Abnormalities of chromosome 1 in myeloproliferative disorders

RABGAP1L gene rearrangement resulting from a der(Y)t(Y;1)(q12;q25) in acute myeloid leukemia arising in a child with Klinefelter syndrome

In this study, we report the molecular cytogenetic characterization of an acute myeloid leukemia with a der(Y)t(Y;1)(q12;q25) in bone marrow cells in a child with Klinefelter syndrome. Conventional cytogenetics demonstrated the unbalanced translocation, i.e., a trisomic 1q25-qter juxtaposed to Yq12 replaced the terminal segment of chromosome Y was acquired and present only on bone marrow cells. Fluorescence in situ hybridization showed that the breakpoint at 1q25 disrupted RABGAP1L, a strongly expressed gene in CFU-GEMM, erythroid cells, and megakaryocytes, while the Yq12 breakpoint fell within the heterochromatic region. As der(Y)t(Y;1)(q12;q25) was an isolated cytogenetic change, RABGAP1L rearrangement as well as gene(s) dosage effects correlated to 1q25-qter trisomy, and Yq12-qter loss may make a major contribution to leukemogenesis and/or disease progression.

Therapy-related patterns of cytogenetic abnormalities in acute myeloid leukemia and myelodysplastic syndrome post polycythemia vera: single center experience and review of literature

A minor fraction of patients with polycythemia vera (PV) develop a terminal acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Analysis of the cytogenetic abnormalities during AML or MDS may help in understanding if this development is part of the natural course of the disease or induced by myelosuppressive therapy. Thirty-six cases with AML or MDS post PV, collected in a single Swedish institution during a 33-year period, are described with special regard to time to development of AML or MDS, therapy given during active PV, and cytogenetic findings during AML or MDS. A further 118 cases of AML or MDS post PV, in whom type of therapy during active PV and cytogenetic findings during AML or MDS were reported, were collected from the literature. AML or MDS developed in our own series after 1-30 years with a fairly constant rate (two cases per year). The most frequent cytogenetic abnormalities were +1q, -5, 5q-, -7, 7q-, +8, +9, 11q-, 13q-, and 20q-. When patients in the total material (n = 154) were divided with regard to treatment during active PV, marked differences were observed. The highest frequency of abnormalities was found in patients given multiple lines of therapy (n = 61), dominating features being -5/5q- in 28 patients (46%), -7/7q- in 19 patients (31%), numerous translocations in 24 patients (39%), and unidentified markers in 22 patients (36%). Half of the patients treated with hydroxyurea alone showed a -5 or 5q- abnormality. In patients treated with phlebotomy alone, +8 and +9 were the most frequent findings. The type of therapy given during active PV influences the type of chromosome abnormalities present during terminal AML or MDS and can also be instrumental in the development of leukemia.

A der(1;15)(q10;q10) is a rare nonrandom whole-arm translocation in patients with acute lymphoblastic leukemia

A rare karyotypic event, der(1;15)(q10;q10), which involves the whole long arms of chromosomes 1 and 15, has been reported in patients with various conditions, including acute myelogenous leukemia, myelodysplastic syndrome, polycythemia vera, and multiple myeloma. Only 27 cases of unbalanced der(1;15)(q10;q10) have been documented in the literature as single or complexed chromosomal abnormalities in hematological malignancies. Here, we describe two cases of acute lymphoblastic leukemia with der(1;15)(q10;q10), and review the previous reports. Although more case studies are needed, we suggest that der(1;15)(q10;q10) should be considered a nonrandom chromosomal abnormality in hematological malignancies including both lymphoid and myeloid neoplasms.

Der(8)t(1;8) in myeloblastic transformation of ET with hydroxyurea as the sole prior treatment

We described a patient with ET that evolved into MF and then subsequently developed myeloblastic transformation. A novel derivative chromosome der(8)t(1;8) was identified in the AML phase. The only prior treatment had been hydroxyurea. We hypothesized that AML in this case resulted from a complex pre-disposition by the natural progression of ET, prolonged use of HU, and the prior evolution into MF. The leukemogenic risk of HU is critically appraised.

Cytogenetic evaluation of a large series of hepatoblastomas: Numerical abnormalities with recurring aberrations involving 1q12-q21

Hepatoblastoma is a malignant embryonal liver tumor that occurs almost exclusively in infants and very young children. Previous cytogenetic studies of hepatoblastoma have investigated small series or individual cases. This report is on the cytogenetics of a large series of 111 hepatoblastoma specimens, with cytogenetic results consecutively karyotyped over a 12-year period. Abnormal karyotypes were observed in 55 cases (approximately 50% of the total). Numerical aberrations were observed in 41 cases (36% of the total), particularly trisomies of chromosomes 2, 8, and 20. Chromosome losses were less common than chromosome gains. Structural abnormalities were observed in 43 cases (39% of the total). Unbalanced translocations resulting in trisomy 1q and involving breakpoints at 1q12-21 were the most common structural abnormality, observed in 20 tumors (18% of total cases); the corresponding translocated chromosome was highly varied. The previously reported t(1;4) was observed in seven cases. Most tumors with translocations involving 1q12-21 also displayed numerical chromosome aberrations, the most common of which were chromosomal trisomies, whereas tumors with other structural rearrangements had fewer numerical abnormalities.

Der(6)t(1;6)(q21-23;p21.3): a specific cytogenetic abnormality in myelofibrosis with myeloid metaplasia

Chromosome anomalies are detected in approximately half of patients with myelofibrosis with myeloid metaplasia (MMM) although none of the most prevalent lesions are specific to the disease. In a prospective cytogenetic study of 81 patients with MMM, we encountered three with an unbalanced translocation between chromosomes 1 and 6 with specific breakpoints; der(6)t(1;6)(q21-23;p21.3). A subsequent Mayo Clinic cytogenetic database search identified 12 patients with this chromosome anomaly among 17 791 consecutive patients. A similar database search from Royal Hallamshire Hospital in Sheffield, UK revealed two additional patients among 8000 cases. The clinical phenotype and survival for each of these 14 patients was typical of MMM. These findings suggested that der(6)t(1;6)(q21-23;p21.3) is a highly specific cytogenetic anomaly that may harbour gene(s) specifically associated with MMM. In a preliminary fluorescence in situ hybridization study, the breakpoints on chromosome 6 in two additional cases were found to be telomeric to the gene for 51 kDa FK506-binding protein (FKBP51).

Derivative (1;18)(q10;q10): a recurrent and novel unbalanced translocation involving 1q in myeloid disorders

We report two cases of hematological malignancies, comprising a case of myelodysplastic syndrome (MDS) that rapidly evolved into acute myeloid leukemia, and a case of myeloproliferative disorder (MPD), in which der(1;18)(q10;q10) was found as the sole acquired karyotypic abnormality. This observation indicates that the unbalanced translocation is a recurrent aberration in myeloid disorders. To the best of our knowledge, centromeric fusion between long arms of chromosomes 1 and 18, leading to a normal chromosome 18 substituted with a der(1;18) chromosome, is novel and has not been described in cancer. Mechanistically, either trisomy 1q or monosomy 18p that results from the translocation may potentially contribute to leukemogenesis. Finally, chromosomes with large constitutive heterochromatin bands such as chromosome 1 may be at risk of centromeric instability and be predisposed to centromeric fusion with other chromosomes.

Molecular genetics and cytogenetics of myeloproliferative disorders

The myeloproliferative disorders are believed to represent clonal malignancies resulting from transformation of a pluripotent stem cell. X-inactivation patterns of peripheral blood cells have been proposed as a useful diagnostic tool but this method is limited by the finding of a clonal X-inactivation pattern in a significant proportion of normal elderly women. There is no pathognomonic chromosomal abnormality associated with the myeloproliferative disorders. However, consistent acquired cytogenetic changes include del(20q), del(13q), trisomy 8 and 9 and duplication of segments of 1q, all of which have been observed at diagnosis or before cytoreductive therapy and therefore represent early lesions which contribute to the pathogenesis of these disorders. Although, the acquired molecular defects underlying most myeloproliferative disorders have not yet been elucidated, translocations associated with the rare 8p11 syndrome have permitted identification of a novel fusion protein. The role of a number of candidate genes in the other myeloproliferative disorders has also been studied, but no mutations have been identified so far. It is likely that a number of genes will be involved, given the varied phenotypes of the diseases. Identification of causal genes will be of considerable interest to both clinicians, who currently lack a specific and sensitive diagnostic test, and scientists interested in fundamental issues of stem cell behaviour.

Askin tumor and acute myeloid leukemia in a patient with constitutional partial Y disomy

We report the case of a young adult male carrying a constitutional unbalanced t(Y;13)(q11-12;p13) leading to a partial Y disomy, and presenting successively, in a 39-month interval, with an Askin tumor and a t(8;21) acute myeloid leukemia. The origin of the two neoplasias in this patient is discussed.

Derivative (y)t(Y;1)(q12;q12),+9 in a patient with polycythemia vera during transition into myelodysplasia

Cytogenetic analysis of bone marrow cells of a 63-year-old male Caucasian patient with polycythemia vera (PV) who developed anemia, thrombocytopenia, and increased granulocytic immaturity revealed a 47, X,der(Y) t(Y;1)(q12;q12),+9 karyotype. The breakpoint in chromosome 1 appeared to map to q12 and not to q21, as has been described in previous reports without FISH confirmation. In the 4 years before this transition the patient was polycythemic and, accordingly, treated with phlebotomy and three short courses of busulfan. The cytogenetic picture observed has been described before in seven patients: three with PV, three with myelodysplasia, and one with Fanconi anemia. In 5/7 cases, like in our patient, the abnormality was observed during transition of the disease into either myelodysplasia or AML.

Translocation (Y;1)(q12;q12) in hematologic malignancies. Report on two new cases, FISH characterization, and review of the literature

Translocation (Y;1)(q12;q12) is a rare cytogenetic anomaly occurring in hematologic disorders thought to affect stem cells. We report here on two new cases, one end-stage myelofibrosis and one chronic myelomonocytic leukemia. The translocation breakpoints were assessed by conventional cytogenetic techniques in both cases and by FISH in the second case. A partial trisomy of the 1q21-qter region could be demonstrated. The data of the literature are reviewed and the possible pathogenetic mechanisms are discussed.

der(1;15)(q10;10): a nonrandom chromosomal abnormality of myeloid neoplasia

The occurrence of an unusual karyotypic abnormality der(1;15)(q10;q10) is reported in three patients, one with acute megakaryoblastic leukemia and two with myelodysplastic syndrome. A literature review shows that this cytogenetic abnormality is a rare but nonrandom change in myeloid neoplasia/neoplasia.

Karyotypic and ras gene mutational analysis in idiopathic myelofibrosis

Karyotypic analysis was performed in a total of 69 patients with well-characterized idiopathic myelofibrosis. Karyotypic abnormalities were detected in 46% of cases examined during the chronic phase (29/63); with three abnormalities, del(13q), del(20q) and partial trisomy 1q, accounting for 75% of all abnormalities at diagnosis. The absence of del(5q), trisomy 8 and 21, as well as the rarity of monosomy 7, contrasts with pooled published data and may reflect our exclusion of closely related disorders, in particular MDS with fibrosis. Chromosomal aberrations increased to approximately 90% (8/9) in patients analysed during acute transformation. Mutational activation of codons 12, 13 and 61 of N-, Ha- and Ki-ras genes were assessed by polymerase chain reaction and hybridization with synthetic non-radioactive digoxigenin-labelled probes. Three mutations were detected in samples of peripheral blood DNA taken from 50 patients during the chronic phase of their disease: one N12 Asp (GGT-->GAT) and two N12 Ser (GGT-->AGT) mutations. The results from this study indicate that karyotypic abnormalities are present in at least 29% of cases at diagnosis and that del(13q), del(20q) and partial trisomy 1q are the most frequent findings. Ras mutations were relatively infrequent (6%) and appeared restricted to the N-ras gene. Karyotypic analysis at diagnosis was found to be of prognostic significance.

Translocation (Y;1)(q12;q21) in acute leukemia

This report documents one patient with myelodysplasia evolving into acute leukemia who showed a t(Y;1) translocation confirmed by in situ hybridization. Most of the q arm of the Y chromosome was translocated to an additional q arm of chromosome 1, resulting in trisomy 1q. To our knowledge only four other cases with this t(Y;1) have been reported.

Partial trisomy 1q in idiopathic myelofibrosis

Three cases of idiopathic myelofibrosis with partial trisomy of the long arm of chromosome 1 are described. Partial trisomy 1q was the only karyotypic change detectable in unstimulated peripheral blood cell cultures of one and bone-marrow cultures of two patients at diagnosis. The extra segment from chromosome 1 was located on different karyotype sites, i.e. 1qter, 1p34 and 6p22-23; 1q21-32 was the shortest overlapping region and the only trisomic segment in one of the three patients. These findings suggest that partial trisomy 1q is a primary chromosome aberration in myelofibrosis relevant in the pathogenesis of this hematologic disorder.

An identical t(Y;1)(q12;q21) in two patients with myelodysplastic syndromes

Two male patients with myelodysplastic syndromes, one with refractory anemia with excess blasts (RAEB), the other with chronic myelomonocytic leukemia both had in their bone marrow and peripheral blood cells the same abnormal karyotype 46,X,-Y, + der (Y)t(Y;1)(q12;q21). This abnormality produced trisomy for the 1q21-1qter region of chromosome 1. In addition to the t(Y;1), the patient with RAEB had a del(20)(q11) abnormality in separate CFU-GM and BFUe progenitor cell populations. The t(Y;1) clone of this patient underwent chromosomal evolution with the acquisition of trisomies for chromosomes 2, 6, 8, and 9. Cytogenetic analysis of serial peripheral blood samples showed that the t(Y;1) clone and its derivatives gradually replaced that with the 20q- abnormality. Metaphase cells trisomic for chromosomes 2, 6, 8, and 9 were found predominantly in the CFU-GM population and only rarely in BFUe colonies, suggesting that chromosomal evolution was largely confined to the granulocytic lineage.

Cytogenetics of acutely transformed chronic myeloproliferative syndromes without a Philadelphia chromosome. A multicenter study of 55 patients. Groupe Français de Cytogénétique Hématologique

In a multicenter study by the Groupe Français de Cytogénétique Hématologique, chromosome investigation was undertaken in 55 cases of acutely transformed Philadelphia-negative chronic myeloproliferative syndromes (polycythemia vera, 34 cases; essential thrombocythemia, two cases; myelofibrosis with myeloid metaplasia of the spleen, 12 cases; other, unclassified myeloproliferative disorders, seven cases). Thirty-seven patients had received 32P radiotherapy and/or alkylating agents during the chronic phase, eight had received other cytotoxic drugs, and ten had received a noncytotoxic treatment. The duration of chronic phase ranged from 1 to 29 years (mean, 9.2 years). Nineteen karyotypes were established at the onset of transformation, when the percentage of bone marrow blasts was still low; 31 were performed at an overt acute leukemia stage, and five were carried out at both stages. Clonal abnormalities were seen in 96.3% of the karyotypes, of which 80.0% were structural defects, 20.0% hypoploidies, 36.4% hyperploidies, and 36.4% complex karyotypes or karyotypes with variations. In 20 cases the chromosome changes were of the type usually found in secondary leukemias; however, no clear relationship could be established between chromosomal defects and chronic phase treatments. The most frequently involved chromosomes were: #1 in 11 cases, #5 in 13, #6 in 13, #7 in 13, #8 in six, #12 in seven, #13 in 12, #17 in 14, #20 in seven, and #21 in four. Simple karyotypes, partial trisomy 1(q), del(6p), +8, +9, der(12q), del(13q), i(17q), and del(20q) are probably related to the disease, whereas, complex karyotypes, -5, del(5q), -7, del(7q), -17, and der(17) [other than an i(17q)] probably reflect treatment-induced events.

Acute monoblastic leukemia as a second malignancy following chemotherapy for osteogenic sarcoma: a case report

A patient with well-differentiated monoblastic leukemia (ANLL FAB-M5b) is described in whom acute leukemia was diagnosed 25 months after having completed postoperative adjuvant chemotherapy for osteogenic sarcoma of the femur. All analyzed metaphases showed 48xy, dup 1(q12), +3, +9.

Idiopathic myelofibrosis in blast transformation with 4;12 and 5;12 translocations and a 7q deletion

A case of a patient who developed a leukemic transformation following an 8.5-year history of idiopathic myelofibrosis (IMF) with myeloid metaplasia is presented. Surface marker analysis identified the blast cells as myeloid in lineage. The karyotype of unstimulated peripheral blood cells was 46,XY,t(4;12)(q26;15),t(5;12)(q13;q24),del(7)(q22). In the literature, the 7q- has a minor association with IMF, and the t(5;12) translocation has been reported in one case of acute nonlymphocytic leukemia, but neither the t(4;12) nor the combination of these three abnormalities has been reported in IMF.

Trisomy 1q in polycythemia vera and its relation to disease transition

Clinical and cytogenetic details of 12 patients with polycythemia vera and complete or partial trisomy of the long arm of chromosome 1 are reported. All patients had trisomy for at least the segments 1q22 to 1qter. The 1q or material from 1q was translocated to another chromosome in eight patients. This was chromosome 9 in four patients, and those cases all had trisomy also for 9p. The trisomy 1q was found at the time of diagnosis in three patients, later during the polycythemic phase in five, and in four patients when they were first examined during a late stage of the disease. Acute leukemia or a myelodysplastic syndrome developed in eight of the 12 patients. Signs of advanced disease, eg, myeloid metaplasia or myelofibrosis, preceded the leukemia in four cases and was noted in one more patient. Trisomy 1q was the most frequent structural chromosome abnormality in patients with polycythemia vera. It is thus one of several nonrandom abnormalities that can appear at any stage of the disease. It seems to occur with higher frequency in patients with myelofibrosis and/or leukemia, but it is not a specific characteristic of these complications.

Chromosome 1 aberrations in cancer

Evidence for chromosome #1 involvement in structural rearrangements in cancer is reviewed. There have been adequate studies of cancer at most of the common sites, and at all of these, nonrandom chromosome #1 involvement has been demonstrated. In general, a variety of changes is encountered, irrespective of the site; most commonly, however, the changes result in the duplication of long arm material. It seems that these nonrandom changes, which tend to occur at a relatively late stage, may contribute to the progression of all forms of cancer. However, a small number of chromosome #1 aberrations are also now known, which may represent specific and possibly initiating changes in particular forms of cancer. These include short arm deletions in neuroblastoma and translocations in leukemias and myelodysplasia.

An identical translocation between chromosome 1 and 15 in two patients with myelodysplastic syndromes

An identical translocation between the long arm of chromosome no. 1 and the short arm of chromosome no. 15 was found in two unrelated patients with refractory anaemia type I, according to the FAB classification of myelodysplastic syndromes. In the first patient the typical translocation was associated with anomalies commonly found in preleukaemic states, i.e. a 5q- and a 20q- chromosome. Furthermore, in both patients the long arm of chromosome no. 1 was trisomic. Cytogenetic follow-up in the second patient demonstrated a proliferative advantage of the cells bearing a t(1;15) translocation over the cells with trisomy 8 as well as over normal cells. This karyotypic evolution, however, was not accompanied by a transformation of the haematological disorder into acute leukaemia.

Chromosome analysis on a cell line (CE48T/VGH) derived from a human esophageal carcinoma

The cell line CE48T/VGH was established from an epidermoid carcinoma of the middle third of the esophagus of a 58-year-old male patient. Cytogenetic analysis at passages 90-99 showed that the line was hypotetraploid, with a mean chromosome number of 73. None of the 50 karyotyped cells had a normal chromosome #1 or Y. Cells with multiple copies of some of the autosomes were observed frequently. Structural rearrangements were numerous, especially of chromosomes #1, #9, #14, X, and Y.

Nonrandom chromosome structural aberrations and oncogene loci in human malignant melanoma

Short-term cultures of 10 malignant melanomas derived from 8 patients were analyzed cytogenetically. The chromosome composition of the tumors was found to be similar in terms of modal number and structural and numerical aberrations, especially the nonrandom nature of breakpoints. Six chromosomes were consistently involved in marker formation. Aberrations of chromosomes #1 and #9 were identified in every tumor, whereas structural alterations of chromosome #2 were found in 9 tumors. In contrast, aberrations of chromosomes #6, #3, and #7 were identified in 7, 7, and 8 of the tumors, respectively. The nonrandom breakpoints on these chromosomes frequently coincided with known oncogenic loci and resulted in morphologically identical marker chromosomes. Consecutive lesions were obtained for two patients. Common markers were identified in both cases, indicating the clonal origin of the tumors. In addition, many marker chromosomes characteristic of the individual lesions were also identified. The presence of these lesion-specific markers indicates the nonrandom selective nature of the metastatic process and suggests the possible heterogeneity of the original tumor cell population.

Noninvolvement of chromosome 16 in karyotype evolution of acute myeloid leukemia in a patient with a heritable fragile site on 16q22

A fragile site on the long arm of chromosome #16 (q22) was detected in a 24-year-old man with pancytopenia. During the course of the disease he developed an inverted duplication of region q11-12 of chromosome #1 and a translocation between chromosomes #9 and #13: t(9;13)(p22;q32). These abnormalities, as well as an additional iso-like marker chromosome that consisted of one normal 9p and the abnormal 9p arm, were detected in Epstein-Barr nuclear antigen-positive B-cell cultures. Two years later, evolution of the abnormal clone with loss of chromosome #7 and, subsequently, chromosome #22 occurred in connection with development of acute myeloid leukemia. Although the heritable fragile site on chromosome #16 was present in all cell populations investigated, it was not involved in the evolution of the abnormal karyotype. This fragile chromosome #16 also was found in 4 of 11 family members in whom chromosome analysis was performed, thus suggesting this aberration was inherited in a dominant autosomal pattern. The incidence of the heritable fragile site in normal and leukemic cells of the patient, as well as stimulated blood cultures of his relatives, are reported. In addition, the possible relationship between this constitutional chromosome breakage syndrome and the occurrence of leukemia is analyzed.

Translocation 1;7 in dyshematopoiesis: possibly induced with a nonrandom geographic distribution

Eight patients with various hematologic disorders had an identical chromosomal aberration in their bone marrow or unstimulated peripheral blood, a translocation t(1;7) interpreted as t(1;7)(p11;p11). The translocation chromosome replaced one normal chromosome #7; therefore, the karyotype of the abnormal cells was trisomic for 1q and monosomic for 7q. Including four cases from the literature, a total of 12 patients (4 women, 8 men) with this translocation are known at the moment. The translocation does not seem to be associated with a specific disorder, but almost all patients had a preleukemic syndrome during some stage of their disease. It is very remarkable that 11 of the 12 patients lived in the Netherlands, and 7 patients had a history of iatrogenic exposure to alkylating agents or irradiation; one patient was a radiation worker and another one had a history of toxic exposure to chloramphenicol. It is suggested, therefore, that the t(1;7) is a possibly induced chromosomal aberration with a clearly nonrandom geographic distribution.

Chromosomes in human large bowel tumors. A study of chromosome #1

Chromosome studies on 49 patients with large bowel adenocarcinomas showed abnormalities of chromosome #1 in 19 cases (39%). One had monosomy, 13 showed trisomy, and 5 cases had structural abnormalities. Eighteen patients had tumors on the right side of the colon; of these, only 3 had an abnormal #1 (17%); 16 of 28 tumors (57%) located on the left side had abnormalities of #1. The regions of consistent duplication of 1q were q24----q44? The presence or absence of changes of chromosome #1 may be useful as a prognostic indicator in large bowel cancer.

Associated abnormalities of chromosomes 1, 5, and 11 in dysmyelopoietic syndromes

Two patients with dysmyelopoietic syndrome presented the same cytogenetic pattern in their bone marrow cells, i.e., trisomy of chromosomes #1 and #11, and terminal deletion of chromosome #5 (q13-q14). Two similar cases have been described in the literature. It is suggested that this cytogenetic pattern could be a nonrandom event.

Cytogenetic studies on acute nonlymphocytic leukemias following polycythemia vera

Chromosome studies were performed on 15 patients suffering from acute nonlymphocytic leukemia (ANLL) and in one patient in a preleukemic state following polycythemia vera (PV). Clonal chromosome abnormalities that were present in all cases were clearly nonrandom and involved chromosomes #1, #5, #7, #8, #9, #11, and #21. A subdivision of ANLL into two categories occurring in the course of PV is proposed from the clinical, hematologic, and cytogenetic data: one resembling de novo ANLL with rapid initial evolution, easy classification into one group of the FAB nomenclature, and simple chromosome abnormalities; the other resembling induced leukemia, often with more progressive initial evolution, difficulty or impossibility of classification into one group of the FAB nomenclature, and complex chromosome abnormalities. The consequences for the commitment level of progenitor cell from which the leukemic clones originate are discussed.

Phenotypic and cytogenetic characteristics of a new Epstein-Barr virus negative cell line (SKW 4) derived from a B-cell lymphoma

A new Epstein-Barr virus nuclear antigen (EBNA) negative cell line SKW 4 has been established in vitro from a patient with diffuse histiocytic lymphoma. The SKW 4 seems to be an authentic human tumour cell line as evidenced by its EBV negativity, monoclonality and aneuploidy tested during early in vitro passage. The cell line expresses surface mu and kappa-chains, HLA-DR antigen, C3 and Fc receptors and B-cell lineage antigens. The karyotypic analyses demonstrated many numerical and structural aberrations. No Burkitt lymphoma associated translocations (t8;14, t2;8, t;22) were detected, but most of the markers found are those commonly associated with various types of human cancer. The SKW 4 thus represents the most common type of 'histiocytic lymphoma', that with a B-lymphoid cell phenotype, but is unique among HL derived lymphoma lines in its strong expression of a Helix pomatia A agglutinin binding surface glycoprotein of an apparent molecular weight of 75 000 daltons.

Chromosome 1q+ in erythroid and granulocyte-monocyte precursors in a patient with essential thrombocythemia

A 55-year-old man with essential thrombocythemia had multiplication of bands q21 to q32 of chromosome 1 in all studied mitoses from bone marrow, from unstimulated blood, and from erythroid and granulocyte-monocyte colonies grown in vitro. The multiplication was in the form of triplication in 16 out of 20 mitoses from the marrow and in 4 of 6 mitoses from the blood; the rest showed a duplication of this region. All 20 mitoses from erythroid and granulocyte-monocyte colonies showed the abnormality in the form of duplication. These findings indicate most probably a clonal evolution, the triplication having arisen in the clone with the duplication. This may be associated with early leukemic transformation. The detection of the 1q+ aberration in two different types of hematopoietic colonies indicates the involvement of multipotent stem cells in at least this patient with essential thrombocythemia.

Complete or partial trisomy for the long arm of chromosome 1 in patients with various hematologic malignancies

This study contains data obtained from a cytogenetic investigation of six patients with acute and chronic leukaemia. The karyotypes of bone marrow or blood cells of these patients showed a partial or complete trisomy for the long arm of chromosome 1. Three observations revealed a pronounced resistance of cell clones with 1q+ towards cytostatic therapy, and a comparatively short life span of patients after detection of 1q+. The importance of these changes for the role of some chromosomes and chromosome loci in leukaemogenesis is discussed.

Blastic phase of myeloproliferative syndrome coexisting with a malignant teratoma

A myeloproliferative condition in blastic phase is described in an 18-year-old male who was also found to have a mediastinal malignant teratoma. Myeloid metaplasia was found in the lymph nodes and spleen, and an infiltration of granulocytic blast cells was observed in the bone marrow and the lymph nodes. Aneuploidy with an extra chromosome (trisomy 8) was present in bone marrow cells. To our knowledge the combination of a myeloproliferative disorder and a malignant teratoma has not been earlier described.

Karyotype consistency in human colorectal carcinoma cell lines established in vitro

Karyotypes of nine human colorectal cell lines deposited with the ATCC were studied by trypsin-Giemsa banding. CCL 229,230,231 and 235 (Modal chromosome number, Sm, was 49, 68, 47, and 40, respectively) belong in the stable type that is characterized by karyotypes consisting mostly of normal chromosomes and stable markers. CCL 228, 234, and 238 (Sm=55,79, and 70 respectively) belong in the unstable type that has karyotypes consisting of numerous markers in addition to normal chromosomes and stable markers. The remaining intermediate type (CCL 233 and 237, Sm = 60 and 64, respectively) has karyotypic characteristics between the above two types usually with two or less unstable markers per cell. The stable markers (together with normal chromosomes) are constitutive components of a cell genome and are common to most cells within the same cultured population. Unstable markers, which generally constitute only a small portion of the total chromosome complement are the likely cause of karyotypic variations between cells and often are produced by balanced inter- or intrachromosome changes, or both. Consequently, total chromosome length per cell genome is remarkably consistent within a cell population, and karyotypes between cells, such as from four stable lines, are profoundly stable and mostly identical. Chromosome deletions and interhomologue exchanges (including isochromosomes) had the highest incidences among both stable and unstable markers. The complex markers occurred relatively infrequently. There were neither common markers nor unique chromosome breakages common to all of these established cell lines. However, chromosomes No. 7 and 1 had the highest incidence (15 and 12, respectively) of structural modifications resulting in the formation of stable markers (82 total exchanges in nine cell lines), and chromosomes No. 7 and 2 were involved at high incidence (21 and 15, respectively) in the formation of both stable and unstable markers (181 total exchanges). Moreover, No. 7 is overrepresented in eight of nine lines. The significance of chromosome changes involving No. 7 in this as well as other tumor pathotypes is briefly discussed.

Abnormalities of chromosome No. 17 in myeloproliferative disorders

In routine analyses, abnormalities of chromosome No. 17 were found in the bone marrow cells of 28 patients with Ph1-positive and three patients with Ph1-negative chronic myeloid leukemia (CML), 4 patients with acute nonlymphocytic leukemia (ANLL), and 4 patients with preleukemia. With three exceptions, all patients were in the blastic (CML) or the terminal phase. In 28 patients, the aberrant chromosome No. 17 arose by clonal evolution from the karyotype found at diagnosis or before the terminal phase. The abnormalities encountered were an isochromosome for the long arm, i(17q), (26 cases), translocations involving No. 17 (12 cases), trisomy 17 (three cases), and ring 17 (one case). In 35 patients, there was an unbalanced structural aberration of at least one of the No. 17 chromosomes. In every case (35/35), detailed analysis of the structurally abnormal No. 17 revealed loss of the distal part of the short arm (or possibly most of the short arm). Gain of the long arm (or at least its proximal part) was also common, but not invariably present (26/35). It is suggested that loss of 17p is a highly nonrandom event related to blastic crisis in CML and the terminal phase in other myeloid leukemias.

Break points in chromosome #1 abnormalities of 218 human neoplasms

A survey of 343 break points that lead to chromosome #1 abnormalities in 218 human neoplasms showed that 49.9% were located in or immediately adjacent to the centromeric heterochromatin. Amongst rearrangements with breaks in bands p 12-q21 were 27 isochromosomes, 22 translocations of the long arm, and four translocations of the short arm to the heterochromatic regions of other chromosomes, and 35 deletions resulting in chromosomes consisting mainly or solely of one arm. Deletions following breakage at various sites in the short arm of chromosome #1 are frequent in malignancies and are quite often found in cells that are trisomic for the long arm. It is suggested that fragility of chromosomes generated as a result of early events in carcinogenesis may be one source of chromosome rearrangements, including those of chromosome #1, on which selection can operate and give rise to progressively more malignant clones.

Karyotype analysis of a human mammary sarcoma explant in vitro

Karyotype of a fibroblastic SH-1 cell line derived from a human mammary sarcoma had 86 (80-92) chromosomes including 6 (4-7) markers, and a various number of double minutes. There were generally even numbers (e.g., 2, 4, etc.) of chromosomes in 17 intact and 3 common marker chromosomes. The t(3;14) and del(14), which had 2 each per s cell genome, were probably formed by the balanced translocation between nos. 3 and 14. Three other markers were single and contained a partial or entire no. 1. The presence of these latter markers was often accompanied by the decrease in the number of the intact no. 1, indicating that no. 1 was the only chromosome actively engaged in rearrangements during this stage of karyotypic diversification. Of the no. 2 and 7q that were over-represented on the per cell level, the 7q had a similar observation from many other solid tumors found in this and other laboratories. In contrast, none of the under-represented chromosomes had the concordant changes consistent to other tumors, although the frequent involvement of no. 9 in the chromosome rearrangements was seen in some human heteroploidies.

The pattern of radiation-induced transmissible aberrations in a human cell culture

The G-band pattern in 445 metaphases obtained seven weeks after irradiation (600 rad gamma-ray) was analysed. Approximately 37% of these cells had one or more structural aberrations. The majority of the aberrant events was reciprocal translocation followed by inversion and deletion in the proportion of 9:1:1 respectively. Statistical analyses (Chi-square tests) on the distribution of breakpoints among chromosomes showed an excess number of breaks in chromosomes 1, 7, and 12. Chromosomes 1 and 12 were particularly involved in cells carrying multiple aberrations while chromosome 7 was preferentially involved in deletion. Within chromosomes a significantly large number of breaks were located in (a) the light bands and (b) the terminal segments. The significance of these findings is discussed.

Lymphoblastic lymphoma in adults

Clinical and cytogenetic studied were done on 12 patients with lymphoblastic lymphoma. The ages of the patients ranged from 17 to 58 years (median, 24.5 years). Males predominated by a ration of 5:1. Ten of the 12 patients had a mediastinal mass at diagnosis; two thirds of the patients had involvement of the bone marrow (3 of 12 patients initially were in a leukemic phase), and 5 of 12 patients had involvement of the central nervous system (CNS) with lymphoma. In all patients, the malignant cells were characterized by nuclear convolutions. Cytogenetic studies done on four patients showed clonal chromosome abnormalities in two cases. Six of the 12 patients were treated with the combination chemotherapy regimen COPA and received CNS prophylaxis; their survival was slightly longer than that of the other patients, who were treated with a variety of treatment regimens. Two of the 12 patients achieved a complete remission. The median survival of all patients was 11.5 months but was shorter in patients with initial CNS involvement or leukemia. The poor results achieved thus far in the treatment of this disease demand a new therapeutic approach.

C-group chromosome abnormalities in bone marrow cells of three children with dyshematopoiesis of unknown origin

Clinical and cytogenetic findings in three children with dyshaematopoiesis and bone marrow aneuploidy are described. Monosomy 7 was found in immature cells of one 10-year-old boy with myelofibrosis following a 3 years evolution of severe thrombocytopenia and anaemia. Trisomy 8 was found in 80% of the bone marrow metaphases of a 5 1/2-year-old girl with aplastic anaemia and Australia antigen positivity. During a 3 year observation period the number of cells with trisomy 8 regressed and eventually disappeared. Improvement of her clinical condition is present but still limited. Trisomy 8 was also found in all bone marrow cells of an 8-year-old girl with an undefined myeloproliferative disorder. Her disease was apparently related to collagen-vascular disorders like periarteritis or other necrotizing angiitis and presented with periods of exacerbation and periods of chronic evolution. Periods of exacerbation were accompanied by excessive myeloid proliferation. Repeated bone marrow cytogenetic analysis during the acute and chronic phases showed trisomy 8 in all the metaphases analysed. During the last episode of acute illness, further clonal evolution was observed, characterized by a translocation (8;17).