JAK2 46/1 haplotype is associated with JAK2 V617F--positive myeloproliferative neoplasms in Brazilian patients.

INTRODUCTION: This study aimed to verify the association between the JAK2 46/1 haplotype (V617F positive) and some hematological parameters in BCR-ABL-negative chronic myeloproliferative neoplasms (cMPNs) in our population. METHODS: The blood samples obtained from the patients with cMPN were genotyped for the JAK2 V617F mutation and JAK2 rs10974944 SNP screening using a PCR-RFLP assay. RESULTS: The JAK2 V617F mutation was detected in 80.15% of patients. The G variant of rs10974944 was more frequent in all MPNs, especially those that were JAK2 V617F positive, than in the control population. We also compared the 46/1 haplotype status in each MPN disease entity, polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF), and MPNu with controls. The G allele frequency relative to controls was significantly enriched in patients with PV and ET, but not in those with PMF and MPNu. PV and ET patients especially, all of whom had the JAK2 V617F mutation, showed significant excess of the G allele. The frequency of JAK2 V617F mutation was associated with elevated hematological parameters, but when we analyze the occurrence of the mutation and the presence of the G allele, just the high hemoglobin was significantly. CONCLUSION: In agreement with previous reports, JAK2 46/1 haplotype for JAK2 V617F was associated with cMPN positive in Brazilian patients.

Constitutive JunB expression, associated with the JAK2 V617F mutation, stimulates proliferation of the erythroid lineage.

The JAK2 V617F mutation, present in the majority of polycythemia vera (PV) patients, causes constitutive activation of JAK2 and seems to be responsible for the PV phenotype. However, the transcriptional changes triggered by the mutation have not yet been totally characterized. In this study, we performed a large-scale gene expression study using serial analysis of gene expression in bone marrow cells of a newly diagnosed PV patient harboring the JAK2 V617F mutation and in normal bone marrow cells of healthy donors. JUNB was one of the genes upregulated in PV, and we confirmed, by quantitative real-time PCR, an overexpression of JUNB in hematopoietic cells of other JAK2 V617F PV patients. Using Ba/F3-EPOR cell lines and primary human erythroblast cultures, we found that JUNB was transcriptionally induced after erythropoietin addition and that JAK2 V617F constitutively induced JunB protein expression. Furthermore, JUNB knockdown reduced not only the growth of Ba/F3 cells by inducing apoptosis, but also the clonogenic and proliferative potential of human erythroid progenitors. These results establish a role for JunB in normal erythropoiesis and indicate that JunB may play a major role in the development of JAK2 V617F myeloproliferative disorders.

Frontline therapy with early intensification and autologous stem cell transplantation versus conventional chemotherapy in unselected high-risk, aggressive non-Hodgkin's lymphoma patients: a prospective randomized GEMOH report.

This prospective multicenter randomized trial compares conventional with early intensification with high-dose sequential chemotherapy (HDS) and autologous stem cell transplantation (ASCT) as frontline therapy in high-risk non-Hodgkin lymphomas (NHL). Newly diagnosed patients with aggressive high-risk [intermediate-high (HI) and high-risk (HR)] NHL according to the international prognosis index (IPI) were randomized to receive 12-week VACOP-B (arm A, 27 patients) or 6-week VACOP-B followed by HDS and ASCT (arm B, 29 patients). Complete remission rate was 52% in arm A and 55% in B. Nine patients (16%) died early due to progression. According to intention-to-treat, with a median follow-up of 23 months, the 5-year actuarial overall survival, progression-free survival and disease-free survival in arms A and B were 47 and 40% (p = nonsignificant), 47 and 30% (p = nonsignificant), and 97 and 47% (p = 0.02), respectively. Abbreviated chemotherapy followed by intensification with HDS-ASCT does not seem to be superior to conventional chemotherapy in HI/HR aggressive NHL.

Expression of p190 BCR-ABL fusion gene in a patient with chronic myeloid leukemia / Expressão do rearranjo gênico BCR-ABL com ponto de quebra na região menor do gene BCR em um paciente com leucemia mielóide crônica

A minority of chronic myeloid leukemia cases have breakpoints in the minor cluster region (m-bcr) of the BCR-ABL gene. We report on a patient with Ph-positive and m-bcr breakpoint at diagnosis. She was treated with hydroxyurea and interferon-alpha. Two years later, she developed a lymphoid blast crisis and died shortly after. We discuss herein the different forms of the BCR-ABL oncogene, its products, and the possible influence of them on the clinical outcome of patients with the disease

A leucemia mielóide crônica (LMC) é umadoença mieloproliferativa clonal e caracteriza-se pela presença da translocaçãocromossômica entre os braços longos doscromossomos 9 e 22, o denominadocromossomo Ph. Esta translocação determinaa fusão dos genes BCR e ABL. Os diferentespontos de quebra no gene BCR determinama síntese de proteínas com diferentespesos moleculares pelo gene BCR-ABL.Nós relatamos o caso de uma paciente portadorade LMC com ponto de quebracromossômico na região menor do geneBCR. Foi tratada com hidroxiuréia einterferon alfa. Dois anos após o diagnósticodesenvolveu crise blástica linfóide e evoluiurapidamente para o óbito. Nós discutimos nestaapresentação as diferentes formas do gene BCR-ABL eseus produtos e a possível influência dos mesmos naevolução clínica dos pacientes com a doença.(AU)76.

Apoptosis-regulating proteins and prognosis in diffuse large B cell non-Hodgkin's lymphomas.

We evaluated the expression of apoptosis-regulating proteins (p53, Bcl-2, Bax, Bak and Mcl-1) in paraffin-embedded tissues of 33 patients with diffuse large B cell non-Hodgkin's lymphoma, and assessed the relationship of these proteins to clinical outcome and response to chemotherapy. Our results showed that p53 expression was an independent immunohistochemical parameter related to a poor prognosis in these lymphomas. Bcl-2, Bax, Bak and Mcl-1 proteins, though highly expressed in almost all cases were not associated with prognosis or response to treatment.