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Cytogenetic studies were done in two cases of Burkitt's lymphoma in homosexual individuals with possible acquired immune deficiency syndrome (AIDS). The chromosomal abnormalities found are consistent with those previously described in the nonendemic form of Burkitt's lymphoma, with one of the two patients having the variant translocation, t(8;22). The production of the kappa light chain immunoglobulin by the tumor cells from the patient having t(8;22) and the occurrence of the different sites of translocation of the duplication of 1 q in the second patient are unusual findings. Whether there is an increase in the incidence of the variant translocation t(8;22) is yet to be determined.

Second hematologic malignancies occur rarely in patients previously treated for leukemia. This report describes a patient with acute lymphoblastic leukemia who remained in complete remission for 5 yr and then developed chronic myelocytic leukemia (CML). The original lymphoblasts were associated with a partial deletion of chromosome 21, while CML was associated with a classic Philadelphia marker, indicating the independent origin of the two leukemias.

We have studied, at a molecular level, two small non-cleaved cell malignant lymphomas (Burkitt's type) that were separated by a disease- free interval of 3 years in a patient infected with the human immunodeficiency virus (HIV). The late occurrence of the apparent relapse suggested that the second lymphoma might be caused by a separate malignant transformation in a discrete clone of B cells. Although both tumors expressed the same immunologic surface markers (mu k) and carried the same t(8;14) translocation, Southern blot analysis of DNA from each tumor, using specific restriction endonucleases and probes to the c-myc and the immunoglobulin heavy chain loci, demonstrated that the chromosomal breakpoints relevant to the translocations differed between the tumors. This was corroborated by analysis of the immunoglobulin light-chain rearrangements in the two tumors. These observations indicate that the second tumor was not a recurrence of the first but represented the malignant transformation of a different clone of B cells. Thus late relapses of certain malignancies in individuals at high risk may be caused by the malignant transformation of discrete cell clones (i.e., induction of a new tumor).

Cytogenetic studies of 68 patients who developed secondary leukemia (SL)/dysmyelopoietic syndrome (DMS) after extensive chemotherapy and/or radiation therapy as well as patients who developed SL/DMS without such treatment showed that those patients who received radiation alone or with chemotherapy had more extensive numerical and structural abnormalities than those who received only chemotherapy. In terms of the specific chromosomal abnormalities, there are no differences between the various treatment groups. Hypodiploidy is the most common form of aneuploidy in these patients, with the most common numerical abnormality being the loss of chromosome 7. The most common structural abnormalities involved chromosomes 3 and 5. When compared with patients with de novo leukemia and DMS, the chromosomal abnormalities in these patients are more complex and extensive. Serial studies revealed that cytogenetic abnormalities do not precede the development of hematologic changes by significant time periods.

cDNA clones of the human TOP1 gene encoding DNA topoisomerase I (EC 5.99.1.2) have been obtained by immunochemical screening of phage lambda libraries expressing human cDNA segments, using rabbit antibodies raised against purified HeLa DNA topoisomerase I. Hybridization patterns between the cloned cDNA sequences and human cellular DNA and cytoplasmic mRNAs indicate that human TOP1 is a single-copy gene. The chromosomal location of the gene has been mapped to the long arm of chromosome 20, in the region q12-13.2, by hybridization of a radioactively labeled TOP1 cDNA probe to human metaphase chromosomes and to a panel of rodent-human somatic hybrids retaining overlapping subsets of human chromosomes.

The importance of banded chromosome analyses in predicting long-term outcome in acute lymphoblastic leukemia (ALL) was evaluated in this follow-up study of 329 patients from the Third International Workshop on Chromosomes in Leukemia. Patients were divided into ten groups according to pretreatment karyotype: no abnormalities, one of the following structural abnormalities [the Philadelphia chromosome, translocations involving 8q24, t(4;11), 14q +, 6q-] or, in the remaining cases, modal number [< 46, 46, 47 to 50, > 50]. Achievement and duration of complete remission (CR) and survival differed among chromosome groups (P <. 0001). Karyotype was an independent prognostic factor for duration of first CR and survival, even when age, initial leukocyte count (WBC), French-Ameri-can-British (FAB) type, and immunologic phenotype were considered. Among adults, prolonged remission and survival were uncommon in all chromosome groups. Only in the normal karyotype group was median survival even two years. Among children, striking differences in long-term remission and survival were seen depending upon karyotype. Children in the > 50 group did best, with 70% remaining in first CR for a median duration in excess of five years. Children in the 47–50, 6q —, and normal karyotype groups also had prolonged survivals. In contrast, certain translocations [t(9;22)(q34;q11), t(4;11)(q21;q14-23), t(8;14)(q24;q32)] identified children who had short survivals, even in the presence of favorable prognostic factors including a low WBC, L1 morphology, and non-T, non-B immunologic phenotype. We conclude that chromosome analysis is required at diagnosis in patients with ALL, and that children with these specific translocations should be managed as having high-risk ALL. © 1986 by Grune & Stratton, Inc.

Cytogenetic studies showed both 45XO and 46XY clones in the bone marrow of a 76-yr-old male with a 17-yr history of paroxysmal nocturnal hemoglobinuria (PNH). 55Fe incorporation studies demonstrated that both clones involved the hematopoietic stem cells. The loss of the Y chromosome may reflect an aging phenomenon, rather than be related to the PNH.

A small (2.8-kilobase, kb) major breakpoint region localized to segment 18q21 rearranges in greater than 70% of t(14;18)(q32;q21) lymphomas. This rearrangement interrupts the Bcl-2 gene and introduces it into the Ig locus at 14q32. The rearrangement between the joining region (JH) of Ig on chromosome 14 and the 18q21 region creates a translocation- specific DNA rearrangement. We generated probes that distinguish the 14;18 juncture on the derivative (der) 14 and der (18) chromosomes, providing a molecular approach to t(14;18) identification. Approximately 60% of unselected follicular lymphomas, 20% of diffuse large cell lymphomas, and 50% of adult undifferentiated non-Burkitt lymphomas demonstrated 14;18 rearrangements within the major breakpoint region. Examination of DNA for 14;18 rearrangements resolved the identity of 14q+ chromosomes in two patient's cells that lacked an obvious reciprocal partner. Identification of the exact restriction fragments that mediate translocations complements routine cytogenetics. The detection of DNA rearrangements does not require dividing cells or the presence of an identifiable reciprocal partner and can detect clonal translocation rearrangements when the neoplastic cells are only a minority of all cells present.

We compared the proliferation of mononuclear and multinuclear cells in four Hodgkin's cell lines, HDLM-1, HDLM-1d, L-428, and KM-H2, by examining their capacity to incorporate bromodeoxyuridine (BrdUrd) into nuclei. Approximately 5% of all cells in HDLM-1 cultures had two or more nuclei, a characteristic of Reed-Sternberg (RS) cells. Unlike mononuclear Hodgkin's (H) cells, these RS cells exhibited no uptake, or only minimal uptake of BrdUrd, suggesting that they did not replicate actively. Cytogenetic study showed that 25% of the HDLM-1 cells contained a tetraploid (4X) set of chromosomes with a characteristic two-peak distribution. Following treatment of HDLM-1 cells with phorbol ester, the percentages of 4X cells and RS cells increased to 50% and 12%, respectively. This increase in RS cells was not likely to be due to cell fusion as shown by the absence of hybridization of BrdUrd- positive and -negative nuclei. Phorbol ester has a short-term effect of blocking the exit of cells from G1 into S phase, but no effect on the transition from S phase to G2/M phase. The block is more prominent in 2X cells than in 4X cells, which may explain the increase in percentage of 4X cells in phorbol ester-treated cultures. In addition, phorbol ester induced the differentiation of H-RS cells, which was accompanied by loss of the marker HeFi-1 from the cell surface. Approximately one third of the RS cells did not express HeFi-1, or expressed only minimal amounts. The findings led us to the following conclusions: (1) The 4X cells probably are formed from 2X H cells as a result of disturbed cytokinesis, but not a cell fusion. (2) A considerable number of 4X cells were H cells, because the number of 4X cells consistently exceeded that of RS cells. (3) Since mitotic figures are extremely rare in RS cells and these cells did not show active BrdUrd uptake, the increased number of RS cells must also be a consequence of disturbed cytokinesis of H cells or a result of nuclear transformation (twisting, convolution, or separation of the nucleus) in H cells. (4) Most RS cells lose their proliferating capacity and some RS cells may undergo further differentiation. Uptake of BrdUrd and phorbol ester induction were also studied on the other three H-RS cell lines, HDLM-1d, L-428, and KM-H2, with results similar to those for HDLM-1.

A particular translocation between chromosomes 8 and 14 has been found repeatedly in cytogenetic studies of Burkitt lymphoma, both of African and non-African origin. We report here our findings in cytogenetic studies of direct tumor preparations from 18 non-African Burkitt lymphoma patients, 9 of whom also had cell lines available for study. A t(8;14) was found in direct tumor material in 10 of the 18 patients. Seven of the 9 cell lines had a t(8;14). A total of 15 patients had either a t(8;14) or a 14q+ present in tumor material and/or cell lines. In addition, 8 patients had a peculiar marker chromosome 1. The t(8;14) was not found in every malignant cell and, where present, it was rarely the sole karyotypic abnormality. The relationship of the t(8;14) to the evolution of the tumor is discussed.

A 45-yr-old female presented with a rapidly enlarging bony tumor that was eventually identified as a Philadelphia chromosome (Ph1)-positive myeloproliferative disorder with extramedullary blastic transformation. This transformation occurred in the absence of demonstrable chronic or acute leukemic phase. She had no history of a chronic or prodromal illness in spite of a bone marrow biopsy showing myelofibrosis and liver biopsy documenting extramedullary hematopoiesis. This case represents a unique constellation of features of the myeloproliferative syndrome in which the diagnosis was obscure until special stains of the bony tumor and cytogenetic studies were performed.

The gene for human neutrophil elastase (NE), a powerful serine protease carried by blood neutrophils and capable of destroying most connective tissue proteins, was cloned from a genomic DNA library of a normal individual. The NE gene consists of 5 exons and 4 introns included in a single copy 4-kilobase segment of chromosome 11 at q14. The coding exons of the NE gene predict a primary translation product of 267 residues including a 29-residue N-terminal precursor peptide and a 20-residue C-terminal precursor peptide. Analysis of the N-terminal peptide sequence suggests it contains a 27-residue “pre” signal peptide followed by a “proN” dipeptide, similar to that of other blood cell lysosomal proteases. The sequences for the mature 218-residue NE protein are included in exons II-V. The 5′-flanking region of the gene includes typical TATA, CAAT, and GC sequences within 61 base pairs (bp) of the cap site. The sequence 1.5 kilobases 5′ to exon I contains several interesting repetitive sequences including six tandem repeats of unique 52- or 53-bp sequences. The 5′-flanking region also contains a 19-bp segment with 90% homology to a segment of the 5′-flanking region of the human myeloperoxidase (MPO) gene, a gene also expressed in bone marrow precursor cells and a protein stored in the same neutrophil granules as NE. In addition, like the MPO gene, the NE 5′-flanking region has several regions with greater than or equal to 75% homology to sequences 5′ to c-myc, but there is no overlap between the NE-c-myc and MPO-c-myc homologous sequences.

Atypical lymphocytes (ATL) appear in the circulation of a large proportion of patients during the first week following a blood transfusion. In order to determine the source of these ATL, cytogenetic studies were performed on the peripheral blood leukocytes of ten adult patients who received fresh blood from donors of the opposite sex. Nine of the ten patients had spontaneously dividing mononuclear cells of the recipient or host karyotype circulating during the latter part of the first week after transfusion. In two patients, the spontaneously dividing cells were of donor as well as of host origin. Six patients had circulating phyothemagglutinin-responsive lymphocytes of the donor karyotype noted from 1–7 days after transfusion. These findings lend support to our hypothesis that the increase in circulating atypical lymphocytes seen 1 wk after transfusion represents the counterpart in vivo of the in vitro mixed leukocyte reaction. The dividing donor cells may represent a subclinical graft-versus-host reaction.