The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02 / 中国实验血液学杂志

OBJECTIVE@#To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia.@*METHODS@#CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups.@*RESULTS@#The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01).@*CONCLUSION@#There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.

Establishment of leukemia cell model with inducible AML1-ETO expression and its effect on fatty acid metabolism in leukemia cells / 中华血液学杂志

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (P<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (P<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (P<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (P<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (P<0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.

Study on the Relationship between the Level of Soluble HLA-E Molecules in Plasma and Gene Polymorphism and Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the relationship between the level of soluble HLA-E (sHLA-E) molecules in plasma and gene polymorphism and leukemia in Shenzhen of China.@*METHODS@#Enzyme-linked immunosorbent assay was used to detect sHLA-E level in plasma of 103 leukemia patients and 113 healthy blood donors. PCR-SBT was used to identify the HLA-E genotype of 73 leukemia patients and 76 healthy blood donors.@*RESULTS@#The level of plasma sHLA-E of 103 leukemia patients was significantly higher than that of 113 healthy blood donors (P<0.001); And the level of plasma sHLA-E in 77 myeloid leukemia patients was also significantly higher (P<0.001). The percentage of patients with plasma sHLA-E concentration of 0-199 ng/ml in leukemia and myeloid leukemia patients was 37.86% and 32.47%, respectively, which was significantly lower than 53.98% of healthy donors, the difference was statistically significant (P<0.05, P<0.01); While, when the plasma sHLA-E concentration was more than 400 ng/ml, the percentage was 33.01% and 36.36%, respectively, which was significantly higher than 13.28% of healthy donors, the difference was also statistically significant (P=0.001, P<0.001). There was no significant difference in the level of plasma sHLA-E among different HLA-E genotypes (P>0.05), whether healthy blood donors or leukemia patients.@*CONCLUSION@#The level of plasma sHLA-E in patients with leukemia (especially myeloid leukemia) is significantly higher than that of healthy blood donors, but different HLA-E genotypes do not affect the level of plasma sHLA-E. A cut-off value for the concentration of plasma sHLA-E (recommended risk value >400 ng/ml) can be set to assess the risk of certain pre-leukemia patients.

Analysis of loss of heterozygosity at HLA loci in a patient with leukemia / 中华医学遗传学杂志

OBJECTIVE@#To detect loss of heterozygosity (LOH) at human leukocyte antigen (HLA) loci in a Chinese patient with leukemia after haploidentical hematopoietic stem cell transplantation.@*METHODS@#HLA genotyping was carried out on peripheral blood, hair follicle and buccal swab samples derived from the patient after the transplantation as well as peripheral blood samples from his parents by using PCR-sequence specific oligonucleotide probe method and PCR-sequence based typing method. Short tandem repeat (STR) loci were detected by using a 23 site STR assay kit and a self-developed 6 STR loci assay for the HLA regions.@*RESULTS@#After the transplantation, the HLA genotype of the peripheral blood sample of the patient was identical to his father. The patient was HLA-A*02:01,24:02, C*03:03,03:04, B*13:01,15:01, DRB1*08:03,12:02, DQB1*03:01,06:01 for his hair follicle specimen. However, homozygosity of the HLA loci was found in his buccal swab sample. Only the HLA-A*24:02-C*03:03-B*15:01-DRB1*08:03-DQB1*06:01 haplotype from his father's was present, while the HLA-A*02:01-C*03:04-B*13:01-DRB1*12:02-DQB1*03:01 haplotype from his mother was lost. After the transplantation, the alleles of the 23 STR sites in the patient's peripheral blood sample were consistent to his father, with no allelic loss detected in his buccal swab sample. However, at least 4 STR loci in the HLA region were lost in his buccal swab sample.@*CONCLUSION@#LOH at the HLA loci has been detected in the buccal swab sample of a patient with leukemia who received haploidentical hematopoietic stem cell transplantation.

Alternative Splicing Analysis of LACTB Gene and Expression Characteristics of Different Transcripts in Leukemia Cell Lines / 中国实验血液学杂志

OBJECTIVE@#To detect the expression of different transcripts of lactamase β（LACTB) gene in leukemic cell lines.@*METHODS@#NCBI website and DNAstar software were used to detect the Bioinformatics analysis of LACTB. The expression of different transcripts of LACTB gene in leukemic cell lines (THP-1, HL60, K562, U937, Jurkat and Raji) was detected by reverse transcription PCR (RT-PCR), DNA and clone sequencing; the expression of different transcripts of LACTB gene in leukemic cell lines was detected by Quantitative Real-time PCR.@*RESULTS@#There were a variety of splicing isomers in LACTB, and it could produce a variety of protein isomers with conserved N-terminal and different C-terminal, moreover, there were many splice isoforms of LACTB in leukemia cell lines, and there were different expression patterns in different cell lines, including XR1, V1, V2 and V3. The expression of total LACTB showed high in HL60 cells, while low in Raji cells, and the difference was statistically significant (P<0.05). The V1 was high expression in U937 cells but low in Raji cells, and the difference was statistically significant (P<0.05). V2 was high expression in HL60 cells but lowly in Raji cells, and the difference was statistically significant (P<0.05). The expression of V3 was low in THP-1 cells, which was significantly different as compared with that in normal bone marrow (P<0.05).@*CONCLUSION@#The reaserch found that there are many splice isomers of LACTB in leukemic cell lines, and there are different expression patterns in different cell lines.

Regulatory mechanism of long noncoding RNA in the occurrence and development of leukemia: a review / 生物工程学报

Long noncoding RNAs (lncRNAs) are a class of RNA molecules that are greater than 200 nt in length and do not have protein-coding capabilities or encode micropeptides only. LncRNAs are involved in the regulation of cell proliferation, differentiation, apoptosis and other biological processes, and are closely associated with the occurrence, recurrence and metastasis of a variety of malignant hematologic diseases. This article summarizes the function, regulatory mechanism and potential clinical application of lncRNAs in leukemia. In general, lncRNAs regulate the occurrence and development of leukemia and the multi-drug resistance in chemotherapy through epigenetic modification, ribosomal RNA transcription, competitive binding with miRNA, modulating glucose metabolic pathway, and activating tumor-related signaling pathway. Studies on lncRNAs provide new references for understanding the pathogenesis of leukemia, uncovering new prognostic markers and potential therapeutic targets, and addressing the problems of drug resistance and post-treatment recurrence in patients in clinical treatment of leukemia.

Infant leukemia

An eleven-month-old Bahraini infant girl, born full-term, vaccinated up-to-age, with normal milestone development; she was referred from King Hamad University Hospital [KHUH] with one-month history of high grade on and off fever associated with cough; her CBC showed anemia [7.4g/dl] and thrombocytopenia [30x109/L]. On examination, multiple bruises and small cervical lymph nodes were observed. CBC showed blasts [30%]. Bone marrow aspiration, flow cytometry and cytogenetic were sent for Mixed Lineage Leukemia [MLL] rearrangement. She was low risk; she received chemotherapy. This case was reported because of its rarity and up-to-date chemotherapy modalities which is linked to specific cytogenetic abnormality

Peritraumatic tonic immobility is associated with PTSD symptom severity in Brazilian police officers: a prospective study

Objective: Peritraumatic reactions feature prominently among the main predictors for development of posttraumatic stress disorder (PTSD). Peritraumatic tonic immobility (PTI), a less investigated but equally important type of peritraumatic response, has been recently attracting the attention of researchers and clinicians for its close association with traumatic reactions and PTSD. Our objective was to investigate the role of PTI, peritraumatic panic, and dissociation as predictors of PTSD symptoms in a cohort of police recruits (n=132). Methods: Participants were asked to complete the following questionnaires during academy training and after the first year of work: Posttraumatic Stress Disorder Checklist - Civilian Version (PCL-C), Physical Reactions Subscale (PRS), Peritraumatic Dissociative Experiences Questionnaire (PDEQ), Tonic Immobility Scale (TIS), and Critical Incident History Questionnaire. Results: Employing a zero-inflated negative binomial regression model, we found that each additional point in the TIS was associated with a 9% increment in PCL-C mean scores (RM = 1.09), whereas for PRS, the increment was 7% (RM = 1.07). As the severity of peritraumatic dissociation increased one point in the PDEQ, the chance of having at least one symptom in the PCL-C increased 22% (OR = 1.22). Conclusions: Our findings highlight the need to expand investigation on the incidence and impact of PTI on the mental health of police officers. .

Four Cases of Chronic Myelogenous Leukemia in Mixed Phenotype Blast Phase at Initial Presentation Mimicking Mixed Phenotype Acute Leukemia with t(9;22)

No abstract available.

Inmunofenotipos aberrantes en leucemias agudas en una población hospitalaria de Buenos Aires / Aberrant immunophenotypes in acute leukemia in a Buenos Aires' hospital population

La citometría de flujo multiparamétrica es el método de elección para la caracterización inmunofenotípica de las células hematopoyéticas clonales presentes en los distintos procesos leucémicos agudos. El objetivo fue analizar la expresión de antígenos de membrana y evaluar la presencia de fenotipos aberrantes en los blastos de pacientes con diagnóstico de leucemia aguda, que permiten el monitoreo de la respuesta al tratamiento. Se revisaron los inmunofenotipos de 364 muestras de pacientes adultos derivadas a nuestro laboratorio en un período de 7 años. El inmunofenotipo se realizó por citometría de flujo con un amplio panel de anticuerpos monoclonales con el que se evaluó la expresión de antígenos de linaje linfoide, mieloide y también antígenos de maduración. De las 364 muestras estudiadas, 60.2% presentaron un fenotipo compatible con leucemia mieloide aguda (LMA), 28.8% con leucemia linfoblástica B (LLA-B), 6.6% con leucemia linfoblástica T (LLA-T) y 4.4% con leucemias agudas poco frecuentes. La presencia de fenotipos aberrantes se observó en 89% de los casos, los fenotipos aberrantes identificados fueron: 1) infidelidad de linaje: LMA (54%), LLA-B (40%), LLA-T (29%); 2) ausencia de expresión antigénica: LMA (21%), LLA-B (35%), LLA-T (70%); 3) alteración de la expresión antigénica: LMA (67%), LLA-B (66%), LLA-T (84%); 4) asincronismo madurativo: LMA (26%), LLA-B (37%) y 5) fenotipo ectópico: LLA-T 96%). El análisis por citometría de flujo multiparamétrica de las leucemias agudas permitió la identificación de fenotipos aberrantes en la mayoría de nuestros pacientes, que son de utilidad para el monitoreo de la respuesta al tratamiento.

Multiparameter flow cytometry (MFC) has become the preferred method for the lineage assignment and maturational analysis of malignant cells in acute leukemias. Multiparametric immunophenotyping analysis allows the detection of aberrant antigen expression and the analysis of heterogeneity and clonality of malignant cells in leukemias. Our objectives were to analyze the membrane antigen expression and to evaluate if the aberrant phenotypes occurrence in blasts cells of patients with acute leukemia is useful in monitoring the response to the treatment. We have retrospectively analyzed the MFC data of 364 samples sent to our laboratory in a 7 years period. For this purpose we have used a large panel of monoclonal antibodies against lymphoid, myeloid and precursors antigens. From the 364 analyzed samples, 60.2% showe d a phenotype compatible with acute myeloid leukemia (AML), 28.8% with B lymphoblastic leukemia (B-LLA), 6.6% with T lymphoblastic leukemia (T-LLA) and 4.4% with rare leukemias. Aberrant phenotypes were found in 86% of the samples. The aberrant phenotypes identified were:1) lineage infidelity AML (54%), B-ALL (40%), T-ALL (29%); 2) absence of antigen expression: AML (21%), B-ALL (35%), T-ALL (70%); 3) altered antigen expression: AML (67%), B-ALL (66%),T-ALL (84%); 4) asynchronous expression: AML (26%), B-ALL (37%) and 5) ectopic phenotype: T-ALL (96%). Multiparameter flow cytometry of acute leukemias allowed identification of aberrant phenotypes in the majority of our patients, that are helpful for monitoring treatment response.

A novel deletion cluster at 13q14.2-q21.33 in an 80-year man with late onset leukemia: Clinical and molecular findings.

Chromosomal deletions are among the most common genetic events observed in hematologic malignancies; loss of genetic material is regarded as a hallmark of putative tumor suppressor gene localization. We have identified an unusual cluster of deletions at 13q14.2-13q21.33 in an 80-year-old father of a monozygotic twin pair discordant for schizophrenia, who developed chronic leukemia (CLL) at age 69. MATERIALS AND METHODS: The breakpoints for individual deletions in this cluster was identified by Affymetrix Human Array 6.0 screening. RESULTS: The deleted segments harbours a number of genes, most associated with cancer as well as a high concentration of LINEs, SINEs and related repeats. The derived chromosome represents an intra-chromosomal re-arrangement that quickly overtook blood progenitor cells probably before age 69 as a cause of CLL. CONCLUSIONS: The study highlights the role of ongoing de novo changes at susceptible sites, such as repeat rich regions, in the human genome. Also, it argues for the involvement of genes/deletions in the 13q(14.2-21.33) region in the development of CCL.

Two Cases of Near-Tetraploidy in Acute Leukemias of Ambiguous Lineage

No abstract available.

Letter to the Editor: Diagnostic Standardization of Leukemia Fusion Gene Detection System using Multiplex Reverse Transcriptase-polymerase Chain Reaction in Korea

No abstract available.

The Author Response: Diagnostic Standardization of Leukemia Fusion Gene Detection System using Multiplex Reverse Transcriptase-polymerase Chain Reaction in Korea

No abstract available.

Polimorfismos genéticos y su influencia en la efectividad del tratamiento quimioterapéutico de pacientes leucémicos / Genetic polymorphisms and its influence in chemotherapeutic treatment of leukemic patients

En Chile la incidencia de leucemia es de 4.2/100.000 adultos al año. Dentro de ellas, 2,8/100.000 son leucemias agudas y 1,4/100.000 son leucemias crónicas. La quimioterapia para el cáncer ha progresado desde su introducción a la práctica clínica y constituye una modalidad terapéutica muy útil en las leucemias. Sin embargo, su uso se ve limitado por la imposibilidad de predecir la respuesta individual, por lo que la elección de la terapia suele ser en base a criterios médicos y de las guías clínicas establecidas. Esta variación inter-individual en la respuesta a un fármaco antineoplásico puede deberse a factores farmacocinéticos y/o farmacodinámicos, relacionados con otros factores genético-metabólicos, que se traducen en variantes polimórficas de las enzimas encargadas de la biotransformación de estos fármacos o receptores. Al respecto, se estima que la genética da cuenta entre un 20 a un 95 por ciento de la variabilidad en la respuesta terapéutica y toxicológica. De todas las drogas conocidas involucradas en reacciones adversas un 80 por ciento son metabolizadas por estas enzimas. Este artículo pretende dar una visión general acerca de la respuesta potencial de los pacientes sometidos a los protocolos quimioterapéuticos establecidos en Chile para las leucemias de acuerdo a sus perfiles genéticos en las enzimas de biotransformación involucradas.

In Chile, the incidence of leukemia is 4.2/100.000 adults a year. Among them, 2.8/100.000 is acute leukemia and 1.4/100.000 chronic leukemia. The chemotherapy for cancer has been improved through the years in clinical practice and it constitutes a very useful therapeutic option in leukemia. However, its use is limited due to uncertain response; therefore, the pharmacotherapy choice is mainly empiric. In this sense the inter-individual differences in response to antineoplastic drugs could be due to pharmacokinetic factors (affecting absorption, distribution, metabolism and excretion) or pharmacodinamics (affecting receptors or another pharmacological target). It is estimated that genetics accounts for 20 to 95 percent of variability in therapeutics and toxicological response to drugs, which are mainly metabolized through polymorphic biotransformation enzymes (80 percent). Therefore, the present review gives a comprehensive study of the probable response of patients to established leukemia chemotherapy treatment in Chile according their genetic profiles on involved metabolizing enzymes.

Preferential induction of MLL (Mixed Lineage Leukemia) rearrangements in human lymphocyte cultures treated with etoposide

Topoisomerase II inhibitors are effective chemotherapeutic agents in the treatment of cancer, in spite of being associated with the development of secondary leukemia. Our purpose was to determine the effects of etoposide on different genomic regions, aiming at discovering whether there are preferential sites which can be targeted by this drug in peripheral lymphocytes from healthy individuals. The in vitro treatment with low doses of etoposide (0.25, 0.5, and 1 µg/mL, in 1 hour-pulse or continuous-48 h treatment) induced a significant increase in chromosomal aberrations, detected by conventional staining and FISH with specific probes for chromosomes 8 and 11, compared with untreated controls (p < 0.05). Additionally, the frequencies of alterations at 11q23, detected by MLL specific probes, were significantly higher (p < 0.005) in treated cells than in controls. In contrast, an analysis of rearrangements involving the IGH gene did not disclose differences between treatments. The present results demonstrated the potential of etoposide to interact with preferential chromosome sites in human lymphocytes, even at concentrations below the mean plasma levels measured in cancer patients. This greater susceptibility to etoposide-induced cleavage may explain the more frequent involvement of MLL in treatment-related leukemia.

Leucemia: fatores prognósticos e genética: [revisão] / Leukemia: genetics and prognostic factors: [review]

OBJETIVO: Apresentar as implicações da genética, particularmente das técnicas de citogenética, no diagnóstico e prognóstico das leucemias. FONTES DOS DADOS: Levantamento de artigos selecionados no MEDLINE, através dos programas educacionais da American Society of Hematology, Portal de Periódicos da CAPES, National Comprehensive Cancer Network e capítulos de livros. SÍNTESE DOS DADOS: Desde a descoberta por Peter C. Nowel e David Hungerford da translocação 9:22 (cromossomo Philadelphia) em 1960, a genética passou a ter importante papel na hematologia, possibilitando, neste caso, o diagnóstico da leucemia mielóide crônica e abrindo portas para a pesquisa nesta área para toda a oncologia. Um ponto de altíssimo interesse é a implicação destes achados no prognóstico de diversos tipos de leucemia. Na leucemia mielóide aguda, o cariótipo é fundamental na decisão da terapêutica pós-remissão, e fatores moleculares definem o tratamento em indivíduos de cariótipo normal. Na leucemia mielóide crônica, a evolução clonal está associada à evolução para a fase blástica. Pacientes em uso de imatinibe com perda de resposta podem apresentar mutações do gene ABL. Finalmente, na leucemia linfóide aguda, fatores como hiperdiploidia, t 12:21, estão associados a bom prognóstico, ao passo que portadores da t 4:11 e t 9:22 são considerados de alto risco. CONCLUSÃO: A genética veio para ficar na hematologia e, em particular, no manuseio da leucemia e seus fatores prognósticos. Para a melhor evolução do paciente, estes estudos devem ser sempre realizados, e a conduta terapêutica adequada deve ser tomada.

OBJECTIVE: To present the implications of genetics, particularly of cytogenetic techniques, for the diagnosis and prognosis of leukemia. SOURCES: A survey of articles selected from MEDLINE, American Society of Hematology educational programs, the CAPES web portal, the National Comprehensive Cancer Network and textbook chapters. SUMMARY OF THE FINDINGS: Since the discovery in 1960 by Peter C. Nowel and David Hungerford of the 9:22 translocation (the Philadelphia chromosome), genetics has come to play an important role in hematology, in this case making it possible to diagnose chronic myeloid leukemia and opening doors to research avenues for the whole field of oncology. One point of great interest refers to the implications of these findings for the prognosis of a range of types of leukemia. In acute myeloid leukemia, the karyotype is of fundamental importance to postremission treatment decisions, and molecular factors determine the treatment of individuals with normal karyotypes. In chronic myeloid leukemia, clonal evolution is associated with progression to the blast crisis. Patients on imatinib who cease responding may have mutations on their ABL gene. Finally, in acute lymphoblastic leukemia, factors such as hyperdiploidy and t 12:21 are associated with good prognosis, whereas carriers of t 4:11 and t 9:22 are considered high risk patients. CONCLUSIONS: Genetics has come to stay as far as hematology and, in particular, the management of leukemia and its prognostic factors are concerned. These tests should always be carried out and the appropriate treatment adopted in the light of their results, so that optimal patient outcomes can be achieved.

Comparison between philadelphia positive and philadelphia negative adult acute leukemias

This was a retrospective study designed to evaluate the frequency and clinical significance of Philadelphia [Ph] chromosome in acute leukaemia. The place and duration of this work was Armed forces Institute of Pathology Rawalpindi from April 1988 to January 1990 and a private medical center from June 1999 to July 2002. A total of 50 cases of acute leukaemia were included in the study. Thirteen cases presenting de-novo ALL and thirty two cases as denovo ANLL [AML and AMML]. Two patients were diagnosed as blast transformation phase of CGL with ALL phenotype whereas 03 cases presented with acute leukaemia transformation from MDS with AML/ AMML phenotype. The samples received were either peripheral blood or bone marrow aspirate. Chromosomal analysis was performed using culture, banding and staining technique. Morphology, clinical findings, therapeutic response and survival were compared in patients with and without the Ph chromosome. Ph chromosome was found to be +ve in 02 newly diagnosed patients presenting with ALL. Ph chromosome in association with additional chromosomal abnormalities persisted in 02 cases transformed into ALL from CGL, and it was found in 05 cases of de novo AML. The study failed to reveal any consistent chromosomal translocation involving chromosome 9 and 22 in 03 AML cases transformed from MDS. Patients with Ph+ ALL differed from those with Ph-ALL in being older, in having more frequent lymphadeno-pathy and splenomegaly and in demonstrating higher initial leucocyte count and more peripheral blasts. Complete remission was obtained in 09 patients with Ph -ve ALL but in only 2 of 4 with Ph +ve ALL. Adults with Ph -ve ALL also survived significantly longer. Five adults with ANLL [AML/AMML] who were Ph +ve did not respond to treatment and survived significantly shorter than adults with Ph -ve AML. No clinical or morphological features indicated which patients with acute leukemia would have Ph chromosome. The Philadelphia chromosome has been considered relatively specific for chronic granulocytic leukaemia. However patients with acute leukaemia [ALL and AML] can also present with positive Philadelphia chromosome. In our study, we have described 09 cases with positive Philadelphia chromosome. Comparison was made with the remaining 41 cases who were Ph negative. Thus it can be concluded that the presence of Ph chromosome in adult acute leukaemia may have biological and clinical significance

Associação entre HLA e leucemia em uma população brasileira de etnia mista / Association between HLA and leukemia in a mixed Brazilian population

OBJETIVOS: O objetivo deste estudo foi investigar a freqüência de antígenos HLA Classe I e de alelos HLA Classe II em 164 pacientes com vários tipos de leucemias: 35 pacientes com LLA (leucemia linfóide aguda), 50 com LMA (leucemia mielóide aguda) e 78 com LMC (leucemia mielóide crônica). MÉTODOS: A tipagem HLA Classe I foi realizada por microlinfocitotoxicidade e a de Classe II por PCR-SSP (polymerase chain reaction - sequence specific of primers), ambas da One Lambda (Canoga Park, CA, US). RESULTADOS: Em pacientes com LLA, as freqüências das variantes HLA-B45 e HLA-B56 foram maiores (P = 0,02; OR = 3,13; 95 por centoIC = 0,94-10,44; P = 0,03; OR = 3,61; 95 por centoIC = 0,47-27,64, respectivamente), quando comparadas com controles. Nos pacientes com LMA, a freqüência de HLA-B7 (P = 0,01; OR = 2,41; 95 por centoIC = 1,25-4,67) foi maior que em controles. A presença de HLA-B45 (P= 0,01; OR = 3,29; 95 por centoIC = 1,46-7,40) e de HLA-DRB1*04 (P = 0,002; OR = 2,17; 95 por centoIC = 1,36-3,46) e HLA-DRB1*08 (P = 0,004; OR = 2,36; 95 por centoIC = 1,34-4,16) foi associada ao maior risco de desenvolver LMC. CONCLUSÃO: Nossos resultados sugerem que variantes HLA conferem susceptibilidade a algumas formas de leucemia e podem prover novas ferramentas para a investigação da genética e etiologia desta doença.

OBJECTIVE: The main purpose of this study was to investigate the class I HLA antigens and class II HLA allele frequencies in 164 patients with leukemia: 35 patients with ALL (acute lymphoid leukemia), 50 with AML (acute myeloid leukemia) and 78 with CML (chronic myeloid leukemia). METHODS: The genotyping of class I HLA was performed by microlymphocytotoxicity and of class II by PCR-SSP (polymerase chain reaction - sequence specific of primers) (One Lambda, Canoga Park, CA, USA). RESULTS: In patients with LLA, frequencies of HLA-B45 and HLA-B56 were higher (P = 0.02; OR = 3.13; 95 percentIC = 0.94-10.44; P = 0.03; OR = 3.61; 95 percentIC = 0.47-27.64, respectively), than in controls. In patients with AML, the frequency of HLA-B7 (P = 0.01; OR = 2.41; 95 percentIC = 1.25-4.67) was higher than in controls. The presence of HLA-B45 (P= 0.01; OR = 3.29; 95 percentIC = 1.46-7.40), HLA-DRB1*04 (P = 0.002; OR = 2.17; 95 percentIC = 1.36-3.46) and HLA-DRB1*08 (P = 0.004; OR = 2.36; 95 percentIC = 1.34-4.16) was associated to increased risk of CML developing. CONCLUSION: Our results suggest that variants of HLA confer susceptibility to the same forms of leukemia, and could provide new tools for the investigation of genetics and etiology of this disease.

TNF-alpha upregulates PTEN via NF-kappaB signaling pathways in human leukemic cells

TNF-alpha plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between the two molecules are suggested. TNF-alpha has been known to downregulate PTEN via NF-kappaB pathway in the human colon cell line, HT-29. However, here we show the opposite finding that TNF-alpha upregulates PTEN via activation of NF-kappaB in human leukemic cells. TNF-alpha increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of NF-kappaB with p65 anisense phosphorothioate oligonucleotide or pyrrolidine dithiocarbamate. We found that TNF-alpha activated the NF-kappaB pathways, evidenced by the translocation of p65 to the nucleus in TNF-alpha-treated cells. We conclude that TNF-alpha induces upregulation of PTEN expression through NF-kappaB activation in human leukemic cells.