Significance of chromosome 14 anomaly at band 14q11 in Japanese patients with adult T-cell leukemia

Genomic instability and rapid clinical course in adult T-cell lymphoma/leukemia patient

Adult T-cell leukemia/lymphoma is a distinct clinical entity characterized by a clonal proliferation of malignant T-lymphocytes. The etiologic agent of the disease is a Human T-cell lymphotropic virus type I. It occurs almost exclusively in areas where the virus is endemic; however the disease develops only in the minority of patients who are virus carriers. Karyotyping findings and their correlation with clinical features are still limited in T-cell malignancies, complicated by clinical heterogeneity and a plethora of secondary abnormalities. This study describes detailed chromosomal and fluorescence in situ hybridization results observed in a patient with adult T-cell leukemia/lymphoma and correlates them with clinical characteristics.

Cytogenetic analysis and clinical significance in adult T-cell leukemia/lymphoma: a study of 50 cases from the human T-cell leukemia virus type-1 endemic area, Nagasaki

Identification of cytogenetic abnormalities is an important clue for the elucidation of carcinogenesis. However, the cytogenetic and clinical significance of adult T-cell leukemia/lymphoma (ATLL) is still unclear. To address this point, cytogenetic findings in 50 cases of ATLL were correlated with clinical characteristics. Karyotypes showed a high degree of diversity and complexity. Aneuploidy and multiple breaks (at least 6) were observed frequently in acute and lymphoma subtypes of ATLL. Breakpoints tended to cluster at specific chromosomal regions, although characteristic cytogenetic subgroups of abnormalities were not found. Of these, aberrations of chromosomes 1p, 1q, 1q10-21, 10p, 10p13, 12q, 14q, and 14q32 correlated with one or more of the following clinical features: hepatosplenomegaly, elevated lactate dehydrogenase, hypercalcemia, and unusual immunophenotype, all indicators of clinical severity of ATLL. Multiple breaks (at least 6); abnormalities of chromosomes 1p, 1p22, 1q, 1q10-21, 2q, 3q, 3q10-12, 3q21, 14q, 14q32, and 17q; and partial loss of chromosomes 2q, 9p, 14p, 14q, and 17q regions correlated with shorter survival. These cytogenetic findings are relevant in predicting clinical outcome and provide useful information to identify chromosomal regions responsible for leukemogenesis. This study also indicates that one model of an oncogenic mechanism, activation of a proto-oncogene by translocation of a T-cell–receptor gene, may not be applicable to the main pathway of development of ATLL and that a multistep process of leukemogenesis is required for the development of ATLL.

Expression of the Gfi-1 gene in HTLV-1-transformed T cells

Human T-cell leukemia virus type I (HTLV-I) is the causative agent of adult T-cell leukemia/lymphoma (ATLL) and immortalizes human T cells interleukin-2 (IL-2)-dependently in vitro. Protracted culture of HTLV-I-infected T cells enables them to grow IL-2-independently. Although acquisition of IL-2-independent growth has been correlated with activation of signal transducers and activators of transcription (STATs), the precise mechanism of IL-2-independent growth is unknown. We found that expression of the Gfi-1 (growth factor independence-1) gene was elevated in most HTLV-I-transformed IL-2-independent cell lines but in few HTLV-I-infected IL-2-dependent cell lines. We also found elevated expression of Gfi-1 in fresh leukemic cells of ATLL patients. Although expression of Gfi-1 is correlated with activation of STAT3, induction of the dominant negative form of STAT3 in the HUT102 cell line does not alter the level of Gfi-1 expression. Furthermore, MT2 cells treated with Gfi-1 antisense oligonucleotide had reduced [3H]thymidine uptake compared with MT2 cells treated with Gfi-1 sense oligonucleotide. These findings indicate that Gfi-1 activation is involved in the IL-2-independent growth of HTLV-I-transformed T cells in vitro and in the development of ATLL in vivo, but is not induced by STAT activation.

High rate of chromosomal abnormalities in HTLV-I-infected T-cell colonies derived from prodromal phase of adult T-cell leukemia: a study of IL-2-stimulated colony formation in methylcellulose

To detect chromosomal abnormalities in prodromal phase of adult T-cell leukemia (ATL), we established a clonal culture method for human T-lymphotropic virus type I (HTLV-I) infected T-cells in methylcellulose containing recombinant human interleukin 2 (rhIL-2). We tried to analyze chromosomes of 187 colonies (4, 23, 69, 74, and 17, from HTLV-I-uninfected normal T-cells, HTLV-I-Infected normal T-cells, HTLV-I carriers, smoldering ATL, and chronic ATL, respectively), using chromosomal banding methods. In the prodromal group, 53% of colonies (84/160) (36/69, 37/74, 11/17 in HTLV-I carriers, smoldering ATLs, and chronic ATL, respectively) had chromosomal abnormal clones. In HTLV-I carriers, multiple clones with simple chromosomal abnormalities were observed. In more progressed chronic ATL, more complex chromosomal abnormalities were detected, and specific colonies were selected. Thus, colonies in the prodromal phase of ATL are characterized by cytogenetical clonal evolution and clonal changes.

Classification of peripheral T-cell lymphomas: cytogenetic findings support the updated Kiel classification

The cytogenetic findings in peripheral T-cell lymphomas enabled us to distinguish not only between low and high grade peripheral T-cell lymphomas (PTL) but also between different morphologically defined subtypes. High grade lymphomas exhibited a higher frequency of aberrant clones, polyploid chromosome numbers, a higher complexity of aberrant clones and a lower proportion of normal metaphases than low grade PTL. Moreover, deletions in 6q, trisomies of 7q and monosomy 13 or changes of 13q14 were significantly more frequent in high grade than in low grade PTL. Translocation t(2;5)(p23;q35) was only seen in large cell anaplastic lymphoma. T-CLL/T-PLL was associated with the simultaneous presence of inversion inv(14)(q11q32.l) and trisomy 8q, mostly due to i(8q)(q10). Trisomy 3 was a characteristic chromosome aberration of lymphoepithelioid lymphoma, AILD-type T-cell lymphoma and T-zone lymphoma. In contrast to the other low grade PTL, AILD-type T-ceIl lymphoma and cutaneous T-cell lymphoma showed a high frequency of unrelated clones. In summary, the cytogenetic findings paralleled the histopathologic classification according to the updated Kiel classification and support the value of the distinction of the different morphologically defined entities.

T-cell lymphoma cell lines (HUT102 and HUT78) established at the National Cancer Institute: history and importance to understanding the biology, clinical features, and therapy of cutaneous T-cell lymphomas (CTCL) and adult T-cell leukemia-lymphomas (ATLL)

Efforts at the National Cancer Institute to generate continuous in vitro cultures from patients with mycosis fungoides and the Sezary syndrome, neoplasms with a mature T-helper phenotype, led to the establishment of two cell lines, HUT78 and HUT102. Further characterization of these cell lines led to the identification of the first human retrovirus, HTLV-1, in the HUT102 cells, and the clinical description of the syndrome of HTLV-1 associated acute T-cell leukemia/lymphoma; the serum antibody test to screen for this virus was developed from the serum of the patient from whom the cell line was derived. The HUT78 cell line was pivotal in the identification and characterization of the HIV retrovirus in that a subclone, H9, proved to be permissive for replication of HIV in vitro. Propagation of HIV in vitro in H9 cells allowed for the development of immunological reagents to screen blood supplies for the presence of the virus. Further biologic and molecular studies of these lines have led not only to a better understanding of the underlying diseases but also to the development of rational therapeutic approaches.

Inversion 14q in acute lymphoblastic leukemia of B-lineage

Many types of leukemia are associated with specific chromosomal rearrangements. Inversion 14(q11q32) has been reported to be specifically associated with post-thymic T-cell malignancies, including T-chronic lymphocytic leukemia. T-prolymphocytic leukemia, and adult T-cell leukemia/lymphoma. We have previously reported its occurrence in T-cell acute lymphoblastic leukemia. Recently, we encountered a case of acute lymphoblastic leukemia with inv(14)(q11q32), which surprisingly showed a B-cell immunophenotype (CD10+CD19+HLA-DR+Ig mu-).

Trisomy 8q due to i(8q) or der(8) t(8;8) is a frequent lesion in T-prolymphocytic leukaemia: four new cases and a review of the literature

Cytogenetic abnormalities found in four cases of T-cell prolymphocytic leukaemia (T-PLL) are described. An isochromosome 8q was found in three patients and a t(8;8) in one. In the four cases, karyotypes were complex and showed a high degree of instability. In addition, we reviewed 27 published cases of cytogenetically studied T-PLL. On the whole, the most frequently recurring anomalies in T-PLL are 14q lesions with nonrandom breakpoints, inversion (14)(q11q32) or tandem translocations (14;14) (not seen in any of our cases) and trisomy for 8q. mainly due to i(8q), found in more than 40% of patients each. Similar structural anomalies were found almost as frequently among the 23 cytogenetically studied cases of so-called T-chronic lymphocytic leukaemia (T-CLL) reported prior to 1989. It is now accepted that the T-cell counterpart of B-CLL either does not exist or is exceedingly rare and thus previously reported cases of T-CLL sharing the chromosomal characteristics of T-PLL may well have been misdiagnosed examples of T-PLL. Isochromosomes 8q are exceptionally found in other types of haematological malignancies. However, i(8q) could not be shown to be the primary lesion in any case in T-PLL and the role of trisomy for 8q, as well of the associated monosomy 8p, is entirely unknown.

DNA aneuploidy of adult T-cell leukemia cells

To clarify the biological characteristics of adult T-cell leukemia (ATL), immunophenotyping and DNA aneuploid analysis were performed in 72 ATL cases, using flow cytometric techniques. DNA aneuploidy was found in 45 cases (62.5%); the DNA index ranged from 1.03 to 2.16 (mean: 1.24). The incidence of aneuploidy in smoldering, chronic, acute, and lymphoma ATL subtypes was 20.0%, 46.6%, 76.3%, and 77.8%, respectively. The aneuploid patients had a greater tumor burden (adenopathy, hepatosplenomegaly, and leukocytosis with ATL cells), a higher level of serum LDH, and a higher incidence of hypercalcemia, compared with the diploid group. Further, unusual aberrant immunophenotypes were identified predominantly in the aneuploid group. Patients with aneuploidy had a 7.6 month median survival time (MST) with a 2 year survival rate of 24.6%, significantly worse than in the patients with diploidy, whose MST was 25.4 months with a 2 year survival of 60.1%. In some aneuploid patients, the disease often progresses from a static to an aggressive form. Thus, the determination of aneuploidy and unusual immunophenotype should be useful for detecting clinical behavior and for monitoring ATL patients, particularly in regard to such progression.

Vacuolated glycogen-laden leukemic cells in a case of crisis type chronic adult T-cell leukemia

We present a unique case of crisis type chronic adult T-cell leukemia (ATL), in which the majority of leukemic cells had abundant periodic acid-Schiff (PAS)-positive cytoplasmic inclusions. These inclusions were found to be composed of glycogen because the PAS-positivity completely disappeared after digestion with amylase or human saliva. Electron microscopy also revealed that the inclusions consisted of aggregated beta particles of glycogen. The mechanism of glycogen accumulation in leukemic cells remains unknown; however, the presence of such inclusions in leukemic cells may be helpful diagnostically in T-lymphocyte malignancies.

Chromosomal localization of HTLV-1 viral integration sites using in situ hybridization: detection of a novel IL2R fragment

The presence of human T-cell leukemia virus (HTLV-1) in patients with adult T-cell leukemia (ATL) was investigated by Southern blotting and in situ hybridization. In all seven patients, HTLV-1 provirus was detected. A large and variable number of labeled restriction fragments were observed, indicating multiple integrations. Two of the patients analyzed by in situ hybridization had two, while the third patient had three, sites of viral integration on six different chromosomes, suggesting random integration. A single site of integration was shared by two patients, which was on chromosome 10 at bands p11-->p15. One of these sites was on an apparently normal chromosome 10 and the other was on a derivative chromosome 10,t(10;14)(p12;q32). The interleukin 2 receptor (IL2R) has previously been localized to this region (10p14-->p15). The alpha-chain of the IL2R is continuously expressed on affected T-cells in this disease. Southern blotting with pIL2R showed the presence of a novel 3.5 kb fragment in five out of the seven patients. This novel fragment has not been previously reported. No direct correlation was found between the novel 3.5 kb fragment, present in patients both cytogenetically normal and abnormal, and viral integration in the 10p11-->p15 region in two patients. Therefore, it is suggested that the presence of the 3.5 kb fragment and the numerous chromosomal breaks associated with this disease may not be direct results of viral integration.

Cytogenetic implication in adult T-cell leukemia. A hypothesis of leukemogenesis

The close association between adult T-cell leukemia (ATL) and human T-cell leukemia virus type I (HTLV-I) has been established. Nevertheless, the mechanism of progression of ATL by HTLV-I infection is still uncertain, because the virus contains no typical oncogene and no significant expression of the viral RNA has been generally found. I propose a model of leukemogenic process in ATL based on our cytogenetic data and molecular results in the literature. It seems that the rearrangement of some proto-oncogene and alpha-chain gene of the T-cell antigen receptor (TCR-alpha) is necessary for the development to overt ATL. A deficiency in the rearrangement of proto-oncogene to TCR-alpha may result in only a minor proliferation of abnormal lymphocytes and remain in the preleukemic state of ATL or in the HTLV-I carrier state.

Chromosome 14 Abnormality with a Breakpoint of p12 in Adult T-cell Leukemia

We describe a patient with adult T-cell leukemia (ATL) with a 14p chromosomal abnormality. Cytogenetic study revealed two clonal populations of leukemic cells in the peripheral blood sample. Both clones were karyotypically related to each other. One of them showed rearrangement of chromosome 14 at break band p 12 (14p12) in addition to + 3, + 7, -X and del(6) (q14q21). The nucleolar organizer region (NOR) is assigned to the band 14p12 and the role of the rearrangement of chromosome 14p12 in the pathogenesis of ATL is discussed.

Cytogenetics in the investigation of haematological disorders

Chronic and acute, myeloid and lymphatic haematological neoplasms are characterized by acquired genetic rearrangements that, in the majority of cases, can be detected as clonal chromosomal abnormalities. The aberrations are either primary, meaning that they contribute to the establishment of the neoplasm, or secondary, in which case they are acquired during the clonal evolution and malignization of the neoplastic cells. The abnormalities are non-randomly distributed; the aberration pattern differs from disease to disease and sometimes is so characteristic that individual rearrangements may be virtually pathognomonic for particular neoplasms. The cytogenetic characterization of haematological malignancies is of two-fold importance. First, the recurrent aberrations provide us with an insight into the pathogenetic mechanisms that are operative. They pinpoint those areas of the human genome that carry genes or regulatory sequences whose function is disturbed in leukaemias and lymphomas. Using DNA recombinant techniques in addition to chromosome-level investigations of these cancer-associated rearrangements, the molecular pathology of leukaemias and lymphomas is now gradually being unravelled. Second, even before the long-term goal of a more fundamental understanding of the neoplastic process is reached, the cytogenetic aberrations have a direct clinical importance. The finding of an acquired, clonal chromosome abnormality in haematopoietic cells (-Y in old men is an exception) means that the patient has a neoplastic disease. Often, but by no means always, the type of aberration is also informative as to which type of neoplasm is present. During therapy, remission and relapse can be monitored by cytogenetic analyses. Finally, the karyotypic pattern influences prognosis and may thus be taken into account when the choice of therapy is made.

Recurrent chromosomal aberrations in peripheral T-cell lymphoma

Histological, immunological, and cytogenetic analysis of the same neoplastic tissues have been performed on seven patients with peripheral T-cell lymphomas (PTCL). Clonal chromosomal abnormalities in five cases are reported. The most common chromosomal aberration, observed in four patients, is a rearrangement of chromosome 14 with a breakpoint in q11.2. Aberrations of chromosome 8 also occurred in four patients, three of whom had an extra 8q. The data indicate that breakpoints of malignant diseases affecting similar cell types might cluster to specific chromosomal regions, which can be helpful in recognition and classification of PTCL.

Deletion of 14q in non-Hodgkin's lymphoma

6 patients with non-Hodgkin's lymphoma [3 with small cell lymphocytic lymphoma of B-cell type (SL), and 1 each with follicular centroblastic/centrocytic, centroblastic, and immunoblastic lymphoma] and with the acquired cytogenetic abnormalities del(14) (q22) or del(14) (q24) are described. An evaluation of these 6 cases and 41 other lymphatic neoplasms with 14q deletion known from the literature revealed that 37 had a breakpoint in bands q22 to q24. The deletions occur significantly more often in lymphomas of SL morphology and in the leukemic counterpart, chronic lymphocytic leukemia, than in other types of lymphatic malignancies (p less than 0.001).

T-cell receptor gene rearrangements and the diagnosis of human T-cell neoplasms

The rearranging antigen receptor genes of lymphoid cells serve as unique clonal markers of lymphoid neoplasms. Gene rearrangement analysis is a highly sensitive and reproducible tool which is useful in the diagnosis and classification of malignant lymphoma/leukemia. Although clonality can often be determined among B cell neoplasms by virtue of immunoglobulin isotype analysis, no such phenotypic marker of clonality exists for T cells. Therefore, clonality of T lymphoproliferative processes is most readily determined by rearrangement analysis of the T cell antigen receptor genes. The alpha, beta, gamma, and delta genes of the T cell receptor gene family encode heterodimeric surface antigen receptors and undergo rearrangement early in T cell differentiation. Identification of rearrangement of T cell antigen receptor genes provides valuable diagnostic information concerning cellular lineage, clonality and classification of T cell neoplasms. This molecular approach is applicable to the diagnosis of occult disease, relapse, and resolution of diagnostic dilemmas in any type of tissue sample including fluids and needle aspirations.

Cytogenetic characterization of a T-cell line, ATN-1, derived from adult T-cell leukemia cells

A T-cell line, ATN-1, was established by culturing peripheral blood mononuclear cells derived from a patient with adult T-cell leukemia/lymphoma (ATL/L). Identities of the patterns of chromosomal abnormalities, cell surface phenotypes, morphologic findings, rearrangement patterns of T-cell receptor beta chain gene, and an integration site of human T-cell leukemia virus I proviral genome indicated that ATN-1 was derived from original leukemic cells. Both ATN-1 and the original leukemic cells showed a variety of patterns of chromosomal abnormalities that include 3q-, 6q-, rearrangements involving 2q31, 7q11.2, 8q11, 8q24, 19p13.3, and also 14q11 and 14q32, where genes for the T-cell receptor alpha chain and the immunoglobulin heavy chain are located. Availability of a genuine ATL/L cell line with these chromosomal abnormalities may greatly facilitate the biologic analysis of ATL/L.

T-cell acute childhood lymphoblastic leukemia with chromosome 14 q 11 anomaly: a morphologic, immunologic, and cytogenetic analysis of 10 patients

Ten patients with T-cell acute lymphoblastic leukemia (ALL) and a chromosome anomaly involving band 14 q 11 are described. Mitotic index of bone marrow blasts was high in all patients (average 3.0%). Lymphoid morphology of the leukemic blasts, however, varied somewhat among the patients. The leukemic cells of 5 patients showed an immunophenotypic profile corresponding to early or common thymic differentiation stages whereas 5 children showed strong expression of CD 3 suggesting a more mature thymic phenotype. Leukemic karyotypes revealed a modal chromosome number of 46 in 9 cases, 92 in one case. A chromosome translocation t(11; 14) (p 13; q 11) was found in 5 cases, a t(1; 14) (p 32; q 11) in 2 cases, a t(10; 14) (q 24; q 11) in one case, a (hitherto undescribed) t(12; 14) (q 22; q 11) in one case, and an inv (14) (q 11 q 32) in one patient. Additional abnormalities were t(3; 10), t(7; 9), dup(7 q), del(6 q), del(10 q), and del(1 q). Of 32 cases with T-cell ALL successfully karyotyped in our laboratory 15 (= 47%) had structural aberrations involving chromosomes 1, 3, 6, 7, 9, 10, 12, 14. Ten of these 15 patients (= 67%) had a chromosome 14 q 11 anomaly. It is concluded that chromosome band 14 q 11, the gene locus of the T-cell receptor alpha-chain, is the most common site for structural chromosome aberrations in T-cell ALL.

Chromosome instability in preleukemic states of adult T-cell leukemia (pre-ATL)

Chromosome analysis was performed on nine patients with subclinical adult T-cell leukemia (pre-ATL), who were asymptomatic ATL virus carriers. Fewer than 30% of their peripheral blood leukocytes were abnormal T-lymphocytes with nuclear abnormalities. ATL-associated antigen (ATLA) and anti-ATLA antibody were found in all patients. Eight had variable abnormal karyotypes in a fraction (5.0%-25.4%) of peripheral blood leukocytes stimulated with phytohemagglutinin or T-cell growth factor. There were no metaphases when a mitogen was not added. Four patients had a clonal chromosome abnormality. The chromosome abnormality seen in one patient was observed in the first study but not in a second study, when a different abnormality was seen. In five patients, an abnormal chromosome #14 with a break at band 14q11 was found. These findings indicate that unstable, chromosomally abnormal clones are characteristic of pre-ATL.

A B-cell line having chromosome 14 aberration at break band q11 derived from an adult T-cell leukemia patient

A B-cell line having translocations of chromosome 14 at break band q11 (the assigned locus of the alpha-chain gene of the T-cell antigen receptor) and chromosome 3 at break band p25 (the assigned locus of the c-raf-1 oncogene) was established from peripheral blood leukocytes of an adult T-cell leukemia (ATL) patient. The same chromosome 14 aberration at break band q11 and chromosome 3 aberration at break band p25 were also found in fresh T-cell leukemia cells. The B-cell line is surface immunoglobulin (sIg)+, immunoglobulin gene rearrangement+, ATL-specific antigen (ATLA)+, HTLV-1 proviral genome+, Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA)+ and the EBV DNA genome+. The fresh T-leukemic cells were T-cell receptor gene rearrangement+, the HTLV-1 proviral genome+ and EBV DNA genome.

Specific abnormalities of chromosome 14 in patients with acute type of adult T-cell leukemia/lymphoma

Chromosome analysis was performed on 1 patient with diffuse lymphoma of mixed type by histologic diagnosis and on 7 patients with the acute type of adult T-cell leukemia (ATL). Specific abnormalities in chromosome 14 at break band q11 with the assigned locus of the alpha-chain gene of the T-cell antigen receptor were identified in 6 of 8 patients. Inv(14) (q11q32) was found in 2 patients and translocation of chromosome 14 at break band q11 was observed in 4. Donor chromosomes involved in translocation of the 14q11 varied, i.e., chromosomes 3, 7 or X, with the exception of one patient whose donor chromosome origin could not be determined. The breakpoint in chromosome 3 was in band p25, a region reported to include the locus of the c-raf-I oncogene. In chromosome 7, it was in band p11, a region reported to include the locus of the c-erb-B oncogene, and in the sex chromosome X, it was in band q11. One patient also had a chromosome 14 aberration at break band q32. Of the 2 remaining patients, one had lost chromosome 14 and the other had an isochromosome 14q. Our observation and other reported findings suggest that the rearrangement of chromosome 14 at break band q11 is specific for lymphoma-type or acute-type ATL patients, and aberrations of proto-oncogene expression or the coding sequence by recombination involving a T-cell antigen receptor gene due to chromosome inversion or chromosome translocation may play an important role in T-cell neoplasia including ATL.