Acute leukemias with the t(4;11)(q21;q23).

The t(4;11)(q21;q23) has been associated with marked lineage heterogeneity. Most of the reported cases were classified as acute lymphoblastic leukemia (ALL). The t(4;11) is one of the commonest specific chromosomal translocations in ALL, occurring in 2% of childhood and 5% of adult cases. In childhood ALL, this translocation is associated with female sex, age less than 1 year, hyperleukocytosis, CD10-/CD19+ B-precursor cell immunophenotype, and myeloid-associated antigen (CD15) expression. There also appears to be an age-related difference in treatment outcome. Adults had the worst prognosis, and children aged 1 to 9 years appeared to have a better outcome than infants or adolescents. Reported cases of acute myeloid leukemia (AML) or secondary leukemia with the t(4;11) have not been well characterized. It is intriguing that virtually all of the reported cases with secondary leukemia had received epipodophyllotoxins or doxorubicin, agents that affect topoisomerase II and are associated with secondary AML characterized by 11q23 abnormalities. Identification of the involved gene(s) in the t(4;11) will provide a molecular approach permitting more accurate classification of these cases.     

Cloning of ALL-1, the locus involved in leukemias with the t(4;11)(q21;q23), t(9;11)(p22;q23), and t(11;19)(q23;p13) chromosome translocations.

Chromosomal region 11q23 participates in a number of reciprocal translocations with specific regions of chromosomes 4, 9, 19, and others. These translocations are associated with acute lymphocytic leukemia and acute myelomonocytic, monocytic, and myelogenous leukemia. From a yeast artificial chromosome containing human DNA derived from 11q23 we cloned a DNA fragment which can be used as a probe to detect rearrangements in leukemic cells from the majority of patients with the t(4;11), t(9;11), and t(11;19) translocations. The breakpoints cluster in a small DNA region of less than 5.8 kilobases.     

Molecular characterization of a t(11;14)(q23;q32) chromosome translocation in a B-cell lymphoma

We have analyzed the molecular features of a t(11;14)(q23;q32) chromosome translocation of a cell line established from a B-cell lymphoma. Somatic hybrid cells carrying the 11q- and/or 14q+ chromosome(s) were produced in order to map the breakpoints. Southern blot analyses of DNAs from these hybrid cell lines together with various probes from the IGH locus on chromosome 14 and the ETS-1 and CD3 genes on chromosome 11 showed that the breakpoints of the translocation occurred between the constant regions of the C phi gamma and C gamma 2 genes on chromosome 14 and between the CD3 and ETS-1 genes on chromosome 11. The t(11;14)(q23;q32) translocation does not seem to involve the same mechanism that is responsible for translocations occurring at the immunoglobulin heavy chain joining segment (JH).     

t(11;18)(q21;q21) is the most common translocation in MALT lymphomas

Background: Low grade malignant lymphomas arising from mucosa associated lymphoid tissue (MALT) represent a distinct clinicopathological entity. The cytogenetic findings and molecular genetics of MALT lymphomas remain minimally defined. Cytogenetic studies infrequently constitute part of the diagnostic work-up of MALT lymphomas, most commonly due to small biopsy size and their extranodal localization. Only 28 MALT cases with a clonal karyotype have been published to date. A number of chromosomal abnormalities have been observed with the majority of the cases featuring trisomy of chromosome 3 which is present in up to 78% of the cases.Materials and methods: A total of 116 cases of MALT lymphoma were diagnosed at BCCA between 1988 and 1997. Eleven cases of pathologically confirmed MALT lymphomas were subjected to cytogenetic analysis at the time of the initial evaluation. Eight of 11 cases yielded successful cultures and the presence of a clonal karyotype using standard cytogenetic methodology. In addition, a single case of orbital MALT lymphoma with a clonal karyotype has been obtained through our consultative practice from University of Nebraska Medical Center. These nine cases of MALT lymphoma with a clonal karyotype are the subject of this report.Results and conclusion: In this study we report nine cytogenetically studied MALT lymphomas, three of which feature a novel t(11;18)(q21;q21) translocation which has also been observed in five other MALT cases described in the literature. This recurrent translocation is the most common translocation associated with MALT lymphomas being present in 33% (three of nine) of our cases and 18% (five of 28) of the previously published cases. The results suggest that a potentially important gene located at one of these breakpoints may be involved in the pathogenesis of MALT lymphomas.     

Cloning of the t(11;14)(q13;q32) translocation breakpoints from two human leukemia cell lines

The t(11;14)(q13;q32) translocation has been associated with several subtypes of human leukemia and lymphoma. It has been proposed that this translocation activates a proto-oncogene designated BCL1. In an effort to better understand the mechanism by which this translocation leads to malignancy, we have studied this translocation in two human cell lines. MO1094 and MO2058 were derived from patients with prolymphocytic variants of chronic lymphocytic leukemia. Southern blotting of the MO2058 cell line documented that the translocation linked the Jh region in the immunoglobulin heavy chain gene to the previously described BCL1 major translocation cluster (MTC). Using the polymerase chain reaction, we cloned this translocation and showed that the chromosome 11 breakpoint was within 7 bp of two other samples reported previously. Southern blotting of the MO1094 cell line suggested that the translocation in this cell line might link Jh sequences to a new region in the BCL1 locus on chromosome 11. Therefore, the MO1094 breakpoint was cloned from a genomic library. Comparison with normal cloned DNA from the BCL1 locus showed that the chromosome 11 breakpoint occurred 24 kb telomeric of the MTC. This work reinforces the concept that translocation breakpoints in the BCL1 locus are scattered over at least 63 kb.     

Detection of minimal residual disease in leukemic patients with the t(10;14)(q24;q11) chromosomal translocation

Early relapse and minimal residual disease during clinical remission was examined in two patients having acute T-cell leukemia/lymphoma with the t(10;14)(q24;q11) chromosomal translocation. Molecular probes which can detect T-cell receptor alpha/delta clonal rearrangements and a TCL-3 probe which can detect the clonal rearrangement due to the chromosomal translocation failed to detect the leukemic clones during clinical remission by Southern filter hybridization. However, application of the polymerase chain reaction technology in amplification of the t(10;14)(q24;q11) chromosomal juncture during clinical remission permitted us to increase the detection level of neoplastic cells up to 1 leukemic cell/125,000 normal cells using 1 microgram of DNA. Amplified junction fragments were detected in both patients. In one case, during the period of clinical remission no amplified fragments were detected.     

A novel translocation t(3;22)(q21;q11) involving 3q21 in myelodysplastic syndrome-derived overt leukemia with thrombocytosis

We report here a novel translocation t(3;22)(q21;q11) in myelodysplastic syndrome (MDS)-derived overt leukemia with thrombocytosis. A 44-year-old female was initially diagnosed as MDS with a low platelet count and normal karyotype. After 4 months, blood leukemic cells and platelets rapidly increased concomitantly and a diagnosis of acute myeloblastic leukemia (AML M1) was made. Chromosome analysis showed 46, XX, t(3;22)(q21;q11) in 14 of 20 metaphases. Fluorescence in situ hybridization analysis confirmed both the der(3)t(3;22) and the der(22)t(3;22). Our results suggest that unidentified gene(s) at 3q21 breakpoint may be implicated in the pathogenesis of abnormal thrombopoiesis as observed in the 3q21q26 syndrome.     

t(4;11)(q21;p15), including one complex translocation t(1;4;11)(p32;q21;p15), in adult T-cell acute lymphoblastic leukemia

We report two adults with T-cell acute lymphoblastic leukemia (ALL). Cytogenetic studies at diagnosis with R banding showed a 46,XX,t(4;11)(q21;p15)/46,XX karyotype in one patient and 46,XY,t(1;4;11)(p32;q21;p15)/46,XY in the other. Fluorescence in situ hybridization with whole chromosome paints (WCP1, WCP4, and WCP11) confirmed the complex rearrangement in the latter patient. Only 10 T-cell ALL patients with the t(4;11)(q21;p15) have been described, all, but one of them, being over 15 years old. Although recurrent in T-cell ALL, its frequency appears to be very low; indeed, it has been identified in only 4 of 193 adults and in 1 of 734 children with T-cell ALL thus far reported in the literature.     

The t(10;11)(p14;q21) translocation in three children with acute myeloblastic leukemia

A total of 161 cases of pediatric de novo acute myeloblastic leukemia (AML) have been reviewed, for which complete karyotyping was available and three cases (2%) were identified with t(10;11)(p14;q21). Two of the three children were infants with monoblastic (FAB M5) leukemia and the third was an adolescent with undifferentiated myeloid (FAB M1) leukemia. Both infants presented with increased levels of lactate dehydrogenase. None of these cases had increased eosinophils. One of the infants is in remission 18+ months after diagnosis and intensive chemotherapy; the two other children attained brief initial remissions but succumbed to their disease within 11 months of diagnosis. The prognosis of such children appears to be similar to that of cases of AML lacking this translocation.     

Rearrangements on chromosome 11q23 in hematopoietic tumor-associated t(11;14) and t(11;19) translocations.

We previously demonstrated that the breakpoint of t(11;14)(q23;q32) in the RC-K8 B cell lymphoma cell line lies between CD3 and THY1/ETS1 on chromosome 11q23, and we cloned this region and named it the rck locus. Pulsed-field gel electrophoresis showed that the rck probe B (distal to the breakpoint) and the porphobilinogen deaminase (PBGD) probe detect the same germ line band and also the same rearranged band when DNA from RC-K8 cells was digested with NotI enzyme. Furthermore, Southern blot analysis with somatic cell hybrids showed that the PBGD gene moved to the 14q+chromosome, which confirmed PBGD to be more distal to the centromere than the rck locus. These data allowed us to construct the following order of genes: 11 cen-q23-CD3-rck-PBGD-THY1/ETS1. In this study, three infantile leukemia cell lines with t(11;19)(q23;p13) translocation were also analyzed by pulsed-field gel electrophoresis. CD3D probe detected the rearranged bands in DNA from two of them after digestion with NotI and SacII enzymes, demonstrating that the breakpoints of both cell lines were estimated to be within 360 kilobases of CD3D.     

Molecular cloning of the chromosomal breakpoint of a B-cell lymphoma with the t(11;14)(q23;q32) translocation

The breakpoint of t(11;14)(q23;q32) chromosome translocation in a B-cell lymphoma line, RC-K8, was cloned. Immunoglobulin heavy chain (IGH) constant gene, C gamma 2 at the 5' end, was involved in this translocation, and the DNA segment juxtaposed to the C gamma 2 was proved to be derived from chromosome 11 by somatic cell hybrid study. The normal counterpart of chromosome 11 was also isolated. With a DNA probe near the breakpoint of chromosome 11, Southern blot analysis of RC-K8 and 10 other cases with translocation involving the 11q23 region was conducted, but no rearrangement bands have been observed thus far except for RC-K8.     

Translocation t(3;22)(q23;q11) in three patients with diffuse large B cell lymphoma

In our series of 134 patients with a diagnosis of non-Hodgkin's lymphoma (NHL) and clonal chromosomal abnormalities, three were found to show an identical t(3;22)(q28;q11) translocation. All were old patients with isolated lymphadenomegaly and diffuse large noncleaved cell lymphoma. All expressed a B cell immunophenotype, and all entered a complete remission when treated with aggressive chemotherapy. This translocation could, therefore, delineate a particular subtype of diffuse large cell NHL.     

Helicobacter pylori and the t(11;18)(q21;q21) translocation in gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type.

The reported regression of mucosa-associated lymphoid tissue (MALT) type gastric low-grade B-cell lymphoma following treatment for Helicobacter pylori (H. pylori) infection has not yet been comprehensively analyzed, especially in relation to the recently identified c-IAP2-MALT1 / MLT gene alteration resulting from the t(11;18)(q21;q21) chromosomal translocation found in MALT lymphoma. The relationship between MALT lymphomas and H. pylori was investigated in 30 patients who received an antibacterial treatment. Patients were followed up by means of endoscopy and biopsy. Molecular genetic analyses focused on the presence or absence of the immunoglobulin heavy chain (IgH) gene and / or MALT1 / MLT gene alteration resulting from t(11;18)(q21;q21) translocation. H. pylori was positive in 26 of the 30 patients. The overall success rate of cure of H. pylori infection was 96% (25 / 26). Thirteen patients (52%) showed complete remission (CR) of lymphoma, nine (36%) partial remission (PR), and three (12%) registered no change (NC). Statistical analysis revealed significant differences between CR and PR / NC patients in age ( < 60 or 60), in lymphoma location (single or multiple sites) and in the presence or absence of gene rearrangement before eradication (P < 0.05). Endoscopy showed a cobblestone appearance only in PR cases and polypoid features predominantly in NC cases. Two NC patients with polypoid gross appearance showed rearrangements involving either c-IAP2 or MALT1 gene in Southern blot analysis, while none of seven other resected patients with non-polypoid superficial gross appearance showed rearrangement. Gastric MALT lymphoma could be pragmatically subdivided into three groups, CR (MALT-A), PR (MALT-B), and NC (MALT-C) on the basis of the reaction to eradication of H. pylori. We speculate that MALT-A may represent an incipient neoplasm or dysplasia, MALT-B a neoplasm activated by antigenic stimulation of H. pylori, and MALT-C a lymphoma independent of H. pylori. Polypoid lesions in MALT-C were associated with c-IAP2-MALT1 / MLT gene alteration resulting from t(11;18)(q21;q21). This classification is thought to be clinically significant for deciding the most appropriate mode of treatment of MALT-type lymphoproliferative disorders.     

Granulocytic differentiation of leukemic cells with t(9;11)(p22;q23) induced by all-trans-retinoic acid

Acute leukemia patients with MLL (mixed linage leukemia) rearrangements tend to respond poorly to conventional therapies. We examined differentiation of human myeloid leukemia cells displaying the MLL-AF9 gene, using several differentiation agents. When MOLM-14 cells were treated with all-trans retinoic acid (ATRA) or 1beta,25-dihydroxyvitamin D3, significant induced differentiation was observed. Trichostatin A (TSA), an inhibitor of histone deacetylase, demonstrated enhance effects with ATRA in regard to growth inhibition and differentiation induction in MOLM-14 cells. Pretreatment with TSA before exposure to ATRA displayed increased effect. Based on these findings, combined treatment with ATRA and TSA may be clinically useful in therapy for acute leukemia displaying MLL-AF9 fusion gene.