RESUMO
The Ewing's sarcoma family of tumours (ESFT) are diagnosed by EWS-ETS gene translocations. The resulting fusion proteins play a role in both the initiation and maintenance of these solid aggressive malignant tumours, suppressing cellular senescence and increasing cell proliferation and survival. EWS-ETS fusion proteins have altered transcriptional activity, inducing expression of a number of different target genes including telomerase. Up-regulation of hTERT is most likely responsible for the high levels of telomerase activity in primary ESFT, although telomerase activity and expression of hTERT are not predictive of outcome. However levels of telomerase activity in peripheral blood may be useful to monitor response to some therapeutics. Despite high levels of telomerase activity, telomeres in ESFT are frequently shorter than those of matched normal cells. Uncertainty about the role that telomerase and regulators of its activity play in the maintenance of telomere length in normal and cancer cells, and lack of studies examining the relationship between telomerase activity, regulators of its activity and their clinical significance in patient samples have limited their introduction into clinical practice. Studies in clinical samples using standardised assays are critical to establish how telomerase and regulators of its activity might best be exploited for patient benefit.
Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Sarcoma de Ewing/enzimologia , Telomerase/biossíntese , Telômero/metabolismo , Translocação Genética , Animais , Proliferação de Células , Sobrevivência Celular , Senescência Celular , Humanos , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/mortalidadeRESUMO
Ewing's sarcoma family tumors (ESFT) are characterized by the presence of EWSR1-ETS fusion genes. Secondary chromosome changes are frequently described, although their clinical significance is not clear. In this study, we have collected and reviewed abnormal karyotypes from 88 patients with primary ESFT and a rearrangement of 22q12. Secondary changes were identified in 80% (70/88) of tumors at diagnosis. Multivariate analysis showed a worse overall and relapse free survival (RFS) for those with a complex karyotype (overall survival, P = 0.005; RFS, P = 0.04), independent of metastatic disease. Univariate survival analysis showed that a chromosome number above 50 or a complex karyotype was associated with a worse overall survival (>50 chromosomes, P = 0.05; complex karyotype, P = 0.04). There was no association between type of cytogenetic abnormality and the presence of metastatic disease at diagnosis. Univariate and multivariate survival analysis of a small subgroup with trisomy 20 indicated that trisomy 20 was associated with a worse overall and RFS. There was no difference in outcome associated with other recurrent trisomies (2, 5, 7, 8, or 12) or the common recurrent secondary structural rearrangements (deletions of 1p36, 9p12, 17p13, and 16q, and gain of 1q), although numbers were small. These data demonstrate the continued value of cytogenetics as a genome-wide screen in ESFT and illustrates the potential importance of secondary chromosome changes for stratification of patients for risk. Specifically, karyotype complexity appears to be a powerful predictor of prognosis, and the presence of trisomy 20 may be a marker of a more aggressive subset of this group.
Assuntos
Cariotipagem , Ploidias , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/genética , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Citogenética/métodos , Humanos , Lactente , Prognóstico , Sarcoma de Ewing/mortalidade , Análise de Sobrevida , Reino UnidoRESUMO
Neuroblastoma is the most common childhood solid tumor, yet the prognosis for high-risk disease remains poor. We demonstrate here that arginase 2 (ARG2) drives neuroblastoma cell proliferation via regulation of arginine metabolism. Targeting arginine metabolism, either by blocking cationic amino acid transporter 1 (CAT-1)-dependent arginine uptake in vitro or therapeutic depletion of arginine by pegylated recombinant arginase BCT-100, significantly delayed tumor development and prolonged murine survival. Tumor cells polarized infiltrating monocytes to an M1-macrophage phenotype, which released IL1ß and TNFα in a RAC-alpha serine/threonine-protein kinase (AKT)-dependent manner. IL1ß and TNFα established a feedback loop to upregulate ARG2 expression via p38 and extracellular regulated kinases 1/2 (ERK1/2) signaling in neuroblastoma and neural crest-derived cells. Proteomic analysis revealed that enrichment of IL1ß and TNFα in stage IV human tumor microenvironments was associated with a worse prognosis. These data thus describe an immune-metabolic regulatory loop between tumor cells and infiltrating myeloid cells regulating ARG2, which can be clinically exploited. SIGNIFICANCE: These findings illustrate that cross-talk between myeloid cells and tumor cells creates a metabolic regulatory loop that promotes neuroblastoma progression.
Assuntos
Arginina/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Neuroblastoma/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Arginase/metabolismo , Linhagem Celular Tumoral , Humanos , Interleucina-1beta/imunologia , Sistema de Sinalização das MAP Quinases , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Transgênicos , Células Mieloides/imunologia , Células Mieloides/metabolismo , Células Mieloides/patologia , Neuroblastoma/imunologia , Neuroblastoma/patologia , Sarcoma de Ewing/imunologia , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patologia , Microambiente Tumoral , Fator de Necrose Tumoral alfa/imunologiaRESUMO
AIMS: The aim of this study was to explore the correlation of hTERT splice variant expression with MCPH1/BRIT1 and BRCA1 expression in epithelial ovarian cancer (EOC) samples. BACKGROUND: Telomerase activation can contribute to the progression of tumors and the development of cancer. However, the regulation of telomerase activity remains unclear. MCPH1 (also known as BRIT1, BRCT-repeat inhibitor of hTERT expression) and BRCA1 are tumor suppressor genes that have been linked to telomerase expression. METHODS: qPCR was used to investigate telomerase splice variants, MCPH1/BRIT1 and BRCA1 expression in EOC tissue and primary cultures. RESULTS: The wild type α+/ß+ hTERT variant was the most common splice variant in the EOC samples, followed by α+/ß- hTERT, a dominant negative regulator of telomerase activity. EOC samples expressing high total hTERT demonstrated significantly lower MCPH1/BRIT1 expression in both tissue (pâ¯=â¯0.05) and primary cultures (pâ¯=â¯0.03). We identified a negative correlation between MCPH1/BRIT1 and α+/ß+ hTERT (pâ¯=â¯0.04), and a strong positive association between MCPH1/BRIT1 and both α-/ß+ hTERT and α-/ß- hTERT (both pâ¯=â¯0.02). A positive association was observed between BRCA1 and α-/ß+ hTERT and α-/ß- hTERT expression (pâ¯=â¯0.003 and pâ¯=â¯0.04, respectively). CONCLUSIONS: These findings support a regulatory effect of MCPH1/BRIT1 and BRCA1 on telomerase activity, particularly the negative association between MCPH1/BRIT1 and the functional form of hTERT (α+/ß+).
Assuntos
Proteína BRCA1/genética , Neoplasias Epiteliais e Glandulares/genética , Proteínas do Tecido Nervoso/genética , Neoplasias Ovarianas/genética , Telomerase/genética , Proteína BRCA1/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Epitelial do Ovário , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proteínas do Citoesqueleto , Feminino , Expressão Gênica , Genes Supressores de Tumor , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Estimativa de Kaplan-Meier , Neoplasias Epiteliais e Glandulares/enzimologia , Neoplasias Epiteliais e Glandulares/mortalidade , Proteínas do Tecido Nervoso/metabolismo , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/mortalidade , Telomerase/metabolismo , TranscriptomaRESUMO
PURPOSE: A clinical role for nonquantitative reverse transcription-PCR (RT-PCR) using prostate-specific antigen in blood samples from patients with prostate cancer remains undefined. Assay variation and detection of prostate-specific antigen mRNA illegitimate transcription may explain inconsistent results between studies. Defining levels of prostate-specific antigen mRNA expression in blood samples from healthy volunteers and patients with prostate cancer would allow cutoffs to be established to distinguish the two groups. EXPERIMENTAL DESIGN: Quantitative real-time RT-PCR for prostate-specific antigen mRNA was established and levels of prostate-specific antigen mRNA measured in bloods samples from healthy volunteers (n=21) and patients with localized (n=27) and metastatic (n=40) prostate cancer. RESULTS: Levels of prostate-specific antigen mRNA were significantly higher in blood samples from patients with metastatic prostate cancer than in blood samples from patients with localized prostate cancer (P <0.001) or in blood samples from healthy volunteers (P <0.01); levels between patients with localized prostate cancer and healthy volunteers were no different. Assay sensitivity to detect patients with metastatic prostate cancer was 68% with specificity of 95%. In patients with newly diagnosed metastatic prostate cancer, monitoring response to hormonal therapy was possible with this assay. No correlation between levels of prostate-specific antigen mRNA and serum prostate-specific antigen protein levels was found, suggesting that prostate-specific antigen mRNA and serum prostate-specific antigen protein levels reflect different features of prostate cancer, i.e., circulating tumor cells and total tumor bulk, respectively. CONCLUSIONS: Quantitative RT-PCR discriminates patients with metastatic prostate cancer from healthy volunteers and patients with localized prostate cancer but cannot discriminate patients with localized prostate cancer from healthy volunteers. A role for quantitative RT-PCR has been identified in the assessment and monitoring of patients with metastatic prostate cancer.
Assuntos
Antígeno Prostático Específico/biossíntese , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Linhagem Celular Tumoral , DNA Complementar/metabolismo , Humanos , Leucócitos Mononucleares/citologia , Masculino , Metástase Neoplásica , Neutrófilos/citologia , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Fatores de Tempo , Transcrição Gênica , Microglobulina beta-2/metabolismoRESUMO
The prognostic value of proliferation index (PI) and apoptotic index (AI), caspase-8, -9 and -10 expression have been investigated in primary Ewing's sarcoma family of tumours (ESFT). Proliferating cells, detected by immunohistochemistry for Ki-67, were identified in 91% (91/100) of tumours with a median PI of 14 (range 0-87). Apoptotic cells, identified using the TUNEL assay, were detected in 96% (76/79) of ESFT; the median AI was 3 (range 0-33). Caspase-8 protein expression was negative (0) in 14% (11/79), low (1) in 33% (26/79), medium (2) in 38% (30/79) and high (3) in 15% (12/79) of tumours, caspase-9 expression was low (1) in 66% (39/59) and high (3) in 34% (20/59), and caspase-10 protein was low (1) in 37% (23/62) and negative (0) in 63% (39/62) of primary ESFT. There was no apparent relationship between caspase-8, -9 and -10 expression, PI and AI. PI was predictive of relapse-free survival (RFS; pâ=â0.011) and overall survival (OS; pâ=â<0.001) in a continuous model, whereas AI did not predict outcome. Patients with tumours expressing low levels of caspase-9 protein had a trend towards a worse RFS than patients with tumours expressing higher levels of caspase-9 protein (pâ=â0.054, log rank test), although expression of caspases-8, -9 and/or -10 did not significantly predict RFS or OS. In a multivariate analysis model that included tumour site, tumour volume, the presence of metastatic disease at diagnosis, PI and AI, PI independently predicts OS (pâ=â0.003). Consistent with previous publications, patients with pelvic tumours had a significantly worse OS than patients with tumours at other sites (pâ=â0.028); patients with a pelvic tumour and a PI≥20 had a 6 fold-increased risk of death. These studies advocate the evaluation of PI in a risk model of outcome for patients with ESFT.
Assuntos
Neoplasias Ósseas/diagnóstico , Sarcoma de Ewing/diagnóstico , Apoptose , Neoplasias Ósseas/patologia , Osso e Ossos/patologia , Caspase 10/análise , Caspase 8/análise , Caspase 9/análise , Proliferação de Células , Humanos , Modelos Biológicos , Modelos Estatísticos , Análise Multivariada , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/patologia , Prognóstico , Sarcoma de Ewing/patologia , Análise de SobrevidaRESUMO
PURPOSE EWS-ETS fusion genes are the driving force in Ewing's sarcoma pathogenesis. Because of the variable breakpoint locations in the involved genes, there is heterogeneity in fusion RNA and protein architecture. Since previous retrospective studies suggested prognostic differences among patients expressing different EWS-FLI1 fusion types, the impact of fusion RNA architecture on disease progression and relapse was studied prospectively within the Euro-E.W.I.N.G. 99 clinical trial. PATIENTS AND METHODS Among 1,957 patients who registered before January 1, 2007, 703 primary tumors were accessible for the molecular biology study. Fusion type was assessed by polymerase chain reaction on frozen (n = 578) or paraffin-embedded materials (n = 125). The primary end point was the time to disease progression or relapse. Results After exclusion of noninformative patients, 565 patients were entered into the prognostic factor analysis comparing type 1 (n = 296), type 2 (n = 133), nontype 1/nontype 2 EWS-FLI1 (n = 91) and EWS-ERG fusions (n = 45). Median follow-up time was 4.5 years. The distribution of sex, age, tumor volume, tumor site, disease extension, or histologic response did not differ between the four fusion type groups. We did not observe any significant prognostic value of the fusion type on the risk of progression or relapse. The only slight difference was that the risk of progression or relapse associated with nontype 1/nontype 2 EWS-FLI1 fusions was 1.38 (95% CI, 0.96 to 2.0) times higher than risk associated with other fusion types, but it was not significant (P = .10). CONCLUSION In contrast to retrospective studies, the prospective evaluation did not confirm a prognostic benefit for type 1 EWS-FLI1 fusions.