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A Aventin

Publications and source records attributed to A Aventin.

At least 19 recordsLinked to original sources
PubMed2006

Genomic gain at 6p21: a new cryptic molecular rearrangement in secondary myelodysplastic syndrome and acute myeloid leukemia.

Fluorescence in situ hybridization and comparative genomic hybridization characterized 6p rearrangements in eight primary and in 10 secondary myeloid disorders (including one patient with Fanconi anemia) and found different molecular lesions in each group. In primary disorders, 6p abnormalities, isolated in six patients, were highly heterogeneous with different breakpoints along the 6p arm. Reciprocal translocations were found in seven. In the 10 patients with secondary acute myeloid leukemia/myelodysplastic syndrome (AML/MDS), the short arm of chromosome 6 was involved in unbalanced translocations in 7. The other three patients showed full or partial trisomy of the 6p arm, that is, i(6)(p10) (one patient) and dup(6)(p) (two patients). In 5/7 patients with unbalanced translocations, DNA sequences were overrepresented at band 6p21 as either cryptic duplications (three patients) or cryptic low-copy gains (two patients). In the eight patients with cytogenetic or cryptic 6p gains, we identified a common overrepresented region extending for 5-6 megabases from the TNF gene to the ETV-7 gene. 6p abnormalities were isolated karyotype changes in four patients. Consequently, in secondary AML/MDS, we hypothesize that 6p gains are major pathogenetic events arising from acquired and/or congenital genomic instability.

Acute Disease↗
PubMed1999

Genomic organization of human JAK2 and mutation analysis of its JH2-domain in leukemia.

The Janus kinase family of proteins, with four mammalian members (JAK1, JAK2, JAK3 and TYK2), plays an essential role in the signal transduction pathway from non-catalytic cytokine receptors to the nucleus. We recently reported the involvement of ETV6-JAK2 fusion genes in the development of leukemia of both lymphoid and myeloid origin. Dominant missense mutations of hopscotch, a Drosophila JAK homologue, causing leukemia-like defects were described. One of these mutations affected a conserved residue of the kinase- like JH2 domain and the introduction of this mutation in murine Jak2 resulted in the constitutional activation of its kinase activity. In order to further analyze its role in leukemogenesis, we cloned human JAK2 and determined its genomic organization. Twenty-four exons spanning a region of approximately 150 kb were identified. A mutation analysis of the exons 13 to 19, encoding the kinase-like JH2 domain failed to detect activating mutations in leukemia samples, suggesting that this is a rare event in human leukemia.

Blotting, Northern↗
PubMed1998

Molecular delineation of 13q deletion boundaries in 20 patients with myeloid malignancies.

Fluorescent in situ hybridization (FISH) analysis with a panel of DNA probes for 13q13.1-q14.3 was performed on 20 cases of myeloid malignancies, of which 17 showed a del(13)(q) and three had translocations affecting 13q. By chromosome morphology, deletions consistently involved bands q14 and q21. In addition to confirming the chromosome data, FISH allowed us to delineate a commonly deleted region that was flanked by YAC 833A2 and YAC 854D4. Three cases with 13q translocations unexpectedly showed accompanying cryptic microdeletions of 13q, and in one case the commonly deleted region could be narrowed to a genomic segment, which includes YAC 937C7, RB1, and YAC 745E3. Homozygous deletions were not detected. This region overlaps with the smallest deleted region of 13q14 in chronic lymphocytic leukemia.

Adult↗
PubMed1997

Concomitant chronic lymphocytic leukemia and acute myeloid leukemia with an uncommon immunophenotype.

We report a case of simultaneous diagnosis of chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML), in which the use of flow cytometry analysis allowed the demonstration of two different cell populations and the study of both immunophenotyping patterns with a large panel of monoclonal antibodies (MoAbs). CLL cells showed a typical immunophenotype with coexpression of B cell markers with CD5, CD23, CD43, and weak surface immunoglobulin light chain restriction expression, whereas the AML population had a very uncommon phenotype with expression of myeloid markers and CD56 and lack of expression of other natural killer (NK) antigens, CD34 and HLA-DR. After chemotherapeutic treatment of AML with two induction courses, the patient achieved complete remission of the AML with persistence of a CD19/CD5 positive population. After consolidation chemotherapy, this latter population was no longer detectable despite the presence of lymphoid nodules in a bone marrow biopsy. Six months after diagnosis, the patient relapsed with AML and died shortly afterwards.

Antibodies, Monoclonal↗
PubMed1996

14q+ chromosome marker in a T-cell-rich B-cell lymphoma.

Cytogenetic, in situ hybridization, and molecular studies were performed in a case of T-cell-rich B-cell lymphoma. Demonstration of Ig gene rearrangements for both heavy and light chains confirmed the B-lineage restriction of the neoplastic cell population. Moreover, as expected in B-cell malignancies, all abnormal karyotypes showed a 14q+ chromosome marker involving 14q32. The origin of the extra material on the derivative 14q+, as defined by chromosome painting with a library for chromosome 11, and Southern blotting for c-myc and bcl-2 rearrangements, remains unknown.

Blotting, Southern↗
PubMed1996

Oligoblastic leukaemia with (8;21) translocation and haemophagocytic syndrome and granulocytic cannibalism.

We report a 47-year-old man with oligoblastic leukaemia (8;21) translocation, phenomenon of cannibalism by granulocytic cells and haemophagocytic syndrome. The patient responded to intensive chemotherapy with disappearance of haemophagocytosis, granulocytic and histiocytic. We conclude that: (1) granulocytic cannibalism and haemophagocytic syndrome can be unusual myelodysplastic features; (2) the oligoblastic leukaemia with presence of cytogenetic abnormalities related to AML in young patients are probably more close to acute leukaemia than to myelodysplastic syndrome.

Chromosomes, Human, Pair 21↗
PubMed1996

Mobilization of peripheral stem cells with intensive chemotherapy (ICE regimen) and G-CSF in chronic myeloid leukemia.

Seventeen patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) were treated with the ICE regimen plus G-CSF with the aim of mobilizing and collecting Ph-negative peripheral stem cells (PSC) in the setting of an autotransplant program. Fifteen patients had CML in first chronic phase (CP), and two in accelerated phase (AP). Three patients had been previously treated with interferon alpha 2a (IFN). Twelve patients underwent leukaphereses and a mean of 4.7 x 10(8)/kg mononuclear cells were obtained. Four CP patients did not show a significant mobilization peak of CD34+ cells and leukapheresis was not performed; finally, one patient died before apheresis could be performed. Six of the 12 who underwent leukaphereses obtained more than 1.0 x 10(6)/kg CD34+ cells. Eight of the 12 mobilized patients (67%) obtained a major cytogenetic response, including two complete and six partial; in the remaining four patients minimal or absent cytogenetic responses were observed. A higher rate of Ph purging was obtained in patients mobilized early or showing residual Ph-negative cells before mobilization, even if they were in AP. Infectious complications were frequent with a 38% rate of bacteremia recorded and one case of pulmonary aspergillosis resulting in a toxicity similar to that occurring in acute myeloid leukemia-induction chemotherapy. The ICE regimen can promote 'in vivo' purging of the Ph+ cells in 67% of CML mobilized patients (8/12). Failure of mobilization occurs in 65% of patients (11/17), mainly because of poor CD34+ cell yield.

Adult↗
PubMed1995

TEL gene is involved in myelodysplastic syndromes with either the typical t(5;12)(q33;p13) translocation or its variant t(10;12)(q24;p13).

A t(5;12)(q33;p13) translocation is a recurrent chromosome abnormality in a subgroup of myeloid malignancies with features of both myeloproliferative disorders and myelodysplastic syndromes (MDSs). The molecular consequence of a t(5;12) is a fusion between the platelet-derived growth factor receptor-B gene on chromosome 5 and a novel ETS-like gene, TEL, on chromosome 12. We report on three patients with a t(5;12)(q33;p13) diagnosed as chronic myelomonocytic leukemia, and one case of a t(10;12)(q24;p13) in a progressive MDS, with eosinophilia and monocytosis. Involvement of the TEL gene in these chromosome translocations was investigated by fluorescence in situ hybridization (FISH) with cosmid probes containing selectively the 5' end or 3' end of TEL. Hybridization of these cosmids to the der(5)/der(10) or a der(12), respectively, demonstrated a rearrangement of TEL in both translocations, showing that the t(10;12) is a variant translocation of the t(5;12). Cloning of the fusion cDNA of one case of t(5;12) showed that the breakpoint occurred at the RNA level at exactly the same position as reported by Golub et al (Cell 77:307, 1994). In addition, the TEL gene on chromosome 12 could be localized between two probes previously mapped to 12p13, namely PRB1 and D12S178, leading to a better definition of the position of TEL in this chromosome region. Moreover, in the case involving chromosome 10, the breakpoint occurred between cKTN206 and cKTN312/LYT-10 at 10q24. Clinicohematological data in these studies as well as the restriction mapping of chromosomal breakpoints strongly suggest that (1) common features in MDSs involving the TEL gene are monocytosis and eosinophilia, (2) chromosomes other than no. 5 may be involved and at least a t(10;12)(q24;p13) variant chromosome translocation does exist in these MDSs, and (3) both standard and variant 12p/TEL translocations may be identified by FISH with appropriate probes.

Adult↗
PubMed1991

A variant translocation t(2;18) in follicular lymphoma involves the 5' end of bcl-2 and Ig kappa light chain gene.

We have examined three cases of human lymphoma bearing a t(2;18)(p11;q21) chromosome translocation. The bcl-2 gene appeared to be rearranged in all three cases and breakpoints were clustered in the 5' flanking region of the gene. In all three cases, bcl-2 was juxtaposed to J segments of the Ig kappa gene. This juxtaposition of the bcl-2 and Ig kappa genes is very similar to the variant chromosome translocations of Burkitt lymphoma that juxtapose the c-myc locus to IgL genes.

Adult↗