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C Mecucci

Publications and source records attributed to C Mecucci.

At least 55 records · Page 3Linked to original sources
PubMed1999

Identification of multiple copies of a 20q-chromosome in a case of myelodysplastic syndrome: a FISH study.

In myelodysplastic syndromes (MDS) karyotypic aberrations identify subgroups of patients with distinct clinical-morphological features and can be relevant in risk assessment of developing leukemia. Often conventional cytogenetic analysis is not sufficiently informative due to the presence of partially or completely unrecognizable chromosome markers. By chromosome microdissection (MD) and fluorescence in situ hybridization (FISH) we investigated the nature of a karyotypic marker occurring in multiple copies in one case of MDS arisen in a patient previously treated for breast cancer. Results showed dicentrics derived from telomeric fusion between interstitially deleted 20q-chromosomes. The abnormal karyotype resulted into polysomy for a deleted chromosome 20q.

Aged↗
PubMed1999

Characterization of 12p molecular events outside ETV6 in complex karyotypes of acute myeloid malignancies.

Acute myeloid disorders with rearrangements of 12p outside the ETV6 gene were characterized by fluorescence in situ hybridization (FISH) with a panel of DNA probes. Seven patients with de novo acute myeloid leukaemia (AML), one with secondary acute myeloid leukaemia (sAML), and one in the blast phase of chronic myeloid leukaemia (CML-BP) were enrolled in the study. All AML cases showed multiple karyotypic changes. Chromosome 5 and/or 7 deletions were the most frequent accompanying changes. FISH revealed amplification, cryptic translocation, and fragmentation of chromosome 12, not discernible at karyotypic level. Different karyotypic rearrangements of 12p showed a common molecular event. Among the seven cases in which breakpoints could be determined, six were telomeric and one centromeric to ETV6. In three AML cases a new recurrent breakpoint in the telomeric region was identified distally to locus D12S158 and to pac 922B22 which is the most telomeric probe available for 12p. Accompanying cryptic deletions were also detected in five patients and the commonly deleted region, of around 700 kb, included the ETV6 gene and the D12S391 locus.

Adult↗
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↗
PubMed1999

Genomic instability and recurrent breakpoints are main cytogenetic findings in Hodgkin's disease.

BACKGROUND AND OBJECTIVE: Successful cytogenetic studies in Hodgkin's disease (HD) are rare, and, except for hyperdiploidy, no chromosome changes typical for this disorder have been described. The purpose of this study was to collect cytogenetic information from a new series of lymphoid neoplasms diagnosed either as classical HD or as Hodgkin's-like anaplastic large cell lymphoma (HD-like ALCL), according to the REAL Classification. DESIGN AND METHODS: We studied 27 cases of HD and 10 cases of HD-like ALCL. Cytogenetic investigations were performed on lymph nodes (35 cases), bone marrow or pleural effusion. A large screening of slides was performed to detect abnormal metaphases despite the low mitotic index of Reed-Sternberg cells. In addition to ours, available published data were analyzed in detail to identify recurring cytogenetic events. RESULTS: Metaphases which could be analyzed were obtained in 86.5% of cases, with 59.4% showing abnormal clones. We found a peculiar kind of cytogenetic instability in which, despite variations in the type of structural rearrangements, chromosome breakpoints were non-randomly distributed. Moreover, from our data plus those collected from literature on HD (total 177 cases), the number of breakpoints was higher in patients in a more advanced clinical stage. INTERPRETATION AND CONCLUSIONS: Cytogenetic studies in HD are highly informative regarding clonality, provided large numbers of metaphases are examined. Based on karyotype, genetic changes in HD and HD-like ALCL are similar. Results are consistent with a high degree of chromosomal instability and predominance of hyperdiploid complex karyotypes. Chromosome breakpoints are non-randomly distributed and more numerous in advanced clinical stages.

Adolescent↗
PubMed1999

New reciprocal translocation t(5;10)(q33;q22) associated with atypical chronic myeloid leukemia.

We report a new chromosomal reciprocal translocation t(5;10)(q33;q22) in a 49-year-old man with atypical chronic myeloid leukemia (a-CML) and history of occupational exposure to petroleum products including benzene and other hydrocarbons. The t(5;10) (q33;q22) was found in 94% and 84% of metaphases in peripheral blood and bone marrow cells, respectively. Cytogenetic analysis of single colonies derived from granulocyte-macrophage (CFU-GM), and erythroid (BFU-E) hematopoietic progenitors showed that 88% and 40% of CFU-GM and BFU-E, respectively, had the t(5;10)(q33;q22). In contrast, peripheral blood T-lymphocytes, and cutaneous fibroblasts had normal 46,XY karyotype. Molecular analysis of the t(5;10)(q33;q22) translocation breakpoint is currently underway in order to identify genes located in this region which might provide insights into the pathogenesis of atypical myeloproliferative disorders.

Chromosomes, Human, Pair 10↗
PubMed1998

Fluorescence in situ hybridization characterization of new translocations involving TEL (ETV6) in a wide spectrum of hematologic malignancies.

The ETV6 (also known as TEL) gene on chromosome 12p13 is the target of a number of translocations associated with various hematologic malignancies. The contribution of ETV6 to leukemogenesis occurs through different mechanisms that involve either its helix-loop-helix dimerization domain or its E26 transformation-specific (ETS) DNA-binding domain. Using fluorescence in situ hybridization we characterized seven new ETV6 rearrangements in chronic myeloid leukemia, acute myeloid leukemia, acute lymphoblastic leukemia, and non-Hodgkin's lymphoma. These aberrations, not always discernible at the cytogenetic level, include a t(5;12)(q31;p13), t(6;12;17)(p21;p13;q25), t(7;12)(p15;p13), t(7;12)(p12;p13), t(7;12)(q36;p13), t(12;13)(p13;q12), and a not completely defined t(12;?)(p13;?). Loss or disruption of the second ETV6 allele by a del(12)(p12p13) or by an intragenic ETV6 deletion was detected in two cases. In six cases the 12p13 breakpoint occurred in the 5' end of ETV6, upstream to exons encoding the HLH domain, whereas the remaining case had a breakpoint between the exons coding for the HLH domain and the exons coding for the ETS domain of ETV6. These observations provide further evidence for the multiple contributions of ETV6 in the pathogenesis of a wide range of hematologic malignancies.

Adolescent↗
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↗
PubMed1998

Rearrangement between the MYH11 gene at 16p13 and D12S158 at 12p13 in a case of acute myeloid leukemia M1 (AML-M1).

A case of acute myeloid leukemia (AML) M1 with bone marrow eosinophilia was characterized by cytogenetics and fluorescence in situ hybridization (FISH). A complex karyotype including a der(12)t(12;17)(p12-13;q11) and a der(16)t(16;20)(p13;p11) was found at diagnosis. FISH studies with probes for chromosome 16 and for the short arm of chromosome 12 showed even more complex rearrangements. Analysis with a panel of probes for 12p showed that D12S158 spanned the breakpoint on the der(12). Unexpectedly, FISH signals were found on the der(12) and on the der(6) at band p13, the site of juxtaposition between the short arm of chromosome 16 and chromosome 20. Moreover, both YAC 854E2, containing the MYH11 gene, and cosmid ZIT133, encompassing the MYH11 breakpoint in inv(16) and t(16;16) of AML-M4 with eosinophilia, demonstrated fluorescent signals on the normal 16, on the der(16), and on the der(12). These data clearly support a reciprocal exchange between D12S158 at 12p13.3 and the MYH11 gene at 16p13. In addition, experiments with two PAC clones for the CBFB gene at 16q22 excluded the presence of a masked inv(16). An interstitial deletion, independent from the translocation and flanked by VWF and KRAS2, was also detected on the der(12).

Aged↗
PubMed1998

Molecular features of primary MDS with cytogenetic changes.

Cytogenetic changes in primary myelodysplastic syndromes (MDS) have been extremely useful to identify clonality and to define specific clinico-pathological entities. More recently, with the development of DNA technology, a bulk of new information has been added to classical cytogenetics. Genes corresponding to chromosomal breakpoints implicated in reciprocal translocations have been cloned. Search for the minimal lost region has been the aim of the so-called deletion mapping approach to pick up the hypothetical suppressor gene(s) critical for typical deletions of MDS. Correlation has been found between gene mutations, deletions, expression, and clinical-hematological or cytogenetic features of MDS. Integration of fluorescence in situ hybridization at DNA level and of immunophenotyping at cellular level is an elegant tool to investigate clonal affiliation in MDS with distinct genetic changes.

Chromosome Aberrations↗
PubMed1998

Trisomy 6 is the hallmark of a dysplastic clone in bone marrow aplasia.

Clonal hematopoiesis with trisomy 6 as the sole karyotypic change was revealed by cytogenetics in two cases of aplastic anemia. In both patients, dyserythropoiesis was characterized by asynchrony of maturation between nucleus and cytoplasm, binucleated elements, and intercytoplasmic connections. In addition to conventional cytogenetics, the size of the trisomic clone was evaluated by fluorescence in situ hybridization on fixed cells at diagnosis and in the course of the disease by using an alpha-satellite centromeric probe for chromosome 6. Moreover, in situ hybridization on bone marrow smears showed that dysplastic erythrocytes as well as myeloid cells belonged to the trisomic clone. Trisomy 6 identifies a subgroup of hematologic disorders with bone marrow hypo-aplasia and dyserythropoiesis.

Anemia, Aplastic↗
PubMed1998

Interstitial insertion of AF10 into the ALL1 gene in a case of infant acute lymphoblastic leukemia.

The ALL1 gene at 11q23 is a promiscuous gene participating in chromosomal abnormalities of acute leukemias with 1 of over 30 potential partner genes. Among these, the AF10 gene at band 10p12 has been recently cloned and characterized. Acute leukemias with the ALL1/AF10 chimeric gene frequently show heterogeneity in the breakpoints on 10p, as well as complex insertion (10;11) as a result of complex molecular mechanisms leading to the ALL1/AF10 fusion. In this context, we report the first description of an infant acute lymphoblastic leukemia with an interstitial insertion of the AF10 gene into the 11q23 band, resulting in the transcription of the ALL1/AF10 fusion product. Furthermore, we show how different diagnostic tools such as molecular, cytogenetic, and fluorescence in situ hybridization (FISH) analyses should be combined to resolve complex situations in the 11q23 setting.

Chromosomes, Human, Pair 10↗
PubMed1998

Detection and monitoring of trisomy 8 by fluorescence in situ hybridization in acute myeloid leukemia: a multicentric study.

BACKGROUND AND OBJECTIVE: The role of fluorescence in situ hybridization (FISH) in the detection and monitoring of trisomy 8 (+8) in acute myelogenous leukemia (AML) has not been defined exactly. This multicentric study was performed in order to: i) analyze the sensitivity of interphase FISH with respect to conventional chromosome analysis (CCA) in detecting +8; ii) compare the results of FISH and CCA in the quantitation of the frequency of +8-positive cells; iii) analyze the possible role of FISH in the cytogenetic follow-up of patients with +8. DESIGN AND METHODS: One hundred and ninety-eight nonconsecutive patients with a diagnosis of AML seen at five centers over a 3-year period were studied by CCA and FISH with a chromosome 8-specific centromeric probe. Two hundred interphase cells were scored in each test and the cut-off for the recognition of +8 was set at 3%. An irrelevant pericentromeric probe was used as negative control in those cases with an apparently normal karyotype and trisomy 8 in interphase cells. FISH studies were conducted at diagnosis and, in 14 cases with +8, on 1.5 occasions during follow-up. RESULTS: Karyotype aberrations were seen in 121 cases (61.1%), with +8 being present in 38 of them (16 as the sole aberration). Interphase FISH detected +8 in 37/38 cases; in a patient with 1/10 metaphases with +8, 2.3% interphase cells with 3 signals were seen. Fourteen additional cases with occult +8 were detected by FISH, which showed 4-22% interphase cells with three signals; 6 patients had an abnormal karyotype without +8, 3 had a normal karyotype, 5 had no analyzable mitoses. In 24 cases with > 15 analyzable metaphases, percent variations between CCA and FISH in the estimation of the size of the trisomic clone ranged between 0.4% and 51%, median value 22%. Underestimation of the percent of trisomy 8 by FISH occurred in all 10 cases with > 90% +8 metaphases. In 7/14 cases investigated sequentially, FISH detected 5-35% trisomic cells in the BM after induction therapy (4 CR, 3 PR); 4 cases relapsed with +8 at 8-15 months. The absence of +8 in remission marrows was documented in the remaining 7 cases, 4 of which relapsed at 20-32 months. INTERPRETATION AND CONCLUSIONS: It is concluded that FISH was a valuable method in this multicentric study since it showed greater sensitivity than CCA in detecting minor clones with +8, in patients with both normal and abnormal karyotypes. The role of FISH in the cytogenetic follow-up of trisomies in AML patients may be promising.

Acute Disease↗
PubMed1998

Diagnosis, classification, and cytogenetics of myelodysplastic syndromes.

BACKGROUND AND OBJECTIVE: The diagnosis of myelodysplastic syndromes (MDS) is essentially morphological and based on the presence of dysplastic features in the peripheral blood and bone marrow. The French-American-British (FAB) Cooperative Group proposed a classification based on easily obtainable laboratory information. In spite of some limitations, the FAB criteria have been useful for a long time. Currently, the recognition of other distinct morphological MDS subgroups such as hypocellular MDS and MDS with myelofibrosis, the increasing incidence of MDS in children as well as that of therapy-related MDS, and the finding of specific chromosomal alterations associated with different morphological features, reveal the insufficiency of this classification. The aim of the present review is to examine some new aspects of the diagnosis, classification, and cytogenetics of MDS. EVIDENCE AND INFORMATION SOURCES: The authors of this review have been actively working and contributing original papers on MDS for the last 15 years. They also organized or participated in the Fourth International Symposium on MDS (Barcelona, April 24-27, 1997). In addition, the present review critically examines relevant articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF THE ART AND PERSPECTIVES: Most of investigators working on MDS tend to integrate morphology and cytogenetics in the diagnosis and classification of these disorders. FAB criteria remain useful particularly for patients with not available cytogenetic study. Refractory cytopenia with multilineage dysplasia should be considered as a new MDS subtype. Some authors propose considering all patients with more than 20% of blast cells in peripheral blood or bone marrow as having acute leukemia. Chronic myelomonocytic leukemia with myeloproliferative features may be included among chronic myeloproliferative disorders. MDS with myelofibrosis is recognized as a new MDS subtype. Therapy-related MDS (t-MDS) should be classified according to the involved agents. Finally, besides including chromosomal abnormalities in the diagnosis (e.g., RAEB with trisomy 8), several cytogenetic abnormalities such as deletion 5q and deletion 17q, associated to specific clinical-morphological features, should be of help to identify new MDS syndromes.

Cytogenetics↗
PubMed1997

A new subtype of pre-B acute lymphoblastic leukemia with t(5;12)(q31q33;p12), molecularly and cytogenetically distinct from t(5;12) in chronic myelomonocytic leukemia.

Translocation t(5;12)(q33;p13), resulting in an ETV6/PDGFRB gene fusion, is a recurrent chromosomal abnormality associated with chronic myelomonocytic leukemia (CMML). An analogous translocation was also found in four cell lines with features of pre-B acute lymphoblastic leukemia (ALL). Using fluorescence in situ hybridization (FISH) we show here that in three of these cell lines identical complex rearrangements occurred. However, the regions involved on 5q and 12p are different from the breakpoints in CMML, and the translocation is accompanied by seemingly identical cryptic deletions of both 5q and 12p chromosome sequences in all analyzed pre-B ALL cell lines. The similar cytogenetic, FISH, and immunophenotyping findings in the three cell lines suggest that the t(5;12)(q31q33;p12) defines a new entity of pre-B ALL.

Acute Disease↗
PubMed1997

Philadelphia-like translocation t(9;22)(q34;q11) found in a follicular lymphoma involving not BCR and ABL but IGL-mediated rearrangement of an unknown gene on 9q34.

In a case of follicular center cell lymphoma (FCCL) without evidence of histologic progression towards a high-grade lymphoma, t(9;22)(q34;q11) was found simultaneously with a t(14;18)(q32;q21) and a t(8;14)(q24;q32). Molecular studies of this case showed BCL2 and MYC rearrangements in addition to the rearrangements of immunoglobulin heavy (IGH) and lambda (IGL) loci. Investigation of the t(9;22) using Southern blot and RT-PCR analysis failed to detect M-bcr or m-bcr rearrangements of BCR. Two-color fluorescence in situ hybridization (FISH) with ABL and BCR probes revealed presence of a "fusion" signal, but its atypical localization [der(9)] and gene order [cen-ABL-BCR-tel] indicated that this translocation differed from the t(9;22) in chronic myeloid leukemia and did not involve either ABL or BCR. In addition, further FISH analysis using 9q34- and 22q11-specific probes localized the breakpoint on chromosome 9 distal to the NOTCH1 gene and the breakpoint on 22q11 in the IGL gene cluster. These results indicate an IGL-mediated rearrangement of an unknown gene at 9q34 that together with BCL2 and MYC might be involved in the lymphomagenesis of the present case of FCCL and perhaps in other cases of non-Hodgkin lymphoma in which t(9;22) is sporadically occurring.

Blotting, Southern↗
PubMed1997

Primary effusion Burkitt's lymphoma with t(8;22) in a patient with hepatitis C virus-related cirrhosis.

Hepatitis C virus (HCV) infection may be complicated by non-Hodgkin's lymphoma through yet unknown pathogenetic mechanisms. We describe the case of a patient with HCV-related cirrhosis who developed a primary effusion lymphoma (PEL) of Burkitt's type confined to the peritoneal cavity, in the absence of immunodeficiency or autoimmunity. Paracentesis followed by immunophenotyping, karyotyping, and molecular studies allowed us to diagnose a small noncleaved B-cell lymphoma (CD20+, CD24+, CD10+, CD5-, CD23-, lambda+) with the t(8;22) (q24;q11) translocation and clonal rearrangement of the immunoglobulin heavy chain gene. HCV-RNA, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus were not identified within lymphoma cells. The finding of HCV-RNA in the ascitic fluid suggests a link between HCV and development of lymphoma with HCV playing the role of persistent antigenic stimulation to intraperitoneal B-cell clonal expansion(s).

Ascitic Fluid↗
PubMed1997

del(7q) in chronic B-cell lymphoid malignancies.

Twelve patients with diagnosis of B-cell non-Hodgkin's lymphoma/leukemia and del[7q] were studied for their clinical, cytogenetic, and molecular characteristics. Eleven patients were classified as small cell lymphoma whereas one had a diffuse large cell lymphoma. Lymphoplasmacytic features were observed in six out of eleven small cell lymphomas. Morphologically and immunologically these small cell lymphomas could be classified as chronic lymphocytic leukemia (typical or atypical; 4 cases), marginal zone lymphoma (splenic lymphoma with villous lymphocytes; 1 case), mantle cell lymphoma (2 cases), or nonspecified, non-Hodgkin's lymphoma (4 cases). Eleven of twelve patients presented with peripheral blood and bone marrow involvement. Two of twelve cases showed del[7q] as the sole anomaly. Two different types of deletions were present: ten cases had del(7)(q21q31) and two cases had del(7)(q31q34). Cases that could be molecularly investigated did not show any involvement of BCL2, BCL3, or BCL6, and only one case had BCL1 rearrangement. The data indicate that del(7q) is associated with a subset of mature small B-cell lymphoproliferative disorders of which some but not all show lymphoplasmatic features.

Aged↗