Rearrangement of human T cell receptor beta and gamma chain genes in adult T cell leukemia/lymphoma

We studied rearrangement of human T cell receptor genes (TCR) of C beta, C gamma, V gamma and J gamma in 34 cases of adult T cell leukemia/lymphoma (ATLL), consisting of 29 cases with monoclonally integrated HTLV-I proviral DNA (ATLL-W) and five without monoclonal integration (ATLL-O), in comparison with 12 cases of other peripheral T cell lymphomas (non-ATLL). All cases of both ATLL and non-ATLL showed some rearrangement of T cell receptor genes (TCRs) of C beta, C gamma, V gamma, or J gamma. Rearrangement of TCR beta was found in 28 of 29 cases of ATLL-W, all cases of ATLL-O, and eight of 12 cases of non-ATLL. Rearrangement of TCR gamma was observed in 21 of 22 cases of ATLL-W, and in all cases of ATLL-O and non-ATLL. In TCR gamma, rearrangement of C gamma was seen in six of 20 cases of ATLL-W, none of three ATLL-O cases and three of six cases of non-ATLL. V gamma rearrangement occurred in 14 of 18 cases of ATLL-W, one of two cases of ATLL-O, and three of six cases of non-ATLL. Rearrangement of J gamma was found in 16 of 22 cases of ATLL-W, two of five ATLL-O cases, and six of seven non-ATLL cases. Rearrangement was more frequent in ATLL-W than in ATLL-O and non-ATLL. The incidence rate of rearrangement of V gamma families of V gamma 1, V gamma 2, and V gamma 3 was nearly the same in each group, except for deletion of V gamma 3, which was often observed in ATLL but was absent in non-ATLL. These results indicate the usefulness of detection of TCR and HTLV-I proviral DNA to differentiate ATLL from other T cell malignancies.     

Identification of genes associated with the progression of adult T cell leukemia (ATL).

Patients with adult T-cell leukemia/lymphoma (ATL) exhibit a variety of clinical features, and this disease is therefore clinically subclassified into acute, lymphomatous, chronic, and smoldering types. Acute ATL is a typical leukemic form of ATL with rapid progression, and chronic ATL is a less aggressive clinical form allowing long-term survival even without chemotherapy. In the present study, we used fresh peripheral blood mononuclear cells (PBMC) from both types of ATL patients to identify molecules that may contribute to the difference between acute and chronic ATL. Isolated mRNAs expressed differentially between the two types of ATL include a T-cell differentiation antigen (MAL), a lymphoid-specific member of the G-protein-coupled receptor family (EBI-1 / CCR7), a novel human homologue to a subunit (MNLL) of the bovine ubiquinone oxidoreductase complex, and a human fibrinogen-like protein (hpT49). We found that the former three are upregulated in acute ATL and the last is down-regulated in both chronic and acute ATL. We speculate that dysregulation of the genes may account for the malignant features of ATL cells, in terms of growth, energy metabolism, and motility.     

Impact of visceral involvements and blood cell count abnormalities on survival in adult T-cell leukemia/lymphoma (ATLL)

Multiple visceral involvements and various blood cell count abnormalities are frequently manifested in adult T-cell leukemia/lymphoma (ATLL) at diagnosis. We evaluated the effects of four visceral involvement (bone marrow (BM), skin, liver, spleen) and six blood cell count abnormalities (anemia, neutrophilia, thrombocytopenia, monocytosis, eosinophilia, basophilia) on the overall survival of 168 ATLL patients. In the aggressive type, BM involvement, skin involvement and monocytosis were significantly poor prognostic factors. Furthermore, concomitant involvement of BM and additional visceral organs worsened the prognosis. These data support that multiple organ involvements represent a poor prognostic factor for ATLL and provide clinical significance for BM examinations.     

Effect of tumor promoters on human T cell leukemia/lymphoma virus (HTLV)-structural protein induction in adult T-cell leukemia cells

We assayed the capacity of tumor promoters to induce human T-cell leukemia/lymphoma virus (HTLV) structural proteins p19 and p24 from the HTLV genome-carrying adult T-cell leukemia (ATL) cell lines, MT-1 and KH-2Lo, and fresh ATL cells. Among the tested substances, 12-O-tetradecanoyl phorbol-13-acetate (TPA), 12-hexadecanoyl-phorbol-13-acetate (HPA) and teleocidin induced HTLV structural protein p19 and p24. This suggests that certain environmental substances, especially those known to be tumor promoters, may activate the HTLV-gene in ATL cells.     

Restriction of T cell receptor variable region in lymph nodes of adult T cell leukemia/lymphoma

Adult T cell leukemia/lymphoma (ATLL) is a mature T cell malignancy, especially derived from the CD4 positive T cell. To characterize the T cell, we examined the representation of T cell antigen receptor variable region, using the monoclonal antibodies [β V 5 (a), β V 5 (b), β V 6 (a), β V 8 (a), β V 12 (a), α V 2 (a), α-β V (a)]. Clinicopathologically we classified the lymph nodes of patients with ATLL into three states (1) human T cell leukemia virus type I (HTLV-I) associated lymphadenitis, reactive state; (2) incipient ATLL, early or pre-neoplastic state; and (3) ATLL, neoplastic state. The lymph nodes of all three states were composed of unvarying CD4 positive T cells. Most of the lymph nodes with ATLL consistently presented α V 2 antigen, but no others. In HTLV-I associated lymphadenitis, only a few cells reacted for α V 2, as in non-specific lymphadenitis without ATLL features. One of three cases with incipient ATLL presented α V 2. The selective expression of T cell antigen receptor V region might be associated with the presence of HTLV-I encoded superantigen, similar to human immunodeficiency virus (HIV).     

Methylation analysis of cell cycle control genes in adult T-cell leukemia/lymphoma.

Central to many cancers is the aberrant expression of genes that regulate the cell cycle including the cyclin-dependent kinase inhibitors known as p15INK4b and p16INK4a, p14ARF and the retinoblastoma (RB) protein. We performed a detailed analysis of the methylation status of these genes by methylation specific polymerase chain reaction (MSP) in tumor cells of 35 adult T-cell leukemia/lymphoma (ATL) patients. We found in nine of 35 cases (26%) at least one gene methylated. The frequency of p15INK4b methylation was 7 of 35 (20%). The incidence of methylation of p14ARF and p16INK4a was two of 35 (6%) and one of 35 (3%), respectively. The RB gene was not found to be methylated in any of the ATL samples. The data indicate that inactivation of these cell cycle regulatory genes by hypermethylation is important in the development of ATL.     

Geographic diversity of adult t-cell leukemia/lymphoma in Brazil. The Brazilian ATLL Study Group.

We describe 195 cases of adult T-cell leukemia/lymphoma (ATLL) reported to the national registry of T-cell malignancies in Brazil between 1994 and 1998. We compared the effect of demographic differences and clinical features of 150 consecutive ATLL cases in different regions of this diverse country. At diagnosis, the predominant clinical sub-type was the acute type (60%), followed by lymphoma (22%), chronic (10%) and smoldering (8%) types. Although we expected that different sub-types would be present in different regions, on the basis of immunogenetic factors determined by ethnicity, we did not demonstrate these differences. There were no significant differences among ATLL subtypes by age or gender. No ethnic group predominated in the total population of patients, but significant differences were noted when examining ethnic distribution by region. Reflecting the general population distribution, white patients were seen more often in S?o Paulo and black patients in Bahia, than in other regions. In most regions, cases were equally distributed between blacks and mulattos, except in Pernambuco, where blacks were less frequent. The main clinical features were lymphadenopathy, skin lesions, hypercalcemia and hepatomegaly. Fourteen patients (9%) suffered from HTLV-I-associated myelopathy (HAM/TSP), either at diagnosis or during follow-up of ATLL. All cases but one had antibodies to HTLV-I, with concordant results with ELISA, WB and PCR analyses. For the antibody-negative case, pol and tax gene sequences were present in tumor cells when subjected to PCR analyses. The prognosis was generally poor, suggesting that the disease in Brazil behaves in similar fashion regardless of ethnic or geographical differences.     

HTLV-1-host interactions on the development of adult T cell leukemia/lymphoma: virus and host gene expressions

Background

Adult T-cell leukemia/lymphoma (ATLL) is a lymphoproliferative disorder of HTLV-1-host interactions in infected TCD4+ cells. In this study, the HTLV-1 proviral load (PVL) and HBZ as viral elements and AKT1, BAD, FOXP3, RORγt and IFNλ3 as the host factors were investigated.

Methods

The study was conducted in ATLLs, HTLV-1-associated myelopathy/tropical spastic paraparesis patients (HAM/TSPs) and HTLV-1-asympthomatic carriers (ACs). The DNA and mRNA from peripheral blood mononuclear cells were extracted for gene expression assessments via qRT-PCR, TaqMan assay, and then confirmed by western blotting.

Results

As it was expected, the HTLV-1-PVL were higher in ATLLs than ACs (P?=?0.002) and HAM/TSP (P?=?0.041). The HBZ expression in ATLL (101.76?±?61.3) was radically higher than in ACs (0.12?±?0.05) and HAM/TSP (0.01?±?0.1) (P?=?0.001). Furthermore, the AKT1 expression in ATLLs (13.52?±?4.78) was higher than ACs (1.17?±?0.27) (P?=?0.05) and HAM/TSPs (0.72?±?0.49) (P?=?0.008). However, BAD expression in ATLL was slightly higher than ACs and HAM/TSPs and not significant. The FOXP3 in ATLLs (41.02?±?24.2) was more than ACs (1.44?±?1) (P?=?0.007) and HAM/TSP (0.45?±?0.15) (P?=?0.01). However, RORγt in ATLLs (27.43?±?14.8) was higher than ACs (1.05?±?0.32) (P?=?0.02) but not HAM/TSPs. Finally, the IFNλ3 expression between ATLLs (31.92?±?26.02) and ACs (1.46?±?0.63) (P?=?0.01) and ACs and HAM/TSPs (680.62?±?674.6) (P?=?0.02) were statistically different, but not between ATLLs and HAM/TSPs.

Conclusions

The present and our previous study demonstrated that HTLV-1-PVL and HBZ and host AKT1 and Rad 51 are novel candidates for molecular targeting therapy of ATLL. However, high level of RORγt may inhibit Th1 response and complicated in ATLL progressions.

     

Chemotherapy targeting methylthioadenosine phosphorylase (MTAP) deficiency in adult T cell leukemia (ATL).

Methylthioadenosine phosphorylase (MTAP) is an important enzyme used for the salvage of adenine and methionine. Cells lacking this enzyme are expected to be sensitive to purine synthesis inhibitors and/or methionine starvation. We reported previously that the MTAP gene is deleted in adult T cell leukemia (ATL) cells. In the present study, we expanded our series and used a real-time quantitative PCR assay for accurate diagnosis of the deletion and nine of 65 primary ATL samples (13.8%) were MTAP negative. In spite of this low incidence, ATL cells showed significantly higher sensitivity to L-alanosine, an inhibitor of de novo adenosine monophosphate (AMP) synthesis, than normal lymphocytes, suggesting that the MTAP gene is inactivated not only by deletion but also by other mechanisms. Indeed, a real-time quantitative RT-PCR assay disclosed that primary ATL cells had significantly lower MTAP mRNA expression than normal lymphocytes. Since MTAP-negative ATL cell lines also showed much higher sensitivity to L-alanosine than MTAP-positive ATL cell lines, we used these cell lines to investigate whether it is possible to develop selective therapy targeting MTAP deficiency. A substrate of MTAP, methylthioadenosine (MTA) or its substitutes rescued concanavalin A (Con A)-activated normal lymphocyte proliferation from L-alanosine toxicity. All the compounds except 5'-deoxyadenosine, however, also caused the undesirable rescue of MTAP-negative ATL cell lines. 5'-Deoxyadenosine had the desired ability to rescue hematopoietic progenitor cells without rescuing ATL cell lines. These results support the rationale for a chemotherapy regimen of L-alanosine combined with 5'-deoxyadenosine rescue in MTAP-deficient ATL.     

Nuclear DNA fluorocytophotometric analysis of leukemic cells in adult T-cell leukemia/lymphomas (ATLL)

The nuclear DNA content of the leukemic cells in six cases of ATLL and one of peripheral T-cell malignant lymphoma (PTML) were analyzed by fluorocytophotometry, simultaneously evaluating the nuclear shape and the longest nuclear axis (LNA). The leukemic cells, characterized by the nuclear shape and LNA, had a little hyperdiploid DNA content, and they belonged to GO/GI cells. The life span of the leukemic cells was suggested to be as short as two to three weeks or much longer than the survival time of the patients, evaluating the change of the LNA histogram under chemotherapy from the diagnosis up to the patients' death. One of the ATLLs, showing small leukemic cells and a clinical course of more than three years, might be a new entity, T-CLL-like ATLL.     

Role of tumor suppressor genes in transplacental lung carcinogenesis

Most human cancers involve multiple genetic changes, including activation of oncogenes such as Ki-ras-2 (Kras2) and inactivation of any one of a number of tumor suppressor genes such as p53 and members of the retinoblastoma (Rb) regulatory axis. As part of an ongoing project to determine how in utero exposure to chemical carcinogens affects the molecular pathogenesis of murine lung tumors, the p53 and p16^Cdkn2a genes were analyzed by using paraffin-embedded lung tissues from mice treated transplacentally with 3-methylcholanthrene. Single-strand conformation polymorphism analysis of exons 5–8 of the p53 gene, as well as their flanking introns, demonstrated an absence of mutations at this gene locus. However, a genetic polymorphism was identified at nt 708 in intron 4 of the DBA/2 strain of mice 5 bp downstream of a 3′ branching-point splice signal. Analysis of exons 1 and 2 of the Cdkn2a gene by single-strand conformation polymorphism and sequence analyses revealed mutations in exon 2 in 7% of the tumors examined. Tumor 23-1 exhibited a CAC→TAC transition at nt 301 (His⁷⁴→Tyr⁷⁴), and tumor 36-1 exhibited a GGG→GAG transition at nucleotide 350 (Gly⁹⁰→Glu ⁹⁰). Northern blot analysis of 14 of the larger tumors showed a marked decrease in the levels of Rb RNA expression. Immunohistochemical analysis revealed a spectrum of pRb expression, with the smaller adenomas showing moderate numbers of nuclei with heterogeneous staining for pRb in contrast with a highly reduced or near-complete absence of expression in the nuclei of larger tumors with features of adenocarcinomas. The low incidence of mutations at tumor suppressor loci suggested that inactivation of tumor suppressor genes was a late event in murine lung tumor pathogenesis. The identification of both mutations at the Cdkn2a gene locus and reduced levels of Rb expression combined with previous studies demonstrating a high incidence of mutated Kras2 alleles in these tumors implies that alterations of the Rb regulatory axis, in combination with mutation of Kras2, may be the preferred pathway for the pathogenesis of pulmonary tumors in transplacentally exposed mice. Mol. Carcinog. 21:177–184, 1998. © 1998 Wiley-Liss, Inc.     

Adult T-cell leukemia/lymphoma (ATLL): report of two fully documented Hellenic patients

ATLL is etiologically associated with HTLV-I retrovirus. A population of 10 to 20 million worldwide is estimated to be infected by the virus, but only 1-4% develop ATLL during a 70-year lifespan. The latency period is more than 30 years. The aim of this study was to report two cases of ATLL in Greek patients with the concomitant study of their family members. A 55-year-old woman and a 59-year-old man presented with leucocytosis and lymphocytosis. Both were asymptomatic and physical examination was unremarkable except for minimal lymphadenopathy in the second patient. In both patients blood smears showed small-to-medium-sized, multilobulated lymphocytes, with different degrees of nuclear irregularity. Immunophenotypic study was as follows: CD2 + (97%), CD3 + (95%), CD5 + (95%), CD3/CD4 + (93%), CD3/CD25 + (84%), CD7 -/CD4 + (89%) CD2 + /HLA-DR + (53%), TCRabeta + (96%) and CD7-(7%). Bone marrow biopsy revealed a normal cellularity with dyserythropoiesis and scattered small lymphocytes (CD4 + on immunostaining) Serum HTLV I and II antibodies were positive. T-cell receptor gamma-chain rearrangement was positive in blood lymphocytes by PCR. Cytogenetic analysis showed complex karyotypic abnormalities. DNA analysis by PCR demonstrated the integration of the HTLV-I DNA in the DNA of the neoplastic T cells. Both patients rapidly developed acute type ATLL. In the first patient multiple subcutaneous nodules on the palmar surface of both hands were also observed. She received deoxycoformycin, which was stopped because of autoimmune hemolytic anemia. Corticosteroid treatment was initiated, with gradual improvement. She suffered from recurrent opportunistic infections. She is currently under interferon and zidovudine therapy with stable blood parameters. Chemotherapy was administered to the other patient with > 50% initial response. Both patients' families were tested for serum anti HTLV-I antibodies and their mates were found to be positive; they also had detectable viral DNA by PCR analysis while asymptomatic, with no abnormal clinical findings and normal white blood cell count and morphology. In conclusion, the two aforementioned patients are the first fully documented ATLL patients described in Greece. Investigation for HTLV-I antibodies should be mandatory in all patients with T-cell lymphoproliferative disorders.     

Microsatellite instability as a potential marker for poor prognosis in adult T cell leukemia/lymphoma.

Microsatellite instability (MSI) represents a replication error resulting from the dysfunction of mismatch repair gene products. In this study, MSI was analyzed in 18 patients with various subtypes of adult T cell leukemia/lymphoma (ATL/L). Using six different microsatellite loci, we defined MSI as positive when replication errors were observed in at least two loci. The MSI was positive in four cases (22.2%)with acute type ATL, who tended to show more prognostically unfavorable factors and shorter overall survival. These results suggest that genomic instability may be associated with tumor progression rather than the development of ATL/L itself. In addition, the presence of the MSI at initial presentation could appear to warrant consideration as an additional prognostically unfavorable factor.     

Identifying progression-associated genes in adult T-cell leukemia/lymphoma by using oligonucleotide microarrays

Adult T-cell leukemia/lymphoma (ATL) is associated with human T-lymphotropic virus type-1 (HTLV-1). To understand the changes in expression that occur in the progression of chronic phase of ATL to acute crisis, the gene expression profiles of fresh ATL cells were compared in 4 pairs of samples (progression of chronic to acute phase in 3 patients, as well as 1 typical chronic phase sample vs. 1 typical acute phase sample) using high-density oligonucleotide DNA arrays. We identified 203 genes that were commonly upregulated in acute vs. chronic phase samples including ribosomal proteins, proteosome subunits, eukaryotic translation factors, immunophilins, heat shock proteins and genes important for DNA replication. Additionally, we identified 91 commonly downregulated genes including immune molecules related to MHC and a phosphatase. Several of the genes were previously identified to be associated with the Tax protein of HTLV-1. Some of the upregulated genes were located in amplified regions identified by comparative genomic hybridization in the corresponding chronic/acute ATL sample. Using real-time quantitative PCR, we confirmed the array-results in those specimens analyzed by microarray. These results demonstrated that distinct sets of genes that are known to be critical in cellular transformation and/or activation are up- or down-regulated during the transition to the acute phase of ATL.     

Inactivation of p14ARF as a key event for the progression of adult T cell leukemia/lymphoma

The INK4a/ARF locus encodes two different proteins, p16^INK4a and p14^ARF, which are crucial for two tumor suppressor pathways. We found that p14^ARF mRNA expression was suppressed in 13 of 37 cases, among which 9 cases showed the inactivation of both of p14^ARF and p16^INK4a, and 4 cases showed the inactivation of p14^ARF alone. The inactivation of p14^ARF and the mutation of p53 are mutually exclusive. The patients with the p14^ARF inactivation had shorter survival, similar to that of patients with the p53 mutation. These results indicate that the inactivation of p14^ARF plays a key role in the progression of ATLL.