Asunto(s)
Linfocitos B/metabolismo , Cromosomas Humanos Par 22/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Antineoplásicos/uso terapéutico , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Incidencia , Persona de Mediana Edad , Cromosoma Filadelfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/genética , Transducción de Señal/genéticaAsunto(s)
Proteína de la Leucemia Mieloide-Linfoide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Translocación Genética , N-Metiltransferasa de Histona-Lisina , Humanos , Lactante , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Pronóstico , Resultado del TratamientoAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , ADN (Citosina-5-)-Metiltransferasas/genética , Exones/genética , Leucemia Mieloide Aguda/mortalidad , Mutación/genética , Anciano , Anciano de 80 o más Años , Citarabina/administración & dosificación , ADN Metiltransferasa 3A , Daunorrubicina/administración & dosificación , Etopósido/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Masculino , Persona de Mediana Edad , Mitoxantrona/administración & dosificación , Estadificación de Neoplasias , Pronóstico , Tasa de SupervivenciaRESUMEN
Gamma secretase inhibitors (GSIs) comprise a growing class of compounds that interfere with the membrane-bound Notch signaling protein and its downstream intra-nuclear transcriptional targets. As GSI-I (Z-LLNle-CHO) is also a derivative of a widely used proteosome inhibitor MG-132, we hypothesized that this compound might be active in precursor-B acute lymphoblastic leukemia (ALL) cell lines and patient samples. We found that GSI-I treatment of precursor-B ALL blasts induced apoptotic cell death within 18-24 h. With confirmation using RNA and protein analyses, GSI-I blocked nuclear accumulation of cleaved Notch1 and Notch2, and inhibited Notch targets Hey2 and Myc. Microarray analyses of 207 children with high-risk precursor-B ALL demonstrate that Notch pathway expression is a common feature of these neoplasms. However, microarray studies also implicated additional transcriptional targets in GSI-I-dependent cell death, including genes in the unfolded protein response, nuclear factor-κB and p53 pathways. Z-LLNle-CHO blocks both γ-secretase and proteosome activity, inducing more robust cell death in precursor-B ALL cells than either proteosome-selective or γ-secretase-selective inhibitors alone. Using Z-LLNle-CHO in a nonobese diabetes/severe combined immunodeficiency (NOD/SCID) precursor-B ALL xenograft model, we found that GSI-I alone delayed or prevented engraftment of B-lymphoblasts in 50% of the animals comprising the experimental group, suggesting that this compound is worthy of additional testing.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteínas de Neoplasias/antagonistas & inhibidores , Oligopéptidos/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/enzimología , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasoma , Receptores Notch/fisiología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Antineoplásicos/uso terapéutico , Linfocitos B/efectos de los fármacos , Linfocitos B/enzimología , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/enzimología , Niño , Estudios de Cohortes , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas de Neoplasias/efectos de los fármacos , Proteínas de Neoplasias/metabolismo , Oligopéptidos/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Inhibidores de Proteasas/uso terapéutico , Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , ARN Mensajero/metabolismo , ARN Neoplásico/metabolismo , Receptores Notch/genética , Riesgo , Organismos Libres de Patógenos Específicos , Transcripción Genética/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto JovenRESUMEN
Recent whole-genome sequencing efforts led to the identification of IDH1(R132) mutations in acute myeloid leukemia (AML) patients. We studied the prevalence and clinical implications of IDH1 genomic alterations in pediatric and adult AML. Diagnostic DNA from 531 AML patients treated on Children's Oncology Group trial COG-AAML03P1 (N=257), and Southwest Oncology Group trials SWOG-9031, SWOG-9333 and SWOG-9500 (N=274), were tested for IDH1 mutations. Codon R132 mutations were absent in the pediatric cohort, but were found in 12 of 274 adult patients (4.4%, 95% CI 2.3-7.5). IDH1(R132) mutations occurred most commonly in patients with normal karyotype, and those with FLT3/ITD and NPMc mutations. Patients with IDH1(R132) mutations trended toward higher median diagnostic white blood cell counts (59.2 x 10(9) vs 29.1 x 10(9) per liter, P=0.19) than those without mutations, but the two groups did not differ significantly in age, bone marrow blast percentage, overall survival or relapse-free survival. Eleven patients (2.1%) harbored a novel V71I sequence alteration, which was found to be a germ-line polymorphism. IDH1 mutations were not detected in pediatric AML, and are uncommon in adult AML.
Asunto(s)
Biomarcadores de Tumor/genética , Codón/genética , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Mutación/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Cariotipificación , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Proteínas Nucleares/genética , Nucleofosmina , Prevalencia , Pronóstico , Secuencias Repetidas en Tándem/genética , Adulto Joven , Tirosina Quinasa 3 Similar a fms/genéticaAsunto(s)
Glutatión Transferasa/genética , Leucemia Mieloide Aguda/genética , Polimorfismo Genético , Anciano , Anciano de 80 o más Años , Método Doble Ciego , Femenino , Genotipo , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Farmacogenética , Resultado del TratamientoAsunto(s)
Cromosomas Humanos Par 6 , Cromosomas Humanos Par 9 , Leucemia Mieloide/genética , Leucemia Mieloide/terapia , Translocación Genética , Enfermedad Aguda , Adolescente , Adulto , Anciano , Niño , Preescolar , Ensayos Clínicos como Asunto , Femenino , Humanos , Leucemia Mieloide/clasificación , Masculino , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Pronóstico , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
Relapse of acute promyelocytic leukemia (APL) following all-trans retinoic acid (ATRA) therapy has been associated with the acquisition of mutations in the high-affinity ATRA binding site in PML-RARalpha, but little information is available about the selection dynamics of the mutation-harboring subclones. In this study, 6/18 patients treated with sequential ATRA and chemotherapy on protocol INT0129 relapsed with complete replacement of the nonmutant pretreatment APL cell population by a PML-RARalpha mutant subclone. Two patients relapsed in proximity of ATRA treatment; however, in four patients there was a 6-48 month hiatus between the last ATRA treatment and relapse. The mutant subclones were not detectable in samples tested > or = 3 months before relapse at > or = 1 in 10(2) (10(-2)) sensitivity. In one patient, a functionally weak mutation was detected at 10(-4) sensitivity before therapy but only limited pre-relapse enrichment of the mutant subclone was observed on subsequent ATRA therapy. These results indicate that proximate ATRA selection pressure is frequently not the main determinant for the emergence of strongly dominant PML-RARalpha mutant subclones and suggest that APL subclones harboring PML-RARalpha mutations are predisposed to the acquisition of secondary genetic/epigenetic alterations that result in a growth/survival advantage.
Asunto(s)
Resistencia a Antineoplásicos/genética , Leucemia Promielocítica Aguda/genética , Proteínas de Neoplasias/genética , Proteínas de Fusión Oncogénica/genética , Tretinoina/efectos adversos , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Sitios de Unión , Linaje de la Célula , Células Clonales , Epigénesis Genética , Humanos , Leucemia Promielocítica Aguda/tratamiento farmacológico , Mutación , Proteínas de Neoplasias/efectos de los fármacos , Proteínas de Fusión Oncogénica/efectos de los fármacos , Recurrencia , Inducción de Remisión , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Relación Estructura-Actividad , Tretinoina/farmacología , Tretinoina/uso terapéuticoRESUMEN
Minimal residual disease (MRD) can be detected in the marrows of children undergoing chemotherapy either by flow cytometry or polymerase chain reaction. In this study, we used four-color flow cytometry to detect MRD in 1016 children undergoing therapy on Children's Oncology Group therapeutic protocols for precursor-B-cell ALL. Compliance was excellent, with follow-up samples received at the end of induction on nearly 95% of cases; sensitivity of detection at this time point was at least 1/10,000 in more than 90% of cases. Overall, 28.6% of patients had detectable MRD at the end of induction. Patients with M3 marrows at day 8 were much more likely to be MRD positive (MRD+) than those with M2 or M1 marrows. Different genetically defined groups of patients varied in their prevalence of MRD. Specifically, almost all patients with BCR-ABL had high levels of end-of-induction MRD. Only 8.4% of patients with TEL-AML1 were MRD+>0.01% compared with 20.3% of patients with trisomies of chromosomes 4 and 10. Our results show that MRD correlates with conventional measures of slow early response. However, the high frequency of MRD positivity in favorable trisomy patients suggests that the clinical significance of MRD positivity at the end of induction may not be the same in all patient groups.
Asunto(s)
Neoplasia Residual/etiología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Adolescente , Médula Ósea/patología , Niño , Cromosomas Humanos Par 10 , Cromosomas Humanos Par 4 , Subunidad alfa 2 del Factor de Unión al Sitio Principal , Femenino , Citometría de Flujo/normas , Proteínas de Fusión bcr-abl/análisis , Humanos , Masculino , Técnicas de Diagnóstico Molecular/normas , Neoplasia Residual/diagnóstico , Proteínas de Fusión Oncogénica/análisis , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Factores de Riesgo , Sensibilidad y Especificidad , TrisomíaRESUMEN
The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is a rate-limiting enzyme in the mevalonate biochemical pathway and HMG-CoA reductase inhibitors (statins) show toxicity for certain tumors, including acute myeloid leukemia (AML). This toxicity has been attributed to statin inhibition of Ras isoprenylation in tumors like AML where oncogenic ras mutations and/or overexpression are common. We show that mevastatin kills certain AML cell lines and is more toxic to a majority of primary AML cell samples than to myeloid cells in bone marrow (BM) samples from normal donors, and that mevastatin can produce more than additive kill with standard chemotherapeutics. Mevastatin reduces Ras membrane localization, but statin sensitivity in primary AML cells is not consistently associated with ras mutations nor with Ras overexpression, suggesting that another mevalonate pathway by-product(s) is the statin target in at least some AMLs.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Leucemia Mieloide/patología , Lovastatina/análogos & derivados , Lovastatina/farmacología , Enfermedad Aguda , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/patología , Estudios de Casos y Controles , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Leucemia Mieloide/tratamiento farmacológico , Mutación , Células Mieloides/efectos de los fármacos , Células Tumorales Cultivadas , Proteínas ras/genética , Proteínas ras/metabolismoRESUMEN
We have developed a sensitive and quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay for detection of PML-RARalpha, the fusion oncogene present as a specific marker in >99% of cases of acute promyelocytic leukemia (APL). The assay is linear over at least 5 orders of magnitude of input DNA or RNA, and detects as few as 4 copies of PML-RARalpha plasmid DNA. PML-RARalpha transcripts could be detected in mixtures containing 2 to 5 pg of RNA from fusion-containing cells in a background of 1 microg of RNA from PML-RARalpha-negative cells. Using 1.0 to 2.5 microg of input RNA, the sensitivity of the assay was between 10(-5) and 10(-6). Furthermore, determination of GAPDH copy number in each reaction allowed an accurate assessment of sample-to-sample variation in RNA quality and reaction efficiency, with consequent definition of a detection limit for each sample assayed. Using an internal calibrator, assay precision was high, with coefficients of variation between 10 and 20%. An interlaboratory study using coded samples demonstrated excellent reproducibility and high concordance between laboratories. This assay will be used to test the hypothesis that sensitive and quantitative measurement of leukemic burden, during or after therapy of APL, can stratify patients into discrete risk groups, and thereby serve as a basis for risk-adapted therapy in APL.
Asunto(s)
Leucemia Promielocítica Aguda/diagnóstico , Proteínas de Neoplasias/genética , Proteínas de Fusión Oncogénica/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Biomarcadores de Tumor , Sistemas de Computación , ADN Recombinante/genética , Gliceraldehído-3-Fosfato Deshidrogenasas , Humanos , Plásmidos/genética , ARN Mensajero/análisis , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Células Tumorales CultivadasRESUMEN
Cyclosporine A (CsA) inhibits P-glycoprotein (Pgp)-mediated cellular export of anthracyclines at clinically achievable concentrations. This randomized controlled trial was performed to test the benefit of CsA addition to treatment with cytarabine and daunorubicin (DNR) in patients with poor-risk acute myeloid leukemia (AML). A total of 226 patients were randomly assigned to sequential treatment with cytarabine and infusional DNR with or without intravenous CsA. Remitting patients received one course of consolidation chemotherapy that included DNR with or without CsA as assigned during induction. Addition of CsA significantly reduced the frequency of resistance to induction chemotherapy (31% versus 47%, P =.0077). Whereas the rate of complete remission was not significantly improved (39% versus 33%, P =.14), relapse-free survival (34% versus 9% at 2 years, P =.031) and overall survival (22% versus 12%, P =.046) were significantly increased with CsA. The effect of CsA on survival was greatest in patients with moderate or bright Pgp expression (median 12 months with CsA versus 4 months for controls) compared to patients with absent or low Pgp expression (median 6 months in both arms). The frequency of induction deaths was 15% with CsA and 18% in controls. Steady-state serum concentrations of DNR (P =.0089) and daunorubicinol (P <.0001) were significantly higher in CsA-treated patients. Survival (P =.0003) and induction response (P =.028) improved with increasing DNR concentration in CsA-treated patients but not in controls, suggesting a targeted interaction by CsA to enhance anthracycline cytotoxicity. These results indicate that addition of CsA to an induction and consolidation regimen containing infusional DNR significantly reduces resistance to DNR, prolongs the duration of remission, and improves overall survival in patients with poor-risk AML.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Ciclosporina/uso terapéutico , Resistencia a Antineoplásicos , Leucemia Mieloide Aguda/tratamiento farmacológico , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/análisis , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ciclosporina/administración & dosificación , Ciclosporina/efectos adversos , Citarabina/administración & dosificación , Citarabina/efectos adversos , Citarabina/uso terapéutico , Análisis Citogenético , Daunorrubicina/administración & dosificación , Daunorrubicina/efectos adversos , Daunorrubicina/uso terapéutico , Supervivencia sin Enfermedad , Interacciones Farmacológicas , Expresión Génica , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , Inducción de Remisión , Factores de RiesgoRESUMEN
Internal tandem duplications (ITDs) of the FLT3 gene occur in approximately 20-30% of acute myeloid leukemia (AML) patients. We investigated if FLT3 ITDs could be used as minimal residual disease (MRD) markers for AML patients. Patient-specific polymerase chain reaction (PCR) assays for FLT3 ITDs were developed for four AML samples that contained FLT3 ITDs of varying size and location. The real-time, quantitative PCR assays for FLT3 ITDs were highly sensitive and specific, detecting between 0.01 and 0.001% of FLT3 ITD positive DNA in a background of 1 microg of normal bone marrow DNA. Our findings suggest that FLT3 ITDs can be used as molecular markers for MRD in patients with AML.
Asunto(s)
Leucemia Mieloide Aguda/diagnóstico , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras/genética , Secuencias Repetidas en Tándem , Humanos , Neoplasia Residual , Sensibilidad y Especificidad , Tirosina Quinasa 3 Similar a fmsRESUMEN
While beta 2 integrin ligand-receptor recognition interactions are well characterized, less is known about how these events trigger signal transduction cascades to regulate the transition from tethering to firm adhesion, spreading, and transendothelial migration. We have identified critical positive and negative regulatory components of this cascade in monocytes. Whereas the Syk tyrosine kinase is essential for beta 2 integrin signaling and cell spreading, the Src family kinase Fgr is a negative regulator of this pathway. Fgr selectively inhibits beta 2 but not beta 1 integrin signaling and Syk kinase function via a direct association between the Fgr SH2 domain and Syk tyrosine Y342. The inhibitory effects of Fgr are independent of its kinase activity, are dose dependent, and can be overcome by chemokines and inflammatory mediators.
Asunto(s)
Antígenos CD18/fisiología , Adhesión Celular , Precursores Enzimáticos/antagonistas & inhibidores , Monocitos/fisiología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/fisiología , Transducción de Señal , Animales , Adhesión Celular/efectos de los fármacos , Línea Celular , Tamaño de la Célula , Células Cultivadas , Quimiocinas/farmacología , Precursores Enzimáticos/química , Precursores Enzimáticos/fisiología , Péptidos y Proteínas de Señalización Intracelular , Macrófagos/citología , Macrófagos/fisiología , Ratones , Ratones Noqueados , Monocitos/citología , Proteínas Tirosina Quinasas/química , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/fisiología , Proteínas Proto-Oncogénicas/química , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-hck , Quinasa Syk , Transfección , Dominios Homologos src , Familia-src QuinasasRESUMEN
The prevalence and significance of genetic abnormalities in older patients with acute myeloid leukemia (AML) are unknown. Polymerase chain reactions and single-stranded conformational polymorphism analyses were used to examine 140 elderly AML patients enrolled in the Southwest Oncology Group study 9031 for FLT3, RAS, and TP53 mutations, which were found in 34%, 19%, and 9% of patients, respectively. All but one of the FLT3 (46 of 47) mutations were internal tandem duplications (ITDs) within exons 11 and 12. In the remaining case, a novel internal tandem triplication was found in exon 11. FLT3 ITDs were associated with higher white blood cell counts, higher peripheral blast percentages, normal cytogenetics, and less disease resistance. All RAS mutations (28 of 28) were missense point mutations in codons 12, 13, or 61. RAS mutations were associated with lower peripheral blast and bone marrow blast percentages. Only 2 of 47 patients with FLT3 ITDs also had a RAS mutation, indicating a significant negative association between FLT3 and RAS mutations (P =.0013). Most TP53 mutations (11 of 12) were missense point mutations in exons 5 to 8 and were associated with abnormal cytogenetics, especially abnormalities in both chromosomes 5 and 7. FLT3 and RAS mutations were not associated with inferior clinical outcomes, but TP53 mutations were associated with a worse overall survival (median 1 versus 8 months, P =.0007). These results indicate that mutations in FLT3, RAS, or TP53 are common in older patients with AML and are associated with specific AML phenotypes as defined by laboratory values, cytogenetics, and clinical outcomes. (Blood. 2001;97:3589-3595)
Asunto(s)
Envejecimiento , Genes ras/genética , Leucemia Mieloide Aguda/genética , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras/genética , Proteína p53 Supresora de Tumor/genética , Anciano , Anciano de 80 o más Años , Exones , Frecuencia de los Genes , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Pronóstico , Tirosina Quinasa 3 Similar a fmsAsunto(s)
Leucemia Mieloide Aguda/tratamiento farmacológico , Metilación de ADN , Perfilación de la Expresión Génica , Inhibidores de Histona Desacetilasas , Humanos , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/fisiología , Proteínas de Fusión Oncogénica/fisiología , Translocación Genética , Tretinoina/uso terapéuticoRESUMEN
Aberrant methylation of multiple CpG islands has been described in acute myeloid leukemia (AML), but it is not known whether these are independent events or whether they reflect specific methylation defects in a subset of cases. To study this issue, the methylation status of 14 promoter-associated CpG islands was analyzed in 36 cases of AML previously characterized for estrogen-receptor methylation (ERM). Cases with methylation density of 10% or greater were considered positive. Seventeen cases (47%) were ERM(+) while 19 cases were ERM(-). Hypermethylation of any of the following, p15, p16, CACNA1G, MINT1, MINT2, MDR1, THBS1, and PTC1 (2 promoters), was relatively infrequent (6% to 31% of patients). For each of these CpG islands, the methylation density was positively correlated with ERM density (rank order correlation coefficients, 0.32-0.59; 2-tailed P < or = .058 for each gene). Hypermethylation of MYOD1, PITX2, GPR37, and SDC4 was frequently found in AML (47% to 64% of patients). For each of these genes as well, methylation density was positively correlated with ERM density (correlation coefficients 0.43 to 0.69, P < or = .0087 for each gene). MLH1 was unmethylated in all cases. Hypermethylation of p15, MDR1, and SDC4 correlated with reduced levels of expression. There was an inverse correlation between age and the number of genes methylated (P = .0030). It was concluded that CpG-island methylation in AML results from methylation defects in subsets of cases. These results have potential implications for the classification and prognosis of AML and for the identification of patients who may benefit from treatment with methylation inhibitors.
Asunto(s)
Metilación de ADN , ADN de Neoplasias/genética , Leucemia Mieloide/genética , Enfermedad Aguda , Adolescente , Adulto , Factores de Edad , Anciano , ADN de Neoplasias/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Regiones Promotoras GenéticasRESUMEN
In vitro culture systems that parallel in vivo growth conditions are needed to study leukemia biology and to accurately test therapeutic efficacies. We investigated the effects of the HS-5 human bone marrow stromal cell line on cultured primary leukemia cell survival and chemosensitivity.A total of 30 bone marrow (BM) samples from untreated acute myeloid leukemia (AML) patients were cultured for 96 hours with serum and growth factors, without HS-5, or in direct contact with HS-5 monolayers, or with HS-5 separated from AML cells by transwell inserts. In some experiments, cytosine arabinoside or daunomycin was added for the last 18 hours of culture. Apoptosis frequencies, bcl-2 protein expression, proliferating cell nuclear antigen expression, and cell cycle distributions were determined in four-color flow cytometry analyses of CD45(+) leukemia cells. In comparison to control growth conditions, direct contact with HS-5 significantly inhibited culture-induced and drug-induced apoptosis of AML cells. Direct contact of AML cells with HS-5 significantly increased short-term proliferation and viability, and colony formation of primary AML cells. HS-5-mediated apoptosis inhibition was not consistently associated with increased bcl-2 protein in AML cells. Noncontact conditions inhibited drug-induced apoptosis significantly less than direct contact with HS-5. Coculture of AML cells on HS-5 monolayers improved in vitro leukemia cell survival and attenuated chemotherapy-induced leukemia cell killing. This has practical significance, increasing the fraction of primary AML samples that can be analyzed in vitro, and allows drug sensitivity testing in growth conditions more similar to the bone marrow microenvironment.