FcRγ-deficient natural killer (NK) cells (g-NK cells) have been associated with cytomegalovirus (CMV) infection. However, the frequency of g-NK cells in a CMV-endemic area (i.e., Korea) has not yet been studied. We examined the frequency of g-NK cells and expression of CD57 on NK cells in cord blood (CB) and adult blood (AB).
Of the 24 AB samples collected, 95.8% (23/24) were CMV IgG+/IgM-, while 100% of the 13 healthy CB samples were CMV IgG+/IgM-. We performed whole-blood flow cytometry assays to analyze intracellular FcRγ and CD3ζ expression of CD3-/CD56dim NK cells from 13 CB and 24 AB samples, and surface CD57 expression on CD3-/CD56dim/CD16+ NK cells from 13 CB and 19 AB samples.
All CMV seropositive AB samples contained g-NK cells (23/23), and the median proportion of g-NK cells in the CD3-/CD56dim NK cell pool was 35.0% (range: 11-77%). CD57+ NK cells in the CD3-/CD56dim/CD16+ NK cell population were detected in all 19 AB samples tested, but not in any CB samples.
Our data suggest that g-NK cells and CD57+ NK cells are present at a very high frequency in CMV-seropositive AB, but rare in CMV-naïve CB.
Adult; Blood; Cord; Cytomegalovirus; Infection; FcRγ; Natural killer cell
Beroctocog alfa is a second generation recombinant factor VIII manufactured by removing the B-domain from factor VIII. This prospective clinical trial was conducted to evaluate the efficacy, safety, and pharmacokinetics of beroctocog alfa in patients of ages ≥12 years previously treated for severe hemophilia A.
Materials and Methods
Seventy subjects received beroctocog alfa as an on-demand treatment for acute hemorrhage.
The final hemostatic effect was excellent in 35 subjects (50%) and good in 26 subjects (37.1%). The drug showed an overall efficacy rate of 87.1%. The majority of acute hemorrhages was treated by administering the study drug once (86.2%) or twice (10.0%), and the mean dose administered per single infusion was 28.55±6.53 IU/kg. Ten subjects underwent 12 surgical procedures, and hemostatic efficacy was excellent in seven cases (58.3%) and good in five cases (41.7%), showing a 100% efficacy rate. A total of 52 of 88 subjects (59.0%) experienced 168 adverse events. There were 18 serious adverse events (10.7%) in 11 subjects, and two (mild dyspnea and facial edema) in one subject were related to the study drug. Only one subject formed a de novo factor VIII inhibitor, for an occurrence rate of 1.4% (one-sided 95% upper confidence limit: 3.85%). The final elimination half-life was 13.3 h and 12.6 h at baseline and 6 months after administration, respectively.
Our results suggest that beroctocog alfa is safe and efficacious as either an on-demand treatment for acute hemorrhage or a surgical prophylaxis in patients with hemophilia A.
Hemophilia A; factor VIII; B-domain-deleted factor VIII
Histone H3K9 methyltransferase (HMTase) G9a-mediated transcriptional repression is a major epigenetic silencing mechanism. UHRF1 (ubiquitin-like with PHD and ring finger domains 1) binds to hemimethylated DNA and plays an essential role in the maintenance of DNA methylation. Here, we provide evidence that UHRF1 is transcriptionally downregulated by H3K9 HMTase G9a. We found that increased expression of G9a along with transcription factor YY1 specifically represses UHRF1 transcription during TPA-mediated leukemia cell differentiation. Using ChIP analysis, we found that UHRF1 was among the transcriptionally silenced genes during leukemia cell differentiation. Using a DNA methylation profiling array, we discovered that the UHRF1 promoter was hypomethylated in samples from leukemia patients, further supporting its overexpression and oncogenic activity. Finally, we showed that G9a regulates UHRF1-mediated H3K23 ubiquitination and proper DNA replication maintenance. Therefore, we propose that H3K9 HMTase G9a is a specific epigenetic regulator of UHRF1.
Recurrent somatic SET-binding protein 1 (SETBP1) and splicing pathway gene mutations have recently been found in atypical chronic myeloid leukemia and other hematologic malignancies. These mutations have been comprehensively analyzed in adult AML, but not in childhood AML. We investigated possible alteration of the SETBP1, splicing factor 3B subunit 1 (SF3B1), U2 small nuclear RNA auxiliary factor 1 (U2AF1), and serine/arginine-rich splicing factor 2 (SRSF2) genes in childhood AML.
Cytogenetic and molecular analyses were performed to reveal chromosomal and genetic alterations. Sequence alterations in the SETBP1, SF3B1, U2AF1, and SRSF2 genes were examined by using direct sequencing in a cohort of 53 childhood AML patients.
Childhood AML patients did not harbor any recurrent SETBP1 gene mutations, although our study did identify a synonymous mutation in one patient. None of the previously reported aberrations in the mutational hotspot of SF3B1, U2AF1, and SRSF2 were identified in any of the 53 patients.
Alterations of the SETBP1 gene or SF3B1, U2AF1, and SRSF2 genes are not common genetic events in childhood AML, implying that the mutations are unlikely to exert a driver effect in myeloid leukemogenesis during childhood.
SETBP1; SF3B1; U2AF1; SRSF2; AML; Childhood
Despite the rapid improvement in survival rate from Burkitt lymphoma and mature B-cell lymphoblastic leukemia (B-ALL) in children, a small subset of patients do not respond to first-line chemotherapy or experience relapse (RL). Herein, we report the clinical characteristics and outcomes of these patients.
Materials and Methods
RL or refractory Burkitt lymphoma and mature B-ALL in 125 patients diagnosed from 1990 to 2009 were retrospectively analyzed.
Nineteen patients experienced RL or progressive disease (PD). Among them, 12 patients had PD or RL less than six months after initial treatment and seven had late RL. Seven patients achieved complete response (CR), 11 had PD, and one had no more therapy. Six patients who achieved CR survived without evidence of disease and four of them underwent high-dose chemotherapy (HDC) followed by stem cell transplantation (SCT). However, 11 patients who failed to obtain CR eventually died of their disease. Five-year overall survival (OS) was 31.6±10.7%. OS of patients with late RL was superior to that of patients with early RL (57.1±18.7%, vs. 16.7±10.8%, p=0.014). Achievement of CR after reinduction had significant OS (p < 0.001). OS for patients who were transplanted was superior (p < 0.01). In multivariate analysis, achievement of CR after reinduction chemotherapy showed an association with improved OS (p=0.05).
Late RL and chemotherapy-sensitive patients have the chance to achieve continuous CR using HDC/SCT, whereas patients who are refractory to retrieval therapy have poor prognosis. Therefore, novel salvage strategy is required for improvement of survival for this small set of patients.
Burkitt lymphoma; Recurrence; Children
This study investigated the profiling of polycyclic aromatic hydrocarbon- (PAH-) induced genotoxicity in cell lines and zebrafish. Each type of cells displayed different proportionality of apoptosis. Mitochondrial DNA (mtDNA) copy number was dramatically elevated after 5-day treatment of fluoranthene and pyrene. The notable deregulated proteins for PAHs exposure were displayed as follows: lamin-A/C isoform 3 and annexin A1 for benzopyrene; lamin-A/C isoform 3 and DNA topoisomerase 2-alpha for pentacene; poly[ADP-ribose] polymerase 1 (PARP-1) for fluoranthene; and talin-1 and DNA topoisomerase 2-alpha for pyrene. Among them, lamin-A/C isoform 3 and PARP-1 were further confirmed using mRNA and protein expression study. Obvious morphological abnormalities including curved backbone and cardiomegaly in zebrafish were observed in the 54 hpf with more than 400 nM of benzopyrene. In conclusion, the change of mitochondrial genome (increased mtDNA copy number) was closely associated with PAH exposure in cell lines and mesenchymal stem cells. Lamin-A/C isoform 3, talin-1, and annexin A1 were identified as universal biomarkers for PAHs exposure. Zebrafish, specifically at embryo stage, showed suitable in vivo model for monitoring PAHs exposure to hematopoietic tissue and other organs.
The aim of this study was to characterize Korean patients with Fanconi anemia (FA), which is a rare but very challenging genetic disease.
The medical records of 12 FA patients diagnosed at Chonnam National University Hospital from 1991 to 2012 were retrospectively reviewed.
The median age at diagnosis was 6.2 years. All patients showed evidence of marrow failure and one or more physical stigmata. Chromosome breakage tests were positive in 9 out of 11 available patients. The median follow-up duration was 69.5 months. The Kaplan-Meier (KM) survival of all patients was 83.3% at 10 years and 34.7% at 20 years, respectively. Seven patients underwent 9 stem cell transplantations (SCTs). Among them, 5 were alive by the end of the study. Ten-year KM survival after SCT was 71.4% with a median follow-up of 3.4 years. All 5 patients treated with supportive treatment alone died of infection or progression at the median age of 13.5 years, except for one with short follow-up duration. Acute leukemia developed in 2 patients at 15.4 and 18.1 years of age. Among 6 patients who are still alive, 3 had short stature and 1 developed insulin-dependent diabetes mellitus.
We provide information on the long-term outcomes of FA patients in Korea. A nation-wide FA registry that includes information of the genotypes of Korean patients is required to further characterize ethnic differences and provide the best standard of care for FA patients.
Fanconi anemia; Korean; Stem cell transplantation; Long-term outcome
SUV39H1 is a histone 3 lysine 9 (H3K9)-specific methyltransferase that is important for heterochromatin formation and the regulation of gene expression. Chaetocin specifically inhibits SUV39H1, resulted in H3K9 methylation reduction as well as reactivation of silenced genes in cancer cells. Histone deacetylase (HDAC) inhibitors inhibit deacetylases and accumulate high levels of acetylation lead to cell cycle arrest and apoptosis. In this study, we demonstrated that treatment with chaetocin enhanced apoptosis in human leukemia HL60, KG1, Kasumi, K562, and THP1 cells. In addition, chaetocin induced the expression of cyclin-dependent kinase inhibitor 2B (p15), E-cadherin (CDH1) and frizzled family receptor 9 (FZD9) through depletion of SUV39H1 and reduced H3K9 methylation in their promoters. Co-treatment with chaetocin and HDAC inhibitor trichostatin A (TSA) dramatically increased apoptosis and produced greater activation of genes. Furthermore, this combined treatment significantly increased loss of SUV39H1 and reduced histone H3K9 trimethylation responses accompanied by increased acetylation. Importantly, co-treatment with chaetocin and TSA produced potent antileukemic effects in leukemia cells derived from patients. These in vitro findings suggest that combination therapy with SUV39H1 and HDAC inhibitors may be of potential value in the treatment of leukemia.
Histone Methyltransferase; Histone Deacetylase; Tumor Suppressor Genes; Leukemia
Histone lysine methylation and demethylation are considered critical steps in transcriptional regulation. In this report, we performed chromatin immunoprecipitation with microarray technology (ChIP-chip) analysis to examine the genome-wide occupancy of H3K9-me2 during all-trans-retinoic acid (ATRA)-induced differentiation of HL-60 promyelocytic leukemia cells. Using this approach, we found that KDM3B, which contains a JmjC domain, was downregulated during differentiation through the recruitment of a corepressor complex. Furthermore, KDM3B displayed histone H3K9-me1/2 demethylase activity and induced leukemogenic oncogene lmo2 expression via a synergistic interaction with CBP. Here, we found that KDM3B repressed leukemia cell differentiation and was upregulated in blood cells from acute lymphoblastic leukemia (ALL)-type leukemia patients. The combined results of this study provide evidence that the H3K9-me1/2 demethylase KDM3B might play a role in leukemogenesis via activation of lmo2 through interdependent actions with the histone acetyltransferase (HAT) complex containing CBP.
The repopulating lymphocytes after allogeneic hematopoietic stem cell transplantation have an important role not only on the prevention of serious infections in the early transplantation period, but also on the killing of residual leukemic cells by graft-versus-leukemia effect. The aim of this study was to analyze the impact of lymphocyte recovery after allogeneic stem cell transplantation in children with hematologic malignancies.
Materials and Methods
We evaluated 69 children transplanted for acute lymphoblastic leukemia (ALL) (n=34), acute myeloid leukemia (AML) (n=26), chronic leukemia (n=7) and juvenile myelomonocytic leukemia (n=2) between 1996 and 2008 at the Chonnam National University Hospital, Korea. The patients were grouped based on absolute lymphocyte counts (ALC) <500/µL or ≥500/µL at D+21 and D+30 after transplant.
Patients with a High ALC at D+21 and D+30 had a faster neutrophil and platelet engraftment. The High at D+30 group had a better 5 year overall survival (71% vs. 53%, p=0.043) and event-free survival (72% vs. 53%, p=0.065) than the Low at D+30 group. The incidence of grade II-IV acute and chronic graft-versus-host disease (GVHD), and relapse rate did not differ by the ALC counts. However, the Low at D+30 group had a significantly increased risk for transplant-related mortality (p=0.019). The univariate analysis showed that the factors associated with decreased survival were a Low ALC at D+30, patients with high risk ALL, and grade II-IV aGVHD in patients with ALL and AML.
Early posttransplant serial lymphocyte measurement would be a simple but useful method for predicting transplant outcomes.
Absolute lymphocyte count; allogeneic stem cell transplantation; children; leukemia
Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years.
The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study.
The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1±1.9 g/dL, mean corpuscular volume was 93.4±11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%).
The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.
Diamond Blackfan anemia; Anemia; Congenital defects
Aim of this study was to compare the outcomes of transplantation by donor source and to help select the best alternative donor in children with leukemia. Donor sources included matched related donor (MRD, n = 35), allele-matched unrelated donor (M-UD, n = 10) or -mismatched (MM)-UD (n = 13) or unrelated umbilical cord blood (UCB, n = 11). UCB group had a significantly higher incidence of grade II-IV acute graft versus host disease (MRD, 11.8%; M-UD, 30.0%; MM-UD, 15.4%, UCB, 54.4%, P = 0.004) but there was no difference in incidence of chronic graft versus host disease between 4 groups. The 5-yr leukemia-free survival (LFS) was 76.7%, 60.0%, 69.2%, and 45.5%, respectively (P = 0.128). MRD group showed higher LFS rate than UCB group (P = 0.022). However, LFS of M-UD and MM-UD together (65.2%) was not different from that of MRD group (76.7%, P = 0.325), or from that of UCB (45.5%, P = 0.190). The relapse incidence at 5 yr was 17.1%, 20.0%, 15.4%, and 0%, respectively (P = 0.460). The 100-day treatment-related mortality was 2.9%, 20.0%, 7.7%, and 36.4%, respectively (P = 0.011). Despite the limitations of small number of patients, unrelated donor transplants including even allele-mismatched ones, seem to be as effective in children with leukemia lacking suitable relative donors. Also, UCB transplant may serve as another possible option in urgent transplants.
Allogeneic Hematopoietic Stem Cell Transplantation; Leukemia; Unrelated Donor; Umbilical Cord Blood
This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and developed optimal profiles of leukemic fusion genes for multiplex RT-PCR. We prospectively analyzed blood and bone marrow specimens of patients with acute leukemia. Twenty types of chromosomal abnormalities were detected in 42% from all patients by commercially available multiplex RT-PCR for detecting 28 fusion genes and in 35% by cytogenetic analysis including FISH analysis. The most common cytogenetic aberrations in acute myeloid leukemia patients was PML/PARA, followed by AML1/MGT8 and MLL1, and in acute lymphoid leukemia patients was BCR/ABL, followed by TEL/AML1 and MLL1 gene rearrangement. Among the negative results for multiplex RT-PCR, clinically significant t(3;3)(q21;q26.2), t(8;14)(q24;q32) and i(17)(q10) were detected by conventional cytogenetics. The spectrum and frequency of chromosomal abnormalities in our leukemia patients are differed from previous studies, and may offer optimal profiles of leukemic fusion genes for the development of new molecular detection systems.
Leukemia; Chromosomal Abnormalities; Molecular Detection System
Acute internal hemorrhage is an occasionally life-threatening complication in pediatric cancer patients. Many therapeutic approaches have been used to control bleeding with various degrees of success. In this study, we evaluated the efficacy of selective internal iliac artery embolization for controlling acute intractable bleeding in children with malignancies.
We retrospectively evaluated the cases of 6 children with various malignancies (acute lymphoblastic leukemia, acute myelogenous leukemia, chronic myelogenous leukemia, T-cell prolymphocytic leukemia, Langerhans cell histiocytosis, and rhabdomyosarcoma), who had undergone selective arterial embolization (SAE) of the internal iliac artery at the Chonnam National University Hwasun Hospital between January 2004 and December 2009. SAE was performed by an interventional radiologist using Gelfoam® and/or Tornado® coils.
The patients were 5 boys and 1 girl with median age of 6.9 years (range, 0.7-14.8 years) at the time of SAE. SAE was performed once in 4 patients and twice in 2, and the procedure was unilateral in 2 and bilateral in 4. The causes of hemorrhage were as follows: hemorrhagic cystitis (HC) in 3 patients, procedure-related internal iliac artery injuries in 2 patients, and tumor rupture in 1 patient. Initial attempt at conservative management was unsuccessful. Of the 6 patients, 5 (83.3%) showed improvement after SAE without complications.
SAE may be a safe and effective procedure for controlling acute intractable hemorrhage in pediatric malignancy patients. This procedure may obviate the need for surgery, which carries an attendant risk of morbidity and mortality in cancer patients with critical conditions.
Therapeutic embolization; Pediatric patient; Neoplasms
Even though exposure to benzene has been linked to a variety of cancers including leukemia, the detailed molecular mechanisms relevant to benzene-induced carcinogenesis remain to be clearly elucidated. In this study, we evaluated the effects of benzene on differential gene expression in a leukemia cell line. The K562 leukemia cell line used in this study was cultured for 3 h with 10 mM benzene and RNA was extracted. To analyze the gene expression profiles, a 41,000 human whole genome chip was employed for cDNA microarray analysis. We initially identified 6,562 genes whose expression was altered by benzene treatment. Among these, 3,395 genes were upregulated and 3,167 genes were downregulated by more than 2-fold, respectively. The results of functional classification showed that the identified genes were involved in biological pathways including transcription, cell proliferation, the cell cycle, and apoptosis. These gene expression profiles should provide us with further insights into the molecular mechanisms underlying benzene-induced carcinogenesis, including leukemia.
Microarray; Benzene; Cell proliferation; Gene expression; Leukemia
A 7-year-old boy presented with hematochezia and abdominal pain. A 3.7-cm-sized mass was identified in the ascending colon by abdominal computed tomography and colonoscopy. The patient underwent surgical resection. Pathological examination revealed a low-grade perivascular epithelioid cell tumor (PEComa). PEComa in the colon is very rare. Only a few cases have been reported so far. An effective treatment method for this rare tumor has not been established yet. The patient received adjuvant interferon-α immunotherapy for 1 year. He has been tumor-free for 26 months since the initial diagnosis. This report is the first documented case of the use of interferon-α for pediatric PEComa of the colon.
Perivascular epithelioid cell tumor; PEComa; Colon; Interferon-alpha
The dynamic exchange of histone lysine methylation status by histone methyltransferases and demethylases has been previously implicated as an important factor in chromatin structure and transcriptional regulation. Using immunoaffinity TAP analysis, we purified the WHISTLE-interacting protein complexes, which include the heat shock protein HSP90α and the jumonji C-domain harboring the histone demethylase JMJD1C. In this study, we demonstrate that JMJD1C specifically demethylates histone H3K9 mono- and di-methylation, and mediates transcriptional activation. We also provide evidence suggesting that both WHISTLE and JMJD1C performs functions in the development of mouse testes by regulating the expression of the steroidogenesis marker, p450c17, via SF-1-mediated transcription. Furthermore, we demonstrate that WHISTLE is recruited to the p450c17 promoter via SF-1 and represses the transcription of prepubertal stages of steroidogenesis, after which JMJD1C replaces WHISTLE and activates the expression of target genes via SF-1-mediated interactions. Our results demonstrate that the histone methylation balance mediated by HMTase WHISTLE and demethylase JMJD1C perform a transcriptional regulatory function in mouse testis development.
The efficacy of tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) was investigated in patients with high-risk neuroblastoma. Patients over 1 yr of age who were newly diagnosed with stage 4 neuroblastoma from January 2000 to December 2005 were enrolled in The Korean Society of Pediatric Hematology-Oncology registry. All patients who were assigned to receive HDCT/ASCR at diagnosis were retrospectively analyzed to investigate the efficacy of single or tandem HDCT/ASCR. Seventy and 71 patients were assigned to receive single or tandem HDCT/ASCR at diagnosis. Fifty-seven and 59 patients in the single or tandem HDCT group underwent single or tandem HDCT/ASCR as scheduled. Twenty-four and 38 patients in the single or tandem HDCT group remained event free with a median follow-up of 56 (24-88) months. When the survival rate was analyzed according to intent-to-treat at diagnosis, the probability of the 5-yr event-free survival±95% confidence intervals was higher in the tandem HDCT group than in the single HDCT group (51.2±12.4% vs. 31.3±11.5%, P=0.030). The results of the present study demonstrate that the tandem HDCT/ASCR strategy is significantly better than the single HDCT/ASCR strategy for improved survival in the treatment of high-risk neuroblastoma patients.
Neuroblastoma; High-dose Chemotherapy; Transplantation, Autologous
Iron overload is a predictable and life-threatening complication in patients dependent on the regular transfusion of RBCs. The aims of this study were to investigate the efficacy and safety of deferiprone in a variety of pediatric hematologic and/or oncologic patients with a high iron overload.
Seventeen patients (age: 1.1-20.4 years; median: 10.6 years) from 7 hospitals who were treated with deferiprone from 2006 to 2009 were enrolled in this study. Medical records of enrolled patients were reviewed retrospectively.
Serum ferritin levels were 4,677.8±1,130.9 µg/L at baseline compared to 3,363.9±1,149.7 µg/L at the end of deferiprone treatment (P=0.033). Only 1 patient developed neutropenia as a complication.
Deferiprone treatment is relatively safe for pediatric patients suffering from various hematologic and oncologic diseases that require RBC transfusions as part of treatment. However, the potential development of critical complications such as agranulocytosis and/or neutropenia remains a concern.
Deferiprone; Iron overload; Transfusion; Neutropenia
We investigated the outcome of idarubicin plus N4-behenoyl-1-β-D-arabinofuranosyl cytosine (BHAC)-based chemotherapy (BHAC group, n=149) compared to idarubicin plus cytarabine-based chemotherapy (cytarabine group, n=191) for childhood acute myeloid leukemia (AML). Between January 1996 and December 2005, 340 children with AML from 5 university hospitals in Korea received the BHAC-based or cytarabine-based chemotherapy, with or without hematopoietic stem cell transplantation. After induction therapy, 264 (77.6%) of 340 children achieved a complete remission (CR) and 43 (12%) achieved a partial remission (PR). The CR rate in the BHAC group was higher than in the cytarabine group (85.2% vs. 71.7%, P=0.004). However, the overall response rate (CR+PR) was not different between the two groups (93.3% vs. 87.9%, P=0.139). The 5-yr estimates of overall survival (OS) of children in the two groups were similar (54.9% for the BHAC group vs. 52.4% for the cytarabine group, P=0.281). Although the results were analyzed according to the treatment type and cytogenetic risk, the OS showed no significant difference between the BHAC group and the cytarabine group. In the present study, the clinical outcomes of the BHAC-based chemotherapy, consisting of BHAC, idarubicin, and 6-TG, are comparable to that of the cytarabine-based chemotherapy for childhood AML.
Leukemia, Myeloid, Acute; Enocitabine; Childhood
Histone methylation is crucial for transcriptional regulation and chromatin remodeling. It has been suggested that the SET domain containing protein RE-IIBP (interleukin-5 [IL-5] response element II binding protein) may perform a function in the carcinogenesis of certain tumor types, including myeloma. However, the pathogenic role of RE-IIBP in these diseases remains to be clearly elucidated. In this study, we have conducted an investigation into the relationship between the histone-methylating activity of RE-IIBP and transcriptional regulation. Here, we report that RE-IIBP is up-regulated in the blood cells of leukemia patients, and we characterized the histone H3 lysine 27 (H3-K27) methyltransferase activity of RE-IIBP. Point mutant analysis revealed that SET domain cysteine 483 and arginine 477 are critical residues for the histone methyltransferase (HMTase) activity of RE-IIBP. RE-IIBP also represses basal transcription via histone deacetylase (HDAC) recruitment, which may be mediated by H3-K27 methylation. In the chromatin immunoprecipitation assays, we showed that RE-IIBP overexpression induces histone H3-K27 methylation, HDAC recruitment, and histone H3 hypoacetylation on the IL-5 promoter and represses expression. Conversely, short hairpin RNA-mediated knockdown of RE-IIBP reduces histone H3-K27 methylation and HDAC occupancy around the IL-5 promoter. These data illustrate the important regulatory role of RE-IIBP in transcriptional regulation, thereby pointing to the important role of HMTase activity in carcinogenesis.
X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the γc chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for γc chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the γc chain gene is useful for definite diagnosis and genetic counseling for X-SCID.
Severe Combined Immunodeficiency; Genetic Diseases, X-linked; Mutation; Genetic Counseling; Korea
Autologous stem cell transplantation (ASCT) for the treatment of high-risk neuroblastoma (NBL) is an accepted method for restoring bone marrow depression after high dose chemotherapy. We retrospectively analyzed eighty eight cases of NBL that underwent ASCT following marrow ablative therapy at 12 transplant centers of the Korean Society of Pediatric Hematology-Oncology between January 1996 and September 2000. Seventy nine children were of stage IV NBL and 9 were of stage III with N-myc amplification. Various cytoreductive regimens were used. However, the main regimen was 'CEM' consisting of carboplatin, etoposide and melphalan, and this was used in 66 patients. Total body irradiation was also added in 36 patients for myeloablation. To reduce tumor cell contamination, stem cell infusions after CD34+ cell selection were performed in 16 patients. Post-transplantation therapies included the second transplantation in 18 patients, interleukin2 therapy in 45, 13-cis retinoic acid in 40, 131-meta-iodobenzylguanidine in 4, conventional chemotherapy in 11, and local radiotherapy in 8. Twenty two patients died, sixty six patients are surviving 1 to 46 months after ASCT (median followup duration, 14.5 months). Although the follow-up period was short and the number of patients small, we believe that ASCT might improve the survival rate in high-risk NBL.
We investigated the effect and outcome of allogeneic peripheral blood stem cell (PBSC) rescue for aplastic anemia (AA) patients with graft failure after allogeneic bone marrow transplantation (BMT). Seven (28%) of 25 AA patients who received BMT from HLA-identical sibling donors developed late graft failure at a median of 7 months (range, 2.0-9.3 months) after transplantation. The patients with graft failure were treated with PBSC collected from the original donor after mobilization with granulocyte-colony stimulating factor (G-CSF). The median boost dose of peripheral blood mononuclear cells was 3.1 x 10(8)/kg (range, 1.4-11.9 x 10(8)/kg). Median times to reach an absolute neutrophil count greater than 0.5 x 10(9)/L and a platelet count greater than 50 x 10(9)/L were 7 days (range, 4-14 days) and 9 days (range, 3-41 days), respectively. There was sustained graft function in 6 of 7 patients, with a median follow-up duration of 3.3 yr (range, 1.0-6.2 yr). Grade-I acute graft-versus-host disease (GVHD) occurred in 2 patients, while extensive chronic GVHD developed in 3 patients. This report shows that G-CSF-mobilized allogeneic PBSC rescue is very effective in achieving complete and sustained engraftment in patients with AA after graft failure. However, more efficacious measures to prevent extensive chronic GVHD remain to be developed.
X-linked hyper-IgM syndrome (XHIM) is a rare primary immunodeficiency disorder, caused by mutations of the gene encoding CD40 ligand (CD40L; CD154). We report the clinical manifestations and mutational analysis of the CD40L gene observed in a male patient from a XHIM family. Having hypogammaglobulinemia and elevated IgM, the 3-yr-old boy exhibited the characteristic clinical features of XHIM. The patient suffered from frequent respiratory infections, and chronic enteritis caused by Cryptosporidium parvum. In addition, a lymph node biopsy and a culture from this sample revealed C. neoformans infection. Activated lymphocytes from the patient failed to express CD40L on their surface as assessed by flow cytometry and a missence mutation (W140R) was found at the XHIM hotspot in his CD40L cDNA to confirm the diagnosis. Genetic analysis of the mother and sister showed a heterozygote pattern, indicating carrier status. To our knowledge, this is the first report on the molecular diagnosis of an XHIM patient in Korea.