Myelodysplastic syndrome: review of the cytogenetic and molecular data

Cytogenetic features in primary myelodysplastic syndrome Egyptian patients

Karyotype is the most important diagnostic and prognostic parameter in myelodysplastic syndromes (MDS) and is abnormal in approximately 50% of patients. We emphasized the importance of chromosomal analysis and reported the most frequent cytogenetic abnormalities in 50 MDS (29 males (58%) and 21 females (42%), median age: 57.5 years) Egyptian patients using conventional banding analysis (CBA). Karyotype description was conducted according to the International System for Human Cytogenetic Nomenclature (ISCN, 2013). Patients were diagnosed based on complete history, bone marrow (BM) aspirate, peripheral blood (PBL) examination, and Iron stain. MDS with multilineage dysplasia (MDS-MLD) was the most frequently encountered subtype; 19/50 (38%) followed by MDS with single lineage dysplasia (MDS-SLD); 11/50 (22%). 27/50 patients (54%) showed a normal karyotype while 23 patients (46%) showed clonal nonrandom chromosomal abnormalities. Most patients with MDS with excess blasts-II (MDS-EB-II) showed abnormal karyotype (3/4; 75%) followed by MDS-EB-I (3/5, 60%) and MDS-MLD (10/19, 53%). Among 50 primary MDS patients; 14/50 (28%) had a single chromosomal abnormality, 3/50 (6%) had double chromosomal abnormality, and 6/50 (12%) had complex karyotype. Male sex was more frequently associated with higher IPSS prognostic risk categories than female gender. The most common single chromosomal abnormalities were −5/del5q; 7/50 (14%) patients followed by −7; 4/50 (8%) patients. +8, del20q and delY were each detected in 1/50 patient (2%). Abnormalities of chromosome 5 (−5/del5q) as a single chromosomal abnormality was the most frequent chromosomal abnormality among Egyptian primary MDS patients followed by complex karyotype. Cytogenetic characteristics of MDS Egyptian patients were similar to North African and European patients. Karyotype offers useful information in establishing accurate diagnosis and male gender is an important predisposing factor that can predict worse prognosis in MDS patients.

Risks and benefits of sex-mismatched hematopoietic cell transplantation differ according to conditioning strategy

Sex-mismatched hematopoietic cell transplantation is linked to increased graft-versus-host disease and mortality in myeloablative conditioning. Here we evaluated outcomes of 1,041 adult transplant recipients at two centers between 2006 and 2013 and investigated how the effect of sex-mismatching differed in myeloablative, reduced-intensity, and non-myeloablative total lymphoid irradiation with anti-thymocyte globulin conditioning. Among patients who underwent myeloablative conditioning, male recipients with female donors had increased chronic graft-versus-host disease (hazard ratio 1.83, P<0.01), increased non-relapse mortality (hazard ratio 1.84, P=0.022) and inferior overall survival (hazard ratio 1.59, P=0.018). In contrast, among patients who received reduced-intensity conditioning, male recipients with female donors had increased acute graft-versus-host disease (hazard ratio 1.96, P<0.01) but no difference in non-relapse mortality or overall survival. Among the patients who underwent total lymphoid irradiation with anti-thymocyte globulin, male recipients with female donors showed no increase in graft-versus-host disease or non-relapse mortality. Notably, only in the cohort receiving total lymphoid irradiation with anti-thymocyte globulin were male recipients with female donors significantly associated with reduced relapse (hazard ratio 0.64, P<0.01), and allo-antibody responses against H-Y antigens were predictive of reduced relapse. In the cohort given total lymphoid irradiation with anti-thymocyte globulin, the graft-versus-leukemia effect resulted in superior overall survival in recipients of sex-mismatched grafts (HR 0.69, P=0.037). In addition, only in the cohort treated with total lymphoid irradiation with anti-thymocyte globulin were female recipients with male donors associated with reduced relapse (hazard ratio 0.59, P<0.01) and superior survival (hazard ratio 0.61, P=0.014) compared with sex-matched pairs. We conclude that the risks and benefits of sex-mismatched transplants appear to differ according to conditioning strategy and this could affect donor selection.

Genetics factors associated with myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a clinically and cytogenetically heterogeneous group of clonal diseases. Clonal chromosomal abnormalities are observed in 30-50% of patients with MDS. The deletions are among the most common alterations, and often involve the long arms of chromosomes 5, 7, 8, 13, and 20 and the short arms of chromosomes 12 and 17. The advent of new technologies for the detection of genetic abnormalities led to the description of a new set of recurrent mutations, leading to new insights into the pathophysiology of MDS. The recent recognition that genes involved in the regulation of histone function (EZH2, ASXL1, and UTX) and DNA methylation (DNMT3A, IDH1/IDH2, and TET2) are frequently mutated in MDS, has led to the proposal that there is an important link between genetic and epigenetic alterations in this disease. In fact, regulatory factors have also been considered as miR-143/miR-145, miR-146a, miR-125a and MiR-21. Somatic mutations may influence the clinical phenotype but are not included in current prognostic scoring systems. In recent years research has brought new insights into these diseases, but few of the findings are sufficiently robust to be incorporated into the clinical routine at this time. Thus, the aim of this study was to review the role of genetic factors involved in the diagnosis and development of the different phenotypes of MDS.

Establishment and characterization of a rare atypical chronic myeloid leukemia cell line NT-1

Human leukemia cell lines are of great value in leukemia research. In this study, we established and described the biological characteristics of a rare atypical chronic myeloid (aCML) leukemia cell line (NT-1). Mononuclear cells were isolated from the bone marrow of a patient with atypical chronic myeloid leukemia (Ph(-)/bcr(-)/abl(-)), and were passaged by liquid culture. Cells were maintained without any cytokines for over 1 year, and named NT-1. This cell line was extensively characterized using morphological assays, flow cytometry, cytogenetic analysis, clonogenic culture, quantitative fluorescent PCR, short tandem repeating sequence PCR (STR-PCR) and array-CGH. Its tumorigenic capacity was also examined in nude mice. The NT-1 cell line had morphological features of chronic myeloid leukemia and major myeloid markers (CD13, CD33, CD11b). Additionally, NT-1 expressed progenitor cells and natural killer cell-related antigens such as CD34, CD117, CD56. Cytogenetic analysis initially demonstrated two abnormalities: 47, xx, +8 and 47, xx, +8 accompanied by t(5;12)(q31;p13) translocation. The one-year passage process did not alter the karyotype. NT-1 cells maintained the same morphology, immunophenotyping and cytogenetic features as primary leukemia cells, which was strongly supported by STR-PCR results. Neither Epstein-Barr virus nor mycoplasma was detected in the NT-1 line. In addition, NT-1 cells showed high tumorigenic capacity in nude mice. NT-1 is a new atypical chronic myeloid leukemia cell line with the +8 and t(5,12) translocation, and exhibits high tumorigenicity in nude mice. This new cell line provides a useful tool for the study of leukemogenesis.

The genetics of the myelodysplastic syndromes: Classical cytogenetics and recent molecular insights

Myelodysplastic syndromes (MDS) are a complex group of clonal hematopoietic disorders with an attendant diverse array of associated genetic changes. Conventional cytogenetics plays a prominent and well-established role in determining the contemporary diagnosis and prognosis of these disorders. More recently, molecular approaches have been useful in further characterizing this group of diseases, albeit in a largely experimental context, with the detection of changes at the single gene level including mutations, amplification and epigenetic phenomena. Nevertheless, we remain largely ignorant of the genetic underpinnings of MDS. Here we briefly review the established role of cytogenetics in MDS, and emphasize recent advances in unraveling the genetics of MDS, with a view towards how such findings might facilitate our ability to understand, diagnose and treat these disorders in a more rational manner.

Review of therapeutic options and the management of patients with myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a poorly understood group of disorders caused by one or more genetic aberrations in the bone marrow-derived cell line responsible for hematopoiesis. Recent advances in genetic medicine have offered new insights into the epigenesis as well as the prognosis of MDS, but have not resulted in new or improved curative treatment options. Bone marrow transplantation, introduced before the advent of genetic medicine, is still the only potential cure. Advances in other medical and pharmaceutical areas have broadened the scope of supportive care and disease-modifying therapies, and treating physicians now have a broad range of disease management options depending on a patient's likely prognosis. There is now clear evidence that appropriate supportive care and therapeutic intervention can improve progression-free and overall survival of MDS patients.

Pleomorphic adenoma gene-like 2 regulates expression of the p53 family member, p73, and induces cell cycle block and apoptosis in human promonocytic U937 cells

The proto-oncogene, pleomorphic adenoma gene-like 2 (PLAGL2), is implicated in a variety of cancers including acute myeloid leukemia (AML), malignant glioma, colon cancer, and lung adenocarcinoma. There is additional evidence that PLAGL2 can function as a tumor suppressor by initiating cell cycle arrest and apoptosis. Interestingly, PLAGL2 has also been implicated in human myelodysplastic syndrome, a disease that is characterized by ineffective hematopoiesis and can lead to fatal cytopenias (low blood counts) as a result of increased apoptosis in the marrow, or, in about one-third of cases, can progress to AML. To gain a better understanding of the actions of PLAGL2 in human myeloid cells, we generated a stable PLAGL2-inducible cell line, using human promonocytic U937 cells. PLAGL2 expression inhibited cell proliferation which correlated with an accumulation of cells in G1, apoptotic DNA-laddering, an increase in caspase 3, 8, and 9 activity, and a loss of mitochondrial transmembrane potential. There was significant increase in the p53 homologue, p73, with PLAGL2 expression, and consistent with mechanisms of p73-regulated cell cycle control and apoptosis, there was increased expression of known p73 target genes p21, DR5, TRAIL, and Bax. PLAGL2-induced cell cycle block was abolished in the presence of p73 siRNA. Together, these data support a role for PLAGL2 in cell cycle regulation and apoptosis via activation of p73.

Myelodysplastic syndrome and histone deacetylase inhibitors: "to be or not to be acetylated"?

Myelodysplastic syndrome (MDS) represents a heterogeneous group of diseases with clonal proliferation, bone marrow failure and increasing risk of transformation into an acute myeloid leukaemia. Structured guidelines are developed for selective therapy based on prognostic subgroups, age, and performance status. Although many driving forces of disease phenotype and biology are described, the complete and possibly interacting pathogenetic pathways still remain unclear. Epigenetic investigations of cancer and haematologic diseases like MDS give new insights into the pathogenesis of this complex disease. Modifications of DNA or histones via methylation or acetylation lead to gene silencing and altered physiology relevant for MDS. First clinical trials give evidence that patients with MDS could benefit from epigenetic treatment with, for example, DNA methyl transferase inhibitors (DNMTi) or histone deacetylase inhibitors (HDACi). Nevertheless, many issues of HDACi remain incompletely understood and pose clinical and translational challenges. In this paper, major aspects of MDS, MDS-associated epigenetics and the potential use of HDACi are discussed.

Internuclear chromosome distribution of dysplastic megakaryocytes in myelodysplastic syndromes is dependent on the level of ploidy

Megakaryopoiesis is largely disturbed in myelodysplastic syndromes (MDS), and megakaryocytes (MKs) frequently show multinucleation. Here, we investigated dysplastic mono-, bi-, and multinuclear MKs (n = 169) of seven patients with MDS and one patient with myelodysplastic/myeloproliferative neoplasm by sequential multilocus FISH. Analysis of binuclear MKs with a combined DNA content of 4 N (n = 46) indicated a significantly even (symmetric) chromosome distribution between the two separate nuclei (p = 0.0223), which suggests bipolar spindle orientation and symmetric chromosome segregation during the first endomitotic cell cycle. In contrast, multinuclear MKs of higher ploidy (>4 N, n = 108) demonstrated a significantly uneven (asymmetric) chromosome distribution between the separate nuclei (p = 0.0248). Thus, the internuclear chromosomal distribution of dysplastic MKs depends on the level of ploidy. In addition, centrosomal aberrations were not found in dysplastic MKs. Our results indicate that megakaryocytic multinucleation in MDS originates from dysregulated endomitosis, including restoration of karyokinesis.

Cytogenetic evolution correlates with poor prognosis in myelodysplastic syndrome

Clonal chromosomal abnormalities are observed in 30-50% of primary myelodysplastic syndrome (MDS) patients. Although the prognostic relevance of cytogenetics is generally appreciated, the prognostic value of cytogenetic evolution has rarely been evaluated. In this study, we retrospectively analyzed cytogenetic features at diagnosis and during follow-up in 85 patients with primary MDS. Cytogenetic evolution occurred in 18 of the 85 patients (21%), with chromosomes 8, 5, and 1 most often involved. Patients with higher levels of marrow blasts (P = 0.034), more advanced stages of World Health Organization (WHO) subtypes (44% vs. 16%, P = 0.035), and higher risk International Prognostic Scoring System (IPSS) subgroups (47% vs. 16%, P = 0.021) had higher incidences of developing cytogenetic evolution. Furthermore, the median survival of patients in the group with cytogenetic evolution was 25.8 months, compared with 45.4 months for patients in the group without cytogenetic evolution (P = 0.01). The same result was also found for time to progression: patients with cytogenetic evolution progressed more rapidly than those without cytogenetic evolution (P = 0.007). Knowledge of cytogenetic evolution offers useful information for clinicians to make more accurate prognostic assessments for patients with MDS.

Comparative analysis of remission induction therapy for high-risk MDS and AML progressed from MDS in the MDS200 study of Japan Adult Leukemia Study Group

A total of 120 patients with high-risk myelodysplastic syndrome (MDS) and AML progressed from MDS (MDS-AML) were registered in a randomized controlled study of the Japan Adult Leukemia Study Group (JALSG). Untreated adult patients with high-risk MDS and MDS-AML were randomly assigned to receive either idarubicin and cytosine arabinoside (IDR/Ara-C) (Group A) or low-dose cytosine arabinoside and aclarubicin (CA) (Group B). The remission rates were 64.7% for Group A (33 of 51 evaluable cases) and 43.9% for Group B (29 out of 66 evaluable cases). The 2-year overall survival rates and disease-free survival rates were 28.1 and 26.0% for Group A, and 32.1 and 24.8% for Group B, respectively. The duration of CR was 320.6 days for Group A and 378.7 days for Group B. There were 15 patients who lived longer than 1,000 days after diagnosis: 6 and 9 patients in Groups A and B, respectively. However, among patients enrolled in this trial, intensive chemotherapy did not produce better survival than low-dose chemotherapy. In conclusion, it is necessary to introduce the first line therapy excluding the chemotherapy that can prolong survival in patients with high-risk MDS and MDS-AML.

Update on genetic and molecular markers associated with myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms defined by morphologic dysplasia, peripheral cytopenia and clonal instability with enhanced risk of transformation into acute myeloid leukemia. The prognosis and clinical picture in MDS vary depending on patient-related factors (age, gender, comorbidity), the disease variant, cell types affected and genes involved in the malignant process. In fact, more and more data suggest that cytogenetic and molecular defects and gene variants are associated with the clinical course and prognosis in MDS. Although certain molecular defects are indicative of distinct cytogenetic abnormalities, others represent point mutations in critical target genes (RUNX1, N-RAS, JAK2, KIT, others) and sometimes are associated with a particular type of MDS, an overlap disease, a co-existing hematopoietic neoplasm or disease progression. Although most are somatic mutations, germ line mutations and gene polymorphisms have also been described in MDS. Some of these mutations may influence the natural course of disease, iron accumulation or disease progression. The present article provides a summary of our current knowledge about molecular and genetic markers in MDS, with special reference to their potential prognostic and therapeutic implications.

Granulocytic Sarcoma of the Ovotestis: An Association of Myelodysplastic Syndrome and Hermaphroditism

Granulocytic sarcomas are extramedullary tumors (EMD) of malignant myeloid precursor cells. EMD or granulocytic sarcoma of ovary is rare disease. A 15-year-old girl had complaints of abdominal pain and weight loss for 3 months. On physical examination, there were hepatosplenomegaly and a painless mass under the umbilicus. Breast development was grade II. There was no clitoris hypertrophy. Her labia majora were separate and vagina hypoplastic. Hemoglobin level was 9.3 g/dl, white blood cells count 2.8 x 10(6)/1, platelet count 31.6 x 10(9)/1. There were dysplastic features in the blood and bone marrow cells. There were 10 and 22% blasts in the peripheral blood smear and bone marrow, respectively. The levels of serum follicle stimulating and luteinizing hormones were high. An inguinal mass (diameter 9.5 x 7.6) cm was detected on computed tomography. The histopathological diagnosis of this was obtained from laporascopy was composed of ovotestis and there was marked blastic infiltration in this ovotestis which had myeloid markers on flow cytometry. In the immunohistochemical analyses of ovotestis and bone marrow, blasts were positive for LCA, CD-13, CD-33 and CD 68. The cytogenetic analysis of the bone marrow shaved 46 XY karyotype. No response was achieved with combination chemotherapy and the patient died from progressive leukemia. Here we report a rare patient with myelodysplastic syndrome, EMD and hermaphroditism. To our knowledge this is the first case of MDS, EMD and hermaphroditism.

Diagnostic challenges in the myelodysplastic syndromes: the current and future role of genetic and immunophenotypic studies

Myelodysplastic syndromes (MDS) comprise a clinically and pathologically diverse collection of hematopoietic neoplasms, most commonly presenting with peripheral cytopenias typically in the context of bone marrow hypercellularity. Mechanistically, at least in the early phases of the disease, this apparently paradoxical picture is primarily due to ineffective hematopoiesis, which is accompanied by a variety of morphologic abnormalities in hematopoietic cells. The identification of recurrent, clinically relevant cytogenetic defects in MDS has spurred the research of molecular mechanisms that contribute to its inception as well as to the development of heterogeneous subtypes. Although conventional cytogenetic analyses remain a diagnostic mainstay in MDS, the application of contemporary techniques including molecular cytogenetics, microarray technologies and multiparametric flow cytometry may ultimately reveal new diagnostic parameters that are theoretically more objective and sensitive than current morphologic approaches. This review aims to outline the role of genetic and immunophenotypic studies in the evaluation of MDS, including findings that may potentially influence future diagnostic classifications, which could refine prognostication and ultimately facilitate the growth of targeted therapies.

Myelodysplastic syndromes: diagnosis and staging

Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematologic disorders characterized by ineffective hematopoiesis and an increased risk of developing acute myelogenous leukemia (AML). Accurate diagnosis of MDS can be difficult, and its classification requires evaluation of cytopenias, bone marrow morphology, blast percentage, and cytogenetics. These factors, as well as patient performance status and red blood cell transfusion dependence, can be used to predict prognosis in MDS. Accurate diagnosis and classification are essential for subgroup identification and prognostic assessment of patients with MDS. This article reviews essential criteria for staging and subgroup classification and summarizes prognostic scoring systems that aid in risk stratification and selection of optimal therapy. Classification systems such as the World Health Organization (WHO) classification are widely used but do not always provide sufficient prognostic information. This limitation led to the creation of the International Prognostic Scoring System (IPSS). However, this system was designed to be used only at diagnosis and may not be suitable for serial assessment of patients whose disease can evolve over time. The WHO classification-based prognostic scoring system (WPSS) permits dynamic estimation of survival and risk of AML transformation at multiple time points during the natural course of MDS. Prognostic scoring systems such as WPSS allow for prediction of survival and risk of leukemic evolution at any time during the course of the disease. Such an approach may provide a useful adjunct for clinical decision making, including selection of appropriate treatment options.

Establishment and characterization of a new human acute myelocytic leukemia cell line SH-2 with a loss of Y chromosome, a derivative chromosome 16 resulting from an unbalanced translocation between chromosomes 16 and 17, monosomy 17, trisomy 19, and p53 alteration

OBJECTIVE

To report here a new acute myelocytic leukemia (AML) cell line SH-2 and describe its biological characteristics.

MATERIALS AND METHODS

Mononuclear cells isolated from a patient with AML-M2 subtype were passaged by liquid culture medium. Interleukin-3 and bone marrow stromal cells were used to support cell proliferation at the first 3 months. Various methods, including cytogenetic analysis, fluorescence in situ hybridization (FISH), multiplex FISH (M-FISH), reverse transcriptase polymerase chain reaction (RT-PCR), multiplex RT-PCR, short tandem repeat (STR)-PCR, direct sequencing of DNA, clonogenic assay, and tumorigenicity in nude and severe combined immunodeficient (SCID) mice were employed to identify and characterize SH-2 cell line.

RESULTS

SH-2 cells were maintained without cytokine and stromal cells for 3 years. It had no Epstein-Barr virus or mycoplasma contamination. The SH-2 cell line showed typical myelocytic features in morphology and simultaneous strongly expressed myeloid antigens (CD13, 99.6% and CD33, 99.26%) and natural killer (NK)-related antigens (CD56, 99.5% and CD16/56, 99.62%) suggesting that SH-2 is an AML cell line with NK-antigen expression. SH-2 cell line initially showed a karyotype of 45, X, -Y, der(16)t(16;17)(q24;q12), -17, +19. During the passage period, the cells with a hypodiploid karyotype gradually decreased and were replaced by the near-tetraploid cells with a karyotype of 71-105(86), XX, -Y, -Y, der(16)t(16;17)x2, -17, -17, +19, +19. FISH and M-FISH delineated all abnormalities. SH-2 cells had the approximately same morphological, immunophenotypical, and cytogenetic features as the patient's leukemia cells had. STR-PCR provided powerful evidence for the derivation of SH-2 cell line from the patient's leukemia cells. SH-2 cells showed multiple drug resistance (MDR), which may be related to the p53 gene alteration, including the loss of one p53 allele due to the monosomy 17 and a point mutation of CAG to CAT at codon 576 of exon 5 in another p53 allele resulting in the loss of p53 gene function. In addition, SH-2 cell line did not express MDR-related genes, such as MDR1, multidrug resistance-related protein, and lung resistance protein, but expressed apoptosis-related genes, such as Bcl-2, Fas, glutathione S-transferase-pi, and p21, which were also related to the MDR. SH-2 cell line had tumorigenic capacities in nude and SCID mice.

CONCLUSION

Because SH-2 cell line had a clear biology background, it will provide a useful tool for the study of the pathogenesis and treatment strategy of AML with MDR.

Risk factor analysis in myelodysplastic syndrome patients with del(20q): prognosis revisited

The deletion of the long arm of chromosome 20, or del(20q), is a common cytogenetic abnormality in various myeloid disorders and is known to be a favorable prognostic factor in myelodysplastic syndromes (MDS) when it is the sole change. However, del(20q) occurs with one or more cytogenetic changes when it is associated with disease progression. Here, we analyzed 33 patients with MDS and del(20q) to ascertain the risk factors in MDS. We categorized del(20q) into two groups: one with the del(20q) clone (> or =50% marrow metaphases), corresponding to genomic integrity, and the other with a late appearance of a minor del(20q) clone (<50% metaphases) with additional cytogenetic changes, representing genomic instability. Of the MDS patients with del(20q) at initial presentation, the negative factors in predicting prognosis on survival are (i) INT-2/High risk according to the International Prognostic Scoring System, (ii) any additional cytogenetic changes, or (iii) minor del(20q) clone. The late appearance of del(20q) at any phase is linked to a significantly unfavorable prognosis, thus indicating the clinical and biological heterogeneity of del(20q) in MDS.

Clonal karyotype evolution involving ring chromosome 1 with myelodysplastic syndrome subtype RAEB-t progressing into acute leukemia

Karyotypic evolution is a well-known phenomenon in patients with malignant hematological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hematological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes [46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome [46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hematological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease.

Cytogenetic aspects of adult primary myelodysplastic syndromes: Clinical implications

Myelodysplastic syndrome (MDS) is a heterogeneous disease from the clinical, biological and morphological point of view. The pathogenesis of MDS is not well established and it appears to occur complex changes in the stem cell biology. Clonal chromosomal aberrations are found in 30-50% of primary MDS and no specific cytogenetic abnormality has as yet been defined. The chromosomal abnormalities are predominantly characterized by partial/total chromosomal losses or chromosomal gains. These chromosomal abnormalities include mainly -5/del(5q), -7/del(7q), del(11q), del(12p), del(20q), -Y, and +8. The role of cytogenetic analysis in the diagnosis, prognosis, taking treatment decisions and follow up of patients with MDS has been clearly defined. Despite its difficulties in obtaining for analysis high quality metaphases conventional cytogenetics continues to be the basic technique for cytogenetic evaluation of a MDS patient. Other molecular cytogenetic methods have been shown to be complementary, without replacing the information obtained with this technique. Further investigations with both conventional and molecular cytogenetics in relation to clinical features as well as other molecular methods will undoubtedly contribute to improve understanding of the underlying genetic events responsible for the development and evolution of MDS leading to more accurate classification and management of MDS patients.

Additional cytogenetic changes and previous genotoxic exposure predict unfavorable prognosis in myelodysplastic syndromes and acute myeloid leukemia with der(1;7)(q10;p10)

We analyzed 23 patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) showing a der(1;7)(q10;p10) [hereafter der(1;7)] to identify the exact predictive factor of this cytogenetic change. Eight (34.8%) patients, including six with MDS and two with AML patients, had a previous history of genotoxic exposure, especially radiation and/or antimetabolites. Patients with der(1;7) consisted of three groups: one third of patients had a previous history of genotoxic agents, one third had additional cytogenetic changes at the time of MDS/AML diagnosis without previous exposure history, and the remaining one third had neither a previous exposure history nor additional cytogenetic changes. The current study demonstrated that the poor outcome of MDS/AML with der(1;7) is caused by the high frequency of associated risk factors (i.e., previous history of genotoxic exposure, the presence of additional cytogenetic changes, or both). Identification of prognostic disadvantage might be required for applying the appropriate strategy in managing MDS/AML patients with rare der(1;7) abnormality.

Absence of p16 and p27 gene rearrangements and mutations in de novo myelodysplastic syndromes

Myelodysplastic syndromes (MDS) represent a group of clonal hematopoietic disorders characterized by dyshemopoiesis and frequent evolution to acute leukemia. Tumor suppressor gene inactivation may be involved in MDS pathogenesis. The two families of cyclin-dependent kinase inhibitors (CDKIs) (INK4 family of p15, p16, p18 and p19 and CIP/KIP family of p21, p27 and p57) that negatively regulate cell cycle progression are known tumor suppressor genes. To determine whether genetic alterations of p16 and p27 genes play an important role in MDS pathogenesis, we examined DNA from 51 patients classified as 17 refractory anemias (RA), four refractory anemias with ringed sideroblasts (RARS), 19 refractory anemias with an excess of blasts (RAEB), 5 refractory anemias with excess of blasts in transformation (RAEB-t) and 6 chronic myelomonocytic leukemias (CMML). Southern blot analysis detected no homozygous deletions of p16 and p27. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing did not reveal point mutations for both genes with the exception of two allelic polymorphisms, namely a C --> G transition at 447 bp of p16exon3 and a T --> A transition at 791 bp of p27exon1 genes. Our results suggest that mutations of p16 and p27 genes resulting in abnormal p16 and p27 proteins do not represent a mechanism of gene inactivation involved in the pathogenesis of MDS.

Genotoxicity and sister chromatid exchange in patients with myelodysplastic disorders

In this study, we aimed to evaluate genotoxicity by sister chromatid exchange frequency in the peripheral lymphocytes of patients with myelodysplastic syndrome (MDS). The study population consisted of 16 patients (females/males:6/10; mean age: 61.68 +/- 13.08 years) diagnosed with "refractory anemia" according to FAB classification. The results were compared with an age- and sex-matched control group. The sister chromatid exchange frequency in the study group was found to be significantly higher than the control group (8.3 +/- 11 vs. 6.83 +/- 1.07, P=0.0046). We suggest that increased DNA damage, which is revealed by the increased sister chromatid exchange in the present study may play a role in the etiopathogenesis of MDS.

Epigenetic and chromatin modifiers as targeted therapy of hematologic malignancies

Epigenetic regulation of gene expression is mediated through alterations in the DNA methylation status, covalent modifications of core nucleosomal histones, rearrangement of histones, and by RNA interference. It is now abundantly clear that deregulation of epigenetic mechanisms cooperates with genetic alterations in the development and progression of cancer and leukemia. Epigenetic deregulation affects several aspects of tumor cell biology, including cell growth, cell cycle control, differentiation, DNA repair, and cell death. This raises the strong possibility that reversing deregulated epigenetic mechanisms may be an effective treatment strategy for leukemia and cancer. This treatment strategy may either be designed to separately or collectively target the specific perturbations in the epigenetic mechanisms found in human hematologic malignancies. The following review describes our current understanding of the important deregulated epigenetic mechanisms and the preclinical and clinical development of epigenetic and chromatin modifiers in the therapy of these disorders.

Simultaneous demonstration of clonal chromosome abnormalities and apoptosis in individual marrow cells in myelodysplastic syndrome

Bone marrow samples from 18 patients with myelodysplastic syndrome (MDS) with clonal cytogenetic abnormalities were characterized by combining fluorescence in situ hybridization (FISH) with in situ end-labeling (ISEL) or with annexin V staining and flow cytometry (AV/FLOW) to determine the clonal nature of hematopoietic cells undergoing apoptosis in marrow cells. Apoptosis occurred in both normal and clonal cells. However, the proportion of clonal cells identified by FISH among apoptotic cells was lower than the proportion among nonclonal cells in 17 of 18 patients, regardless of whether ISEL or AV/ FLOW was used to identify apoptosis. This technique allows us to identify simultaneously clonality (as determined by FISH) and apoptosis in individual cells and shows that although apoptosis occurs predominantly in residual normal (FISH-negative) cells, a proportion of clonal precursors in MDS marrow also die from programmed cell death. Such a mechanism may be responsible for the generally slow expansion of the clone in MDS.

Several chromosomes involved in translocations with chromosome 5 shown with fluorescence in situ hybridization in patients with malignant myeloid disorders

In many patients with myelodysplastic syndromes or acute myeloid leukemia, complex chromosome aberrations can be seen, among which aberrations of chromosome 5 constitute a substantial part. With conventional cytogenetic technique, these aberrations are often identified as deletions or monosomy 5. We analyzed nine patients who, under conventional cytogenetic analysis, showed deletion or monosomy 5. We used fluorescence in situ hybridization with whole-chromosome painting probes to identify the counterpart chromosome and locus-specific identifiers for 5q31 and 5q33 approximately q34. A deletion of 5q was found concomitant with unbalanced translocations. Our results and cases from the literature showed that material from chromosome 5 could be translocated to almost all chromosomes. All patients but one had short survival; this one patient had a preserved 5q31 and 5q33 approximately q34 but a deletion of the q-arm more centromeric than these bands. In eight of the nine patients, further 14 translocations were revealed, not involving chromosome 5.

Myelodysplasia and Radiation

Reasons are given why myelodysplasia should be considered in any assessment in humans of radiation exposure as an etiological factor for the development of leukemia.

Dermatomyositis and myelodysplastic syndrome with myelofibrosis responding to methotrexate therapy

Dermatomyositis (DM) has not yet been reported as a complication of myelodysplastic syndrome (MDS). A 50-year-old man was diagnosed as having MDS because of the presence of anemia, the appearance of immature cells in peripheral blood, and the abnormal cellular morphology. A few months later, high fever, myalgia and erythema developed. Although DM symptoms were resistant to high-dose corticosteroid administration, methotrexate (MTX) therapy improved not only the symptoms of DM but also hematologic findings related to MDS. This indicates that immunosuppressive therapy including MTX administration can be useful for patients with MDS with autoimmune symptoms.

Cloning and characterization of a gene expressed during terminal differentiation that encodes a novel inhibitor of growth

We report here the cloning and initial characterization of a novel growth-related gene (EEG-1) that is located on the short arm of chromosome 12. Two spliced transcripts were cloned from human bone marrow and human erythroid progenitor cells: EEG-1L containing a 4350-nucleotide open reading frame encoding a putative protein of 1077 amino acids including a C1q-like globular domain, and an alternatively spliced transcript lacking exon 5 (EEG-1S) encodes a significantly smaller coding region and no C1q-like domain. Quantitative PCR revealed expression of both EEG-1 transcripts in all analyzed tissues. Plasmids encoding green fluorescent protein-tagged genes (GFP-EEG-1) were transfected into Chinese hamster ovary cells for localization and functional assays. In contrast to the diffuse cellular localization of the GFP control, GFP-EEG-1L was detected throughout the cytoplasm and excluded from the nucleus, and GFP-EEG-1S co-localized with aggregated mitochondria. Transfection of both isoforms was associated with significantly increased levels of apoptosis. Stable transfection assays additionally demonstrated decreased growth in those cells expressing EEG-1 at higher levels. Quantitative PCR analyses of mRNA obtained from differentiating erythroid cells from blood donors were performed to determine the transcriptional pattern of EEG-1 during erythropoiesis. EEG-1 expression was highly regulated with increased expression at the stage of differentiation associated with the onset of global nuclear condensation and reduced cell proliferation. We propose that the regulated expression of EEG-1 is involved in the orchestrated regulation of growth that occurs as erythroblasts shift from a highly proliferative state toward their terminal phase of differentiation.

Wilms tumor gene peptide-based immunotherapy for patients with overt leukemia from myelodysplastic syndrome (MDS) or MDS with myelofibrosis

The Wilms tumor gene, WT1, is overexpressed not only in leukemias and myelodysplastic syndrome (MDS) but also in various types of solid tumors, including lung and breast cancer, and the WT1 protein is a tumor antigen for these malignancies. In clinical trials of WT1 peptide-based cancer immunotherapy, patients with overt leukemia from MDS or MDS with myelofibrosis were injected intradermally with 0.3 mg of an HLA-A*2402-restricted, 9-mer WT1 peptide emulsified with Montanide ISA51 adjuvant. Only a single dose of WT1 vaccination resulted in an increase in WT1-specific cytotoxic T-lymphocytes, which was followed by a rapid reduction in leukemic blast cells. Severe leukopenia and local erythema at the injection sites of WT1 peptide were observed as adverse effects. These results have provided us with the first clinical evidence suggesting that WT1 peptide-based immunotherapy is an attractive treatment for patients with leukemias or MDS.

Pure red cell aplasia developing into myeloproliferation with myelodysplasia and subsequent leukemia after cyclosporin A therapy

We describe a very rare case of a patient who presented with red cell aplasia that later developed into myeloproliferation with myelodysplasia and eventually leukemia. A 63-year-old man presented with anemia and reticulocytopenia in May 1997. A bone marrow examination revealed erythroid aplasia with normal production of myeloid cells and megakaryocytes with a normal karyotype. After the diagnosis of pure red cell aplasia was made, the patient was treated with prednisolone and then with cyclosporin A (CyA). Two weeks after the initiation of CyA treatment, the peripheral reticulocyte count began to increase with a regrowth of erythroid cells in the bone marrow. Meanwhile, the peripheral white blood cell and platelet counts also increased to more than 10,000/microL and 1,000,000/microL, respectively. Examination of a bone marrow aspirate in December 1997 revealed myelodysplastic changes with trisomy 8. Despite the discontinuation of CyA and the administration of 1-beta-D-arabinofuranosylcytosine stearyl monophosphate, leukemia developed in August 1998. In September 1998, the patient died of sepsis during a neutropenic period that followed remission-induction therapy. In the mechanism of pathogenesis, CyA may induce upon pure red cell aplasia a secondary myeloproliferative disorder with myelodysplasia and leukemia. An alternative possibility is that CyA reduces autoimmune-mediated suppression of the underlying stem cell disorder and that the result of this reduction is the manifestation of myeloproliferation and leukemia.