Karolina Matiakowska

Cladribine added to daunorubicin-cytarabine induction prolongs survival of FLT3-ITD+ normal karyotype AML patients.

To the editor: Internal tandem duplication in the FLT3 gene ( FLT3- ITD) has been recognized as a marker conferring poor outcome in patients with normal karyotype acute myeloid leukemia (NK-AML).[1][1] Because of the inferior outcome of FLT3- ITD+ NK-AML patients when treated with standard

CEBPA copy number variations in normal karyotype acute myeloid leukemia: Possible role of breakpoint-associated microhomology and chromatin status in CEBPA mutagenesis

Copy number variations (CNV) in CEBPA locus represent heterogeneous group of mutations accompanying acute myeloid leukemia (AML). The aim of this study was to characterize different CEBPA mutation categories in regard to biological data like age, cytology, CD7, and molecular markers, and identify possible factors affecting their etiology. We report here the incidence of 12.6% of CEBPA mutants in the population of 262 normal karyotype AML (NK-AML) patients. We confirmed that double mutant AMLs presented uniform biological features when compared to single CEBPA mutations and accompanied mostly younger patients. We hypothesized that pathogenesis of distinct CEBPA mutation categories might be influenced by different factors. The detailed sequence analysis revealed frequent breakpoint-associated microhomologies of 2 to 12bp. The analysis of distribution of microhomology motifs along CEBPA gene showed that longer stretches of microhomology at the mutational junctions were relatively rare by chance which suggests their functional role in the CEBPA mutagenesis. Additionally, accurate quantification of CEBPA transcript levels showed that double CEBPA mutations correlated with high-level CEBPA expression, whereas single N-terminal CEBPA mutations were associated with low-level CEBPA expression. This might suggest that high-level CEBPA expression and/or accessibility of CEBPA locus contribute to B-ZIP in-frame duplications.

Selected Parameters of Angiogenesis and the JAK2, CALR, and MPL Mutations in Patients With Essential Thrombocythemia:

The aim of the study was to evaluate selected angiogenic factors in patients with essential thrombocythemia (ET) depending on JAK2V617F, calreticulin gene (CALR) and myeloproliferative leukemia virus oncogene (MPL) mutations. Sixty ET patients and 20 healthy volunteers were enrolled in the study. The following tests were performed: vascular endothelial growth factor- A (VEGF-A), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1),soluble vascular endothelial growth factor receptor-2 (sVEGFR-2), platelet-derived growth factor( PDGF-BB), and stromal-derived factor-1α (SDF-1α). We observed an increased PDGF-BB level in patients with ET compared to the controls. Patients with CALR mutation had significantly higher concentration of PDGF-BB and lower concentration of SDF-1α than patients with JAK2V617F mutation. High concentration of PDGF-BB and low concentration of SDF-1α in patients with CALR(+) ET may indicate a contribution of these chemokines in disturbed Ca2+ metabolism in platelets.

Heterogeneity of human WT1 gene

The WT1 gene, characterized by an extremely complex structure, is located on chromosome 11. It is involved in cell growth and differentiation, and has a strong impact on consecutive stages of the functioning of the body. The WT1 gene may undergo many different mutations, as well as may be overexpressed without a mutation. The molecular basis of diseases such as Wilms tumor, WAGR, Denys-Drash or Frasier syndromes are congenital WT1 mutations, while somatic mutations of this gene occur in acute and chronic myeloid leukemia, myelodysplastic syndrome and also in some other blood neoplasms, as acute lymphoblood leukemia. Increased expression of this gene without its mutation is observed in leukemias and solid tumors. The WT1 may function both as a tumor suppressor gene and as an oncogene. The diversity of WT1 changes causes many controversies, therefore investigations are still carried out to determine the function of this gene, its interaction with other molecules and its prognostic significance in various diseases.

Prognostic significance of BCR-ABL rearrangement in childhood acute lymphoblastic leukemia

B a c k g r o u n d . Acute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy. Presence of adverse risk factors determines risk group stratification in this disease. O b j e c t i v e . The aim of study was the analysis of results of therapy and role of prognostic risk factors in treatment of childhood ALL in kujawsko-pomorskie region in 1995-2010. P a t i e n t s a n d m e t h o d s . During this period, ALL was diagnosed in 223 patients. With respect to time period and therapy protocol, the patients were divided into two groups: group 1 A/B (1995-2002) and group 2 (2002- 2010). Probability of overall survival (OS), event-free survival (EFS) and relapse-free survival (RFS) were analyzed. Uni- and multivariate analyzes for risk factors were performed. R e s u l t s . Over the analyzed 17-year period, OS has increased from 77.9% in group 1A and 73.7% in group 1B to 86.2% in group 2. Results of RFS and EFS have also increased during this time. The death rate has decreased from 26% in group 1A and 26.3% in group 1B to 10.2% in group 2. The most important adverse prognostic risk factors during the first period included involvement of liver, spleen, lymph nodes as well as poor response to initial therapy, while during the second period the most important independent risk factor was BCR-ABL rearrangement in lymphoblasts. C o n c l u s i o n s . The most important independent prognostic risk factors in pediatric ALL include advanced disease, BCR-ABL rearrangement, and initial response to therapy. These factors are used for stratification to treatment groups, intensification of therapy and hematopoietic stem cell transplantation.

The hematological malignancies related to primary hypereosinophilia and their diagnostics

Published in 2008, by experts of the World Health Organization, the new classification of hematological malignancies forced a change of look at chromosomal aberrations and gene mutations, which are important in establishing the diagnosis and prognosis for patients with these malignancies. The new classification includes a new category of neoplasms - hematological malignancies with hypereosinophilia. Due to the high diversity of causes of hypereosinophilia and underlying genetic changes, their differential diagnosis is based on classical cytogenetics, fluorescence in situ hybridization (FISH) and genetic molecular techniques. Cytogenetic analysis of bone marrow cells showed that the majority of hypereosinophilia cases can be characterized by the presence of normal karyotype. Therefore, routine cytogenetic diagnostics should be complemented by FISH with break-apart probes for potentially rearranged genes (e.g., CBFB, ETV6) and unique probes for fusion genes (e.g., FIP1L1-PDGFRA), specific for hypereosinophilia-associated diseases. In differential diagnosis of hypereosinophilia, the analysis of characteristic gene mutations (e.g., cKIT) and gene fusions (e.g., ETV6-PDGFRB) is also applied, using molecular genetic methods.