RESUMEN
Over the last decade, the rho-associated kinases and several metastasis-associated microRNAs have emerged as important contributors of tumor invasion. However, despite prominence, our understanding of their involvement in the metastatic potential of Ewing Sarcoma (EWS) is incomplete. The expression profiles of ROCK1 or ROCK2 and miR-124-3p, miR-138-5p, miR-139-5p, miR-335-5p and miR-584-5p (all of which were previously predicted or validated to regulate these kinases) were evaluated through qRT-PCR and associated with clinical parameters. In vitro assays to evaluate colony formation and invasion/migration capacieties were performed on SK-ES-1 cells transfected with pre-miR mimics. ROCK1 expression was significantly reduced in EWS tissues, though there was no association with pathological parameters. miR-124-3p, miR-139-5p and miR-335-3p were also found significantly downregulated and positively correlated with ROCK1. Stratification indicated an association between lower levels of miR-139-5p and miR-584-5p with disease progression (p < 0.05), while reduced expression of the former and miR-124-3p were associated with reduced survival. In vitro miR-139-5p overexpression yielded inconsistent results: while mir-139-5p restoration significantly reduced invasion, the clonogenic capacity of cells was increased. Our study demonstrated that down-regulation of miR-124-3p, miR-139-5p and miR-584-5p are associated with disease progression in EWS and may serve as a risk assessment biomarkers though, as seen for mir-139-5p, their specific role remain to be elucidated for considering tailoring treatment options.
Asunto(s)
Neoplasias Óseas/patología , MicroARNs/genética , Sarcoma de Ewing/patología , Quinasas Asociadas a rho/genética , Adolescente , Adulto , Neoplasias Óseas/genética , Línea Celular Tumoral , Movimiento Celular/genética , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Invasividad Neoplásica/genética , Sarcoma de Ewing/genética , Adulto JovenRESUMEN
miRNAs have been identified as key regulators of almost all cellular processes, therefore, their dysregulation is involved with several diseases, including cancer. miRNAs specifically related to the metastastic cascade are called metastamiRs and can be involved with different steps of this process, including loss of adhesion. Osteosarcoma (OS) is the most common primary malignant pediatric bone tumor that often presents metastatic disease at diagnosis; therefore, a deeper study of adhesion-associated miRNAs could shed light on its pathophysiology. Online databases were used to select four miRNAs (miR-139; miR-181b; miR-584; miR-708) predicted or validated to target proteins related to adherent junctions and focal adhesion pathways, and their expression levels and possible associations with clinical features evaluated in primary OS samples. Our results showed downregulation of miR-139-5p and miR-708-5p in OS samples compared to non-neoplastic controls. Moreover, lower expression of miR-708-5p was associated with poor overall survival and higher expression of miR-181b-5p related to worst chemotherapy response (low HUVOS level). Based on these results, we selected miR-139-5p and miR-708-5p for further functional testing. Inducing the expression of miR-139-5p diminished the clonogenic capacity of the HOS cell line, while upregulation of miR-708-5p was related to a lower cellular adhesion. In summary, this work identified new signatures of microRNA dysregulation that may serve as useful prognostic markers in this aggressive pediatric bone tumor.
Asunto(s)
Uniones Adherentes/genética , Biomarcadores de Tumor/genética , Neoplasias Óseas/secundario , Adhesiones Focales/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Osteosarcoma/patología , Adolescente , Adulto , Neoplasias Óseas/genética , Neoplasias Óseas/cirugía , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Masculino , Osteosarcoma/genética , Osteosarcoma/cirugía , Pronóstico , Tasa de Supervivencia , Adulto JovenRESUMEN
Recent innovations in the genomic understanding of medulloblastomas have provided new ways to explore this highly invasive malignant brain cancer arising from the cerebellum. Among the four different medulloblastoma subgroups described to date, the sonic hedgehog (SHH) genetic pathway is the pathway activated in the tumorigenesis of medulloblastoma. SHH-related medulloblastomas are usually of nodular/desmoplastic histology and frequently occur in children under the age of three, an age group highly susceptible to the acute and long-term effects of treatment. Several new drugs aimed at SHH modulation are currently under development. This review focuses on the role of arsenic trioxide, a drug well established in clinical practice and probably an under-explored agent in medulloblastoma management, in the SHH pathway.
Asunto(s)
Antineoplásicos/administración & dosificación , Arsenicales/administración & dosificación , Neoplasias Cerebelosas/tratamiento farmacológico , Proteínas Hedgehog/metabolismo , Meduloblastoma/tratamiento farmacológico , Óxidos/administración & dosificación , Adolescente , Antineoplásicos/farmacología , Trióxido de Arsénico , Arsenicales/farmacología , Neoplasias Cerebelosas/metabolismo , Niño , Preescolar , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Lactante , Meduloblastoma/metabolismo , Óxidos/farmacología , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Polo-like kinase 1 (PLK1) is a conserved kinase that mediates various mitotic events. Compelling data have repeatedly demonstrated its upregulation in different neoplasia, being frequently associated with poor prognosis. However, in childhood acute lymphoblastic leukemia (ALL), no studies have yet been conducted. PROCEDURE: PLK1 expression and association with biological features were evaluated in 65 consecutively diagnosed childhood ALL samples by quantitative real-time PCR. Moreover, the effects of a specific PLK1 inhibitor, BI 2536, was tested against a panel of nine ALL cell lines at nanomolar concentrations (10, 50, 100 nM). RESULTS: The mRNA expression of PLK1 showed great variability in pediatric ALL, but no difference was evidenced compared to normal bone marrow. Additionally, no association was found between PLK1 mRNA expression with any clinical or biological features. Alternatively, high mRNA expression of PLK1 was present in ALL cell lines. In vitro treatment with BI 2536 strongly diminished growth, while presenting significant reduction in colony formation capacity and increased apoptosis rates. Moreover, strong G2/M arrest was detected suggesting important impaired proliferation after treatment. CONCLUSIONS: PLK1 mRNA expression level is not associated with prognosis in childhood ALL; however, considering the great variability observed in the sample and the in vitro experiments presented herein, BI 2536 treatment might serve as a promising therapeutic to enhance the efficacy of conventional treatment modalities in some childhood ALL cases.
Asunto(s)
Proteínas de Ciclo Celular , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas , Pteridinas/farmacología , Adolescente , Médula Ósea/metabolismo , Médula Ósea/patología , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/biosíntesis , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Lactante , Células Jurkat , Puntos de Control de la Fase M del Ciclo Celular/efectos de los fármacos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/biosíntesis , ARN Mensajero/biosíntesis , ARN Neoplásico/biosíntesis , Estudios Retrospectivos , Tasa de Supervivencia , Quinasa Tipo Polo 1RESUMEN
Despite advances in neurosurgery and aggressive treatment with temozolomide (TMZ) and radiation, the overall survival of patients with glioblastoma (GBM) remains poor. Vast evidence has indicated that the nuclear factor NF- κ B is constitutively activated in cancer cells, playing key roles in growth and survival. Recently, Dehydroxymethylepoxyquinomicin (DHMEQ) has shown to be a selective NF- κ B inhibitor with antiproliferative properties in GBM. In the present study, the ability of DHMEQ to surmount tumor's invasive nature and therapy resistance were further explored. Corroborating results showed that DHMEQ impaired cell growth in dose- and time-dependent manners with G2/M arrest when compared with control. Clonogenicity was also significantly diminished with increased apoptosis, though necrotic cell death was also observed at comparable levels. Notably, migration and invasion were inhibited accordingly with lowered expression of invasion-related genes. Moreover, concurrent combination with TMZ synergistically inhibited cell growth in all cell lines, as determined by proliferation and caspase-3 activation assays, though in those that express O(6)-methylguanine-DNA methyltransferase, the synergistic effects were schedule dependent. Pretreatment with DHMEQ equally sensitized cells to ionizing radiation. Taken together, our results strengthen the potential usefulness of DHMEQ in future therapeutic strategies for tumors that do not respond to conventional approaches.
RESUMEN
Genetic instability is frequent in human cancer. Unscheduled tetraploidization can trigger cell transformation and tumorigenesis. We made a cytogenetic analysis by Giemsa-trypsin banding of a stage I, biphasic Wilms tumor diagnosed in a 10-month-old male. An evident karyotypic heterogeneity was found. Four different subclones of tumor cells were observed, with DNA content varying from diploid to near-tetraploid complements. The genetic events involved in the acquisition of aneuploidy in Wilms tumor remain unclear. We hypothesize that initial tetraploidization caused aberrant cell division, leading to abnormal chromosomal segregation, cell transformation and tumorigenesis.
Asunto(s)
Aneuploidia , Tumor de Wilms/genética , Humanos , Lactante , Cariotipificación , MasculinoRESUMEN
OBJECTIVE: To correlate clinical prognosis to the expression of p65, c-Fos, GRalpha and GRbeta in patients with nasal polyps. METHODS: A biopsy was obtained at the first evaluation for patients with nasal polyps (20), and at rhinoplasty for control mucosa (8). Patients with nasal polyps were treated with glucocorticoids and followed for at least 30 months. The expression of each gene (p65, c-Fos, GRalpha and GRbeta) was determined by Real Time-PCR and correlated to clinical outcome. The indication for surgery was considered the end-point of resistance to glucocorticoid therapy. RESULTS: Patients with nasal polyps presented a higher expression of p65 (P<0.05), and a lower expression of GRalpha (P<0.0001), and of GRalpha/GRbeta relation (P<0.0001) than controls. The nasal polyps patients with higher expression of p65 correlated with a poorer response to glucocorticoids (P<0.05), with a four-fold higher risk for surgery to control symptoms. CONCLUSION: Patients with nasal polyps presented higher gene expression of p65, and a reduced expression of GRalpha and of GRalpha/GRbeta relation than controls. Higher p65 (NFkappaB) expression at diagnosis was also associated to a worst response to medical treatment, suggesting this could be considered as one mechanism of cell resistance to glucocorticoid treatment in patients with nasal polyps.
Asunto(s)
Resistencia a Medicamentos/genética , Glucocorticoides/uso terapéutico , FN-kappa B/metabolismo , Pólipos Nasales/genética , Pólipos Nasales/terapia , Factor de Transcripción ReIA/metabolismo , Adolescente , Adulto , Femenino , Expresión Génica , Genes fos/fisiología , Humanos , Masculino , Persona de Mediana Edad , Pólipos Nasales/patología , Pólipos Nasales/fisiopatología , Receptores de Glucocorticoides/metabolismo , Resultado del TratamientoRESUMEN
Epithelioid sarcoma is a rare, aggressive soft tissue tumor of unknown histogenesis showing predominantly epithelioid cytomorphology. We conducted a conventional and molecular cytogenetic study of a 27-year-old male with epithelioid sarcoma with angiomatoid features. Cytogenetic analysis of epithelioid sarcoma metaphase spreads by GTG-banding revealed a diploid chromosome complement with structural and numerical aberrations. Comparative genomic hybridization analysis demonstrated the amplification of 3p24-pter, 4p15.2-p16 and 18q23, while chromosome losses involved 3p13-p14, 3q24-q26.1, 9q21, and 11q21. Fluorescence in situ hybridization assessment showed normal hybridization patterns for the C-MYC and CCND1 loci; CCND1 RNA overexpression was detected by real-time polymerase chain reaction analysis. Genetic evaluation of this rare condition may be useful in determining if epithelioid sarcoma is associated with a distinct genetic background.
Asunto(s)
Aberraciones Cromosómicas , Sarcoma/genética , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Humanos , Hibridación Fluorescente in Situ , Masculino , Reacción en Cadena de la Polimerasa , Sarcoma/tratamiento farmacológicoRESUMEN
OBJECTIVES: To study the incidence of galactosaemia in the state of São Paulo and the benefit/cost (B/C) ratio of the introduction of neonatal screening for galactosaemia, comparing it with a selective approach. METHODS: An enzymatic-colorimetric assay was used for the screening of total galactose (TG) in a sample of 10% of the births in São Paulo in one year and positive cases were confirmed by the activity of galactose-1-phosphate uridyltransferase (GALT). Detected and referred cases were genotyped using enzyme restriction studies for Q188R, N314D and S135L mutations of the GALT gene. The economic analysis was determined by calculating the B/C ratio and by analysis of sensitivity as a function of the incidence of the disease detected and the variation of the interest rate in the economy. RESULTS: 59 953 newborns were screened for TG, with 3 cases of galactosaemia being identified (0.26% false positives), corresponding to a frequency of 1:19 984 liveborns (95% confidence interval: 1:7494 to 1:59 953). One classical case and one Duarte 2 variant referred to as a selective approach were confirmed. With an incidence of 1:19 984, the B/C ratio was 1.04 for the 11.75% interest rate in effect in Brazil, with values already decapitalized. With a maximum possible incidence of 1:7494, the B/C ratio was 2.79. DISCUSSION: There is an economic advantage in introducing neonatal screening for galactosaemia in the national neonatal screening programme. This advantage could increase with a reduction of the current interest rates in the economy.
Asunto(s)
Galactosemias/economía , Galactosemias/epidemiología , Tamizaje Neonatal/economía , Análisis Químico de la Sangre/economía , Brasil/epidemiología , Colorimetría/economía , Análisis Costo-Beneficio , Análisis Mutacional de ADN/economía , Femenino , Galactosa/sangre , Galactosemias/diagnóstico , Humanos , Incidencia , Recién Nacido , Masculino , UDP-Glucosa-Hexosa-1-Fosfato Uridiltransferasa/sangre , UDP-Glucosa-Hexosa-1-Fosfato Uridiltransferasa/genéticaRESUMEN
BACKGROUND: Cell resistance to glucocorticoids is a major problem in the treatment of nasal polyposis (NP). OBJECTIVES: The objectives of this study were to observe the effect of budesonide on the expression of IL-1beta, TNF-alpha, granulocyte macrophage-colony stimulating factor, intercellular adhesion molecule (ICAM)-1, basic fibroblast growth factor, eotaxin-2, glucocorticoid receptor (GR)-alpha, GR-beta, c-Fos and p65 in nasal polyps and to correlate their expression to clinical response. METHODS: Biopsies from nasal polyps were obtained from 20 patients before and after treatment with topical budesonide. Clinical response to treatment was monitored by a questionnaire and nasal endoscopy. The mRNA levels of the studied genes were measured by real-time quantitative (RQ)-PCR. RESULTS: There was a significant decrease in the expression of TNF-alpha (P<0.05), eotaxin-2 (P<0.05) and p65 (P<0.05) in NP after treatment. Poor responders to glucocorticoids showed higher expression of IL-1beta (3.74 vs. 0.14; P<0.005), ICAM-1 (1.91 vs. 0.29; P<0.05) and p65 (0.70 vs. 0.16; P<0.05) before treatment. Following treatment, IL-1beta (4.18 vs. 0.42; P<0.005) and GR-beta (0.95 vs. 0.28; P<0.05) mRNA expression was higher in this group. CONCLUSION: Topical budesonide reduced the expression of TNF-alpha, eotaxin-2 and p65. Poor responders to topical budesonide exhibit higher levels of IL-1beta, ICAM-1 and nuclear factor (NF)-kappaB at diagnosis and higher expression of both IL-1beta and GR-beta after treatment. These results emphasize the anti-inflammatory action of topical budesonide at the molecular level and its importance in the treatment of NP. Nevertheless, IL-1beta, ICAM-1 and NF-kappaB may be associated with primary resistance to glucocorticoids in NP, whereas higher expression of GR-beta in poor responders only after glucocorticoid treatment may represent a secondary drug resistance mechanism in this disease.
Asunto(s)
Antiinflamatorios/uso terapéutico , Budesonida/uso terapéutico , Resistencia a Medicamentos , Glucocorticoides/uso terapéutico , Pólipos Nasales/tratamiento farmacológico , Adolescente , Adulto , Antiinflamatorios/administración & dosificación , Budesonida/administración & dosificación , Citocinas/genética , Citocinas/metabolismo , Endoscopía , Glucocorticoides/administración & dosificación , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Persona de Mediana Edad , Mucosa Nasal/inmunología , Pólipos Nasales/inmunología , Valor Predictivo de las Pruebas , Encuestas y Cuestionarios , Resultado del Tratamiento , Adulto JovenRESUMEN
Cadherins are cell-to-cell adhesion molecules that play an important role in the establishment of adherent-type junctions by mediating calcium-dependent cellular interactions. The CDH1 gene encodes the transmembrane glycoprotein E-cadherin which is important in maintaining homophilic cell-cell adhesion in epithelial tissues. E-cadherin interacts with catenin proteins to maintain tissue architecture. Structural defects or loss of expression of E-cadherin have been reported as a common feature in several human cancer types. This study aimed to evaluate the expression of E-cadherin and their correlation with clinical features in microdissected brain tumor samples from 81 patients, divided into 62 astrocytic tumors grades I to IV and 19 medulloblastomas, and from 5 white matter non-neoplasic brain tissue samples. E-cadherin (CDH1) gene expression was analyzed by quantitative real-time polymerase chain reaction. Mann-Whitney, Kruskal-Wallis, Kaplan-Meir, and log-rank tests were performed for statistical analyses. We observed a decrease in expression among pathological grades of neuroepithelial tumors. Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than did neuroepithelial tumors. Expression of E-cadherin gene was higher in astrocytic than embryonal tumors (P = 0.0168). Low-grade malignancy astrocytomas (grades I-II) showed higher CDH1 expression than did high-grade malignancy astrocytomas (grades III-IV) and medulloblastomas (P < 0.0001). Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than grade I malignancy astrocytomas, considered as benign tumors (P = 0.0473). These results suggest that a decrease in E-cadherin gene expression level in high-grade neuroepithelial tumors may be a hallmark of malignancy in dedifferentiated tumors and that it may be possibly correlated with their progression and dissemination.
Asunto(s)
Cadherinas/genética , Perfilación de la Expresión Génica , Neoplasias Neuroepiteliales/genética , Adolescente , Adulto , Encéfalo/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Neoplasias Neuroepiteliales/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: The treatment and prognosis of nasal polyposis (NP) may be influenced by transcription factors, but their expression is poorly understood. OBJECTIVE: To determine the expression of transcription factors [(nuclear factor-kappaB) NF-kappaB and (activator protein) AP-1], cytokines [IL-1beta, TNF-alpha and (granulocytes and macrophage colony-stimulating factor) GM-CSF], growth factor (b-FGF), chemokine (eotaxin-2) and adhesion molecule (ICAM-1) in NP in comparison with nasal mucosa controls. Methods Cross-sectional study. Twenty biopsies of nasal polyps were compared with eight middle turbinate biopsies. p65, c-Fos, IL-1beta, TNF-alpha, ICAM-1, b-FGF, eotaxin-2 and GM-CSF were analysed through RQ-PCR, and p65 and c-Fos were also analysed through Western blotting. RESULTS: NF-kappaB expression was increased in patients with NP when compared with control mucosa (P<0.05), whereas AP-1 expression did not differ significantly between groups. Expressions of IL-1beta, eotaxin-2 and b-FGF were also increased in patients with NP compared with controls (P<0.05). CONCLUSIONS: The transcription factor NF-kappaB is more expressed in NP than in control mucosa. This is important in NP because NF-kappaB can induce the transcription of cytokines, chemokines and adhesion molecules, which play an important role in the inflammatory process. Moreover, transcription factors influence the response to corticosteroids, which are the basis of NP treatment. Transcription factor AP-1 does not seem to have a significant role in the pathological process.
Asunto(s)
FN-kappa B/genética , Pólipos Nasales/genética , Factor de Transcripción AP-1/genética , Adolescente , Adulto , Western Blotting , Quimiocinas/biosíntesis , Quimiocinas/genética , Estudios Transversales , Citocinas/biosíntesis , Citocinas/genética , Femenino , Factor 2 de Crecimiento de Fibroblastos/biosíntesis , Factor 2 de Crecimiento de Fibroblastos/genética , Humanos , Molécula 1 de Adhesión Intercelular/biosíntesis , Molécula 1 de Adhesión Intercelular/genética , Masculino , Persona de Mediana Edad , FN-kappa B/biosíntesis , Pólipos Nasales/metabolismo , Pólipos Nasales/patología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reproducibilidad de los Resultados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción AP-1/biosíntesisRESUMEN
Cadherins are cell-to-cell adhesion molecules that play an important role in the establishment of adherent-type junctions by mediating calcium-dependent cellular interactions. The CDH1 gene encodes the transmembrane glycoprotein E-cadherin which is important in maintaining homophilic cell-cell adhesion in epithelial tissues. E-cadherin interacts with catenin proteins to maintain tissue architecture. Structural defects or loss of expression of E-cadherin have been reported as a common feature in several human cancer types. This study aimed to evaluate the expression of E-cadherin and their correlation with clinical features in microdissected brain tumor samples from 81 patients, divided into 62 astrocytic tumors grades I to IV and 19 medulloblastomas, and from 5 white matter non-neoplasic brain tissue samples. E-cadherin (CDH1) gene expression was analyzed by quantitative real-time polymerase chain reaction. Mann-Whitney, Kruskal-Wallis, Kaplan-Meir, and log-rank tests were performed for statistical analyses. We observed a decrease in expression among pathological grades of neuroepithelial tumors. Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than did neuroepithelial tumors. Expression of E-cadherin gene was higher in astrocytic than embryonal tumors (P = 0.0168). Low-grade malignancy astrocytomas (grades I-II) showed higher CDH1 expression than did high-grade malignancy astrocytomas (grades III-IV) and medulloblastomas (P < 0.0001). Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than grade I malignancy astrocytomas, considered as benign tumors (P = 0.0473). These results suggest that a decrease in E-cadherin gene expression level in high-grade neuroepithelial tumors may be a hallmark of malignancy in dedifferentiated tumors and that it may be possibly correlated with their progression and dissemination.
Asunto(s)
Humanos , Adolescente , Adulto , Persona de Mediana Edad , Cadherinas/genética , Perfilación de la Expresión Génica , Neoplasias Neuroepiteliales/genética , Cerebro/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias Neuroepiteliales/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
The advances in the cure rates observed in the oncology field in the past decades were not fully assembled by primary brain tumors. In this heterogeneous group of diseases, resistance to either chemotherapy or radiotherapy still is a major problem to be addressed. Several genetic and epigenetic events may directly influence the response to treatment in these tumors. Throughout recent discoveries, drug resistance in brain tumors was better understood as a final product of different and complexes pathways that interact and modulate cell performance to treatment. The last years experienced a new paradigm in the way brain tumor drug-resistance genes are elected out of the vast human genomic universe. In the former era, models of cell resistance that were documented on solid tumors other than brain were investigated at the central nervous system's counterpart. Nowadays, genomic-based hypothesis generation, supported by modern genetic technique tolls, seem effective in revealing new candidate-genes that might confer the resistance phenotype. Nevertheless, new treatment approaches and novel drugs based on the pharmacogenomic resistance profile, particularly for brain tumors, are just starting to become a reality for clinical purposes.
Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Resistencia a Antineoplásicos/genética , Epigénesis Genética/genética , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/prevención & control , Epigénesis Genética/efectos de los fármacos , Predisposición Genética a la Enfermedad/genética , HumanosRESUMEN
Infant acute lymphoblastic leukemia (IALL) is characterized by mixed lineage leukemia (MLL) gene rearrangements, unique gene expression profiles, poor prognosis, and drug resistance. One exception is cytosine arabinoside (Ara-C) to which IALL cells seem to be more sensitive. We quantified mRNA expression of Ara-C key enzymes in leukemic lymphoblasts from 64 Brazilian ALL children, 15 of them presenting MLL gene rearrangement, and correlated it with clinical and biological features. The diagnosis was based on morphological criteria and immunophenotyping using monoclonal antibodies. MLL gene rearrangements were detected by conventional cytogenetic analysis, RT-PCR and/or fluorescence in situ hybridization. The DCK and HENT1 expression levels were determined by real-time quantitative PCR using SYBR Green I. Relative quantification was made by the standard curve method. The results were analyzed by Mann-Whitney and Fisher exact tests. A P value of Asunto(s)
Antimetabolitos Antineoplásicos/metabolismo
, Citarabina/metabolismo
, Reordenamiento Génico/genética
, Proteína de la Leucemia Mieloide-Linfoide/genética
, Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
, Antimetabolitos Antineoplásicos/uso terapéutico
, Estudios de Casos y Controles
, Niño
, Preescolar
, Citarabina/uso terapéutico
, Desoxicitidina Quinasa/efectos de los fármacos
, Desoxicitidina Quinasa/genética
, Tranportador Equilibrativo 1 de Nucleósido/efectos de los fármacos
, Tranportador Equilibrativo 1 de Nucleósido/genética
, Femenino
, Regulación Neoplásica de la Expresión Génica
, Humanos
, Lactante
, Masculino
, Proteína de la Leucemia Mieloide-Linfoide/efectos de los fármacos
, Neoplasia Residual
, Reacción en Cadena de la Polimerasa/métodos
, Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico
, Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología
, ARN Mensajero/análisis
, Factores de Tiempo
RESUMEN
Infant acute lymphoblastic leukemia (IALL) is characterized by mixed lineage leukemia (MLL) gene rearrangements, unique gene expression profiles, poor prognosis, and drug resistance. One exception is cytosine arabinoside (Ara-C) to which IALL cells seem to be more sensitive. We quantified mRNA expression of Ara-C key enzymes in leukemic lymphoblasts from 64 Brazilian ALL children, 15 of them presenting MLL gene rearrangement, and correlated it with clinical and biological features. The diagnosis was based on morphological criteria and immunophenotyping using monoclonal antibodies. MLL gene rearrangements were detected by conventional cytogenetic analysis, RT-PCR and/or fluorescence in situ hybridization. The DCK and HENT1 expression levels were determined by real-time quantitative PCR using SYBR Green I. Relative quantification was made by the standard curve method. The results were analyzed by Mann-Whitney and Fisher exact tests. A P value of ú0.05 was considered to be statistically significant. DCK and HENT1 expression levels were significantly lower in children with MLL gene-rearranged ALL compared to children with MLL germ line ALL (P = 0.0003 and 0.03, respectively). Our results differ from previous ones concerning HENT1 mRNA expression that observed a higher expression level in MLL gene-rearranged leukemias. In conclusion, the expression of the genes related to Ara-C metabolism was lower in MLL-positive children in the sample studied, suggesting the presence of population differences in the expression profile of these genes especially for HENT1.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Antimetabolitos Antineoplásicos/uso terapéutico , Citarabina/uso terapéutico , Reordenamiento Génico/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras , Estudios de Casos y Controles , Desoxicitidina Quinasa/efectos de los fármacos , Desoxicitidina Quinasa/genética , Tranportador Equilibrativo 1 de Nucleósido/efectos de los fármacos , Tranportador Equilibrativo 1 de Nucleósido/genética , Regulación Neoplásica de la Expresión Génica , Proteína de la Leucemia Mieloide-Linfoide/efectos de los fármacos , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras , Reacción en Cadena de la Polimerasa/métodos , ARN Mensajero/análisis , Factores de TiempoRESUMEN
Neuroblastoma, the most common extracranial tumor in childhood, has a wide spectrum of clinical and biological features. The loss of heterozygosity within the 9p21 region has been reported as a prognostic factor. Two tumor suppressor genes located in this region, the CDKN2B/p15 and CDKN2A/p16 (cyclin-dependent kinase inhibitors 2B and 2A, respectively) genes, play a critical role in cell cycle progression and are considered to be targets for tumor inactivation. We analyzed CDKN2B/p15 and CDKN2A/p16 gene alterations in 11 patients, who ranged in age from 4 months to 13 years (male/female ratio was 1.2:1). The most frequent stage of the tumor was stage IV (50%), followed by stages II and III (20%) and stage I (10%). The samples were submitted to the multiplex PCR technique for homozygous deletion analysis and to single-strand conformation polymorphism and nucleotide sequencing for mutation analysis. All exons of both genes were analyzed, but no deletion was detected. One sample exhibited shift mobility specific for exon 2 in the CDKN2B/p15 gene, not confirmed by DNA sequencing. Homozygous deletions and mutations are not involved in the inactivation mechanism of the CDKN2B/p15 and CDKN2A/p16 genes in neuroblastoma; however, these two abnormalities do not exclude other inactivation pathways. Recent evidence has shown that the expression of these genes is altered in this disease. Therefore, other mechanisms of inactivation, such as methylation of promoter region and unproperly function of proteins, may be considered in order to estimate the real contribution of these genes to neuroblastoma genesis or disease progression.
Asunto(s)
Proteínas de Ciclo Celular/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , ADN de Neoplasias/análisis , Eliminación de Gen , Mutación/genética , Neuroblastoma/genética , Proteínas Supresoras de Tumor/genética , Adolescente , Niño , Preescolar , Inhibidor p15 de las Quinasas Dependientes de la Ciclina , Progresión de la Enfermedad , Femenino , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-SimpleRESUMEN
Neuroblastoma, the most common extracranial tumor in childhood, has a wide spectrum of clinical and biological features. The loss of heterozygosity within the 9p21 region has been reported as a prognostic factor. Two tumor suppressor genes located in this region, the CDKN2B/p15 and CDKN2A/p16 (cyclin-dependent kinase inhibitors 2B and 2A, respectively) genes, play a critical role in cell cycle progression and are considered to be targets for tumor inactivation. We analyzed CDKN2B/p15 and CDKN2A/p16 gene alterations in 11 patients, who ranged in age from 4 months to 13 years (male/female ratio was 1.2:1). The most frequent stage of the tumor was stage IV (50 percent), followed by stages II and III (20 percent) and stage I (10 percent). The samples were submitted to the multiplex PCR technique for homozygous deletion analysis and to single-strand conformation polymorphism and nucleotide sequencing for mutation analysis. All exons of both genes were analyzed, but no deletion was detected. One sample exhibited shift mobility specific for exon 2 in the CDKN2B/p15 gene, not confirmed by DNA sequencing. Homozygous deletions and mutations are not involved in the inactivation mechanism of the CDKN2B/p15 and CDKN2A/p16 genes in neuroblastoma; however, these two abnormalities do not exclude other inactivation pathways. Recent evidence has shown that the expression of these genes is altered in this disease. Therefore, other mechanisms of inactivation, such as methylation of promoter region and unproperly function of proteins, may be considered in order to estimate the real contribution of these genes to neuroblastoma genesis or disease progression.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Adolescente , Inhibidor p16 de la Quinasa Dependiente de Ciclina , Proteínas de Ciclo Celular/genética , ADN de Neoplasias/análisis , Eliminación de Gen , Mutación/genética , Neuroblastoma/genética , Proteínas Supresoras de Tumor/genética , Progresión de la Enfermedad , Datos de Secuencia Molecular , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-SimpleRESUMEN
CONTEXT: The CDR-3 region of heavy-chain immunoglobulin has been used as a clonal marker in the study of minimal residual disease in children with acute lymphoblastic leukemia. Southern blot and polymerase chain reaction studies have demonstrated the occurrence of bi/oligoclonality in a variable number of cases of B-lineage acute lymphoblastic leukemia, a fact that may strongly interfere with the detection of minimal residual disease. Oligoclonality has also been associated with a poorer prognosis and a higher chance of relapse. OBJECTIVES: To correlate bi/oligoclonality, detected by polymerase chain reaction in Brazilian children with B-lineage acute lymphoblastic leukemia with a chance of relapse, with immunophenotype, risk group, and disease-free survival. DESIGN: Prospective study of patients outcome. SETTING: Pediatric Oncology Unit of the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo. PARTICIPANTS: 47 children with acute lymphoblastic leukemia DIAGNOSTIC TEST: Polymerase chain reaction using consensus primers for the CDR-3 region of heavy chain immunoglobulin (FR3A, LJH and VLJH) for the detection of clonality. RESULTS: Bi/oligoclonality was detected in 15 patients (31.9%). There was no significant difference between the groups with monoclonality and biclonality in terms of the occurrence of a relapse (28.1% versus 26.1%), presence of CALLA+ (81.2% versus 80%) or risk group (62.5% versus 60%). Disease-free survival was similar in both groups, with no significant difference (p: 0.7695). CONCLUSIONS: We conclude that bi/oligoclonality was not associated with the factors investigated in the present study and that its detection in 31.9% of the patients may be important for the study and monitoring of minimal residual disease.
Asunto(s)
Linfoma de Burkitt/genética , Adolescente , Linfoma de Burkitt/inmunología , Línea Celular , Niño , Preescolar , Regiones Determinantes de Complementariedad/genética , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Inmunofenotipificación , Lactante , Masculino , Neprilisina/análisis , Reacción en Cadena de la Polimerasa , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Pronóstico , Estudios Prospectivos , Recurrencia , Factores de RiesgoRESUMEN
PURPOSE: B cell precursors acute lymphoblastic leukemia (ALL) present rearrangements in the heavy chain immunoglobulin and T cell receptor genes, especially in the complementarity determining region 3 (CDR-3) and T cell receptor delta (TCR delta) (V delta 2 D delta 3) regions. These rearrangements may be amplified by the polymerase chain reaction (PCR) and used as clonal markers of B lineage ALL. Our purpose was to study clonality at the DNA level by PCR in B lineage ALL. PATIENTS AND METHODS: Fifty-three pediatric patients (36 with B lineage ALL, 7 with ALL-T, and 10 with nonlymphocytic disease) were investigated using consensus primers for the CDR-3 regions of IgH and TCR delta. RESULTS: Clonality was detected in 86.1% of the patients with B lineage ALL when the primers for the CDR-3 regions were used, in 41.6% when the primers for TCR delta were used, and in 91.6% when the two primers were used together. Biclonality was found in 22.5% and 6.6% of patients that have shown clonality for CDR-3 and TCR delta, respectively. Clonality was not detected in any other samples using these primers. CONCLUSIONS: PCR using CDR-3 and TCR delta primers can be used as an aid for B lineage ALL diagnosis and clonal evolution of theses disease.