RESUMEN
Secondary acute myelocytic leukemia (AML) and myelodysplastic syndromes (MDS) are known to develop in patients previously treated with different chemotherapeutic regimens. Nonrandom chromosomal abnormalities have been demonstrated in these therapy-related myeloid disorders which often evolve into refractory AML. The prognosis of these patients with conventional chemotherapy has been dismal and only allogeneic bone marrow transplantation offers a potential cure. We describe two patients who developed MDS after chemo/radiotherapy and had a spontaneous recovery. One patient was treated with MOPP-ABVD hybrid therapy for Hodgkin's disease, developed pancytopenia, marrow hypoplasia and dyserythropoiesis associated with monosomy 7. The other was treated with a combination of chemotherapy including VP-16 for Ewing's sarcoma, developed thrombocytopenia, marrow hypoplasia and dyserythropoiesis associated with an 11q23 translocation. Both patients received rhG-CSF after their cycles of chemotherapy and were considered for a bone marrow transplant. Marrow aspirates at frequent intervals showed gradual disappearance of the abnormal clone with parallel normalization of the peripheral count. In both patients G-CSF might have played a role in the development of the abnormal clone. We suggest that patients with therapy-related MDS without excess of blasts could be closely monitored for karyotypic and hematological improvement rather than transplanted immediately.
Asunto(s)
Cromosomas Humanos Par 11 , Cromosomas Humanos Par 7 , Leucemia Mieloide Aguda/genética , Monosomía , Síndromes Mielodisplásicos/genética , Neoplasias Primarias Secundarias/genética , Translocación Genética , Adolescente , Adulto , Femenino , Humanos , MasculinoRESUMEN
Contemporary chemotherapy has significantly improved event-free survival among patients with T cell-lineage acute lymphoblastic leukemia (T-ALL). Unlike B-precursor ALL, most investigators are still using cranial radiation (CRT) and are hesitant to rely solely on intrathecal therapy for T-ALL. In this study we assessed the effects of CRT upon event-free survival and central nervous system (CNS) relapses in a cohort of children with high risk features of T cell leukemia. In a series of six consecutive studies (1987-1995) patients were non-randomly assigned their CNS prophylaxis per individual protocol. These protocols were based on POG 8704 which relied on rotating drug combinations (cytarabine/cyclophosphamide, teniposide/Ara-C, and vincristine/doxorubicin/6-MP/prednisone) postinduction. Modifications such as high-dose cytarabine, intermediate-dose methotrexate, and the addition of G-CSF, were designed to give higher CNS drug levels (decreasing the need for CRT), to eliminate epidophyllotoxin (decreasing the risk of secondary leukemia), and to reduce therapy-related neutropenia (pilot studies POG 9086, 9295, 9296, 9297, 9398). All patients included in this analysis qualified for POG high risk criteria, WBC >50000/mm3 and/or CNS leukemia. Patients without CNS involvement received 16 doses of age-adjusted triple intra-thecal therapy (TIT = hydrocortisone, MTX, and cytarabine) whereas patients with CNS disease received three more doses of TIT during induction and consolidation. Patients who received CRT were treated with 2400 cGy (POG 8704) or 1800 cGy (POG 9086 and 9295). CNS therapy included CRT in 144 patients while the remaining 78 patients received no radiation by original protocol design. There were 155 males and 57 females with a median age of 8.2 years. The median WBC for the CRT+ and CRT- patients were 186000/mm3 and 200000/mm3, respectively. CNS involvement at diagnosis was seen in 16% of the CRT+ and 23% of the CRT- groups. The complete continuous remission rate (CCR) was not significantly different for the irradiated vs. non-irradiated groups (P = 0.46). The 3-year event-free survival was 65% (s.e. 6%) and 63% (s.e. 4%) for the non-irradiated vs. the radiated group. However, the 3-year CNS relapse rate was significantly higher amongst patients who did not receive CRT; 18% (s.e. 5%) vs. 7% (s.e. 3%) in the irradiated group (P = 0.012). Our analysis in a non-randomized setting, suggests that CRT did not significantly correlate with event-free survival but omitting it had an adverse effect on the CNS involvement at the time of relapse.
Asunto(s)
Irradiación Craneana , Leucemia-Linfoma de Células T del Adulto/radioterapia , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Sistema Nervioso Central/patología , Niño , Preescolar , Estudios de Cohortes , Terapia Combinada , Ciclofosfamida/administración & dosificación , Citarabina/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Inyecciones Espinales , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Infiltración Leucémica/prevención & control , Masculino , Metotrexato/administración & dosificación , Podofilotoxina/administración & dosificación , Pronóstico , Inducción de Remisión , Riesgo , Tenipósido/administración & dosificación , Resultado del TratamientoRESUMEN
Folypoly-gamma-glutamate synthetase (FPGS) is essential for the cytotoxicity of "classical" antifolates and their efficacy in cancer chemotherapy. The expression of the FPGS gene appears controlled by both tissue/lineage-specific and proliferation-dependent mechanisms. Four alternative exon 1 splice variants of the FPGS gene have been described previously, but their significance in gene regulation has not been determined. Furthermore, alternative splicing of the human FPGS gene in normal or transformed cells in vivo has not been reported. We have examined the mRNA expression of these FPGS splice variants in primary human leukemia cells, cell lines, and normal human hematopoietic progenitors using reverse transcription-PCR. Specific primers were designed to amplify splice variants 1, 1A, 1B, and 1C; and full-length FPGS mRNA was amplified using primers for exons 14 and 15 at the 3' end of the gene. In this study, we demonstrate that all four alternative exon 1 variants are expressed in all primary leukemia cells and cell lines (ALL and AML), as well as in normal human hematopoietic progenitors. No significant differences in mRNA expression were detected in primary cells or cell lines for the four exon 1 splice variants. Normal circulating human lymphocytes (peripheral blood mononuclear cells) also expressed mRNA amplified from full-length FPGS and the four exon 1 splice variants, although no detectable FPGS activity was found. Using Western immunoblotting, we show that FPGS protein is expressed in these peripheral blood mononuclear cells; thus, we propose that posttranslational modification(s) is required for expression of a functional FPGS protein in human lymphohematopoietic cells. In addition, poly(A)(+) RNA from normal human adult and fetal tissues and leukemia cell lines was analyzed by Northern blot methodology. Total FPGS mRNA expression showed tissue-specificity, and higher levels were observed in human fetal tissues compared with adult tissues. The data presented herein demonstrate the existence of these FPGS mRNA splice variants in normal and transformed human hematopoietic cells and indicate that alternative splicing of the 5' end of the human FPGS gene does occur in primary cells in vivo. However, its role in regulating the expression of its mRNA remains to be determined.
Asunto(s)
Empalme Alternativo , Leucemia/genética , Péptido Sintasas/genética , Células de la Médula Ósea/enzimología , Catálisis , Línea Celular , Exones , Feto/enzimología , Expresión Génica , Células HL-60 , Células Madre Hematopoyéticas/enzimología , Humanos , Células K562 , Leucemia/enzimología , Leucemia/patología , Péptido Sintasas/biosíntesis , ARN Mensajero/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The effects of in vitro radiation and exposure to 4-hydroperoxycyclophosphamide (4-HC) on the production of G- and GM-CSF by different components of the human hematopoietic microenvironment are described. The marrow microenvironment is composed of fibroblasts, endothelial cells, macrophages, and adipocytes. To study the effects of radiation/4-HC on colony-stimulating factor (CSF) production by stromal cells, confluent layers of umbilical cord endothelial cells (EC), marrow fibroblasts (MF), and heterogeneous adherent layers (HAL) derived from long-term marrow cultures were established. These layers were exposed to radiation up to 3000 cGy and/or 100 mumol/ml of 4-HC and subsequently stimulated with IL-1 beta on day 0, 7, or 14 after radiation/4-HC. Following IL-1 exposure conditioned medium (CM) was collected and G- and GM-CSF levels were measured by ELISA and their ability to support colony formation was assessed. G- and GM-CSF levels after exposure to 4-HC and radiation were 12,460 +/- 172 pg/ml and 2268 +/- 160 pg/ml for EC, 2214 +/- 94 pg/ml and 263 +/- pg/ml for MF, and 3168 +/- 316 pg/ml and 356 +/- 34 pg/ml for HALs, respectively. For each cell group there was no significant difference between levels obtained without exposure and levels after exposure to 4-HC and/or radiation (p > 0.6). Comparison of levels obtained from different cell groups showed significant differences with EC media being the highest (p < 0.0001). To test the activity of these measured factors, CM of different sources was used in colony assays of CD 34+ cord blood progenitors.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Médula Ósea/metabolismo , Factor Estimulante de Colonias de Granulocitos/biosíntesis , Factor Estimulante de Colonias de Granulocitos y Macrófagos/biosíntesis , Médula Ósea/efectos de los fármacos , Médula Ósea/efectos de la radiación , Trasplante de Médula Ósea , Ensayo de Unidades Formadoras de Colonias , Medios de Cultivo Condicionados , Ciclofosfamida/análogos & derivados , Ciclofosfamida/farmacología , Humanos , Técnicas In VitroRESUMEN
The development of graft-versus-host disease (GVHD) in patients undergoing allogeneic bone marrow transplantation for leukemias and lymphomas has been associated with a lower incidence of relapse. This phenomenon is thought to be secondary to the anti-tumor effect of adoptively transferred cells. Cyclosporin A (CsA) therapy is known to cause autologous and syngeneic GVHD in experimental models and humans, and has been used in patients undergoing autologous bone marrow transplantation. It has been the consensus to date that CsA-induced autologous GVHD is generally mild, confined to the skin, self-limiting and non-life-threatening. We report by case of severe and progressive GVHD induced by CsA in a child following autologous bone marrow transplantation for acute lymphoblastic leukemia in second remission.
Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Ciclosporina/efectos adversos , Enfermedad Injerto contra Huésped/inducido químicamente , Inmunosupresores/efectos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Preescolar , Humanos , Masculino , Trasplante AutólogoRESUMEN
Even though folate antimetabolites were introduced over forty years ago, they continue to be the backbone of many active chemotherapeutic regimens used by medical and pediatric oncologists. The recognition of polyglutamylation by folylpolyglutamate synthetase (FPGS) as an important metabolic step in the "activation" of classical antifolates and novel drugs aimed at thymidylate synthase (TS) and de novo purine synthesis, has resulted in renewed interest in this class of drugs. In addition, the emergence of secondary neoplasms in patients treated with alkylating agents and topoisomerase inhibitors in contrast to the exceptional safety record of antimetabolites, underscores the need for clinical trials that incorporate new strategies with known active antimetabolites and novel promising agents. In that context, FPGS is an important target for further laboratory and clinical investigations.
Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/uso terapéutico , Antagonistas del Ácido Fólico/farmacocinética , Antagonistas del Ácido Fólico/uso terapéutico , Péptido Sintasas/metabolismo , Animales , Biotransformación , Ácido Fólico/farmacocinética , Ácido Fólico/uso terapéutico , HumanosRESUMEN
Children with acute lymphoblastic leukemia (ALL) diagnosed with resistant phenotypes, and those who relapse, have a dismal prognosis for cure. The antifolate methotrexate (MTX), a universal component of ALL therapies, is metabolized by folylpoly-gamma-glutamate synthetase (FPGS) into long-chain polyglutamates (MTX-PG(3-7)), resulting in enhanced cytotoxicity from prolonged inhibition of dihydrofolate reductase (DHFR) and thymidylate synthetase (TS). Using DNaseI assays, we identified a hypersensitive site upstream from exon-1, suggesting chromatin remodeling could alter FPGS expression. We demonstrated that histone deacetylase-1 (HDAC1) is recruited by NFY and Sp1 transcription factors to the FPGS promoter in ALL cell lines. We examined the effect of histone deacetylase inhibitors (HDACIs) sodium butyrate and suberoylanilide hydroxamic acid (SAHA) on the expression of FPGS and other folate-related genes. HDACIs increased FPGS mRNA expression by 2- to 5-fold, whereas DHFR and TS mRNA expression was decreased. Combination treatment with MTX plus SAHA significantly increased cytotoxicity and apoptosis in B- and T-ALL cell lines as compared with each drug alone (CIAsunto(s)
Inhibidores de Histona Desacetilasas/farmacología
, Metotrexato/análogos & derivados
, Péptido Sintasas/genética
, Ácido Poliglutámico/análogos & derivados
, Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico
, Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
, Factor de Unión a CCAAT/fisiología
, Línea Celular Tumoral
, Exones
, Regulación Enzimológica de la Expresión Génica/efectos de los fármacos
, Histona Desacetilasa 1/fisiología
, Inhibidores de Histona Desacetilasas/administración & dosificación
, Humanos
, Ácidos Hidroxámicos/administración & dosificación
, Metotrexato/administración & dosificación
, Metotrexato/metabolismo
, Ácido Poliglutámico/metabolismo
, Leucemia-Linfoma Linfoblástico de Células Precursoras/genética
, Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo
, Factor de Transcripción Sp1/fisiología
, Vorinostat
RESUMEN
In children with acute lymphoblastic leukemia (ALL) with isolated central nervous system (CNS) relapse and a human leucocyte antigen (HLA)-matched sibling, the optimal treatment after attaining second remission is unknown. We compared outcomes in 149 patients enrolled on chemotherapy trials and 60 HLA-matched sibling transplants, treated in 1990-2000. All patients achieved a second complete remission. Groups were similar, except the chemotherapy recipients were younger at diagnosis, less likely to have T-cell ALL and had longer duration (> or = 18 months) first remission. To adjust for time-to-transplant bias, left-truncated Cox's regression models were constructed. Relapse rates were similar after chemotherapy and transplantation. In both treatment groups, relapse rates were higher in older children (11-17 years; RR 2.81, P=0.002) and shorter first remission (< 18 months; RR 3.89, P<0.001). Treatment-related mortality rates were higher after transplantation (RR 4.28, P=0.001). The 8-year probabilities of leukemia-free survival adjusted for age and duration of first remission were similar after chemotherapy with irradiation and transplantation (66 and 58%, respectively). In the absence of an advantage for one treatment option over another, the data support use of either intensive chemotherapy with irradiation or HLA-matched sibling transplantation with total body irradiation containing conditioning regimen for children with ALL in second remission after an isolated CNS relapse.
Asunto(s)
Antineoplásicos/uso terapéutico , Trasplante de Médula Ósea/métodos , Neoplasias del Sistema Nervioso Central/terapia , Histocompatibilidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Neoplasias del Sistema Nervioso Central/etiología , Niño , Preescolar , Recolección de Datos , Supervivencia sin Enfermedad , Femenino , Antígenos HLA , Humanos , Infiltración Leucémica/etiología , Infiltración Leucémica/terapia , Estudios Longitudinales , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Radioterapia/métodos , Recurrencia , Inducción de Remisión , Hermanos , Acondicionamiento Pretrasplante/métodos , Resultado del TratamientoRESUMEN
PURPOSE: The treatment of infant acute lymphoblastic leukemia (ALL) continues to be a significant challenge for pediatric oncologists due to the high incidence of early relapses. Salvage regimens used to date have met limited success. We describe two cases of relapsed infant ALL who have achieved long-term survival with an intensive antimetabolite-based salvage regimen. PATIENTS AND METHODS: Two consecutive infants with relapsed ALL presented at our institution and were treated with an antimetabolite-based regimen. Both cases exhibited clinical and biological phenotypes previously associated with infantile ALL. RESULTS: Both patients have achieved prolonged and sustained remissions 48 and 30 months EFS respectively following therapy with intensive antimetabolite-based salvage regimen. CONCLUSIONS: An intensive multiagent antimetabolite based salvage regimen resulted in prolonged EFS in two cases of relapsed infant ALL. Dose intensification was achieved by administering repeated cycles of the same treatment schema using high dose chemotherapy throughout therapy. These infants were spared prophylactic cranial irradiation without a negative impact on outcome. The use of L-asparaginase, timed after high-dose Cytarabine (ARA-C) throughout therapy, might have contributed to their cure.
Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Femenino , Humanos , Lactante , Masculino , Inducción de RemisiónRESUMEN
Immunophenotype might be an important indicator for multidrug resistance (MDR) profiles in childhood acute lymphoblastic leukemia (ALL). The authors analyzed the messenger RNA (mRNA) levels of MDR1, multidrug resistance-associated protein (MRP), and lung resistance-related protein (LRP) by reverse transcriptase-polymerase chain reaction (RT-PCR) in childhood pre-B ALL, T-cell ALL, and acute nonlymphoblastic leukemia (ANLL). Results showed that MRP and LRP, but not MDR1, mRNAs are overexpressed, particularly in children with pre-B ALL compared with T-cell ALL and ANLL tested. In addition, the MRP and LRP mRNA expression levels in initial diagnosis and first relapse samples of one patient with pre-B ALL were similar. Consequently, these preliminary results suggest that the expression of these MDR-related genes in childhood ALL might be regulated differently in a lineage dependent manner.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/biosíntesis , Transportadoras de Casetes de Unión a ATP/genética , Proteínas de Neoplasias/biosíntesis , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , ARN Mensajero/biosíntesis , Partículas Ribonucleoproteicas en Bóveda/biosíntesis , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/biosíntesis , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Adolescente , Niño , Preescolar , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Femenino , Células HL-60 , Humanos , Lactante , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Masculino , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , Proteínas de Neoplasias/genética , Partículas Ribonucleoproteicas en Bóveda/genéticaRESUMEN
African Americans have a lower registration rate for becoming potential bone marrow and stem cell donors. The same attitudes and behaviors are exhibited in regard to solid organ and blood donations, causing a serious under-representation of the African-American population in the donor pool. In our efforts to increase donor availability for African Americans through a project funded by the Medical University of South Carolina, we used a survey to determine the reasons African Americans do not participate as donors for bone marrow. We surveyed 589 African Americans, a great majority of whom were women. Our survey identified major barriers to donation to be the lack of awareness that transplantation can save lives, the cost of donation, and the lack of opportunities to donate. The most effective interventions in increasing donation have been to provide both educational programs preceding marrow drives and the opportunity to donate. Through these efforts, the number of potential African-American donors has increased from 768 (accrued over a period of 12 years) to 1977 in less than 2 years. We conclude that a minority recruitment program targeting African-American volunteers for the National Marrow Donor Program (NMDP) should include an education component addressing the most common barriers before drives.
Asunto(s)
Donantes de Tejidos , Adolescente , Adulto , Negro o Afroamericano , Anciano , Trasplante de Médula Ósea , Recolección de Datos , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Masculino , Persona de Mediana Edad , Educación del Paciente como AsuntoRESUMEN
BACKGROUND: We present and discuss the successful treatment of pleuropulmonary blastoma metastatic to the brain using a multimodality regimen with surgery, high-dose chemotherapy and radiation therapy. PROCEDURE: A 3-year-old boy referred to our institution with bilateral pulmonary cysts was diagnosed with pleuropulmonary blastoma (PPB). Initial treatment included surgery and multiagent chemotherapy with vincristine, dactinomycin, cyclophosphamide, cisplatin, and doxorubicin. One year after the completion of therapy, his PPB recurred as an intracerebral metastasis, and required further treatment with a multimodality salvage regimen. The child was successfully treated with a subtotal surgical resection, followed by high-dose cyclophosphamide, and radiation therapy. He is now disease-free 24 months later. RESULTS: Intracerebral metastases of PPB have been a uniformly fatal complication of this tumor. Postsurgical chemotherapy and radiation therapy appear to have contributed to the prolonged survival and potential for cure in our patient. CONCLUSIONS: The use of this multimodality regimen may be warranted in other patients with recurrent PPB metastatic to the brain.
Asunto(s)
Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/terapia , Neoplasias Pulmonares/patología , Neoplasias Pleurales/patología , Blastoma Pulmonar/secundario , Blastoma Pulmonar/terapia , Terapia Combinada , Humanos , Lactante , Neoplasias Pulmonares/terapia , Masculino , Neoplasias Pleurales/terapiaRESUMEN
Folylpolyglutamate synthetase (FPGS) is responsible for the metabolism of natural folates and a broad range of folate antagonists to polyglutamate derivatives. Recent studies indicated increased accumulation of methotrexate (MTX) polyglutamates (MTX-PG) in blast cells as a predictor of favorable treatment outcome in childhood acute lymphoblastic leukemia (ALL). We determined the expression of FPGS activity in blasts from children with ALL at diagnosis and after treatment with MTX as a single agent, before conventional remission induction therapy. The levels of enzyme activity in ALL blasts at diagnosis (median of 689 pmol/h/mg protein) were significantly higher (P = .003) than those found in acute nonlymphoblastic leukemia (ANLL) blasts (median of 181 pmol/h/mg protein). Comparable lineage differences in normal lymphoid versus nonlymphoid cells suggest a lineage-specific control of FPGS expression, FPGS activity increased in ALL blasts after in vivo exposure to MTX. The median increase in FPGS activity was significantly higher (P = .003) in B-lineage ALL (188%) than in T-lineage ALL (37%). Likewise, the percentage of intracellular long chain MTX-PG (Glu3-6) was significantly higher (P = .02) in B-lineage ALL (92%) than in T-lineage ALL (65%), consistent with higher FPGS activity in B-lineage blasts. This finding could explain, at least in part, the superior outcome in children with B-lineage ALL treated with antimetabolite therapy.
Asunto(s)
Linfoma de Burkitt/tratamiento farmacológico , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Metotrexato/uso terapéutico , Péptido Sintasas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Linfoma de Burkitt/enzimología , Niño , Células Madre Hematopoyéticas/enzimología , Humanos , Leucemia-Linfoma de Células T del Adulto/enzimología , Metotrexato/análogos & derivados , Metotrexato/metabolismo , Ácido Poliglutámico/análogos & derivados , Ácido Poliglutámico/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologíaRESUMEN
Cellular accumulation of methotrexate polyglutamates (MTXPGs) is recognized as an important determinant of the cytotoxicity and selectivity of methotrexate in acute lymphoblastic leukemia (ALL). We identified a significantly lower cellular accumulation of MTXPGs in T-lineage versus B-lineage lymphoblasts in children with ALL, which is consistent with the worse prognosis of T-lineage ALL when treated with conventional antimetabolite-based therapy. Maximum MTXPG accumulation in leukemic blasts in vivo was 3-fold greater in lymphoblasts of children with B-lineage ALL (129 children) compared with those with T-lineage ALL (20 children) (p < 0.01) and was characterized by a saturable (Emax) model in both groups. The human leukemia cell lines NALM6 (B-lineage) and CCRF/CEM (T-lineage) were used to assess potential mechanisms for these lineage differences in MTX accumulation, revealing i) greater total and long-chain MTXPG accumulation in NALM6 over a wide range of methotrexate concentrations (0.2-100 microM), ii) saturation of MTXPG accumulation in both cell lines, with a higher maximum (Emax in NALM6, iii) 3-fold higher constitutive FPGS mRNA expression and enzyme activity in NALM6 cells, iv) 2-fold lower levels of DHFR mRNA and protein in NALM6 cells, and v) 4-6 fold lower extracellular MTX concentration and 2-fold lower intracellular MTXPG concentration to produce equivalent cytotoxicity (LC50) in NALM6 versus CEM. There was a significant relationship between FPGS mRNA and enzyme activity in lymphoblasts from children with newly diagnosed ALL, and blast FPGS mRNA and activity increased after methotrexate treatment. These data indicate higher FPGS and lower DHFR levels as potential mechanisms contributing to greater MTXPG accumulation and cytotoxicity in B-lineage lymphoblasts.
Asunto(s)
Antimetabolitos Antineoplásicos/metabolismo , Linfoma de Burkitt/enzimología , Leucemia-Linfoma de Células T del Adulto/enzimología , Metotrexato/análogos & derivados , Metotrexato/metabolismo , Péptido Sintasas/metabolismo , Ácido Poliglutámico/análogos & derivados , Tetrahidrofolato Deshidrogenasa/metabolismo , Secuencia de Bases , Linfoma de Burkitt/tratamiento farmacológico , Humanos , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Metotrexato/farmacología , Datos de Secuencia Molecular , Péptido Sintasas/genética , Ácido Poliglutámico/metabolismo , ARN Mensajero/análisis , Tetrahidrofolato Deshidrogenasa/genética , Células Tumorales CultivadasRESUMEN
PURPOSE: Previous studies have not determined the correlation between dural puncture and postural headache in paediatric patients. Furthermore, no studies have evaluated the correlation between atypical headache and dural puncture in the paediatric population. Therefore, we prospectively analyzed the incidence of typical postdural puncture headache (PDPHA) and atypical headache in paediatric oncology patients following dural puncture. METHODS: The study population consisted of 66 paediatric patients undergoing 128 consecutive procedures, including 99 lumbar punctures and 29 bone marrow aspirations without concomitant lumbar puncture. Patients were prospectively randomized into four groups: Group I, preteens (< 13 yr) undergoing lumbar puncture, Group II, adolescents (13-21 yr) undergoing lumbar puncture, Group III, preteens undergoing bone marrow aspiration, and Group IV, adolescents undergoing bone marrow aspiration. The presence and description of headache was documented immediately after dural puncture or bone marrow aspiration, and on post-procedure days # 1, 3 and 5 by personnel blinded to the type of procedure. RESULTS: There was an increase in the incidence of headache (9.1%) after lumbar puncture in patients < 21 yr relative to patients undergoing bone marrow aspiration (P < 0.05). No difference was found between the incidence of typical PDPHA after dural puncture in preteens and adolescents. There was also no difference in the incidence of atypical headache after dural puncture or after bone marrow aspiration among preteens and adolescents. CONCLUSIONS: Paediatric patients experience an increased incidence of typical postdural puncture headache after dural puncture compared with age-matched patients undergoing bone marrow aspiration only. Atypical headache is relatively common in the paediatric population after dural puncture or bone marrow aspiration.
Asunto(s)
Cefalea/etiología , Punción Espinal/efectos adversos , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Neoplasias/cirugía , Estudios ProspectivosRESUMEN
The involvement of 11q23-balanced translocations in acute leukemia after treatment with drugs that inhibit the function of DNA topoisomerase II (topo II) is being recognized with increasing frequency. We and others have shown that the gene at 11q23 that is involved in all of these treatment-related leukemias is MLL (also called ALL1, Htrx, and HRX). In general, the translocations in these leukemias are the same as those occurring in de novo leukemia [eg, t(9;11), t(11;19), and t(4;11)], with the treatment-related leukemias accounting for no more than 5% to 10% of any particular translocation type. We have cloned the t(11;16)(q23;p13.3) and have shown that it involves MLL and CBP (CREB binding protein). The CBP gene was recently identified as a partner gene in the t(8;16) that occurs in acute myelomonocytic leukemia (AML-M4) de novo and rarely in treatment-related acute myeloid leukemia. We have studied eight t(11;16) patients, all of whom had prior therapy with drugs targetting topo II with fluorescence in situ hybridization (FISH) using a probe for MLL and a cosmid contig covering the CBP gene. Both probes were split in all eight patients and the two derivative (der) chromosomes were each labeled with both probes. Use of an approximately 100-kb PAC located at the breakpoint of chromosome 16 from one patient revealed some variability in the breakpoint because it was on the der(16) in three patients, on the der(11) in another, and split in four others. We assume that the critical fusion gene is 5'MLL/3'CBP. Our series of patients is unusual because three of them presented with a myelodysplastic syndrome (MDS) most similar to chronic myelomonocytic leukemia (CMMoL) and one other had dyserythropoiesis; MDS is rarely seen in 11q23 translocations either de novo or with t-AML. Using FISH and these same probes to analyze the lineage of bone marrow cells from one patient with CMMoL, we showed that all the mature monocytes contained the fusion genes as did some of the granulocytes and erythroblasts; none of the lymphocytes contained the fusion gene. The function of MLL is not well understood, but many domains could target the MLL protein to particular chromatin complexes. CBP is an adapter protein that is involved in regulating transcription. It is also involved in histone acetylation, which is thought to contribute to an increased level of gene expression. The fusion gene could alter the CBP protein such that it is constitutively active; alternatively, it could modify the chromatin-association functions of MLL.