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H Avet-Loiseau

Publications and source records attributed to H Avet-Loiseau.

At least 55 records · Page 3Linked to original sources
PubMed1998

High incidence of translocations t(11;14)(q13;q32) and t(4;14)(p16;q32) in patients with plasma cell malignancies.

Abnormalities involving the 14q32 region are recurrent chromosomal changes in plasma cell malignancies. Recent preliminary molecular analyses found IGH rearrangements in almost 100% of human myeloma cell lines and in 75% of patients. However, no systematic study analyzing the nature of the partner chromosomal regions have been reported thus far. To define the exact incidence of illegitimate IGH rearrangements and the respective incidence of partner genes cloned to date, we analyzed 141 patients with either multiple myeloma (MM, n = 127) or primary plasma cell leukemia (PCL, n = 14) using fluorescence in situ hybridization. The overall incidence of illegitimate recombinations was 57% (80 of 141 patients). Analysis of this incidence according to Durie and Salmon stage, patients' status, i.e., MM versus primary PCL and diagnosis versus relapse, immunoglobulin type and subtype, and beta2-microglobulin value, did not show any correlation. To analyze the nature of the partner chromosomal region, we selected probes specific for the following genes: FGFR3 (4p16), MYC (8q24), CCND1 (11q13), MAF (16q23), and BCL2 (18q21). These probes, combined with differentially labeled 14q32 probes, were used for dual-color fluorescence in situ hybridization on interphase plasma cells. Among the 80 patients with illegitimate IGH rearrangement, we identified 23 IGH-CCND1 fusion cases [i.e., t(11;14)], 17 IGH-FGFR3 fusion cases [i.e., t(4;14)], 3 IGH-MYC fusion cases [i.e., t(8;14)], and only one IGH-MAF fusion case. No IGH-BCL2 fusion case was detected. In 37 of 80 patients, none of these partner genes was involved. Analysis of cases with specific translocations according to their bioclinical features at diagnosis did not show any correlation. This study demonstrated that CCND1 and FGFR3 genes are involved together in about 50% of MM and primary PCL patients with illegitimate IGH rearrangements.

Aneuploidy↗
PubMed1998

Recent human-specific spreading of a subtelomeric domain.

The recent spreading of a subtelomeric region at nine different human chromosome ends was characterized by a combination of segregation analyses, physical mapping, junction cloning, and FISH investigations. The events occurred very recently in human genome evolution as demonstrated by sequence analysis of different alleles and the single location of the ancestral site at chromosome 17qter in chimpanzee and orangutan. The domain successfully colonized most 1p, 5q, and 6q chromosome ends and is also present at a significant frequency of 6p, 7p, 8p, 11p, 15q, and 19p ends. On 6qter, the transposed domain is immediately distal to the highly conserved, single-copy gene PDCD2.

Animals↗
PubMed1998

Detection of t(11;14) using interphase molecular cytogenetics in mantle cell lymphoma and atypical chronic lymphocytic leukemia.

The chromosomal translocation t(11;14)(q13;q32) fuses the IGH and CCND1 genes and leads to cyclin D1 overexpression. This genetic abnormality is the hallmark of mantle cell lymphoma (MCL), but is also found in some cases of atypical chronic lymphocytic leukemia (CLL), characterized by a poor outcome. For an unequivocal assessment of this specific chromosomal rearrangement on interphase cells, we developed a set of probes for fluorescence in situ hybridization (FISH). Northern blotting was performed for analysis of the cyclin D1 expression in 18 patients. Thirty-eight patients, with either a typical MCL leukemic phase (17 patients) or atypical CLL with an MCL-type immunophenotype, i.e., CD19-, CD5+, CD23-/low, CD79b/sIgM(D)++, and FMC7+ (21 patients), were analyzed by dual-color interphase FISH. We selected an IGH-specific BAC probe (covering the JH and first constant regions) and a commercially available CCND1 probe. An IGH-CCND1 fusion was detected in 28 of the 38 patients (17 typical MCL and 11 cases with CLL). Cyclin D1 was not overexpressed in two patients with typical MCL and an IGH-CCND1 fusion. In view of the poor prognosis associated with MCL and t(11;14)-positive CLL, we conclude that this set of probes is a valuable and reliable tool for a rapid diagnosis of these entities.

Adult↗
PubMed1998

Characterization of two add(4qter) chromosomes by comparative genomic hybridization.

We describe the combined use of comparative genomic hybridization (CGH) and fluorecence in situ hybridization (FISH) to identify the origin of de novo unbalanced translocations in a fetus with abnormalities on ultrasound examination and in a newborn with multiple congenital abnormalities. RHG banding of amniocytes and lymphocytes respectively showed a unbalanced karyotype: 46,XX,add(4)(q34), with normal parental karyotypes in both cases. CGH revealed a gain of material from distal 15q (q23qter) in the fetus and a gain of distal 7q (q31qter) in the newborn. CGH results were confirmed using FISH with painting probes in both cases. These cases demonstrate the efficiency of CGH in identifying the chromosomal origin of extramaterial in unbalanced de novo translocations.

Chromosomes, Human, Pair 15↗
PubMed1997

Construction of a 780-kb PAC, BAC, and cosmid contig encompassing the minimal critical deletion involved in B cell chronic lymphocytic leukemia at 13q14.3.

A putative tumor suppressor gene involved in B cell chronic lymphocytic leukemia (B-CLL) was mapped to human chromosome 13q14.3 close to the genetic markers D13S25 and D13S319. We constructed a 780-kb-long contig composed of cosmids, bacterial artificial chromosomes, and bacteriophage P1-derived artificial chromosomes that provides essential information and tools for the positional cloning of this gene. The conting contains both flanking markers as well as several additional genetic markers, three ESTs, and one potential CpG island. In addition, using one B-CLL patient, we characterized a small internal deleted region of 550 kb. Comparing this deletion with other recently published deletions narrows the minimally deleted area to less than 100 kb in our physical map. This deletion core region should contain all or part of the disrupted in B cell malignancies tumor suppressor gene.

Bacteriophages↗
PubMed1997

Molecular cytogenetic abnormalities in multiple myeloma and plasma cell leukemia measured using comparative genomic hybridization.

Comparative genomic hybridization (CGH) was used to identify recurrent regions of DNA sequence loss and gain in 21 multiple myeloma (MM) and plasma cell leukemia (PCL) primary tumor specimens and cell lines. Multiple regions of non-random sequence loss and gain were observed in 8/8 primary advanced stage tumors and 13/13 cell lines. Identification of sequence copy number changes was facilitated by statistical analyses that reduce subjectivity associated with identification of copy number changes and by requiring that sequence changes are visible using both red- and green-labeled tumor DNA. Loss of sequence on 13q and 14q and gain of sequence on 1q and chromosome 7 occurred in 50-60% of the population. In general, cell lines carry more and larger regions of sequence gain and loss than primary tumors. Regions of sequence copy number change that recur among MM cell lines and primary tumors include, in order of prevalence, enh(1q12qter), dim(13), enh(7), enh(3q22q29), enh(11q13.3qter), dim(14q11.2q31), enh(8q21qter), enh(3p25pter), dim(17p11.2p13), and dim(6q22.1q23). Population distributions of genome-wide changes in primary tumors reveal "hot-spots" of sequence loss from 13q12.1-q21, 13q32-q34, 14q11.2-q13, and 14q23-q31. Genomic changes detected using CGH are consistent with those identified using banding analyses, although recurrent involvement of additional regions of the genome are also evident. A higher prevalence of genomic changes is visible using CGH compared to banding. Identification of recurrent regions of sequence gain and loss provides opportunities to identify regions of the genome that may be involved in the malignant phenotype and/or disease progression.

DNA, Neoplasm↗
PubMed1997

Ifosfamide and etoposide in childhood osteosarcoma. A phase II study of the French Society of Paediatric Oncology.

The aim of this phase II study was to determine the efficacy of high-dose ifosfamide with moderate dose etoposide in childhood osteosarcoma. From January 1992 to January 1995, 27 children (15 male, 12 female) with relapsed or refractory evaluable osteosarcoma were included in a phase II study of two courses of ifosfamide 3g/m2/day and etoposide 75 mg/m2/day for 4 days. Median age was 14 years (7-19 years). All but one had received high-dose methotrexate and doxorubicin as first-line treatment. 22 patients had previously received ifosfamide. This regimen was given as first-line in 1 patient, second-line in 23 and third-line in 3. Evaluable disease was lung metastases in 21 patients, local relapse in 5 and adenopathy in 1. There were six complete responses, seven partial responses, three minor responses, six stable disease and five progressive disease (including one mixed response). Response rate was 48% (95% confidence interval, 29-67%). Duration of response was not available (10 responding patients had other treatments). Response rate was equivalent in the subgroup of 22 patients who had previously received ifosfamide (4 CR, 6 PR). Among 3 patients who received the phase II regimen as third-line chemotherapy, there was 1 PR. All but 4 patients had a well tolerated grade 4 neutropenia. Transient mild confusion or seizures were each observed once. 5 patients are alive 15-31 months after the beginning of chemotherapy. This combination of drugs at this dosage has tolerable toxicity, is efficient and deserves evaluation in phase III studies.

Adolescent↗
PubMed1997

Comparative genomic hybridization is a powerful tool, complementary to cytogenetics, to identify chromosomal abnormalities in childhood acute lymphoblastic leukaemia.

Cytogenetics has a strong prognostic value in childhood acute lymphoblastic leukaemia (ALL), but results are often incomplete because of the poor chromosome morphology. To improve this analysis, we tested comparative genomic hybridization (CGH) for the detection of chromosomal imbalances. 72 children were retrospectively analysed using CGH. Only 53% of the patients had been fully banded by standard methods. With CGH, 36 patients retained a normal chromosomal profile and 36 had unbalanced abnormalities. No amplification was detected. Fluorescence in situ hybridization (FISH) with centromeric and unique sequence probes was used in those cases with discrepancies or unsuccessful karyotype to validate CGH results. CGH enabled clear identification of unbalanced chromosomal abnormalities, even in some cases which had a normal karyotype. In view of the strong prognostic value of hyperdiploidy in childhood ALL, CGH appears to be a powerful technique, complementary to conventional cytogenetics.

Adolescent↗
PubMed1997

Comparative genomic hybridization detects genomic abnormalities in 80% of follicular lymphomas.

Comparative genomic hybridization (CGH) was used to analyse 34 follicular lymphoma (FL) samples. 27 samples showed DNA sequence copy number changes of at least one genomic region (26 samples with at least one gain and nine with at least one loss). Some chromosomes or chromosomal regions were preferentially involved. The most frequently gained regions were chromosome 18q (29% of samples), chromosome X (21%), chromosome 7 (18%), chromosomes 2, 6p and 8q (12%). Two regions were preferentially lost: 6q (12%) and 17p (9%). All these gained and lost regions have been previously reported in cytogenetic studies, confirming the accuracy of CGH in detecting genetic abnormalities in FL. 21% of samples displayed normal profiles, probably reflecting the absence of unbalanced abnormality, which is also in agreement with the cytogenetic data. In conclusion, we showed that CGH is an accurate, reliable and rapid method and we propose the inclusion of CGH in the evaluation of FL at diagnosis.

Chromosome Aberrations↗
PubMed1997

N-Myc gene amplification is a major prognostic factor in localized neuroblastoma: results of the French NBL 90 study. Neuroblastoma Study Group of the Société Francaise d'Oncologie Pédiatrique.

PURPOSE: To assess the relevance of N-Myc gene amplification (NMA) as a prognostic factor in localized neuroblastoma (NB) and to evaluate whether less intensive adjuvant treatment is advisable in infants without NMA. PATIENTS AND METHODS: Assessment of NBs included clinical and imaging data to allow tumor-node-metastasis (TNM) staging, biologic determinations (N-Myc gene analysis), and standard histology and work-up to eliminate metastatic spread (metaiodobenzylguanidine [MIBG] scintigraphy and extensive bone marrow staging). Resectability was defined according to imaging findings. Chemotherapy was indicated in children older than 1 year at diagnosis who had postoperative residual disease or lymph node (LN) involvement, in infants with NMA, or as primary treatment in children with an unresectable NB, including dumbbell tumors. Radiotherapy was recommended in children older than 1 who presented with persistent gross residual disease at the end of therapy. RESULTS: Between 1990 and 1994, 316 consecutive children who presented with a localized NB were registered in the NBL 90 study. The median age was 12 months, and 42 patients had dumbbell tumors (13%). NMA was found in 22 of 225 assessable children (10%) and correlated with adverse prognostic indicators such as age older than 1 year, an abdominal primary tumor, a large tumor (T3), and unresectability. Among 186 children who had primary excision, five died of surgery-related complications. Primary chemotherapy was given to 130 patients, which allowed removal of the tumor in all but four. The 5-year overall survival (OS) and event-free survival (EFS) rates were, respectively, 91% and 84% with a median follow-up time of 36 months. The outcome of infants and older children was similar (P = .2). EFS of patients with resectable tumors was slightly better than with unresectable primary tumors (EFS, 89% v 78%; P = .02). In dumbbell NBs, neurologic recovery was achieved in 74% of cases that presented with symptoms, and initial laminectomy was avoided in 75% of children. In a univariate analysis, large tumors, high neuron-specific enolase (NSE) and lactate dehydrogenase (LDH) levels, positive LNs, macroscopic residue, and NMA adversely influenced outcome. In the multivariate analysis, NMA was the most powerful unfavorable predictive indicator: OS and EFS rates for these children were 36% and 32%, compared with 98% and 90% in nonamplified tumors (P < .001). CONCLUSION: Our data confirm the overall good prognosis of localized NBs, even when unresectable. NMA is the most relevant adverse prognostic factor in localized NBs, and more intensive treatment should be investigated in these patients. Prospective studies of other biologic factors are warranted to tailor therapy more accurately. The EFS of children who underwent primary surgery was excellent, and further justifies elimination of adjuvant treatment provided they have no NMA. Despite the elimination of postoperative therapy, infants with non-NMA tumors have an excellent outcome, which suggests that initial chemotherapy can be further reduced in case of unresectable NBs.

Adolescent↗
PubMed1996

Rothmund-Thomson syndrome and osteosarcoma.

The Rothmund-Thomson syndrome (RTS), also called poikiloderma congenitale is a rare autosomal recessive disease first described in 1868. This syndrome includes most frequently seen skin lesions (atrophy, telangiectases, pigmentation), cataracts and bone defects (dysostosis, dysplasia). Some authors describe an association with malignancy. We report three cases of Rothmund-Thomson syndrome associated with osteosarcoma. After cutaneous epithelioma, osteosarcoma is the most frequent malignancy. Thus, patients with RTS need a careful survey. The treatment did not differ from sporadic osteosarcoma. Chemosensitivity and toxicity are also not different.

Bone Neoplasms↗
PubMed1996

Additional copies of a 25 Mb chromosomal region originating from 17q23.1-17qter are present in 90% of high-grade neuroblastomas.

Neuroblastoma shows remarkable heterogeneity, ranging from spontaneous regression to progression toward highly malignant tumors. In search of genetic abnormalities that could explain this variability, we have characterized neuroblastoma tumors by using multiple fluorescent hybridizations. Our results indicate that chromosome 17 is rearranged very frequently in the form of unbalanced translocations with numerous chromosomal partners, all leading to the presence of supernumerary copies of a 25 Mb chromosomal region originating from 17q23.1-qter. Additional 17q material was detected in more than 90% of untreated high-grade neuroblastomas and, along with 1p36 deletion, should represent the most frequent genetic abnormality of neuroblastoma observed until now.

Blotting, Southern↗
PubMed1996

13q14 deletions are not primary events in B-cell chronic lymphocytic leukemia: a study of 100 patients using fluorescence in situ hybridization.

Fluorescence in situ hybridization with a chromosome 12-specific alpha-centromeric probe and a 13q14 yeast artificial chromosome probe was performed on interphase cells from 100 patients with B-cell chronic lymphocytic leukemia. Thirty-one patients exhibited a 13q14 deletion. No correlation was found between 13q14 deletions and clinical stage, sex, or morphology. Sixteen patients had trisomy 12, including 6 (of 12) with an atypical morphology. Trisomy 12 and 13q14 abnormalities were detected concomitantly in three patients only. The analysis of patients with deletions clearly showed that in five cases a significant number of cells retained two signals with the yeast artificial chromosome probe, indicating a genetic heterogeneity among the leukemic population. Our data confirm that the 13q14 deletion is a frequent event, indicate that the concomitant occurrence of 13q14 deletion and trisomy 12 is rare but possible, and show that both abnormalities are secondary events in B-cell chronic lymphocytic leukemia.

Chromosome Deletion↗
PubMed1995

Cytogenetically aberrant cells in the stem cell compartment (CD34+lin-) in acute myeloid leukemia.

Leukemia may be viewed as a clonal expansion of blast cells; however, the role of primitive cells and/or stem cells in disease etiology and progression is unclear. We investigated stem cell involvement in leukemia using fluorescence in situ hybridization (FISH), immunofluorescence labeling of hematopoietic subpopulations, and flow cytometric analysis/sorting to discriminate and quantify cytogenetically aberrant stem cells in 12 acute myeloid leukemia (AML) and three myelodysplastic (MDS) specimens. Flow cytometric analysis and sorting were used to discriminate and collect a primitive subpopulation enriched in stem cells expressing CD34+ and lacking CD33 and CD38 (CD34+lin-). A subpopulation containing progenitors and differentiating myeloid cells expressed CD34, CD33, and CD38 (CD34+lin+). Nine specimens contained less than 10% CD34+ cells and, thus, were considered to be CD34- leukemias. Mature lymphoid, myeloid, and erythroid subpopulations were sorted on the basis of antigen-linked immunofluorescence. Cytogenetically aberrant cells in sorted subpopulations were identified using FISH with enumerator probes selected on the basis of diagnosis karyotype. Cytogenetically aberrant CD34+lin- cells were present at frequencies between 9% and 99% in all specimens. CD34+lin- cytogenetically aberrant cells comprised between 0.05% and 11.9% of the marrow/blood specimens. Cytogenetically aberrant CD34+lin+ cells constituted 0.01% tp 56% of the marrow/blood population. These data demonstrate that aberrant cells are present in primitive CD34+ stem cell compartments, even in CD34- leukemias. Stem cell involvement was confirmed further by sorting lymphoid and erythroid subpopulations from eight specimens in which the predominant leukemic population lacked lymphoid/erythroid differentiation markers. In these specimens, as well as in multiple lineages, suggests involvement of a cell(s) with multilineage capabilities. The ability of aberrant CD34+lin- stem cells to contribute to clonal and compartment expansion within immunofluorescently defined subpopulations was evaluated to explore the functional phenotype of aberrant CD34+lin- cells. Analysis of compartment size and aberrant cell frequency suggests that frequency of cytogenetically aberrant stem cells is uncoupled from compartment size. These data suggest that cytogenetically aberrant cells in the primitive compartment show varying abilities to expand primitive compartments. Cytogenetically aberrant CD34+lin- cells precede the blast subpopulation in hierarchical maturation and may in some cases by considered preleukemic, requiring maturation or additional mutations before transformation (eg, compartmental expansion) occurs.

ADP-ribosyl Cyclase↗
PubMed1995

Morphologic and molecular cytogenetics in neuroblastoma.

BACKGROUND: Some genetic alterations have been shown to have prognostic implication for patients with neuroblastoma: MYCN oncogene amplification, deletion of the short arm of chromosome 1 and di- or tetraploidy. The goal of this study was to analyze these factors in children with neuroblastoma. METHODS: Twenty neuroblastoma samples were analyzed with morphologic cytogenetics, and each of them was compared with MYCN amplification status by Southern blot and fluorescent in situ hybridization (FISH) with a genomic probe. RESULTS: A complete karyotype was obtained for 14 children. A diploid or tetraploid mode and a 1p deletion were found in most children with advanced stages. MYCN amplification status was totally concordant with both methods in all patients, even in a case with low level amplification. A wide intercellular variation in the amplification level in each MYCN amplified sample was shown. CONCLUSION: The use of FISH to assess MYCN amplification rapidly in neuroblastoma is recommended. This method could be very useful in future therapeutic protocols in which treatment is based on MYCN status (and especially for infants and children with localized tumor).

Adolescent↗
PubMed1995

[Neonatal acute leukemia: apropos of 7 cases].

BACKGROUND: Acute leukemia in neonates is rare and is more severe than leukemia in childhood. POPULATION: Seven cases (four girls, three boys) were included in this series. Leukemia was diagnosed at birth in three cases; hepatosplenomegaly was seen in five cases and skin nodules in three. Hyperleukocytosis more than 100,000/mm3 was present in four cases; the WBC and differential counts were normal in two. A meningeal involvement was seen in one case. The leukemia was lymphoblastic (ALL) in three cases and myeloblastic (AML) in four. Intensive chemotherapy induced complete remission in five patients, persisting 5 and 4 years after the diagnosis in two. Classic risk factors such as high white blood counts, central nervous system involvement, myeloblastic lineage, absence of CALLA (common acute lymphoblastic leukemia antigen) expression and abnormal blast cell karyotype interesting the 11q23 area were found again in this series. Risk related to drug toxicities and infectious complications were also noted in this series of very young patients. CONCLUSIONS: The outcome may depend on progress in pharmacology, search for new drugs and use of bone marrow transplantation.

Female↗
PubMed1995

Clonal hematologic disorders in Down syndrome. A review.

PURPOSE: Children with Down syndrome (DS) carry an elevated risk of developing clonal hematologic disorders. In this review, we summarize reported data describing the incidence of leukemia in children with DS and associated leukemic cell phenotypic and functional features. PATIENTS AND METHODS: Major leukemic subtypes, acute lymphoblastic leukemia (ALL), acute nonlymphoblastic leukemia (ANLL), myelodysplastic syndromes (MDS), and transient abnormal myelopoiesis (TAM) are evaluated in the context of patient age and treatment responsiveness. RESULTS: It is apparent that although leukemia in children with DS is a relatively frequent event, prognosis with current conventional therapeutic strategies is excellent. CONCLUSIONS: Treatment options for TAM, a monoclonal cellular proliferation in neonates, are discussed.

Child↗