Chromosome 14q+ in adult T-cell leukemia

Reflections on Some of the Exceptional Features of HTLV-1 and HTLV-1 Research: A Perspective

The report is not a review or a summary. In a manner, it is a perspective but an unusual one. It looks back to the years my colleagues and I (RG) began preparing for human retroviruses (beginning in 1970), how they evolved, and attempts to bring to light or simply to emphasize many exceptional characteristics of a retrovirus known as HTLV-1 and some fortuitous coincidences, with emphasis on the needs of the field. These events cover over one half a century. We have had many reviews on HTLV-1 disease, epidemiology, and basic aspects of its replication, genome, gene functions, structure, and pathogenesis, though continued updates are needed. However, some of its truly exceptional features have not been highlighted, or at least not in a comprehensive manner. This article attempts to do so.

Median Nerve Somatosensory Evoked Potential in HTLV-I Associated Myelopathy

INTRODUCTION

HTLV-I Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a progressive Myelopathy that mainly involves the corticospinal tract. Despite pronounced involvement of the lower limbs, patients also have abnormalities in their upper limbs. So, we studied somatosensory-evoked potentials (SSEPs) of the median nerve in HAM/TSP patients to determine the extent of the involvement of the pathway of the central nervous system, especially the cervical spinal cord.

METHODS

In this cross sectional study, 48 patients with HAM/TSP who were referred to Qaem Hospital in Mashhad from October 2010 to October 2011 were evaluated for various indices, including SSEPs of the median nerve for N9, N11, N13, and N20 waveforms and also N11-13 and N13-20 Inter Peak Latency (IPL), severity of disease (based on Osama criteria), disease duration (less or more than 2 years), age, and gender. SPSS software was used for data analysis. The t-test was used for quantitative data, and the chi-squared test was used for the qualitative variables.

RESULTS

Thirty-four patients (70.2%) were females. The mean age was 45.6 ± 14.2 years. About SSEPs indices of the median nerve, N9 and N11 were normal in all patients, but N13 (50%), N20 (16.7%), IPL11-13 (58.3%), and IPL13-20 (22.9%) were abnormal. No significant relationships were found between age, gender, disease duration, and SSEPs indices (p > 0.05), but IPL11-13 and IPL13-20 had significant relationships with disease disability (p = 0.017 and p = 0.01, respectively).

CONCLUSION

Despite the lack of obvious complaints of upper limbs, SSEPs indices of the median nerve from the cervical spinal cord to the cortex were abnormal, which indicated extension of the lesion from the thoracic spinal cord up to the cervical spinal cord and thalamocortical pathways. Also, abnormalities in the cervical spinal cord had a direct correlation with the severity of disability in patients with HAM/TSP.

Molecular approach to human leukemia: isolation and characterization of the first human retrovirus HTLV-1 and its impact on tumorigenesis in adult T-cell leukemia

Molecular biology of mouse and chicken retroviruses had identified oncogenes and provided a revolutionary concept in understanding of cancers. A human retrovirus was established during 1980-1982 in linkage with a unique human leukemia, concurrently in Japan and USA. This review covers our efforts on the discovery of new retrovirus, Human T-cell Leukemia Virus Type 1 (HTLV-1), first introducing to a new class of retroviruses with a unique regulatory factors, Tax and Rex. Then it is followed by analyses of molecular interaction of the vial Tax with cellular machineries involved in the pathogenesis of Adult T-cell Leukemia (ATL). And then a probable mechanism of pathogenesis of ATL is proposed including recent findings on HBZ after our efforts.

Global epidemiology of HTLV-I infection and associated diseases

Epidemiologic aspects of human T-lymphotropic virus type I (HTLV-I) infection have been thoroughly studied over the course of approximately 25 years since its first description. The geographic distribution of the virus has been defined, with Japan, Africa, Caribbean islands and South America emerging as the areas of highest prevalence. The reasons for HTLV-I clustering, such as the high ubiquity in southwestern Japan but low prevalence in neighboring regions of Korea, China and eastern Russia are still unknown. The major modes of transmission are well understood, although better quantitative data on the incidence of transmission, and on promoting/inhibiting factors, are needed. Epidemiologic proof has been obtained for HTLV-I's causative role in major disease associations: adult T-cell leukemia (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV-associated uveitis and infective dermatitis. However, more and better studies are needed for other apparent disease outcomes such as rheumatologic, psychiatric and infectious diseases. Since curative treatment of ATL and HAM/TSP is lacking and a vaccine is unavailable, the social and financial cost for the individual, his/her family and the health system is immense. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of paramount importance.

Long-term serological outcome of infants who received frozen-thawed milk from human T-lymphotropic virus type-I positive mothers

AIM

Human T-lymphotropic virus type-I (HTLV-I) infection occurs via mothers' milk during feeding. However, freeze-thaw processing can eliminate the infectivity of the mother's milk of HTLV-I carriers.

METHODS

A long-term follow-up survey was conducted to investigate the HTLV-I infectivity of frozen-thawed mothers' milk among infants whose mothers were HTLV-I seropositive.

RESULTS

Infants fed frozen-thawed mothers' milk did not become HTLV-I antibody-positive up until 1 year old, and all children followed up until an age of 11-12 years were antibody negative.

CONCLUSIONS

This study showed that freeze-thaw processing can eliminate the HTLV-I infectivity of mothers' milk, and that HTLV-I carriers can indirectly feed their infants using frozen-thawed mothers' milk as a way to prevent HTLV-I infection.

Long-term follow up study of vertical HTLV-I infection in children breast-fed by seropositive mothers

Infection of Human T-lymphotropic virus type-I (HTLV-I) was investigated by long-term follow up surveys of mother's milk-fed infants. HTLV-I infections of infants via seropositive mother's milk, that is, anti-HTLV-I antibody-positive infants, increased in number up to the age 2, but no infants became antibody-positive thereafter. Infants who had became antibody positive by age 2 remained so at age 11-12. HTLV-I infection via feeding with mother's milk was established by the age 2. While in epidemiologic surveys an increase of the anti-HTLV-I antibody-positive rate has been reported, this survey revealed that after acquisition of HTLV-I from breast feeding, there was no further horizontal transmission prior to puberty.

Interleukin-2-dependent but not independent T-cell lines infected with human T-cell leukemia virus type 1 selectively express CD45RO, a marker for persistent infection in vivo

Human T-cell leukemia virus type 1 (HTLV-1) is an etiologic agent of adult T-cell leukemia. HTLV-1 is exclusively detected in CD45RO+ T-cells in infected individuals, but CD45RO is weakly expressed in HTLV-1-transformed T-cell lines in vitro. The aim of this study was to investigate the role of CD45RO in the persistent HTLV-1 infection in vivo. Flow cytometry showed that only two out of eight interleukin(IL)-2-independent HTLV-1-transformed T-cell lines expressed CD45RO, whereas all five IL-2-dependent ones expressed CD45RO, and the level of expression was higher in IL-2-dependent than in IL-2-independent cells. The high CD45RO expression in IL-2-dependent cell lines was not due to IL-2, since IL-2 had little effect on the expression of CD45RO in T-cell lines. Using western blotting, we showed that IL-2-dependent HTLV-1-transformed T-cell lines expressed a lower level of expression of the viral transcriptional regulatory protein Tax than IL-2-independent ones, and that the level of expression correlated inversely with that of CD45RO. However, the expression of Tax in one HTLV-1-negative T-cell line little affected the expression of CD45RO, suggesting that Tax at least alone does not suppress the expression of CD45RO in HTLV-1-infected T-cell lines, and that other viral or cellular factor(s) are probably involved in such suppression. Our results suggest that CD45RO+ Tax-low IL-2-dependent T-cell lines in vitro correspond to the persistent HTLV-1-infected cells in vivo, and HTLV-1-infected cells in vivo are immortalized in IL-2-dependent manner.

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.

Primary Ki-1-positive anaplastic large-cell lymphoma: a distinct clinicopathologic entity

The morphology of anaplastic large-cell lymphoma (ALCL) is associated with a clinical syndrome of peripheral lymphadenopathy (> 80%) and frequent extranodal disease (> 40%) in children and young adults (median age < 40 yrs.). Skin lesions occur in more than 20% of patients; other extranodal sites are bone, soft tissue, gastro-intestinal tract, lung, and pleura. Marrow involvement is infrequent (< 10%). Features that distinguish ALCL from Hodgkin's disease (HD) are noncontiguous nodal disease (> 50%), infrequent mediastinal mass (< 20%), and frequent inguinal lymphadenopathy (> 40%). Most patients present with stage III/IV disease. Stage is highly predictive of achieving complete remission, disease-free survival, and overall survival. Localized skin lesions have an excellent prognosis and occasional spontaneous regressions are noted. Distinctive histopathologic features of ALCL are partial lymph node involvement with sinus infiltration, sparing of B-cell regions, and tumor cell pleomorphism. Other features are high mitotic rate, necrosis, fibrosis, and plasma cell infiltrates. Morphologic variants of ALCL resemble carcinoma, syncytial variant of nodular sclerosing HD, true histiocytic lymphoma or interdigitating cell sarcoma, and mycosis fungoides. ALCL can be distinguished from these morphologically similar disorders by immunophenotype (CD30+, CD45+, CD15-, EMA+, BNH9+, keratin-, lysozyme-). A recurrent cytogenetic translocation, t(2;5) (p23; q35), has been observed among morphologic variants, including a small-cell-predominant variant and tumor cell line which contains a spectrum of small cerebriform and large anaplastic CD30+ cells. 70% of ALCL cases are of T-cell lineage, 15% B, 5% T/B, and 10% undefined.(ABSTRACT TRUNCATED AT 250 WORDS)

Partial deletion of chromosome 2 in non-Hodgkin lymphoma

Six patients with non-Hodgkin malignant lymphoma (NHL) in a series of 151 cases showed partial deletion of chromosome 2 when studied cytogenetically. Three had deletions of bands 2p14-p22 and three others had a deletion of bands 2q22-q24 in common. The deletions were associated with other abnormalities in each case and were not associated with a particular subtype of NHL. These deletions are secondary, apparently nonrandom, new abnormalities associated with NHL.

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.

Translocation t(8;14)(q24;q32) and del(1)(p22) in FAB-L1 adult acute lymphoblastic leukemia with long survival

Clonal chromosome changes were found in a patient with FAB-L1 acute lymphoblastic leukemia. The changes consisted of a t(8;14)(q24;q32), Burkitt type, and a rare marker chromosome 1p-. The breakpoint in this chromosome was localized at band 1p22. Both these abnormalities were present in 100% of unstimulated peripheral blood cells. The detection of the t(8;14) in a case of acute lymphoblastic leukemia, without a clear evidence of B immunophenotype and with an unusual long survival (more than 3 years), is discussed.

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

The chromosomes of leukemic blood cells in eight Japanese patients with acute adult T-cell leukemia (ATL) were examined by a direct method or short-term culture method without any mitogens. Six patients showed a chromosome 14 anomaly with a break at band q11-13: inv(14)(q11q32) in two patients, t(11;14)(p13;q13) in one patient, t(14;14)(q11;q32) in addition to del(14)(q11q13) in another, and only del(14)(q11q13) in two patients. Thus, a proximal 14q rearrangement exists in ATL as in other types of T-cell malignancies. Based on these facts, the pathogenesis of ATL is discussed in reference to the literature.

Recurrent chromosome abnormalities in adult T-cell lymphomas of peripheral T-cell origin

Cytogenetic studies were performed on 11 Japanese patients with adult T-cell lymphoma of peripheral T-cell origin. All patients had a histologic diagnosis of diffuse lymphoma, and were treated with intensive combination chemotherapy; their median survival was 6 months. Lymphomas were categorized on the basis of the classification proposed by the Lymphoma Study Group of Japan: 5 patients had the features of pleomorphic lymphoma; 3, mixed lymphoma; 2, large-cell lymphoma; and 1, medium-sized-cell lymphoma. The modal chromosome number of abnormal cells was near-diploid in 7, and hypotetraploid in 4 including 3 patients with pleomorphic lymphoma. Abnormalities of the clonal chromosomes were observed in all 11 patients. A translocation of the short arm of 19 at band 19p13 was found in 2 patients with pleomorphic lymphoma and in one patient each with mixed lymphoma and medium-sized-cell lymphoma. A translocation of the short arm of 14, with a break at band 14p12, occurred in 4 patients with pleomorphic lymphoma. In one patient each with mixed lymphoma and large-cell lymphoma, an extra chromosome 3 was found. The numerical change was unique because their lymphomas were further categorized as "angioimmunoblastic lymphadenopathy with dysproteinemia" and "large-cell immunoblastic lymphoma", respectively. Our findings suggest that characteristic chromosome abnormalities occur in adult T-cell lymphoma, and dividing cells in the tetraploid range tend to be predominant in pleomorphic lymphoma.

Chromosomal abnormalities in a patient with smoldering adult T-cell leukemia: evidence for a multistep pathogenesis

A cytogenetic study was performed on peripheral blood cells from a patient with smoldering adult T-cell leukemia (ATL). Four types of primary abnormal clones were found upon examination of a large number of karyotypically analysed cells cultured with and without phytohemagglutinin (PHA). However, human T-cell leukemia virus (HTLV) proviral DNA was confirmed to be monoclonal. This discrepancy can be explained by the hypothesis that these four primary abnormal clones were all derived from a leukemic clone with a normal karyotype and the same integration site of HTLV proviral DNA.

Chromosome abnormalities, sister chromatid exchanges, and cell cycle analysis in phytohemagglutinin-stimulated adult T cell leukemia lymphocytes

Chromosome abnormalities, sister chromatid exchanges (SCE), and cell cycle kinetics were studied in phytohemagglutinin-stimulated lymphocytes from 8 adult T cell leukemia (ATL) patients. In all these cases, chromosome abnormalities were observed in 5-day PHA-stimulated cultures. Four cases had characteristic marker chromosomes; two were due to a balanced translocation, t(9;21), and two to a simple deletion, 5p-. The other four cases, however, had rather complicated chromosome abnormalities, e.g., 1q+, 2q+, 5q+, 6q-, 14q+, 10p-. When chromosome abnormalities were analyzed in previously reported cases, the abnormalities were mostly distributed among chromosomes #1, #2, #5, #6, #14, and #21. These findings suggest that the abnormalities involving #1, #2, #5, #6, #14, and #21 are intimately related to ATL. The SCE frequency was in the normal range in ATL cells. Cell cycle analysis revealed that the duration of two cell cycles in cells labeled with bromodeoxyuridine (BrdU) required approximately 80 hr in ATL cells, whereas the time of two cell cycles in normal cells is 40 hr. These findings indicate that the ATL cell cycle time is about 40 hr, about double that of normal cells (20 hr), in PHA-stimulated cultures. ATL has been known to be a mature T cell leukemia and to respond poorly to chemotherapy. The latter may be due to the elongated cell cycle or to the mature characteristics of the leukemic cells. The association of ATL with cutaneous T cell lymphoma is also discussed.

Adult T-cell lymphoma/leukemia in a Caribbean patient: cytogenetic, immunologic, and ultrastructural findings

Cytogenetic findings on immunologically and morphologically characterized leukemic cells from a Caribbean patient with adult T-cell lymphoma/leukemia (ATLL) (HTLV+) are reported. Marker studies on peripheral blood lymphoid cells showed a mature postthymic phenotype: TdT-, OKT3+, OKT4+, OKT6-, OKT8-, 3A1-, anti-HLA-DR-. Light and electron microscopic analysis revealed a great cellular pleomorphism with respect to nuclear features. Three main types of leukemic cell were observed: typical multilobed ATLL lymphocytes, Sézary's syndrome (SS) cells, and cells intermediate between those two. Chromosome studies on PHA-stimulated cultures revealed three clones. The predominant clone was hyperdiploid; significant abnormalities were 1q+, 14q+, and 6q- (breakpoint q21), which are known to occur in lymphoid malignancies, together with trisomy 7q and i(17q), which have been reported previously in Japanese ATLL and the small variant of SS, respectively. The 14q+ marker was t(11;14)(q13;q22-24). The incidence of 6q-, trisomy 7q, and i(17q) varied within the main clone, and it is speculated that these chromosome abnormalities might be related to the variation observed in the cell types of this patient. Two minor clones had 6q- (breakpoint q25) and 13q+ markers, respectively. It was not possible to unequivocally establish the relationship between these three clones. The chromosomal, morphologic, and immunologic findings in this case support a close relationship between ATLL in Japan and in the Caribbean basin, as well as between the proliferating cells of ATLL and SS.

Adult T-cell leukemia. Chromosome analysis of 15 cases

Chromosome studies was conducted on 15 patients with adult T-cell leukemia. Cells with chromosomal abnormality were seen in 14 of the 15 patients. The modal chromosome number was near diploid range in all the patients. The most common abnormality was 14q+ marker chromosome and partial deletion of the long arm of chromosome 6, i.e., 6q-, which were seen in eight and seven cases, respectively. Donor chromosomes involved in the 14q+ marker chromosome varies, i.e., Yq, #5p, #5q, #9q, #10q or #12q, except for two patients whose donor chromosome origins were unable to determine. The break point in 14q+ marker chromosome was band at q32. The 6q- chromosome was due to a deletion in one patient and interstitial deletion in six patients. A 14q- chromosome having break point at q24 was found in one patient and duplication of Yq chromosome in two patients. In addition, four patients showed a 5q- chromosome or a 9q- chromosome which was due to a translocation or deletion. The significance of these chromosome abnormalities was discussed.

Lymphoblastic lymphoma: cytogenetic, pathologic, and immunologic studies

Cytogenetic, pathologic, and immunologic studies were done on 10 patients with lymphoblastic lymphoma (LL). The median age was 21 years, and males predominated in a ratio of 9:1. At the time of diagnosis, 6 of the 10 patients had an anterior mediastinal mass, 3 had bone marrow involvement, and 2 had central nervous system involvement. All patients were treated with intensive combination chemotherapy. The median survival of the 8 patients who died (7 of whom were adults) was 10.5 months; all 8 achieved only a partial remission. Two other patients were children; they continue in complete remission. Immunologic marker studies were done on 9 of the patients; 5 had T-cell LL, and the other 4 had non-T, non-B LL. In a study of T-cell subpopulations with the use of monoclonal antibodies, the malignant T cells of the 2 patients tested appeared to be mature thymocytes. Clonal chromosome abnormalities were seen in involved tissues from 8 patients; the other 2 patients had a normal karyotype. A 9q+ chromosome, a 6q- chromosome, and a 1q-chromosome associated with 1q trisomy were each seen in 2 patients. No patients had a 14q+ chromosome, which is the most common abnormality in various lymphoproliferative disorders, including other T-cell malignant diseases. The variable chromosome pattern in LL could be related to the heterogeneity of the immunologic phenotype of the malignant T cells. More data are needed before it can be established whether there are any correlations between a particular karyotype and the immunologic phenotype of LL cells.

Translocations involving chromosomes #3 and #12: hematologic diseases associated with abnormalities of these chromosomes

Two hematologic cases with translocations involving chromosomes #3 and #12 are described. The first case is that of a myeloproliferative disorder (preleukemia?) associated with a (3;12)(q29;q24) translocation in the bone marrow cells. No evidence of leukemic transformation has appeared to date. The second case is that of acute leukemia (AL) (M4 type) in which leukemic cells with t(3;12)(p14;q24) were seen. The roles of chromosomes #3 and #12 in hematopoiesis are considered, and the abnormalities affecting these chromosomes in various hematologic disorders have been tabulated and correlated. Abnormalities in chromosomes #3 and #12 appear to be common and nonrandom in hematologic diseases of a premalignant and a malignant type.