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N Galili

Publications and source records attributed to N Galili.

At least 37 records · Page 2Linked to original sources
PubMed1993

Fusion of a fork head domain gene to PAX3 in the solid tumour alveolar rhabdomyosarcoma.

We have examined the structure and expression of the products associated with the t(2;13)(q35;q14) translocation associated with alveolar rhabdomyosarcoma. The chromosome 13 gene (FKHR) is identified as a member of the fork head domain family of transcription factors characterized by a conserved DNA binding motif. Polymerase chain reaction analysis demonstrates that a 5'PAX3-3' FKHR chimaeric transcript is expressed in all eight alveolar rhabdomyosarcomas investigated. Immunoprecipitation experiments detect the predicted fusion protein. These findings indicate that the t(2;13) generates a potentially tumorigenic fusion transcription factor consisting of intact PAX3 DNA binding domains, a truncated fork head DNA binding domain and C-terminal FKHR regions.

Amino Acid Sequence↗
PubMed1993

Molecular residual disease status at the end of chemotherapy fails to predict subsequent relapse in children with B-lineage acute lymphoblastic leukemia.

PURPOSE: We have investigated whether the extent of residual leukemia in the marrows obtained at the completion of chemotherapy can predict subsequent relapse in children with B-lineage acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Marrow samples of 24 patients were examined for residual disease at the end of treatment using a quantitative method based on the polymerase chain reaction (PCR) amplification of the complementarity determining region-3 of the immunoglobulin heavy chain. RESULTS: Of the 15 patients who remain in continuous bone marrow remission (range, 41 to 98 months), 14 had no detectable leukemic cells; one patient had a very low level (one in approximately 335,000 marrow cells) of residual leukemic cells that underwent clonal evolution. Among the nine patients who had a marrow relapse after the completion of treatment, eight patients whose relapses occurred 4 to 54 months from the end of therapy had no detectable leukemic cells, whereas only the one patient who relapsed 2 months after the completion of therapy had detectable residual disease. CONCLUSION: These observations indicate that the absence of detectable residual leukemia by PCR at the end of chemotherapy is not sufficient to assure that the patient is cured and suggest that frequent serial monitoring is required for the early prediction of relapse off therapy.

Adolescent↗
PubMed1992

Predominance of fetal type DJH joining in young children with B precursor lymphoblastic leukemia as evidence for an in utero transforming event.

The presence of N sequences in the complementarity determining region 3 (CDR3) of the rearranged immunoglobulin H chain is developmentally regulated: N regions are generally present in the DJH joinings of adult B cells but are often absent in fetal B cells. Analysis of the CDR3 in 61 B precursor acute lymphoblastic leukemias indicated that 87.5% of the leukemias obtained from children < or = 3 yr old lacked N regions at the DJH junction. In contrast, in children > 3 yr old, only 11.1% of the leukemias lacked N regions at this junction, a frequency similar to what we have observed in B cells from children and adults. These findings suggest that the majority of leukemias presenting within the first 3 yr of age arise from an in utero transforming event.

Adult↗
PubMed1992

The pattern of joining (JH) gene usage in the human IgH chain is established predominantly at the B precursor cell stage.

Preferential utilization of JH and D genes has been demonstrated in the rearranged IgH chain in human peripheral B cells. We report here that the same hierarchy of JH gene usage is observed in leukemic cells arrested in the B precursor stage of differentiation. Specifically, JH4 and JH6 accounted for 42.9% and 35.7%, respectively, of the JH gene usage in the leukemias compared with an expected frequency of 16.7% assuming unbiased gene usage. Within the D gene families, the DN1 gene appears to be overutilized in both populations, representing about 15% of the total gene usage compared with an expected frequency of 3.2%. Because 21 of the 36 leukemias contained only nonproductive IgH rearrangements, the preferential gene usage could not have arisen from pre-B cells that have undergone clonal selection after a productive rearrangement but before surface Ig expression. Nonproductive rearrangements exhibited the biased gene usage seen for productive rearrangements. These findings suggest that a recombination bias favoring certain segments may be the actual mechanism responsible for the apparent preferential utilization of JH and D genes.

Adolescent↗
PubMed1992

Residual disease at the end of induction therapy as a predictor of relapse during therapy in childhood B-lineage acute lymphoblastic leukemia.

PURPOSE: More than 95% of children with B-lineage acute lymphoblastic leukemia (ALL) achieve a clinical remission after the induction phase of chemotherapy (first 28 days) as evaluated by morphologic criteria. However, relapse occurs in approximately 30% of these children. The objective of this study was to determine whether the outcome of patients in clinical remission at the end of induction therapy could be predicted using a highly sensitive method to detect residual disease. PATIENTS AND METHODS: All children diagnosed with B-lineage ALL at the Children's Hospital of Philadelphia during a 2-year period were eligible. The extent of residual leukemia was quantitated in remission marrow samples obtained at the end of induction therapy in 44 children using a phage clonogenic assay in association with complementarity-determining-region 3 (CDR3)-polymerase chain reaction (PCR). RESULTS: Residual disease was a significant predictor of outcome independent of WBC count, age, or sex. The estimated relapse-free survival (RFS) during therapy was 50.4% (+/- 12.6%) for patients with high residual disease (> or = 0.6% leukemia cells among total marrow B cells) versus 91.9% (+/- 5.5%) for those with lower levels (P < .002). There were no significant differences in off-treatment RFS between patients with high or low residual disease who completed therapy in continuous remission (P = .82). The overall estimated RFS was 32.3% (+/- 11.6%) for patients with high residual disease versus 62.6% (+/- 10.7%) for patients with lower levels of residual leukemia cells, with a median follow-up of 5.3 years for patients in continuous remission (P < .008). CONCLUSION: PCR detection of high residual disease at the end of induction therapy identifies patients at increased risk for relapse during therapy.

Adolescent↗
PubMed1991

Enhanced detection of the t(14;18) translocation in malignant lymphoma using pulsed-field gel electrophoresis.

The t(14;18) chromosomal translocation that results in the juxtaposition of the bcl-2 proto-oncogene with the heavy chain JH locus is a common cytogenetic abnormality in human lymphoma. In particular, it is seen in about 85% of follicular lymphoma (FL) and up to one-third of diffuse lymphomas (DL). The chromosome 18 breakpoints have been shown to cluster into two regions. The major breakpoint region (mbr) within the 3' untranslated region of the bcl-2 proto-oncogene accounts for approximately 60% of the cases and the minor cluster region (mcr) 30 kb 3' of bcl-2 accounts for approximately 25% of the breakpoints. Because of variability in the position of the breakpoint, detection of the t(14;18) by Southern blot analysis provides an important clonal marker for the tumor. However, conventional electrophoresis (CE) fails to detect the translocation in 15% to 25% of cases. We have applied pulsed-field gel electrophoresis (PFGE) to the detection of the t(14;18) in a series of lymphoma prospectively analyzed by CE, polymerase chain reaction (PCR), and cytogenetic analysis. PFGE readily detected t(14;18) rearrangements as indicated by comigration of bands detected with probes for the mbr region (chromosome 18) and the JH locus (chromosome 14). In a series of 40 patients with FL, this method proved to be the most comprehensive for detection of the translocation compared with standard methods; in fact, in one case only PFGE was able to detect the chromosomal rearrangement. Ten percent of the FL cases were negative by all methods tested. In a separate analysis of matched tissue specimens from cases of tumor progression of FL to diffuse lymphoma, PFGE detected a common t(14;18) rearrangement confirming a clonal origin in seven of seven cases, whereas CE detected a rearrangement in only three of seven cases. Overall, PFGE was able to detect a translocation in 8 of 12 cases that were negative by CE and four of eight negative by cytogenetic analysis. In conclusion, PFGE analysis is more comprehensive than CE, PCR, and cytogenetic analysis for the detection of the t(14;18) breakpoint in tissue biopsies of malignant lymphoma.

Chromosome Mapping↗
PubMed1991

The t(1;19)(q23;p13) results in consistent fusion of E2A and PBX1 coding sequences in acute lymphoblastic leukemias.

The t(1;19)(q23;p13) chromosomal translocation is observed cytogenetically in 25% of children with pre-B-cell acute lymphoblastic leukemia (ALL) and is associated with an adverse treatment outcome. The t(1;19) juxtaposes the E2A gene from chromosome 19 with the PBX1 gene on chromosome 1, leading to the production of fusion transcripts and resultant chimeric proteins that contain the transcriptional-activating motif of E2A and the DNA-binding homeodomain of PBX1. To investigate the molecular nature of E2A/PBX1 fusion in patients with t(1;19) ALL we used an RNA-based polymerase chain reaction (PCR) procedure to amplify a portion of the chimeric transcript. We detected E2A/PBX1 fusion transcripts in cells from 97% (37 of 38) of cases in which the t(1;19) had been observed cytogenetically. Molecular evidence of E2A/PBX1 fusion transcripts was also observed in a patient in whom a t(1;19) was not detected cytogenetically and in one patient with subclinical levels of minimal residual disease before overt clinical relapse. In all PCR-positive cases the junction of E2A and PBX1 coding sequences occurred at precisely the same location as demonstrated by hybridization of PCR products with a fusion site-specific detection oligonucleotide. These findings demonstrate the consistent fusion of E2A and PBX1 coding sequences resulting from t(1;19) and suggest that site-specific fusion of E2A and PBX1 is an important pathogenic event in t(1;19) ALL.

Base Sequence↗
PubMed1991

PBX2 and PBX3, new homeobox genes with extensive homology to the human proto-oncogene PBX1.

Two new homeobox genes, PBX2 and PBX3, were isolated on the basis of their extensive homology to PBX1, a novel human homeobox gene involved in t(1;19) translocation in acute pre-B-cell leukemias. The predicted Pbx2 and Pbx3 proteins are 92 and 94% identical to Pbx1 over a large region of 266 amino acids within and flanking their homeodomains, but all three proteins diverge significantly near their amino and carboxy termini. Chromosome in situ hybridizations demonstrated that the PBX genes are not clustered but map to separate chromosomal loci: PBX1, 1q23; PBX2, 3q22-23; PBX3, 9q33-34. Expression of PBX2 or PBX3 was not restricted to particular states of differentiation or development, as mRNA transcripts of these genes were detected in most fetal and adult tissues and all cell lines, unlike PBX1, which is not expressed in lymphoid cell lines. Similar to PBX1 RNA, PBX3 RNA is alternatively spliced to yield two translation products with different carboxy termini, a feature not observed for PBX2. Their extensive sequence similarity and widespread expression suggest a generalized, overlapping role for Pbx proteins in most cell types. Differences in their amino and carboxy termini may modulate their activities, mediated in part by differential splicing and, for PBX1, protein fusion following t(1;19) chromosomal translocation.

Amino Acid Sequence↗
PubMed1990

Detection of non-Hodgkin's lymphoma in the peripheral blood by analysis of antigen receptor gene rearrangements: results of a prospective study.

Analysis of immunoglobulin (Ig) and T-cell receptor gene rearrangements, using Southern blot hybridization, has been applied to peripheral blood lymphocytes (PBL) in 335 samples from patients with non-Hodgkin's lymphoma. The incidence of circulating lymphoma cells detected by gene rearrangement analyses is related to the histologic subtype, clinical stage of disease, and clinical status. Among 104 patients studied at diagnosis, the incidence of positive analyses was 34% in low-grade lymphoma and only 8% in intermediate-grade lymphoma. Clonal Ig gene rearrangements were detected nearly universally in the small lymphocytic histologic subtype. PBL studies were related to the initial stage of disease: positive studies were seen in 35% of patients with stage IV disease, 29% of patients with stage III disease, and 12% of patients with stages I-II disease. The incidence of PBL rearrangements at the time of disease recurrence in 32 patients requiring cytoreductive therapy was 48%, somewhat greater than at initial diagnosis. A group of patients with low-grade lymphoma, who had treatment deferred after diagnosis or recurrence, was also studied; the incidence of PBL rearrangements was 38% in this population. Among 157 patients clinically free of disease, DNA analyses of the PBL were positive in only 10%. Subsequent relapse of disease in 26 patients was antedated by PBL rearrangement in only one patient. Clonal rearrangements detected in 15 patients have been followed by recurrence of clinical disease in only one patient over a median of 24 months from the time of analysis. The lack of detectable rearrangements in the peripheral blood in the majority of patients may be due to methodology or the biology of the disease. These issues may be further addressed with alternative methods for assessment of minimal disease. However, rigorous testing of any new molecular tool requires an adequate patient population in which disease status is closely monitored over a sufficient period of time.

Blotting, Southern↗
PubMed1990

Chromosomal translocation t(1;19) results in synthesis of a homeobox fusion mRNA that codes for a potential chimeric transcription factor.

The gene (E2A) for enhancer binding transcription factors E12 and E47 maps to the t(1;19) chromosomal translocation breakpoint in pre-B cell leukemias. Altered E2A transcripts lacking sequences coding for the helix-loop-helix DNA binding motif were detected in several t(1;19)-carrying cell lines. Fusion cDNAs that crossed the t(1;19) breakpoint were cloned and shown to code for an 85 kd protein consisting of the amino-terminal two-thirds of E2A fused to a chromosome 1-derived protein. The fusion protein has the features of a chimeric transcription factor in which the DNA binding domain of E2A is replaced by the putative DNA binding domain of a homeoprotein from chromosome 1 for which the name Prl (pre-B cell leukemia) is proposed. Identical E2A-prl mRNA junctions were detected by PCR in three t(1;19)-carrying cell lines, indicating that the fusion transcripts and predicted chimeric protein are a consistent feature of this translocation.

Amino Acid Sequence↗
PubMed1990

Rapid, nonradioactive detection of clonal T-cell receptor gene rearrangements in lymphoid neoplasms.

Southern blot hybridization analysis of clonal antigen receptor gene rearrangements has proved to be a valuable adjunct to conventional methods for diagnosing lymphoid neoplasia. However, Southern blot analysis suffers from a number of technical disadvantages, including the time necessary to obtain results, the use of radioactivity, and the susceptibility of the method to various artifacts. We have investigated an alternative approach for assessing the clonality of antigen receptor gene rearrangements in lymphoid tissue biopsy specimens. This approach involves the amplification of rearranged gamma T-cell receptor genes by the polymerase chain reaction and analysis of the polymerase chain reaction products by denaturing gradient gel electrophoresis. By use of this approach, clonal rearrangements from neoplastic lymphocytes constituting as little as 0.1-1% of the total cells in the tissue are detected as discrete bands in the denaturing gel after the gel is stained with ethidium bromide and viewed under ultraviolet light. In contrast, polyclonal rearrangements from reactive lymphocytes appear as a diffuse smear along the length of the gel. Our findings suggest that polymerase chain reaction combined with denaturing gradient gel electrophoresis may offer a rapid, nonradioactive, and sensitive alternative to Southern blot analysis for the diagnostic evaluation of lymphoid tissue biopsy specimens.

Base Sequence↗
PubMed1990

Expression of bcr-abl fusion transcripts following bone marrow transplantation for Philadelphia chromosome-positive leukemia.

A modified polymerase chain reaction (PCR) procedure was used to study the expression of bcr-abl fusion transcripts following allogeneic bone marrow transplantation (BMT) for Philadelphia chromosome (Ph1) positive acute and chronic leukemias. The technique was applied to RNA preparations of peripheral blood and bone marrow cells from 10 patients with chronic myelogenous leukemia (CML) and one patient with acute lymphoblastic leukemia (ALL), all of whom had undergone allogenic BMT and were in clinical and cytogenetic remission. Pre-BMT samples available for eight of 11 patients contained detectable bcr-abl fusion products serving as a baseline for comparison to post-BMT studies. Six patients showed no PCR-detectable bcr-abl transcripts in each of several serial analyses post-BMT (1-36 months post-BMT). The remaining five patients demonstrated various patterns of bcr-abl transcript expression after transplantation. In three patients, bcr-abl transcripts persisted for up to 3 months post-BMT but subsequently were undetectable. Molecular relapse was observed 3 and 6 months post-BMT in the remaining two patients whose earlier post-BMT samples showed no bcr-abl fusion transcripts. No bcr-abl transcripts were detected in subsequent samples from both of these patients 6 months and 1 year post-BMT, respectively. These data confirm that Ph1 carrying cells expressing the bcr-abl fusion mRNA may persist or recur for several months following BMT in the absence of clinical and cytogenetic relapse. The significance of these observations is discussed with respect to results reported recently by others using similar techniques.

Bone Marrow Transplantation↗
PubMed1988

Continuing rearrangement but absence of somatic hypermutation in immunoglobulin genes of human B cell precursor leukemia.

Southern blot analyses revealed that cells from nearly 30% of childhood B cell precursor acute lymphoblastic leukemias (ALLs) contained more than two rearranged, nongermline bands for Ig heavy chain genes. DNA corresponding to these bands was molecularly cloned from two cases which showed three and seven rearranged bands, respectively. Nucleotide sequence analysis of the cloned DNA demonstrated that each band represented different VDJ or DJ rearrangements. While the same DJ joints were shared by several rearrangements, different DJ joints were found in the majority of rearrangements, precluding V region substitution as an explanation for the multiplicity of heavy chain rearrangements in these leukemias. Most of the V region segments involved in these rearrangements were restricted to VH region families that have been shown previously to be preferentially rearranged in human fetal B lineage cells. Sequence analysis of multiple copies of the same VDJ rearrangements from different cells revealed no somatic mutation, a mechanism responsible for detection of extra rearranged Ig DNA bands in certain other B lineage tumors. The data suggest that in some cases of ALL Ig heavy chain genes begin and continue to rearrange de novo within the neoplastic B cell precursor populations derived from an original malignant cell transformed at a stem cell stage of differentiation.

Amino Acid Sequence↗
PubMed1988

Single cell origin of bigenotypic and biphenotypic B cell proliferations in human follicular lymphomas.

To investigate the possible relatedness of the subpopulations that make up so-called biclonal lymphomas, we examined five bigenotypic and biphenotypic follicular lymphomas using DNA probes specific for the t(14;18) chromosomal translocation, which is a characteristic feature of these neoplasms. On Southern blot analysis, both subpopulations from four of five lymphomas contained comigrating t(14;18) DNA rearrangements, confirming the single cell origins for these neoplasms. No comigrating t(14;18) DNA rearrangements were observed in the fifth lymphoma, but nucleotide sequence analysis of cloned, breakpoint DNA showed identical t(14;18) crossovers in the two subpopulations. The migration differences of both the Ig and chromosome 18 DNA rearrangements were shown to result from somatically acquired mutations of the Ig genes from the fifth lymphoma. These studies indicate that Ig gene rearrangements and idiotope expression are not consistently stable clonal markers since they are subject to variability as a result of somatic mutation. Although translocated chromosome 18 DNA rearrangements are more reliable, they may also vary among cells of some tumors since somatic mutation can affect, as well, DNA of translocated alleles in follicular lymphomas.

B-Lymphocytes↗
PubMed1987

Establishment and characterization of a common acute lymphoblastic leukemia cell line with a deletion of chromosome 3 band q26.

This paper describes the establishment and characterization of a new cell line (SUP-B7) which was established from a child with "common" acute lymphoblastic leukemia. The SUP-B7 cells (and the patient's tumor) have been characterized by cytochemical staining, monoclonal antibodies, enzyme analyses, gene rearrangement studies, and karyotype analysis. The SUP-B7 cells are periodic acid-Schiff positive, common acute lymphoblastic leukemia antigen positive, and terminal deoxynucleotidyl transferase positive, and they lack the Epstein-Barr virus genome. In addition, the SUP-B7 cells lack cytoplasmic and surface immunoglobulins, and the immunoglobulin gene rearrangement studies showed rearranged heavy chain genes with germ line light chain genes. Concordance between the cell line and the patient's tumor was established by the immunoglobulin gene rearrangement studies. Using Southern blot analysis of the DNA from the patient's tumor and the SUP-B7 cells, there was comigration of the bands representing the rearranged immunoglobulin heavy chain gene. In addition, the SUP-B7 cells possess a single chromosome abnormality: del(3)(q26q28), with the chromosome breakpoint at or near the transferrin receptor gene. Since the SUP-B7 cell line is concordant with the patient's malignancy and since these cells possess a single chromosomal abnormality, the SUP-B7 cell line may be a useful tool in determining the biological significance of the chromosome deletion: del(3)(q26q28).

Antigens↗
PubMed1987

Epstein-Barr virus-transformed B-cell line (DV-1) derived from bone marrow of a patient with severe combined immunodeficiency and immunoblastic lymphoma.

An Epstein-Barr virus-transformed B-cell line derived from a patient with severe combined immunodeficiency who died of a lymphoreticular malignancy has been characterized. The line derived from bone marrow cultures and designated DV-1 shows surface and cytoplasmic IgM and staining with fluorescent monoclonal antibodies against immunoglobulin heavy and light chains mu, delta, and kappa, Dr, and several other B-cell surface antigens. DV-1 secretes IgM kappa and demonstrates monoclonality on analysis of immunoglobulin heavy and light chain gene rearrangement patterns. Incubation with either phytohemagglutinin or pokeweed mitogen failed to cause significant stimulation of proliferation of DV-1 and another EBV-transformed B-cell line derived from an immunologically normal host (LA-350), whereas incubation with Staphylococcus aureus Cowan strain 1 led to significant inhibition of DV-1 and LA-350. Rabbit IgG antibody specific for human immunoglobulin mu-chains produced a dose dependent stimulation of both lines. The responses of DV-1 and LA-350 to mitogens and anti-mu were not as high as those of normal peripheral blood lymphocytes. This spontaneously derived Epstein-Barr virus-transformed B-cell line from a patient with severe combined immunodeficiency demonstrated functional characteristics similar to a B-cell line derived from an immune competent host. While these cells spontaneously incorporate 200 times more thymidine than normal resting peripheral blood lymphocytes, they retain their ability to be modulated by antiimmunoglobulin, and staphylococcal Cowan strain 1, but are unresponsive to the effects of B-cell growth factor.

B-Lymphocytes↗
PubMed1986

Leukemia of early infancy. Early B-cell lineage associated with t(4:11).

A case of infantile acute leukemia associated with translocation t(4:11)(q21:q23) is reported. This leukemia has a very poor prognosis, and this patient survived for only 9 months. The blast cell morphology was L1/L2 according to the FAB classification and showed a lymphoid appearance on transmission electron microscopy. The histochemical stains showed a pattern of periodic acid-Schiff positivity and variable alpha-naphtyl acetate staining. The cells were TdT-positive and surface-marker phenotyping was positive for Ia-like and B4 antigens but negative for CALLA, T-cell markers, myelocyte and monocyte markers. The leukemic cells represent a frozen state of a very early precursor, corresponding to the earliest recognizable stage of the B-cell lineage. This observation may contribute to the controversion regarding the cell origin of this unique leukemia associated with t(4:11), lymphatic versus null cell, early myeloid, or mixed, and points to the possibility of a very early B-cell lineage leukemia.

Antigens, Neoplasm↗