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To investigate the biologic relevance of microsatellite instability (MSI) in de novo acute myeloid leukemia (AML), 102 consecutive adult patients were analyzed by using a panel of seven microsatellites (BAT25, BAT26, D13S1267, D13S174, D2S123, D5S346 and Mdf15). Frame-shift mutations in the repetitive sequences in the coding region of MSH3, MSH6, BAX, TGFBRII and IGFRII were also investigated by using a fluorescent PCR-based assay. Methylation-specific PCR was used to determine the methylation status of hMLH1 in MSI+ cases. MSH3, MSH6 and MLH1 expression was also analyzed in 68 cases by means of real-time quantitative PCR. MSI was detected in 20 cases: 14 cases had MSI-high (instability of at least two microsatellite markers) and 6 cases corresponded to MSI-low (a single polymorphic marker with instability). Six MSI+ cases showed an associated MLL rearrangement (p=0.002). No single case showed a mutation in the repetitive sequences of the MSH3, MSH6, BAX, TGFBRII and IGFRII genes. Most samples displayed low mRNA levels of the repair genes. hMLH1 promoter was hypermethylated in five MSI+ cases. Overall survival analysis revealed no adverse effect of MSI positivity. These results suggest that MSI may be a common biologic finding in de novo AML. [ABSTRACT FROM AUTHOR]

The prognosis of chronic lymphocytic leukemia (CLL) patients displaying trisomy 12 (+12) remains unclear. In this study, we analyzed the influence of the proportion of cells with +12, and other clinical and biologic factors, in time to first therapy (TTFT) and overall survival (OS), in 289 patients diagnosed with CLL carrying +12. Median OS was 129 months. One hundred seventy-four patients (60.2%) presented +12 in <60% of cells. TTFT and OS for this subgroup were longer than for the subgroup with +12 in ≥60% of cells, with a median TTFT of 49 months (CI95%, 39-58) vs 30 months (CI95%, 22-38) (P = 0.001); and a median OS of 159 months (CI95%, 119-182), vs 96 months (CI95%, 58-134) (P = 0.015). Other factors associated with a shorter TTFT were: Binet stage, B symptoms, lymphadenopathy, splenomegaly, high lymphocyte count, 11q-, high β2 microglobulin, and high LDH. In the multivariate analysis, clinical stage, +12 in ≥60% of cells, high lymphocyte count, B symptoms, and 11q- in addition, resulted of significance in predicting shorter TTFT. Significant variables for OS were: Binet stage, lymphadenopathy, splenomegaly, high LDH, high β2 microglobulin, 11q-, and CD38. In the multivariate analysis, only Binet stage, 11q-, and high β2microglobulin significantly predicted shorter OS. CLL with +12 entails a heterogeneous group with intermediate prognosis. However, a high proportion of cells carrying +12 separates a subgroup of patients with poor outcome. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Acute promyelocytic leukemia is a subtype of acute myeloid leukemia characterized by the t(15;17). The incidence and prognostic significance of additional chromosomal abnormalities in acute promyelocytic leukemia is still a controversial matter., Design and Methods: Based on cytogenetic data available for 495 patients with acute promyelocytic leukemia enrolled in two consecutive PETHEMA trials (LPA96 and LPA99), we analyzed the incidence, characteristics, and outcome of patients with acute promyelocytic leukemia with and without additional chromosomal abnormalities who had been treated with all-trans retinoic acid plus anthracycline monochemotherapy for induction and consolidation., Results: Additional chromosomal abnormalities were observed in 140 patients (28%). Trisomy 8 was the most frequent abnormality (36%), followed by abn(7q) (5%). Patients with additional chromosomal abnormalities more frequently had coagulopathy (P=0.03), lower platelet counts (P=0.02), and higher relapse-risk scores (P=0.02) than their counterparts without additional abnormalities. No significant association with FLT3/ITD or other clinicopathological characteristics was demonstrated. Patients with and without additional chromosomal abnormalities had similar complete remission rates (90% and 91%, respectively). Univariate analysis showed that additional chromosomal abnormalities were associated with a lower relapse-free survival in the LPA99 trial (P=0.04), but not in the LPA96 trial. However, neither additional chromosomal abnormalities overall nor any specific abnormality was identified as an independent risk factor for relapse in multivariate analysis., Conclusions: The lack of independent prognostic value of additional chromosomal abnormalities in acute promyelocytic leukemia does not support the use of alternative therapeutic strategies when such abnormalities are found.

Previous gene function analyses have indicated that HOXA9, DEK, CBL and CSF1R are aberrantly expressed in acute myeloid leukemia (AML). We analyzed the expression of these genes in a series of 41 adult patients with AML using quantitative real-time RT-PCR, and tested the association of the expression with the following hematologic and clinical parameters: age, FAB, immunophenotype and karyotype aberrations. A high proportion of the patients showed over- or underexpression of the analyzed genes. DEK was overexpressed in 98% of the cases, whereas CBL, CSF1R and HOXA9 were either overexpressed in 20%, 17% and 78% or underexpressed in 20%, 42% and 15% of the cases, respectively. Patients whose karyotype contained t(8;21)(q22;q22), showed lower relative expression of HOXA9 at a statistically significant level (p < 0.05). Bone marrow samples without expression of CD34 antigen were associated with either overexpression of DEK or HOXA9. Furthermore, an association was found between the AML-M2 subtype and lower expression of CBL, CSF1R or HOXA9, and between the AML-M5 subtype and CBL or CSF1R overexpression.

Background and Objectives: Chromosome translocations resulting in gene overexpression are commonly associated with lymphoid neoplasia. Enhancer elements of the immunoglobulin or T-cell receptor (TCR) loci are abnormally located in the vicinity of the entire coding sequences of genes which exert an influence on the normal maturation and differentiation program of lymphoid cells., Design and Methods: A patient who presented with a B-cell lineage acute lymphoblastic leukemia had a t(6;14)(p22;q32). Cytogenetic and molecular findings confirmed the involvement of IgH. Molecular cloning of the breakpoint revealed that this was located near the coding sequence of the Id4 gene, a helix-loop-helix (HLH) inhibitor protein. Alu-repeated sequences at the 6p22 end flanked a short stretch of 10 bases shared by the 6p22 and 14q32 ends, suggesting that a deletion or a looping-Alu mediated mispairing mechanism may lead to this chromosome translocation., Results: Northern blot and real-time polymerase chain reaction analyses showed that the Id4 mRNA was abnormally overexpressed in this case. Only the two smaller Id4 mRNA products were detected (1.6 and 1.1 kb). Immunohistochemical analysis of Id4 protein was also assayed in a series of hematologic malignancies. Marked overexpression was found in two cases of T-cell prolymphocytic leukemias and in four B-cell lineage acute lymphoblastic leukemia including one case with the t(8;14) and another case with a p53 mutation., Interpretation and Conclusions: The Id4 gene may behave as an oncogene in some human leukemias, perhaps through its capacity to sequester specific B-cell transcription factors. A genetic recombination between Alu-repeated sequences may not be the exclusive mechanism of generating pathogenic chromosomal translocations.

Background and Objectives: Deletions at the long arm of chromosome 13, mostly at the q14, and monosomy of chromosome 13 are described to be common in multiple myeloma (MM). 13q- has been associated with an adverse outcome and it has been proposed as one of the most important prognostic factors for MM patients. Deletions of 13q14 are rare in monoclonal gammopathy of undetermined significance (MGUS) and are thus believed to be associated with the development of the full myeloma phenotype., Design and Methods: A genotyping analysis on purified neoplastic plasma cells was performed on 14 consecutive MM cases to determine the minimally deleted region at chromosome 13. Freshly obtained bone marrow was analyzed by flow cytometry in order to establish the percentage of plasma cell infiltration (CD38+BB4+CD56+/-CD19-). Neoplastic enrichment was carried out using BB4 coated immunomagnetic beads. This method allowed us to monitor the enrichment process. DNA obtained from the enriched neoplastic population and DNA from the clean fraction was amplified using combination sets of chromosomes 12 and 13. Amplimers were run on acrylamide gels, analyzed by automatic fluorescence quantification, and their size determined using the software programs Genescan and Genotyper., Results: In 11 patients electropherograms were suggestive of loss of heterozygosity (LOH) for polymorphic markers located at the long arm of chromosome 13. Four patients showed monosomy and 7 had interstitial deletions in the telomeric region. LOH was not evidenced at chromosome 12 in any sample. The minimal region with deletion was defined by the markers D13S159 (13q32.2, centromeric) and D13S1267 (13q32.3, telomeric). A gene with a potentially pathogenic role may be located in this very small region. Three patients did not show LOH at chromosome 13 by genotypic analysis; however, in one of these, proximal deletion at the long arm of chromosome 13 (13q2.1-2.2) was demonstrated by comparative genomic hybridization (CGH)., Interpretation and Conclusions: These findings suggest that interstitial deletions of the long arm of chromosome 13 may be more common than previously recognized. The methodologic approach reported in this work may simplify LOH analysis in MM patients. The potential uses of genotyping analysis in risk stratification remain to be investigated.

We describe two cases of acute myelomonocytic leukemia with eosinophilia (AML-M4Eo) that were diagnosed with an inv(16)(p13q22) based on conventional cytogenetics (CC) and fluorescence in situ hybridization (FISH) technique using a chromosome 16p arm specific paint probe. Additional FISH analysis with a dual-color CBFB DNA probe showed that the 3' portion of the CBFB gene was translocated to chromosome 10p13 in the first patient and 1p36 in the other. These two cases indicate that some inv(16)(p13q22) identified by CC and FISH with chromosome arm-specific painting probe may represent cases of inversion-associated translocation. We suggest that all cases with inv(16)(p13q22) should be investigated by FISH with appropriate probes for a possible translocation of 16q22-->qter to another chromosome.