RESUMO
Lasparaginase enzymes have been a vital component of acute lymphoblastic leukemia therapy for >40 years. Lasparaginase acts by depleting plasma Lasparagine, which is essential to the survival of leukemia cells. In contrast to normal cells, tumor cells cannot synthesize Lasparagine and thus depend on its external uptake for growth. Currently, three bacterial Lasparaginases are used in therapy; however, they are associated with severe sideeffects related to high toxicity and immunogenicity. The introduction of human Lasparaginaselike protein 1 in acute lymphoblastic leukemia treatment would avoid the problems caused by the bacterial enzymes; however, a major difficulty in the therapeutic use of the human enzyme comes from the fact that human Lasparaginase must be activated through an autoprocessing step, which is a lowefficiency process in vitro that results in reduced enzymatic activity. The present review article aimed to contribute to the understanding of the enzyme selfactivation process and focuses on the efforts made for the development of a therapeutic variant of human Lasparaginase.
Assuntos
Asparaginase/uso terapêutico , Autoantígenos/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Ativação Enzimática , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologiaRESUMO
Aurora kinases (AURKA and AURKB) are mitotic kinases with an important role in the regulation of several mitotic events, and in hematological malignancies, AURKA and AURKB hyperexpression are found in patients with cytogenetic abnormalities presenting a unfavorable prognosis. The aim of this study was evaluated the mRNA expression profile of pediatric Acute Lymphoblastic Leukaemia (ALL) patients and the efficacy of two AURKA and AURKB designed inhibitors (GW809897X and GW806742X) in a leukemia cell line as a potential novel therapy for ALL patients. Cellular experiments demonstrated that both inhibitors induced cell death with caspase activation and cell cycle arrest, however only the GW806742X inhibitor decreased with more efficacy AURKA and AURKB expression in K-562 leukemia cells. In ALL patients both AURKA and AURKB showed a significant overexpression, when compared to health controls. Moreover, AURKB expression level was significant higher than AURKA in patients, and predicted a poorer prognosis with significantly lower survival rates. No differences were found in AURKA and AURKB expression between gene fusions, immunophenotypic groups, white blood cells count, gender or age. In summary, the results in this study indicates that the AURKA and AURKB overexpression are important findings in pediatric ALL, and designed inhibitor, GW806742X tested in vitro were able to effectively inhibit the gene expression of both aurora kinases and induce apoptosis in K-562 cells, however our data clearly shown that AURKB proves to be a singular finding and potential prognostic biomarker that may be used as a promising therapeutic target to those patients.
Assuntos
Aurora Quinase A/metabolismo , Aurora Quinase B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Biomarcadores Tumorais/metabolismo , Brasil/epidemiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Lactente , Células K562 , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Mapas de Interação de ProteínasRESUMO
PURPOSE: Acute lymphoblastic leukemia (ALL) is an aggressive hematological cancer with limited therapeutic options for adult patients. Aurora kinases have drawn attention as potential targets in hematological neoplasms due to their high expression and biological functions. Aurora kinase A (AURKA) and AURKB are essential for a successful mitosis, acting in spindle mitotic organization and cytokinesis. Reversine is a synthetic purine analog that acts as a multi-kinase inhibitor with anti-neoplastic activity by targeting AURKA and AURKB. METHODS: ALL patient gene expression data were retrieved from the Amazonia! DATABASE: For functional assays, Jurkat (T-ALL) and Namalwa (B-ALL) cells were exposed to increasing concentrations of reversine and submitted to various cellular and molecular assays. RESULTS: We found that AURKB expression was higher in ALL patient samples compared to normal lymphocytes (p < 0.0001). The ALL cell lines tested displayed aberrant AURKA and AURKB expression. In Jurkat and Namalwa cells, reversine reduced cell viability in a dose- and time-dependent manner (p < 0.05). Reversine also significantly reduced the viability of primary ALL cells. Reversine induced apoptosis and autophagy, and reduced cell proliferation in both cell lines (p < 0.05). Mitotic catastrophe markers, including cell cycle arrest at G2/M, increased cell size and DNA damage, were observed upon reversine exposure. Short- and long-term treatment with reversine inhibited autonomous clonogenicity (p < 0.05). At the molecular level, reversine reduced AURKB activity, induced SQSTM1/p62 consumption, and increased LC3BII and γ-H2AX levels. In Namalwa cells, reversine modulated 25 out of 84 autophagy-related genes, including BCL2, BAD, ULK1, ATG10, IRGM and MAP1LC3B, which indicates that reversine acts by initiating and sustaining autophagy signals in ALL cells. CONCLUSIONS: From our data we conclude that reversine reduces the viability of ALL cells by triggering multiple cell death mechanisms, including apoptosis, mitotic catastrophe, and autophagy. Our findings highlight reversine as a potential anticancer agent for ALL.
Assuntos
Morfolinas/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Purinas/farmacologia , Apoptose/efeitos dos fármacos , Aurora Quinase B/metabolismo , Autofagia/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Clonais , Dano ao DNA , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologiaRESUMO
BACKGROUND: Childhood acute lymphoblastic leukaemia (ALL) is a heterogeneous disease associated with multiple risk factors including genetic susceptibility. Polymorphisms in folate genes have been associated with a protective effect against ALL, although some studies contradict these findings. We aimed to test whether there is an association between the MTHFR rs1801133 variant and the occurrence of B-cell precursor ALL (BCP-ALL) taking in account molecularly distinct subtypes of fetal origin. METHODS: We performed a case-control genotyping study with 2067 samples, 1309 ALL and 758 controls, from children aged ≤ 15 years for MTHFR rs1801133 polymorphism. Risk associations were calculated by odds ratios estimated with unconditional logistic regression, adjusted for frequency-matched ethnic groups. RESULTS: Overall, MTHFR rs1801133 does not impact ALL risk in children with more than 6 years of age. A significant positive association for MTHFR rs1801133 variant was found for ALL with KMT2A-r in the dominant model (adj. OR, 1.48, 95 % CI, 1.01-2.17), while ETV6-RUNX1 and Hyperdiploid subgroups have shown a borderline effect (adj. OR, 1.33, 95 % CI, 0.99-1.78). CONCLUSIONS: The polymorphism MTHFR rs1801133 increased the risk of infant ALL in Brazilian population.
Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologiaRESUMO
The IGF1R/IRS1 signaling is activated in acute lymphoblastic leukemia (ALL) and can be targeted by the pharmacological inhibitors NT157 (IGF1R-IRS1/2 inhibitor) and OSI-906 (IGF1R/IR inhibitor). Here we investigate the cellular and molecular effects of NT157 and OSI-906 in ALL cells. NT157 and OSI-906 treatment reduced viability, proliferation and cell cycle progression in ALL cell lines. Similarly, in primary samples of patients with ALL, both OSI-906 and NT157 reduced viability, but only NT157 induced apoptosis. NT157 and OSI-906 did not show cytotoxicity in primary samples from healthy donor. NT157 and OSI-906 significantly decreased Jurkat cell migration, but did not modulate Namalwa migration. Consistent with the more potent effect of NT157 on cells, NT157 significantly modulated expression of 25 genes related to the MAPK signaling pathway in Jurkat cells, including oncogenes and tumor suppressor genes. Both compounds inhibited mTOR and p70S6K activity, but only NT157 inhibited AKT and 4-EBP1 activation. In summary, in ALL cells, NT157 has cytotoxic activity, whereas OSI-906 is cytostatic. NT157 has a stronger effect on ALL cells, and thus the direct inhibition of IRS1 may be a potential therapeutic target in ALL.
Assuntos
Antineoplásicos/farmacologia , Imidazóis/farmacologia , Proteínas Substratos do Receptor de Insulina/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Pirazinas/farmacologia , Pirogalol/análogos & derivados , Receptor IGF Tipo 1/antagonistas & inibidores , Sulfonamidas/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Adulto , Idoso , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Proteínas Substratos do Receptor de Insulina/metabolismo , Células Jurkat , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Pirogalol/farmacologia , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas , Adulto JovemRESUMO
BACKGROUND: Acute lymphoblastic leukemia (ALL) is one of the most frequent oncological disorders in pediatric populations. To date, the drug of choice for the treatment of ALL is methotrexate, a drug associated with a high risk of adverse reactions (ADRs). The xanthine oxidase (XO) polymorphisms, 1936A>G and 2107A>G, as well as the polymorphic variants derived from ATP-binding cassette transporter gene subfamilies, ABCB1 and ABCC5, of drug resistant codifying genes, are implicated as precursors of drug-related neurologic, hepatic, and renal toxicities. Our aim was to determine whether the mentioned polymorphisms are risk or protective factors for the development of adverse reactions by methotrexate in our pediatric population with ALL. METHODS: A total of 35 Mexican children from Centro Estatal de Cancerología-Durango, Mexico, with ALL and the previously noted polymorphisms as determined qPCR were studied. At the same time, a 12-month drug monitoring program was conducted in accordance with WHO-PAHO guidelines for pharmacovigilance. RESULTS: The ABCB11936A>G and 2107A>G and ABCC5 3414+434A>C polymorphisms were not associated with methotrexate ADRs. Single nucleotide polymorphisms (SNPs) of ABCB1 1236C>T (OR 0.19, 95% CI: 0.03-0.9, p<0.05) and ABCC5 3933+313T>C (OR 0.12, 95% CI: 0.027-0.58, p<0.05) were associated with methotrexate ADRs. CONCLUSIONS: SNPs 1236C>T of ABCB1 and ABCC5 3933+313T>C are not associated with the development of typical ADRs by methotrexate, rather, they showed a protective factor for myelosuppression in the studied sick population.
Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Metotrexato/efeitos adversos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Polimorfismo de Nucleotídeo Único , Xantina Oxidase/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Adolescente , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/uso terapêutico , Institutos de Câncer , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Quimioterapia de Manutenção/efeitos adversos , Masculino , Metotrexato/administração & dosagem , Metotrexato/uso terapêutico , México , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Mielopoese/efeitos dos fármacos , Farmacovigilância , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Estudos Prospectivos , Xantina Oxidase/metabolismoRESUMO
Patients with acute lymphoblastic leukemia presenting the immunophenotypic marker CD10+ (calla), usually has treatment profile good. The FLT3 molecular marker is listed as a prognostic factor, an important leukaemogenic marker in acute leukemias, also the polymorphism (G1082A) of the IL10 interleukin can to present pleiotropic effects in many diseases and could is associated to development of ALL. However, the FLT3 expression is variability among patients with calla-ALL. The aim of this study was to determine the FLT3 expression, to associate with the genotypes and allelic of G1082A (IL10) in 50 patients with calla-ALL and assess the overall survival at 98 months follow-up. The expression was assessed by quantitative real time PCR (RT-PCR), the G1082A polymorphism was identified by allele-specific PCR and for immunophenotypic classification was used specific markers of B lineage-calla. We observed that patients who died showed higher FLT3 expression (p = 0.005), worse survival (p = 0.0137) and the IL10G allele may favor the survival, because the IL10 GG and IL10 GA genotypes showed a low FLT3 expression (p < 0.05).
Assuntos
Interleucina-10/genética , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Adolescente , Biomarcadores Tumorais/metabolismo , Criança , Pré-Escolar , Feminino , Expressão Gênica , Estudos de Associação Genética , Humanos , Lactente , Estimativa de Kaplan-Meier , Masculino , Neprilisina/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
PURPOSE: The risk of developing childhood leukemia has been associated with gene polymorphisms that decrease the activity of detoxifying metabolic enzymes and enzymes involved in systemic oxidative stress. We investigated the NQO1 and PON1 polymorphisms for associations with susceptibility to childhood leukemia. METHODS: Samples from 1,027 Brazilian children (519 acute lymphoblastic leukemia, ALL; 107 acute myeloid leukemia, AML; 401 controls) were analyzed. TaqMAN real-time assays were used to determine the NQO1 rs1800566 (C609T), PON1 rs662 (Q192R), and PON1 rs854560 (L55M) frequencies. Logistic regression was used to evaluate the association of polymorphisms with cases and controls, with age and somatic fusion genes (MLL-r and ETV6-RUNX1) as covariables. RESULTS: Children with at least one NQO1 variant allele were at lower risk for developing infant AML (odds ratio (OR) 0.26, 95 % confidence interval (CI) 0.10-0.68); no association was detected for ALL. PON1 rs854560 (L55M) was associated with an increased risk of developing childhood leukemia (LM + MM, OR 1.93, 95 % CI 1.32-2.81). The PON1 rs662 R192R genotype had a statistically significant decreased frequency in ALL (OR 0.64, 95 % CI 0.43-0.93). Infant ALL cases were more likely to harbor homozygous PON1 rs854560 alleles than controls (OR 1.72, 95 % CI 1.03-2.89); at least one M allele was associated with an increased risk of ALL in children older than 1 year (OR 1.99, 95 % CI 1.17-3.3). CONCLUSIONS: The NQO1 rs1800566 (C609T), PON1 rs854560 (L55M), and PON1 rs662 (Q192R) polymorphisms modified risk depending on leukemia subtype (decreased in AML, increased and decreased in ALL, respectively), age strata, and variant genotype combinations.
Assuntos
Arildialquilfosfatase/genética , NAD(P)H Desidrogenase (Quinona)/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Distribuição por Idade , Alelos , Arildialquilfosfatase/metabolismo , Brasil/epidemiologia , Criança , Pré-Escolar , Genótipo , Humanos , NAD(P)H Desidrogenase (Quinona)/metabolismo , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Fatores de RiscoRESUMO
Acute lymphoblastic leukemia is still an incurable disease with resistance to therapy developing in the majority of patients. We investigated the effect of TPEN, an intracellular zinc chelator, in Jurkat and in ex vivo acute lymphoblastic leukemia (ALL) cells resistant to chemotherapy. Changes of nuclei morphology, reactive oxygen species generation, presence of hypodiploid cells, phosphatidylserine translocation, mitochondrial membrane depolarization, immunohistochemical identification of cell death signalling molecules, and pharmacological inhibition were assayed to detect the apoptotic cell death pathways. We found that TPEN induces apoptosis in both types of cells by a molecular oxidative stress pathway involving O(2)(â¢-) > H(2)O(2) >> NF-κB (JNK/c-Jun) >p53> loss ΔΨ(m)> caspase-3, AIF > chromatin condensation/DNA fragmentation. Interestingly, TPEN induced apoptosis independently of glucose; leukemic cells are therefore devoid of survival capacity by metabolic resistance to treatment. Most importantly, TPEN cytotoxic effect can eventually be regulated by the antioxidant N-acetyl-cysteine and zinc ions. Our data suggest that TPEN can be used as a potential therapeutic prooxidant agent against refractory leukemia. These data contribute to understanding the importance of oxidative stress in the treatment of ALL.
Assuntos
Fator de Indução de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Etilenodiaminas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Zinco/farmacologia , Acetilcisteína/farmacologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Quelantes/farmacologia , Cromatina/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Feminino , Glucose/farmacologia , Humanos , Peróxido de Hidrogênio/metabolismo , Células Jurkat , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Transdução de Sinais/efeitos dos fármacos , Superóxidos/metabolismo , Fatores de Tempo , Fatores de Transcrição/metabolismoRESUMO
Las enzimas de biotransformación y eliminación de los fármacos en pacientes con leucemia linfoide aguda tienen una acción determinante en el efecto terapéutico de los medicamentos antineoplßsicos. La presencia y actividad de estos complejos enzimáticos está codificada genéticamente y sujeta a variaciones alélicas, cuyas frecuencias son variables en las diferentes poblaciones humanas. Este polimorfismo genético influye sobre la efectividad terapéutica de los medicamentos y condiciona la carencia de toxicidad o presencia de esta, que en ocasiones puede ser fatal. Las enzimas tiopurin-metil-transferasa, metilén-tetrahidrofolato-reductasa y glutatión-tranferasa son sistemas destoxificadores de algunos de los quimioterápicos empleados en el tratamiento de la leucemia linfoide aguda. En este trabajo se revisan las características genéticas de estas enzimas, la frecuencia de sus polimorfismos y las implicaciones clínicas de su expresión. De igual modo se discute la importancia y los beneficios del genotipaje previo al inicio del tratamiento, con el fin de modificar las dosis de los medicamentos para optimizar su efecto terapéutico y disminuir su toxicidad. La farmacogenética constituye un área de creciente interés que ha tenido un desarrollo considerable en los últimos años, su conocimiento e implementación nos colocará en el camino de la medicina personalizada
The biotransformation and elimination enzymes of drugs in patients suffering from acute lymphoid leukemia play a decisive role on the therapeutical effect of anti-neoplastic drugs. The presence and activity of these enzymatic complexes are genetically coded and subjected to allele variations, the frequency of which is variable in the different human populations. This genetic polymorphism has an impact on the therapeutic effectiveness of drugs and determines the lack or the existence of toxicity that may sometimes become lethal. The enzymes called thiopurine-methyltransferase, methylen-tetrahydropholate-reductase and glutathione-transferase are detoxifying systems of some of the chemotherapeutic drugs that are used for the treatment of acute lymphoid leukemia. This paper reviewed the genetic characteristics of the enzymes, the frequency of polymorphisms and the clinical implications of their expression. Similarly, the importance and the benefits of genotyping before the treatment were discussed in order to change the drug doses to maximize the therapeutic effect and reduce toxicity. Pharmacogenetics has experienced great development in the last few years and draws growing interest; the knowledge about and the implementation of this discipline will take us to the customized medicine
Assuntos
Farmacogenética/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Técnicas de Genotipagem/métodosAssuntos
Citocromo P-450 CYP1A1/genética , NAD(P)H Desidrogenase (Quinona)/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Brasil , Estudos de Casos e Controles , Pré-Escolar , Poluentes Ambientais/metabolismo , Poluentes Ambientais/toxicidade , Feminino , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Genótipo , Humanos , Inativação Metabólica/genética , Inativação Metabólica/fisiologia , Lactente , Masculino , Pessoa de Meia-Idade , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia , Fatores de RiscoRESUMO
Altered expression of histone deacetylases (HDACs) is a common feature in several human malignancies and may represent an interesting target for cancer treatment, including haematological malignancies. We evaluated the mRNA gene expression profile of 12 HDAC genes by quantitative real-time polymerase chain reaction in 94 consecutive childhood acute lymphoblastic leukaemia (ALL) samples and its association with clinical/biological features and survival. ALL samples showed higher expression levels of HDAC2, HDAC3, HDAC8, HDAC6 and HDAC7 when compared to normal bone marrow samples. HDAC1 and HDAC4 showed high expression in T-ALL and HDAC5 was highly expressed in B-lineage ALL. Higher than median expression levels of HDAC3 were associated with a significantly lower 5-year event-free survival (EFS) in the overall group of patients (P = 0·03) and in T-ALL patients (P = 0.01). HDAC7 and HADC9 expression levels higher than median were associated with a lower 5-year EFS in the overall group (P = 0.04 and P = 0.003, respectively) and in B-lineage CD10-positive patients (P = 0.009 and P = 0·005, respectively). Our data suggest that higher expression of HDAC7 and HDAC9 is associated with poor prognosis in childhood ALL and could be promising therapeutic targets for the treatment of refractory childhood ALL.
Assuntos
Biomarcadores Tumorais/biossíntese , Histona Desacetilases/biossíntese , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Adolescente , Biomarcadores Tumorais/genética , Medula Óssea/enzimologia , Criança , Pré-Escolar , Feminino , Perfilação da Expressão Gênica/métodos , Histona Desacetilases/genética , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Prognóstico , RNA Mensageiro/genética , RNA Neoplásico/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Análise de SobrevidaRESUMO
BACKGROUND: Angiogenesis has been shown as an important process in hematological malignancies. It consists in endothelial proliferation, migration, and tube formation following pro-angiogenic factors releasing, specially the vascular endothelial growth factor (VEGF), which angiogenic effect seems to be dependent on nitric oxide (NO). We examined the association among functional polymorphisms in these two angiogenesis related genes: VEGF (-2578C>A, -1154G>A, and -634G>C) and NOS3 (-786T>C, intron 4 b>a, and Glu298Asp) with prognosis of childhood acute lymphoblastic leukemia (ALL). METHODS: The genotypes were determined and haplotypes estimated in 105 ALL patients that were divided in 2 groups: high risk (HR) and low risk of relapse (LR) patients. In addition, event-free survival curves according to genotypes were assessed. RESULTS: The group HR compared to the LR showed a higher frequency of the alleles -2578C and -634C and the haplotype CGC for VEGF (0.72 vs. 0.51, p<0.008; 0.47 vs. 0.26, p<0.008; and 42.1 vs. 14.5, p<0.006; respectively) and a lower frequency of the haplotype CbGlu (0.4 vs. 8.8,p<0.006), for NOS3. CONCLUSION: Polymorphisms of VEGF and NOS3 genes are associated with high risk of relapse, therefore may have a prognostic impact in childhood ALL.
Assuntos
Óxido Nítrico Sintase Tipo III/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fator A de Crescimento do Endotélio Vascular/genética , Sequência de Bases , Criança , Pré-Escolar , Primers do DNA , Intervalo Livre de Doença , Feminino , Genótipo , Haplótipos , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Recidiva , Fatores de RiscoRESUMO
This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real-time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P=0.04) and multivariable analysis (P=0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL.
Assuntos
Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , RNA Mensageiro/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-2/genética , Sequência de Bases , Criança , Pré-Escolar , Primers do DNA , Citometria de Fluxo , Humanos , Lactente , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , PrognósticoRESUMO
BACKGROUND: Acute lymphoblastic leukemia (ALL) is a type of cancer that affects lymphocytes and it is the most common form of cancer in children. Acetylcholinesterase (AChE) is well known as having non-cholinergic functions and has been detected in the blood and plasma of humans including in lymphocytes. Thus, we investigated whole blood and lymphocyte AChE activity in patients with ALL. METHODS: This study was performed on 72 children with ALL divided into 4 groups: newly diagnosed, remission induction, remission maintenance and out-of-treatment and one control group of 50 healthy subjects. We determined AChE activity in whole blood and lymphocytes of these patients. RESULTS: Results demonstrated that whole blood AChE activity was enhanced in the newly diagnosed group and reduced in the remission induction and remission maintenance groups in relation to the control group. For lymphocyte AChE activity we found an increase in the newly diagnosed group and a decrease in the remission induction group in relation to the control. CONCLUSIONS: These results suggest that AChE activity was altered in ALL patients. This fact may be related with the essential role played by AChE in the development of hematological disease and its contribution to the regulation of immune function.
Assuntos
Acetilcolinesterase/sangue , Linfócitos/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Acetilcolinesterase/metabolismo , Adolescente , Antineoplásicos/farmacologia , Criança , Pré-Escolar , Citarabina/farmacologia , Feminino , Humanos , Linfócitos/efeitos dos fármacos , Masculino , Metotrexato/farmacologia , Adulto JovemRESUMO
The frequency of allele variants of gene TPMT*2, *3A, *3B, and *3C was estimated in a population of 116 Brazilian children with acute lymphoblastic leukemia. The association between genotype and clinical and laboratory data obtained during chemotherapy maintenance phase and the correlation of intraerythrocyte concentration of 6-mercaptopurine metabolites (6-tioguanine nucleotide nucleotides and methylmercaptopurine) were analyzed. A multiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) was used in DNA amplification. Twelve patients presented TPMT gene mutation, all in heterozygous form. The most frequent allele variation was TPMT*3A (3.9%), followed by *3C (0.9%), *2 (0.4%), and *3B (0%). There was no significant association between clinical and laboratory data and the presence of mutation in TPMT gene. Of the 36 patients who were monitored for 6-mercaptopurine metabolite levels, only 1 had the mutation. In this patient, high 6-tioguanine nucleotide and low methylmercaptopurine concentrations were found. Event-free survival (EFS) for the whole group was 73.4%. There was no significant difference in event-free survival in the comparison between the groups with and without mutation (P = 0.06).
Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Mercaptopurina/administração & dosagem , Metiltransferases/genética , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Antimetabólitos Antineoplásicos/metabolismo , Antimetabólitos Antineoplásicos/farmacocinética , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Humanos , Lactente , Masculino , Mercaptopurina/metabolismo , Mercaptopurina/farmacocinética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológicoRESUMO
OBJECTIVES: To evaluate the oxidative status and antioxidant defense in patients with acute lymphoblastic leukemia (ALL). DESIGN AND METHODS: We measured concentrations of plasmatic thiobarbituric acid reactive substances (TBARS), serum protein carbonylation, whole blood catalase (CAT) and superoxide dismutase (SOD) activities, as well as the plasmatic and erythrocyte thiol levels and serum vitamin E concentration. This study was performed on 80 children with ALL divided into 4 groups: just diagnosed, remission induction, remission maintenance and out-of-treatment. RESULTS: TBARS levels and serum protein carbonylation were higher in ALL patients than in controls and reduced levels of antioxidants were found in these patients. CONCLUSION: These findings may indicate a possible link between decreased antioxidants and increased levels of cells alterations due to oxidative damage, supporting the idea that there is a persistence of oxidative stress in acute lymphoblastic leukemia.
Assuntos
Antioxidantes/metabolismo , Estresse Oxidativo/fisiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Peroxidação de Lipídeos/fisiologia , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologiaRESUMO
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 Assuntos
Antimetabólitos Antineoplásicos/metabolismo
, Citarabina/metabolismo
, Rearranjo Gênico/genética
, Proteína de Leucina Linfoide-Mieloide/genética
, Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
, Antimetabólitos Antineoplásicos/uso terapêutico
, Estudos de Casos e Controles
, Criança
, Pré-Escolar
, Citarabina/uso terapêutico
, Desoxicitidina Quinase/efeitos dos fármacos
, Desoxicitidina Quinase/genética
, Transportador Equilibrativo 1 de Nucleosídeo/efeitos dos fármacos
, Transportador Equilibrativo 1 de Nucleosídeo/genética
, Feminino
, Regulação Neoplásica da Expressão Gênica
, Humanos
, Lactente
, Masculino
, Proteína de Leucina Linfoide-Mieloide/efeitos dos fármacos
, Neoplasia Residual
, Reação em Cadeia da Polimerase/métodos
, Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
, Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia
, RNA Mensageiro/análise
, Fatores de Tempo
RESUMO
There is evidence supporting a role for 5-10 methylenetetrahydrofolate reductase (MTHFR) gene variants in acute lymphoblastic leukemia (ALL). To provide a more robust estimate of the effect of MTHFR polymorphisms on the risk of ALL, we did a meta-analysis to reevaluate the association between the two most commonly studied MTHFR polymorphisms (C677T and A1298C) and ALL risk. All case-control studies investigating an association between the C677T or A1298C polymorphisms and risk of ALL were included. We applied both fixed-effects and random-effects models to combine odds ratio (OR) and 95% confidence intervals (95% CI). Q-statistic was used to evaluate the homogeneity and both Egger and Begg-Mazumdar tests were used to assess publication bias. The meta-analysis of the C677T polymorphism and risk of childhood ALL included 13 studies with a total of 4,894 individuals. Under a fixed-effects model, the TT genotype failed to be associated with a statistically significant reduction of childhood ALL risk (TT versus CT + CC: OR, 0.88; 95% CI, 0.73-1.06; P = 0.18). However, individuals homozygous for the 677T allele exhibited a 2.2-fold decrease in risk of adult ALL (TT versus CT + CC: OR, 0.45; 95% CI, 0.26-0.77; P = 0.004). In both cases, no evidence of heterogeneity was observed. No association between the A1298C variant and susceptibility to both adult and childhood ALL was disclosed. Our findings support the proposal that the common genetic C677T polymorphism in the MTHFR contributes to the risk of adult ALL, but not to the childhood ALL susceptibility.
Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Brasil/epidemiologia , Canadá/epidemiologia , Estudos de Casos e Controles , Europa (Continente)/epidemiologia , Predisposição Genética para Doença , Genótipo , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/etnologia , Viés de Publicação , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Turquia/epidemiologiaRESUMO
RNA-dependent protein kinase (PKR) mediates the antiviral activity of interferon and also has implications in cell growth, differentiation, and apoptosis. On the other hand, the tumor suppressor function of PKR is still controversial. PKR is a serine/threonine kinase that contains two RNA-binding domains (RBD-I and RBD-II) and RBD-I is critical for its activation. Site-directed mutagenesis studies indicated that a single amino acid substitution in RBD-I is sufficient to abolish the interaction of human PKR with RNA. Also, PKR mutants that are unable to bind RNA are inactive in vitro and have no antiproliferative activity in vivo. There have been no reports of mutations in the RNA-binding domains of PKR of tumor cells taken directly from patients. We investigated the presence of mutations in the RBD-I and RBD-II of PKR gene in children with acute lymphoblastic leukemia (ALL). The RNA extracted from bone marrow samples of 15 patients with ALL (5 patients T-lineage; 10 patients B-lineage) was used for to synthesize cDNA and amplify the sequences corresponding to RBD-I and RBD-II. The PCR products were subsequently cloned and sequenced. A point mutation was detected in the RBD-I of PKR from a patient with ALL of T-cell lineage that is located at cDNA nt 50 A --> G (17 Tyr-->Cys). We also found that activation of a PKR mutant by the polyinosinic acid:polycytidylic acid (poly I:C) is impaired when compared with the wild-type PKR. Additional work is required to elucidate whether this point mutation plays a role in the formation and/or maintenance of leukemic cells. To our knowledge, this study is the first example of detection of a mutation in the RBD-I of PKR gene from tumor cells taken directly from patients.