8.
Br J Cancer ; 119(10): 1267-1277, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30318507

RESUMO

BACKGROUND: Colorectal cancer (CRC) is a heterogeneous disease with distinct clinical subsets based on underlying genetic and epigenetic changes. DNA hypermethylation yields a unique CRC subset with a distinct phenotype and clinical behaviour, but this oncogenic pathway is not fully characterised. This study identifies and characterises miR-1247 as a novel tumour suppressor microRNA in methylated human colon cancers. METHOD: Tumour samples from patients with hypermethylated and non-methylated colon cancer and cell lines were evaluated for miR-1247 expression and function. A murine subcutaneous xenograft model was used for in vivo functional studies. RESULTS: miR-1247 was methylated and underexpressed in methylator colon cancers. Overexpression of miR-1247 significantly inhibited cell proliferation, decreased tumour cell motility, induced apoptosis, and mitigated tumour formation capacity both in vivo and in vitro. Pharmacologic demethylation increased miR-1247 expression and produced similar anti-tumour activities. Mechanistic investigations revealed that MYCBP2, a member of the c-myc oncogene family, is a direct functional target of miR-1247. Furthermore, in CRC patients, MYCBP2 protein levels are associated with miR-1247 levels and survival. CONCLUSIONS: miR-1247 acts as a tumour suppressor by inhibiting MYCBP2 in methylator colon cancer. The MYCBP2/c-myc axis may underlie the anti-tumour activities of miR-1247 and is a potential therapeutic target via demethylation agents.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias do Colo/genética , Metilação de DNA , Epigênese Genética , Genes Supressores de Tumor , MicroRNAs/genética , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Xenoenxertos , Humanos , Camundongos , Camundongos Nus
9.
Surg Endosc ; 32(3): 1533-1539, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28916945

RESUMO

INTRODUCTION: Neoadjuvant chemoradiation (CRT) for rectal cancer induces variable responses, and better response has been associated with improved oncologic outcomes. Our group has previously shown that the administration of HMG-CoA reductase inhibitors, commonly known as statins, is associated with improved response to neoadjuvant CRT in rectal cancer patients. The purpose of this study was to study the effects of simvastatin on colorectal cancer cells and explore its potential as a radiation-sensitizer in vitro. METHODS: Four colorectal cancer cell lines (SW480, DLD1, SW837, and HRT18) were used to test the effects of simvastatin alone, radiation alone, and combination therapy. Outcome measures included ATP-based cell viability, colony formation, and protein (immunoblot) assays. RESULTS: The combination of radiation and simvastatin inhibited colony formation and cell viability of all four CRC lines, to a greater degree than either treatment alone (p < 0.01). In addition, the effects of simvastatin in this combination therapy were dose dependent, with increased concentrations resulting in more potentiated inhibitory effects. The radiosensitizing effects of simvastatin on cell viability were negated by the presence of exogenous GGPP in the media. On protein analyses of irradiated cells, simvastatin treatment inhibited phosphorylation of ERK1/2, in a dose-dependent manner, while the total levels of ERK1/2 remained stable. In addition, the combined treatment resulted in increased levels of cleaved caspase 3, indicating greater apoptotic activity in the cells treated with radiation and simvastatin together. CONCLUSIONS: Treatment with simvastatin hindered CRC cell viability and enhanced radiation sensitivity in vitro. These effects were tied to the depletion of GGPP and the decreased phosphorylation of ERK1/2, suggesting a prominent role for the EGFR-RAS-ERK1/2 pathway, through which statin enhances radiation sensitivity.


Assuntos
Quimiorradioterapia , Neoplasias Colorretais/terapia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Terapia Neoadjuvante , Radiossensibilizantes/uso terapêutico , Sinvastatina/uso terapêutico , Apoptose , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Quimiorradioterapia/métodos , Neoplasias Colorretais/metabolismo , Humanos , Immunoblotting , Sistema de Sinalização das MAP Quinases , Fosforilação , Tolerância a Radiação/efeitos dos fármacos , Células-Tronco
10.
Oncotarget ; 7(49): 80190-80207, 2016 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-27863397

RESUMO

The GLI genes are transcription factors and in cancers are oncogenes, aberrantly and constitutively activated. GANT61, a specific GLI inhibitor, has induced extensive cytotoxicity in human models of colon cancer. The FOXM1 promoter was determined to be a transcriptional target of GLI1. In HT29 cells, inhibition of GLI1 binding at the GLI consensus sequence by GANT61 led to inhibited binding of Pol II, the pause-release factors DSIF, NELF and p-TEFb. The formation of R-loops (RNA:DNA hybrids, ssDNA), were reduced by GANT61 at the FOXM1 promoter. Pretreatment of HT29 cells with α-amanitin reduced GANT61-induced γH2AX foci. Co-localization of GLI1 and BrdU foci, inhibited by GANT61, indicated GLI1 and DNA replication to be linked. By co-immunoprecipitation and confocal microscopy, GLI1 co-localized with the DNA licensing factors ORC4, CDT1, and MCM2. Significant co-localization of GLI1 and ORC4 was inhibited by GANT61, and enrichment of ORC4 occurred at the GLI binding site in the FOXM1 promoter. CDT1 was found to be a transcription target of GLI1. Overexpression of CDT1 in HT29 and SW480 cells reduced GANT61-induced cell death, gH2AX foci, and cleavage of caspase-3. Data demonstrate involvement of transcription and of DNA replication licensing factors by non-transcriptional and transcriptional mechanisms in the GLI-dependent mechanism of action of GANT61.


Assuntos
Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Replicação do DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Piridinas/farmacologia , Pirimidinas/farmacologia , Transcrição Gênica/efeitos dos fármacos , Proteína GLI1 em Dedos de Zinco/antagonistas & inibidores , Sítios de Ligação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Morte Celular/efeitos dos fármacos , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Relação Dose-Resposta a Droga , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Células HT29 , Histonas/metabolismo , Humanos , Componente 2 do Complexo de Manutenção de Minicromossomo/genética , Componente 2 do Complexo de Manutenção de Minicromossomo/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Complexo de Reconhecimento de Origem/genética , Complexo de Reconhecimento de Origem/metabolismo , Regiões Promotoras Genéticas , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Elongação da Transcrição/genética , Fatores de Elongação da Transcrição/metabolismo , Transfecção , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo
11.
Oncotarget ; 7(28): 44023-44038, 2016 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-27281619

RESUMO

At the time of diagnosis, 60% of patients with head and neck squamous cell carcinoma (HNSCC) present tumors in an advanced stage (III-IV) of disease and 80% will relapse within the first two years post-treatment, due to their frequent radio(chemo)resistance. To identify new molecular targets and companion biomarkers, we have investigated the miRNome of 75 stage III-IV oropharynx tumors without relapse (R) or with loco-regional relapse (non-responder, NR) within two years post-treatment. Interestingly, miR-422a was significantly downregulated in NR tumors, in agreement with the increase in cell proliferation and adhesion induced by miR-422a inhibition in vitro. Furthermore, we identified CD73/NT5E oncogene as target of miR-422a. Indeed, modulation of the endogenous level of miR-422a inversely influences the expression and the enzymatic activity of CD73. Moreover, knocking down CD73 mimics the effects of miR-422a upregulation. Importantly, in tumors, miR-422a and CD73 expression levels are inversely correlated, and both are predictive of relapse free survival - especially considering loco(regional) recurrence - in vitro two independent cohorts of advanced oropharynx or HNSCC (N=255) tumors. In all, we reported, for the first time, that MiR-422a and its target CD73 are involved in early loco(regional) recurrence of HNSCC tumors and are new targets for personalized medicine.


Assuntos
5'-Nucleotidase/genética , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , MicroRNAs/genética , 5'-Nucleotidase/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Adesão Celular/genética , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Interferência de RNA
12.
Mol Cancer ; 14: 134, 2015 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-26183089

RESUMO

BACKGROUND: Glioblastoma (GBM) is the most frequent and aggressive type of adult brain tumor. Most GBMs express telomerase; a high level of intra-tumoral telomerase activity (TA) is predictive of poor prognosis. Thus, telomerase inhibitors are promising options to treat GBM. These inhibitors increase the response to radiotherapy (RT), in vitro as well as in vivo. Since typical treatments for GBM include RT, our objective was to evaluate the efficiency of Imetelstat (TA inhibitor) combined with RT. FINDINGS: We used a murine orthotopic model of human GBM (N = 8 to11 mice per group) and µMRI imaging to evaluate the efficacy of Imetelstat (delivered by intra-peritoneal injection) alone and combined with RT. Using a clinically established protocol, we demonstrated that Imetelstat significantly: (i) inhibited the TA in the very center of the tumor, (ii) reduced tumor volume as a proportion of TA inhibition, and (iii) increased the response to RT, in terms of tumor volume regression and survival increase. CONCLUSIONS: Imetelstat is currently evaluated in refractory brain tumors in young patients (without RT). Our results support its clinical evaluation combined with RT to treat GBM.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Indóis/farmacologia , Niacinamida/análogos & derivados , Tolerância a Radiação/efeitos dos fármacos , Telomerase/antagonistas & inibidores , Animais , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Modelos Animais de Doenças , Glioblastoma/diagnóstico , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Humanos , Camundongos , Niacinamida/farmacologia , Oligonucleotídeos , Telomerase/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Mol Neurobiol ; 47(1): 64-76, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23065374

RESUMO

Despite a standard of care combining surgery, radiotherapy (RT), and temozolomide chemotherapy, the average overall survival (OS) of glioblastoma patients is only 15 months, and even far lower when the patient cannot benefit from this combination. Therefore, there is a strong need for new treatments, such as new irradiation techniques. Against this background, carbon ion hadrontherapy, a new kind of irradiation, leads to a greater biological response of the tumor, while minimizing adverse effects on healthy tissues in comparison with RT. As carbon ion hadrontherapy is restricted to RT-resistant patients, photon irradiation resistance biomarkers are needed. Long telomeres and high telomerase activity have been widely associated with photon radioresistance in other cancers. Moreover, telomere protection, telomere function, and telomere length (TL) also depend on the shelterin protein complex (TRF1, TRF2, TPP1, POT1, TIN2, and hRAP1). We thus decided to evaluate an enlarged telomeric status (TL, telomerase catalytic subunit, and the shelterin component expression level) as a potential radioresistance biomarker in vitro using cellular models and ex vivo using patient tumor biopsies. In addition, nothing was known about the role of telomeres in carbon ion response. We thus evaluated telomeric status after both types of irradiation. We report here a significant correlation between TL and the basal POT1 expression level and photon radioresistance, in vitro, and a significant increase in the OS of patients with long telomeres or a high POT1 level, in vivo. POT1 expression was predictive of patient response irrespective of the TL. Strikingly, these correlations were lost, in vitro, when considering carbon irradiation. We thus propose (1) a model of the implications of telomeric damage in the cell response to both types of irradiation and (2) assessment of the POT1 expression level and TL using patient tumor biopsies to identify radioresistant patients who could benefit from carbon hadrontherapy.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Glioblastoma/genética , Glioblastoma/terapia , Medicina de Precisão , Telômero/metabolismo , Linhagem Celular Tumoral , Radioterapia com Íons Pesados , Humanos , Fótons , Tolerância a Radiação , Complexo Shelterina , Análise de Sobrevida , Telomerase/metabolismo , Proteínas de Ligação a Telômeros
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA