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1.
Pigment Cell Melanoma Res ; 37(1): 15-20, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37554041

RESUMO

Despite the improved survival rates of patients with advanced stage melanoma since the introduction of ICIs, many patients do not have (long-term) benefit from these treatments. There is evidence that the exposome, an accumulation of host-extrinsic factors including environmental influences, could impact ICI response. Recently, a survival benefit was observed in patients with BRAF wild-type melanoma living in Denmark who initiated immunotherapy in summer as compared to winter. As the Netherlands lies in close geographical proximity to Denmark and has comparable seasonal differences, a Dutch validation cohort was established using data from our nationwide melanoma registry. In this study, we did not observe a similar seasonal difference in overall survival and are therefore unable to confirm the Danish findings. Validation of either the Dutch or Danish findings in (combined) patient cohorts from other countries would be necessary to determine whether this host-extrinsic factor influences the response to ICI-treatment.


Assuntos
Melanoma , Humanos , Melanoma/genética , Melanoma/terapia , Estações do Ano , Taxa de Sobrevida , Estudos Retrospectivos
3.
Qual Life Res ; 32(9): 2517-2525, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37079262

RESUMO

BACKGROUND: Checkpoint inhibitors have been shown to substantially improve the survival of patients with advanced melanoma. With this growing group of survivors treated with immunotherapies, assessing their health-state utilities is essential and can be used for the calculation of quality-adjusted life years and for cost-effectiveness analyses. Therefore, we evaluated the health-state utilities in long-term advanced melanoma survivors. METHODS: Health-state utilities were evaluated in a cohort of advanced melanoma survivors 24-36 months (N = 37) and 36-plus months (N = 47) post-ipilimumab monotherapy. In addition, the health-state utilities of the 24-36 months survivor group were assessed longitudinally, and utilities of the combined survival groups (N = 84) were compared with a matched control population (N = 168). The EQ-5D was used to generate health-state utility values, and quality-of-life questionnaires were used to establish correlations and influencing factors of utility scores. RESULTS: Health-state utility scores were similar between the 24-36 months'- and the 36-plus months' survival group (0.81 vs 0.86; p = .22). In survivors, lower utility scores were associated with symptoms of depression (ß = - .82, p = .022) and fatigue burden (ß = - .29, p = .007). Utility scores did not significantly change after 24-36 months of survival, and the utilities of survivors were comparable to the matched control population (0.84 vs 0.87; p = .07). DISCUSSION: Our results show that long-term advanced melanoma survivors treated with ipilimumab monotherapy experience relatively stable and high health-state utility scores.


Assuntos
Sobreviventes de Câncer , Melanoma , Humanos , Qualidade de Vida/psicologia , Ipilimumab , Melanoma/tratamento farmacológico , Inquéritos e Questionários
5.
ESMO Open ; 6(6): 100320, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34856511

RESUMO

BACKGROUND: The objective of this study was to evaluate trends in survival and health care costs in metastatic melanoma in the era of targeted and immunotherapeutic drugs. MATERIALS AND METHODS: Data on survival and health care resource use were retrieved from the Dutch Melanoma Treatment Registry. The Kaplan-Meier method was used to estimate overall survival. Health care costs and budget impact were computed by applying unit costs to individual patient resource use. All outcomes were stratified by year of diagnosis. RESULTS: Baseline characteristics were balanced across cohort years. The percentage of patients receiving systemic treatment increased from 73% in 2013 to 90% in 2018. Patients received on average 1.85 [standard deviation (SD): 1.14] lines of treatment and 41% of patients received at least two lines of treatment. Median survival increased from 11.8 months in 2013 [95% confidence interval (CI): 10.7-13.7 months] to 21.1 months in 2018 (95% CI: 18.2 months-not reached). Total mean costs were €100 330 (SD: €103 699); systemic treatments accounted for 84% of the total costs. Costs for patients who received systemic treatment [€118 905 (SD: €104 166)] remained reasonably stable over the years even after the introduction of additional (combination of) novel drugs. From mid-2013 to 2018, the total budget impact for all patients was €452.79 million. CONCLUSION: Our study shows a gain in survival in the era of novel targeted and immunotherapeutic drugs. These novel drugs came, however, along with substantial health care costs. Further insights into the cost-effectiveness of the novel drugs are crucial for ensuring value for money in the treatment of patients with metastatic melanoma.


Assuntos
Melanoma , Estudos de Coortes , Análise Custo-Benefício , Custos de Cuidados de Saúde , Humanos , Imunoterapia/métodos , Melanoma/tratamento farmacológico
7.
BMC Cancer ; 21(1): 323, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33765967

RESUMO

BACKGROUND: The introduction of programmed cell death protein 1 (PD-1) blockers (i.e. nivolumab and pembrolizumab) has significantly improved the prognosis of patients with advanced melanoma. However, the long treatment duration (i.e. two years or longer) has a high impact on patients and healthcare systems in terms of (severe) toxicity, health-related quality of life (HRQoL), resource use, and healthcare costs. While durable tumour responses have been observed and PD-1 blockade is discontinued on an individual basis, no consensus has been reached on the optimal treatment duration. The objective of the Safe Stop trial is to evaluate whether early discontinuation of first-line PD-1 blockade is safe in patients with advanced and metastatic melanoma who achieve a radiological response. METHODS: The Safe Stop trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 200 patients with advanced and metastatic cutaneous melanoma and a confirmed complete response (CR) or partial response (PR) according to response evaluation criteria in solid tumours (RECIST) v1.1 will be included to early discontinue first-line monotherapy with nivolumab or pembrolizumab. The primary objective is the rate of ongoing responses at 24 months after discontinuation of PD-1 blockade. Secondary objectives include best overall and duration of response, need and outcome of rechallenge with PD-1 blockade, and changes in (serious) adverse events and HRQoL. The impact of treatment discontinuation on healthcare resource use, productivity losses, and hours of informal care will also be assessed. Results will be compared to those from patients with CR or PR who completed 24 months of treatment with PD-1 blockade and had an ongoing response at treatment discontinuation. It is hypothesised that it is safe to early stop first-line nivolumab or pembrolizumab at confirmed tumour response while improving HRQoL and reducing costs. DISCUSSION: From a patient, healthcare, and economic perspective, shorter treatment duration is preferred and overtreatment should be prevented. If early discontinuation of first-line PD-1 blockade appears to be safe, early discontinuation of PD-1 blockade may be implemented as the standard of care in a selected group of patients. TRIAL REGISTRATION: The Safe Stop trial has been registered in the Netherlands Trial Register (NTR), Trial NL7293 (old NTR ID: 7502), https://www.trialregister.nl/trial/7293 . Date of registration September 30, 2018.


Assuntos
Inibidores de Checkpoint Imunológico/administração & dosagem , Melanoma/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Suspensão de Tratamento/normas , Adulto , Consenso , Esquema de Medicação , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Inibidores de Checkpoint Imunológico/normas , Masculino , Melanoma/imunologia , Estudos Multicêntricos como Assunto , Guias de Prática Clínica como Assunto , Prognóstico , Receptor de Morte Celular Programada 1/imunologia , Estudos Prospectivos , Qualidade de Vida , Critérios de Avaliação de Resposta em Tumores Sólidos , Neoplasias Cutâneas/imunologia , Padrão de Cuidado/normas , Fatores de Tempo
8.
Acta Oncol ; 60(1): 69-77, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32924708

RESUMO

BACKGROUND: Checkpoint inhibitors have changed overall survival for patients with advanced melanoma. However, there is a lack of data on health-related quality of life (HRQoL) of long-term advanced melanoma survivors, years after treatment. Therefore, we evaluated HRQoL in long-term advanced melanoma survivors and compared the study outcomes with matched controls without cancer. MATERIAL AND METHODS: Ipilimumab-treated advanced melanoma survivors without evidence of disease and without subsequent systemic therapy for a minimum of two years following last administration of ipilimumab were eligible for this study. The European Organization for Research and Treatment of Cancer quality of life questionnaire Core 30 (EORTC QLQ-C30), the Multidimensional Fatigue Inventory (MFI), the Hospital Anxiety and Depression Scale (HADS), and the Functional Assessment of Cancer Therapy-Melanoma questionnaire (FACT-M) were administered. Controls were individually matched for age, gender, and educational status. Outcomes of survivors and controls were compared using generalized estimating equations, and differences were interpreted as clinically relevant according to published guidelines. RESULTS: A total of 89 survivors and 265 controls were analyzed in this study. After a median follow-up of 39 (range, 17-121) months, survivors scored significantly lower on physical (83.7 vs. 89.8, difference (diff) = -5.80, p=.005), role (83.5 vs. 90, diff = -5.97, p=.02), cognitive (83.7 vs. 91.9, diff = -8.05, p=.001), and social functioning (86.5 vs. 95.1, diff = -8.49, p= <.001) and had a higher symptom burden of fatigue (23.0 vs. 15.5, diff = 7.48, p=.004), dyspnea (13.3 vs. 6.7, diff = 6.47 p=.02), diarrhea (7.9 vs. 4.0, diff = 3.78, p=.04), and financial impact (10.5 vs. 2.5, diff = 8.07, p=.001) than matched controls. Group differences were indicated as clinically relevant. DISCUSSION: Compared to matched controls, long-term advanced melanoma survivors had overall worse functioning scores, more physical symptoms, and financial difficulties. These data may contribute to the development of appropriate survivorship care.


Assuntos
Sobreviventes de Câncer , Melanoma , Humanos , Inibidores de Checkpoint Imunológico , Melanoma/tratamento farmacológico , Qualidade de Vida , Inquéritos e Questionários , Sobreviventes
9.
Ann Oncol ; 32(3): 375-383, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33253862

RESUMO

BACKGROUND: It has been claimed, without supporting evidence, that knowledge of sentinel node (SN) status does not provide more accurate prognostic information than basic clinicopathological features of a primary cutaneous melanoma. We sought to investigate this claim and to quantify any additional value of SN status in predicting survival outcome. PATIENTS AND METHODS: Data for a Dutch population-based cohort of melanoma patients (n = 9272) and for a validation cohort from a large Australian melanoma treatment center (n = 5644) were analyzed. Patients were adults diagnosed between 2004 and 2014 with histologically-proven, primary invasive cutaneous melanoma who underwent SN biopsy. Multivariable Cox proportional hazards analyses were carried out in the Dutch cohort to assess recurrence-free survival (RFS), melanoma-specific survival (MSS) and overall survival (OS). The findings were validated using the Australian cohort. Discrimination (Harrell's C-statistic), net benefit using decision curve analysis and net reclassification index (NRI) were calculated. RESULTS: The Dutch cohort showed an improved C-statistic from 0.74 to 0.78 for OS and from 0.74 to 0.76 for RFS when SN status was included in the model with Breslow thickness, sex, age, site, mitoses, ulceration, regression and melanoma subtype. In the Australian cohort, the C-statistic increased from 0.70 to 0.73 for OS, 0.70 to 0.74 for RFS and 0.72 to 0.76 for MSS. Decision curve analyses showed that the 3-year and 5-year risk of death or recurrence were more accurately classified with a model that included SN status. At 3 years, sensitivity increased by 12% for both OS and RFS in the development cohort, and by 10% and 6% for OS and RFS, respectively, in the validation cohort. CONCLUSIONS: Knowledge of SN status significantly improved the predictive accuracy for RFS, MSS and OS when added to a comprehensive suite of established clinicopathological prognostic factors. However, clinicians and patients must consider the magnitude of the improvement when weighing up the advantages and disadvantages of SN biopsy for melanoma.


Assuntos
Melanoma , Neoplasias Cutâneas , Adulto , Austrália/epidemiologia , Humanos , Melanoma/patologia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/patologia
10.
Eur J Cancer ; 144: 242-251, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33373869

RESUMO

BACKGROUND: The treatment landscape has completely changed for advanced melanoma. We report survival outcomes and the differential impact of prognostic factors over time in daily clinical practice. METHODS: From a Dutch nationwide population-based registry, patients with advanced melanoma diagnosed from 2013 to 2017 were analysed (n = 3616). Because the proportional hazards assumption was violated, a multivariable Cox model restricted to the first 6 months and a multivariable landmark Cox model from 6 to 48 months were used to assess overall survival (OS) of cases without missing values. The 2017 cohort was excluded from this analysis because of the short follow-up time. RESULTS: Median OS of the 2013 and 2016 cohort was 11.7 months (95% confidence interval [CI]: 10.4-13.5) and 17.7 months (95% CI: 14.9-19.8), respectively. Compared with the 2013 cohort, the 2016 cohort had superior survival in the Cox model from 0 to 6 months (hazard ratio [HR] = 0.55 [95% CI: 0.43-0.72]) and in the Cox model from 6 to 48 months (HR = 0.68 [95% CI: 0.57-0.83]). Elevated lactate dehydrogenase levels, distant metastases in ≥3 organ sites, brain and liver metastasis and Eastern Cooperative Oncology Group performance score of ≥1 had stronger association with inferior survival from 0 to 6 months than from 6 to 48 months. BRAF-mutated melanoma had superior survival in the first 6 months (HR = 0.50 [95% CI: 0.42-0.59]). CONCLUSION(S): Prognosis for advanced melanoma in the Netherlands has improved from 2013 to 2016. Prognostic importance of most evaluated factors was higher in the first 6 months after diagnosis. BRAF-mutated melanoma was only associated with superior survival in the first 6 months.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Melanoma/mortalidade , Sistema de Registros/estatística & dados numéricos , Idoso , Feminino , Seguimentos , Humanos , Masculino , Melanoma/tratamento farmacológico , Melanoma/epidemiologia , Melanoma/patologia , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prognóstico , Neoplasias Cutâneas , Taxa de Sobrevida , Fatores de Tempo
11.
Cancer Immunol Immunother ; 70(5): 1491-1496, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32929554

RESUMO

INTRODUCTION: Hyperprogression, characterized by a rapid acceleration in tumor growth, is a novel pattern of progression recently described in patients treated with immune checkpoint inhibitors. This study aims to assess the incidence of hyperprogression in patients with advanced melanoma treated with checkpoint inhibitors. METHODS: Clinical and radiological findings of all advanced melanoma patients who started checkpoint inhibitors between January 2013 and March 2019 in a tertiary academic center in the Netherlands were analyzed. Change in tumor burden was calculated by assessing volumetric tumor growth using the criteria as defined by immune Response Evaluation Criteria in Solid Tumors version 1.1. Hyperprogression was defined as a time to treatment failure less than 2 months with doubling of tumor burden and a twofold increase in tumor growth rate during treatment. Possible hyperprogression was defined as the presence of the first two criteria in the absence of a pre-baseline scan. RESULTS: Out of 206 treatment episodes in 168 patients, 75 were evaluable for hyperprogression and 87 for possible hyperprogression. Hyperprogression was observed in one patient (1.3%) and possible hyperprogression was observed in one patient (1.1%). CONCLUSION: Hyperprogression is rare in melanoma patients treated with immune checkpoint inhibitors. Our data question if hyperprogression really is a biological entity in metastatic melanoma.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Inibidores de Checkpoint Imunológico/uso terapêutico , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Estadiamento de Neoplasias , Países Baixos , Falha de Tratamento , Carga Tumoral , Microambiente Tumoral
12.
Eur J Surg Oncol ; 46(5): 918-923, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31901365

RESUMO

INTRODUCTION: Although adjuvant therapy is available for melanoma patients with sentinel lymph node (SLN) metastases (pN+), this is not the case for thick melanomas without SLN involvement (pN-). OBJECTIVES: We assessed overall and relative survival (OS, RS) in patients with >4.0 mm Breslow thickness (BT) pN- and pN + melanomas and ≤4.0  mm pN+ patients. MATERIALS AND METHODS: Clinicopathological data were retrieved from a cohort of >4.0 mm thick and/or pN + melanoma patients in The Netherlands from 2000 to 2014. OS and RS was compared using Kaplan-Meier-curves. A Cox-regression-model was developed to assess determinants of OS in >4.0 mm pN- patients. RESULTS: In 54 645 patients, 3940 (7.2%) had >4.0 mm thick melanomas. SLN biopsy was performed in 1150 (29.2%) patients. Five-year OS was 70.5% for >4.0 mm pN- and 48.1% for >4.0  mm pN+ patients (p < 0.001), with a decreasing trend in OS for every mm BT. Five-year OS in 1877 ≤ 4.0  mm pN+ patients was 71.5%, which was not different from >4.0 mm pN- (p = 0.24). Higher age, higher BT category, ulceration and male gender were significantly associated with poor survival in >4.0 mm pN- patients. CONCLUSIONS: Thick pN- melanomas have a poor prognosis, comparable to that of less thick pN + melanomas, which is not accounted for in current guidelines. We encourage including these high-risk patients in adjuvant trials.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Melanoma/cirurgia , Linfonodo Sentinela/patologia , Neoplasias Cutâneas/cirurgia , Úlcera/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Braço , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Perna (Membro) , Masculino , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Países Baixos , Prognóstico , Modelos de Riscos Proporcionais , Biópsia de Linfonodo Sentinela , Fatores Sexuais , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Taxa de Sobrevida , Tronco , Carga Tumoral , Adulto Jovem
14.
PLoS One ; 10(5): e0127895, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26000714

RESUMO

BACKGROUND: Despite intensive surveillance, a high rate of interval malignancies is still seen in women at increased breast cancer risk. Therefore, novel screening modalities aiming at early detection remain needed. The intraductal approach offers the possibility to directly sample fluid containing cells, DNA and proteins from the mammary ductal system where, in the majority of cases, breast cancer originates. Fluid from the breast can non-invasively be obtained by oxytocin-assisted vacuum aspiration, called nipple fluid aspiration (NFA). The goal of this feasibility study was to evaluate the potential of repeated NFA, which is a critical and essential step to evaluate its possible value as a breast cancer screening method. METHODS: In this multicenter, prospective study, we annually collected nipple fluid for up to 5 consecutive years from women at increased breast cancer risk, and performed a questionnaire-based survey regarding discomfort of the aspiration. Endpoints of the current interim analyses were the feasibility and results of 994 NFA procedures in 451 women with total follow-up of 560 person years of observation. RESULTS: In this large group of women at increased risk of breast cancer, repetitive NFA appeared to be feasible and safe. In 66.4% of aspirated breasts, nipple fluid was successfully obtained. Independent predictive factors for successful NFA were premenopausal status, spontaneous nipple discharge, smaller breast size, bilateral oophorectomy and previous use of hormone replacement therapy or anti-hormonal treatment. The procedure was well tolerated with low discomfort. Drop-out rate was 20%, which was mainly due to repeated unsuccessful aspiration attempts. Only 1.6% of women prematurely declined further participation because of side effects. CONCLUSIONS: Repeated NFA in women at increased breast cancer risk is feasible and safe. Therefore, NFA is a promising method to non-invasively obtain a valuable source of potential breast cancer specific biomarkers.


Assuntos
Biomarcadores Tumorais/análise , Líquidos Corporais/química , Doenças Mamárias/diagnóstico , Neoplasias da Mama/diagnóstico , Mamilos , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
15.
Ann Oncol ; 22(1): 24-29, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20591821

RESUMO

The need for additional breast cancer screening tools is indisputably high, as one may conclude from the high rate of interval malignancies in women undergoing regular screening. DNA promoter methylation frequently occurs during breast carcinogenesis and is an early event in this process. Moreover, a field defect for methylation has been described and methylation values can reliably be assessed in limited amounts of DNA. Simultaneous detection of methylation of a panel of genes in breast fluids and/or blood derivatives could be both sufficiently specific and sensitive to be of additive value to current imaging-based screening methods. This review describes the recent developments in methylation detection in breast fluids, serum and plasma that paved the way for large prospective studies. These studies will provide us with the definite answer as to what will be the additive value of defining the methylation status of specific genes to current imaging-based screening methods.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Metilação de DNA , Neoplasias da Mama/sangue , Detecção Precoce de Câncer/métodos , Feminino , Humanos
16.
Ann Oncol ; 19(11): 1870-4, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18647968

RESUMO

BACKGROUND: Promoter methylation is a common epigenetic mechanism to silence tumor suppressor genes during breast cancer development. We investigated whether BRCA1-associated breast tumors show cancer-predictive methylation patterns similar to those found in sporadic tumors. PATIENTS AND METHODS: Quantitative multiplex methylation-specific PCR of 11 genes involved in breast carcinogenesis (RARB, RASSF1, TWIST1, CCND2, ESR1, SCGB3A1, BRCA1, BRCA2, CDKN2A, APC, CDH1) was carried out on 32 BRCA1-associated and 46 sporadic breast carcinomas and on normal breast tissue from seven BRCA1 mutation carriers and 13 non-carriers. RESULTS: The extent of cumulative methylation increased with age (P < 0.001). The median cumulative methylation index (CMI) of all studied genes was significantly higher in tumors (89) than in normal tissue (13, P < 0.001). The median CMI was significantly lower in BRCA1-associated (59) than in sporadic breast tumors (122, P = 0.001), in estrogen receptor (ER)-negative tumors (73) than in ER-positive tumors (122, P = 0.005) and in lymph node-negative (77) compared with lymph node-positive tumors (137, P = 0.007). In subgroup analysis, the effect of a BRCA1 germline mutation on methylation proved to be independent of ER status, lymph node status and age. CONCLUSIONS: These data indicate that BRCA1-associated breast cancers show less promoter methylation compared with sporadic breast carcinomas indicating a difference in disease etiology.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA , Genes BRCA1 , Adulto , Fatores Etários , Neoplasias da Mama/patologia , DNA de Neoplasias/genética , Feminino , Marcadores Genéticos , Mutação em Linhagem Germinativa , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Receptores de Estrogênio/genética
17.
Oncogene ; 27(11): 1501-10, 2008 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-17873906

RESUMO

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that play a crucial role in oxygen homeostasis. Intratumoral hypoxia and genetic alterations lead to HIF activity, which is a hallmark of solid cancer and is associated with poor clinical outcome. HIF activity is regulated by an evolutionary conserved mechanism involving oxygen-dependent HIFalpha protein degradation. To identify novel components of the HIF pathway, we performed a genome-wide RNA interference screen in Caenorhabditis elegans, to suppress HIF-dependent phenotypes, like egg-laying defects and hypoxia survival. In addition to hif-1 (HIFalpha) and aha-1 (HIFbeta), we identified hlh-8, gska-3 and spe-8. The hlh-8 gene is homologous to the human oncogene TWIST1. We show that TWIST1 expression in human cancer cells is enhanced by hypoxia in a HIF-2alpha-dependent manner. Furthermore, intronic hypoxia response elements of TWIST1 are regulated by HIF-2alpha, but not HIF-1alpha. These results identify TWIST1 as a direct target gene of HIF-2alpha, which may provide insight into the acquired metastatic capacity of hypoxic tumors.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Hipóxia Celular , Regulação da Expressão Gênica , Proteínas Nucleares/metabolismo , RNA Interferente Pequeno/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Animais , Western Blotting , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Células Cultivadas , Desferroxamina/farmacologia , Genoma , Células HeLa , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Pró-Colágeno-Prolina Dioxigenase/antagonistas & inibidores , Pró-Colágeno-Prolina Dioxigenase/metabolismo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Elementos de Resposta , Transcrição Gênica , Ativação Transcricional , Transfecção
19.
Ned Tijdschr Geneeskd ; 151(16): 907-13, 2007 Apr 21.
Artigo em Holandês | MEDLINE | ID: mdl-17500342

RESUMO

Defects in DNA that activate oncogenes or inactivate tumour-suppressor genes are regarded as a crucial step in tumour development. Understanding the processes that modulate gene activity, the so-called epigenetic processes, is gaining importance in the search for factors responsible for uncontrolled cell growth. Cell proliferation is determined by epigenetic and genetic processes. Abnormal patterns of methylation and other epigenetic processes, such as acetylation, nucleosome formation and compact chromatin structure, can suppress transcription and inactivate tumour-suppressor genes. Methylation status is a promising biomarker for malignancy because the process is not patient-specific, it occurs at an early stage oftumour development and may precede morphological changes.


Assuntos
Metilação de DNA , Epigênese Genética/fisiologia , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias/genética , Neoplasias/metabolismo , Biomarcadores Tumorais , Humanos
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