RESUMEN
The occurrence of minimal residual disease is an important prognostic factor under acute lymphoblastic leucosis in children and adults. In overwhelming majority of research studies bone marrow is used to detect minimal residual disease. The comparative characteristic of detection of minimal residual disease in peripheral blood and bone marrow was carried out. The prognostic role of occurrence of minimal residual disease in peripheral blood and bone marrow under therapy according protocol MLL-Baby was evaluated. The analysis embraced 142 pair samples from 53 patients with acute lymphoblastic leucosis and various displacements of gene MLL younger than 365 days. The minimal residual disease was detected by force of identification of chimeric transcripts using polymerase chain reaction in real-time mode in 7 sequential points of observation established by protocol of therapy. The comparability of results of qualitative detection of minimal residual disease in bone marrow and peripheral blood amounted to 84.5%. At that, in all 22 (15.5%) discordant samples minimal residual disease was detected only in bone marrow. Despite of high level of comparability of results of detection of minimal residual disease in peripheral blood and bone marrow the occurrence of minimal residual disease in peripheral blood at various stages of therapy demonstrated no independent prognostic significance. The established differences had no relationship with sensitivity of method determined by value of absolute expression of gene ABL. Most likely, these differences reflected real distribution of tumor cells. The results of study demonstrated that application of peripheral blood instead of bone marrow for monitoring of minimal residual disease under acute lymphoblastic leucosis in children of first year of life is inappropriate. At the same time, retention of minimal residual disease in TH4 in bone marrow was an independent and prognostic unfavorable factor under therapy of acute lymphoblastic leucosis of children of first year of life according protocol MLL-Baby (OO=7.326, confidence interval 2.378-22.565).
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Médula Ósea/patología , N-Metiltransferasa de Histona-Lisina/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras , Femenino , Humanos , Lactante , Masculino , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , PronósticoRESUMEN
AIM: The objective of this study was to investigate expression of drug resistance associated genes in CD34+ and CD34- leukemic subpopulations in childhood acute lymphoblastic leukemia (ALL). METHODS: ALL samples with heterogeneous CD34 expression were separated into CD34-positive and CD34-negative subpopulations and mRNA levels of MDR1, LRP, BCRP and BCL-2 genes were compared. RESULTS: BCL-2 gene expression levels did not differ significantly between CD34+ vs CD34- subpopulations in most analyzed ALL cases. Oppositely, MDR1 gene had >two-fold differences in expression levels between subpopulations in the majority of ALL cases. In T-lineage ALL CD34- fractions had increased level of BCRP and LRP genes in comparison with CD34+ ones whereas in most of B-lineage ALL expression of these genes did not differ. CONCLUSION: It was not found the unique pattern of resistance related genes expression in CD34+ vs CD34- subpopulations. However, in majority of studied pediatric ALL cases with CD34 heterogeneous expression one of subpopulations (positive or negative) could have an advantage for survival through elevated expression of drug resistance related genes.
Asunto(s)
Antígenos CD34/análisis , Resistencia a Antineoplásicos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Subfamilia B de Transportador de Casetes de Unión a ATP , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Adolescente , Línea Celular Tumoral , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Proteínas de Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Partículas Ribonucleoproteicas en Bóveda/genéticaRESUMEN
AIM: To perform the comparative study of the effects of DNA-dependent protein kinase (DNA-PK) inhibitors vanillin and NU7026, ataxia telangiectasia mutated kinase (ATM)/ ATM and Rad3 related (ATR) kinase inhibitor caffeine and multidrug resistance (MDR) protein modulator cyclosporine A (CsA) on fludarabine resistant and sensitive lymphocytes from chronic lymphocytic leukemia (CLL) patients. METHODS: Cells sensitivity in vitro was determined with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). DNA-PKs and ATM expression in CLL cells was evaluated using Western blotting. Multidrug tansporter protein expression and function was assessed by flow cytometry. Pro- or anti-apoptotic genes (BAX, LICE BCL-2, BCL-XS FLICE, FAS, TRAIL) expression on mRNA level was evaluated. RESULTS: Caffeine, vanillin, NU7026 and CsA increased fludarabine cytotoxicity against fludarabine-resistant CLL cells samples in comparison with sensitive cell samples. However, fludarabine-sensitive CLL samples were sensitized with inhibitors to a greater extent compared with resistant CLL samples. ATM expression increased in fludarabine-resistant CLL samples, but no apparent correlation between DNA-PKs level and fludarabine sensitivity in vitro or sensitization effect of DNA-PK inhibitors were observed. Fludarabine-resistant CLL lymphocytes showed tendency for depressed MDR efflux and decreased level of mRNA of pro-apoptotic gene BCL-XS. CONCLUSION: Absence of any definite conformity between fludarabine-resistant cell susceptibility to combined action of fludarabine and inhibitors, and molecular pathways that might be involved in this process does not exclude drugs synergy in fludarabine-resistant cells that could be used for overcoming resistance to nucleoside analogs in CLL.