Identification and Characterization of Novel SET Domain-Containing Histone Lysine Methyltransferase and Implications of Histone Methylation in Acute Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2227-2227
Author(s):  
Hoon Kook ◽  
Nakwon Choe ◽  
Hae-Jin Kee ◽  
Sung-Mi Kim ◽  
Ji-Young Kim ◽  
...  

Abstract Evolutionally conserved SET domains, which methylate histone lysine residues, and thereby methylation of histones have been implicated in diverse malignancies including leukemias or multiple myelomas. Here we describe novel SET domain-containing proteins with histone methyltransferase (HMTase) activity and their characteristics. Using bioinformatics for homology screening, SET-domain containing proteins named WHISTLE, WHSC1-like 1 isoform 9 with methyltransferase activity to lysine, and RE-IIBP, interleukin-5 response element II binding protein, were identified. By mass spectrometric and immunoblot analysis, we demonstrated that WHISTLE dimethylates H9K4 and di-, and tri-methylates H3K27, while RE-IIBP methylates only H9K27. WHISTLE and RE-IIBP repressed transcription of the SV40 and IL-5 promoter activity and they recruited histone deacetylase. Chromatin immunoprecipitation analysis revealed that shRNA-mediated knockdown of RE-IIBP reduces histone methylation on the IL-5 promoter. Both proteins induce apoptosis in leukemic cells via caspase-3 activation. In acute lymphoblastic leukemia patients, the expression of RE-IIBP and WHISTLE was increased, which was accompanied with increase in the methylation histone 3. These data illustrate the important regulatory role of novel SET domain proteins with HMTase activity in transcriptional regulation and apoptosis, thereby pointing to the critical role in leukemogenesis.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 856-856 ◽  
Author(s):  
Roman Crazzolara ◽  
Adam Cisterne ◽  
Marilyn Thien ◽  
John Hewson ◽  
Kenneth Francis Bradstock ◽  
...  

Abstract The Akt/mammalian target of rapamycin (mTOR) signaling pathway is a potential target in acute lymphoblastic leukemia (ALL) due to its constitutive expression and critical role in regulating leukemic cell growth and survival. In this study, we investigated whether RAD001 (Everolimus, Novartis), is effective as a therapeutic agent in a murine model of human ALL. Leukemic cells from 5 separate patient samples were injected into sub-lethally irradiated NOD/SCID mice and treatment was started after leukemia was clearly detectable in the blood (>5% peripheral blasts) and continued for 4 weeks. In 2 of 3 cases examined, animals treated with RAD001 as a single agent (5mg/kg, 3 times weekly) showed 2 to12-fold reduction in the number of circulating blasts and 2.5 to 30-fold decrease in splenomegaly after only 7 days of treatment (p<0.01). In 1 case, blasts completely disappeared by 14 days of treatment accompanied by recovery of normal hematopoiesis. In contrast vehicle treated mice showed progressive leukemia. In all 5 cases examined, decreased leukemic burden was associated with increased survival, with a median survival of 52 days in the RAD001 treated mice compared to 24 days in the control group (p<0.02 for all samples). Combination treatment with RAD001 and Vincristine (0.15–0.25 mg/kg, weekly) was more effective than either agent alone in reducing leukemic cell count and prolonging survival (p<0.02 compared to Vincristine alone). In one case, all mice treated with either RAD001 alone or RAD001 plus Vincristine survived for greater than 10 weeks following the completion of treatment and only one animal (RAD001 treated) showed signs of disease on elective sacrifice. Cell cycle analysis of cells recovered from the spleens of RAD001 treated animals revealed an arrest in the G0/G1 phase. Furthermore, electron microscopy demonstrated the predominant appearance of autophagy as well as limited apoptosis in cells within the sternums of treated animals. In conclusion, we have demonstrated the efficacy of RAD001 alone or with a subtherapeutic dose of Vincristine in an in vivo leukemia model. These preclinical results support further clinical development of mTOR inhibitors for the treatment of ALL patients. RAD001 may provide significant therapeutic benefit when used alone, or in combination with standard chemotherapy agents such as Vincristine.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 7-7 ◽  
Author(s):  
Robert Foa ◽  
Marco Vignetti ◽  
Antonella Vitale ◽  
Giovanna Meloni ◽  
Anna Guarini ◽  
...  

Abstract Dasatinib (SPRYCEL, formerly BMS-354825) is a potent, orally active inhibitor of the BCR-ABL, c-KIT and SRC family of kinases, which play a critical role in oncogenesis and persistence of malignant phenotypes. In preclinical studies, dasatinib has proven to be a more potent inhibitor of BCR-ABL and c-KIT than imatinib mesylate, and has been shown to be effective in the clinical setting in patients with all phases of chronic myeloid leukemia (CML) or Ph+ ALL resistant to or intolerant of imatinib. We present the first interim results of the GIMEMA protocol LAL 1205 designed to assess the efficacy, safety and tolerability of dasatinib in Ph+ ALL patients at the onset of the disease. The protocol enrolls patients ≥18 years who receive dasatinib p.o. at a dose of 70 mg BID. A steroid regimen (prednisone up to 60mg/m2 day po) is started 7 days prior to the first dasatinib administration and is continued until day 31. The 7-day prednisone pre-phase allows identification of the BCR/ABL transcript. Dasatinib is administered for a total of 84 days. Two intrathecal methotrexate infusions at days +22 and +43 are included. All cases are processed and analyzed through central handling of samples at presentation and are investigated for morphology, immunophenotype, cytogenetics and molecular biology. Minimal residual disease (MRD) is also centrally evaluated by flow-cytometry and Q-RT-PCR at days +22, +43, +57 and +84. A total of 23 patients with BCR/ABL+ ALL have been enrolled to date; median age 57 yrs (30–74), 15 females. All 23 patients have shown a complete hematological response by day +22. One patient relapsed after completing dasatinib administration and died of disease progression, while all other patients are at present alive and well after a median time of observation from diagnosis of 4.5 months (1.7 – 8.0). Monitoring of MRD documented that dasatinib plus prednisone was capable of inducing a very marked clearance of leukemic cells already at day +22, confirmed and strengthened in the subsequent steps of observation. The results of the immunophenotypic and BCR/ABL Q-RT-PCR monitoring are reported in the accompanying table: This interim analysis indicates that in adult and elderly Ph+ ALL induction monotherapy with dasatinib plus prednisone is capable of inducing a rapid hematological remission in all patients so far treated without important toxicity and no fatality. This is associated with a very marked and rapid debulking of the disease as documented by the close phenotypic and molecular monitoring of MRD. DAYS IMMUNOPHENOTYPE Q-RT-PCR (% of leukemic cells) (copy number) <3% - >1% <1% - >0.01% <0.01% 0% >1 x 10² <1 x 10² +22 3/18 pts 8/18 pts 7/18 pts 0/18 pts 11/20 pts 9/20 pts +43 0/17 pts 4/17 pts 12/17 pts 1/17 pts 5/20 pts 15/20 pts +57 0/16 pts 4/16 pts 12/16 pts 0/16 pts 2/19 pts 17/19 pts +84 0/16 pts 4/16 pts 11/16 pts 1/16 pts 4/16 pts 12/16 pts


2008 ◽  
Vol 28 (6) ◽  
pp. 2023-2034 ◽  
Author(s):  
Ji-Young Kim ◽  
Hae Jin Kee ◽  
Nak-Won Choe ◽  
Sung-Mi Kim ◽  
Gwang-Hyeon Eom ◽  
...  

ABSTRACT 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.


Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 712-718 ◽  
Author(s):  
SD Smith ◽  
EM Uyeki ◽  
JT Lowman

Abstract An assay system in vitro for the growth of malignant lymphoblastic colony-forming cells (CFC) was established. Growth of malignant myeloblastic CFC has been previously reported, but this is the first report of growth of malignant lymphoblastic CFC. Established assay systems in vitro have been very helpful in elucidating the control of growth and differentiation of both normal and malignant bone marrow cells. Lymphoblastic CFC were grown from the bone marrow aspirates of 20 children with acute lymphoblastic leukemia. Growth of these colonies was established on an agar assay system and maintained in the relative hypoxia (7% oxygen) of a Stulberg chamber. The criteria for malignancy of these colonies was based upon cellular cytochemical staining characteristics, the presence of specific cell surface markers, and the ability of these lymphoid cells to grow without the addition of a lymphoid mitogen. With this technique, specific nutritional requirements and drug sensitivities can be established in vitro, and these data may permit tailoring of individual antileukemic therapy.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tracy Rabilloud ◽  
Delphine Potier ◽  
Saran Pankaew ◽  
Mathis Nozais ◽  
Marie Loosveld ◽  
...  

AbstractChimeric antigen receptor T cell (CAR-T) targeting the CD19 antigen represents an innovative therapeutic approach to improve the outcome of relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL). Yet, despite a high initial remission rate, CAR-T therapy ultimately fails for some patients. Notably, around half of relapsing patients develop CD19 negative (CD19neg) B-ALL allowing leukemic cells to evade CD19-targeted therapy. Herein, we investigate leukemic cells of a relapsing B-ALL patient, at two-time points: before (T1) and after (T2) anti-CD19 CAR-T treatment. We show that at T2, the B-ALL relapse is CD19 negative due to the expression of a non-functional CD19 transcript retaining intron 2. Then, using single-cell RNA sequencing (scRNAseq) approach, we demonstrate that CD19neg leukemic cells were present before CAR-T cell therapy and thus that the relapse results from the selection of these rare CD19neg B-ALL clones. In conclusion, our study shows that scRNAseq profiling can reveal pre-existing CD19neg subclones, raising the possibility to assess the risk of targeted therapy failure.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 214
Author(s):  
Željko Antić ◽  
Stefan H. Lelieveld ◽  
Cédric G. van der Ham ◽  
Edwin Sonneveld ◽  
Peter M. Hoogerbrugge ◽  
...  

Pediatric acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy and is characterized by clonal heterogeneity. Genomic mutations can increase proliferative potential of leukemic cells and cause treatment resistance. However, mechanisms driving mutagenesis and clonal diversification in ALL are not fully understood. In this proof of principle study, we performed whole genome sequencing of two cases with multiple relapses in order to investigate whether groups of mutations separated in time show distinct mutational signatures. Based on mutation allele frequencies at diagnosis and subsequent relapses, we clustered mutations into groups and performed cluster-specific mutational profile analysis and de novo signature extraction. In patient 1, who experienced two relapses, the analysis unraveled a continuous interplay of aberrant activation induced cytidine deaminase (AID)/apolipoprotein B editing complex (APOBEC) activity. The associated signatures SBS2 and SBS13 were present already at diagnosis, and although emerging mutations were lost in later relapses, the process remained active throughout disease evolution. Patient 2 had three relapses. We identified episodic mutational processes at diagnosis and first relapse leading to mutations resembling ultraviolet light-driven DNA damage, and thiopurine-associated damage at first relapse. In conclusion, our data shows that investigation of mutational processes in clusters separated in time may aid in understanding the mutational mechanisms and discovery of underlying causes.


Blood ◽  
1989 ◽  
Vol 74 (4) ◽  
pp. 1355-1359 ◽  
Author(s):  
MX Zhou ◽  
HW Jr Findley ◽  
AH Ragab

Abstract We are reporting here that low-mol wt B-cell growth factor (LMW-BCGF) and recombinant interleukin-2 (rIL-2) are together able to induce CD3+ cytotoxic T lymphocytes (CTL) with lymphokine-activated killer cell (LAK) activity from the bone marrow (BM) cells of children with acute lymphoblastic leukemia (ALL). Ficoll-Hypaque (FH)-separated BM cells were obtained from patients with active disease (at diagnosis N = 13, in relapse N = 15) and in complete remission (CR; N = 12). CD3+ cells were removed by Leu-4 antibody and immunobeads. Cells were cultured (10(5) cells/mL) in semisolid media with rIL-2 (100 mu/mL), LMW-BCGF (0.1 mu/mL), and the combination of rIL-2 plus LMW-BCGF, respectively, for seven to ten days. Pooled colonies were harvested for phenotyping. LMW-BCGF plus rIL-2 induced large numbers of CD3+ colonies from CD3- precursors. rIL-2 alone did not induce colony formation. In addition, cells were cultured in liquid media with LMW-BCGF, rIL-2, and the combination of LMW-BCGF plus rIL-2, respectively, for seven to 21 days. They were harvested for phenotyping, and cytotoxicity assays were performed v K562, Raji, and autologous leukemic cells. LMW-BCGF plus rIL-2 induced significant expansion of CD3+ cells from CD3- precursors, and these cells were activated to kill autologous leukemic cells in addition to Raji and K562 cell lines. LMW-BCGF or rIL-2 alone did not induce significant expansion or activation of cytotoxic CD3- cells. Our hypothesis is that LMW-BCGF plus rIL-2 stimulates the proliferation and activation of CD3- precursors from the BM cells of children with acute leukemia to become CD3+ cells that have LAK activity. This finding may have therapeutic implications.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asmaa M. Zahran ◽  
Azza Shibl ◽  
Amal Rayan ◽  
Mohamed Alaa Eldeen Hassan Mohamed ◽  
Amira M. M. Osman ◽  
...  

AbstractOur study aimed to evaluate the levels of MDSCs and Tregs in pediatric B-cell acute lymphoblastic leukemia (B-ALL), their relation to patients’ clinical and laboratory features, and the impact of these cells on the induction response. This study included 31 pediatric B-ALL patients and 27 healthy controls. All patients were treated according to the protocols of the modified St. Jude Children’s Research Hospital total therapy study XIIIB for ALL. Levels of MDSCs and Tregs were analyzed using flow cytometry. We observed a reduction in the levels of CD4 + T-cells and an increase in both the polymorphonuclear MDSCs (PMN-MDSCs) and Tregs. The frequencies of PMN-MDSCs and Tregs were directly related to the levels of peripheral and bone marrow blast cells and CD34 + cells. Complete postinduction remission was associated with reduced percentages of PMN-MDSCs and Tregs, with the level of PMN-MDCs in this subpopulation approaching that of healthy controls. PMN-MDSCs and Tregs jointly play a critical role in maintaining an immune-suppressive state suitable for B-ALL tumor progression. Thereby, they could be independent predictors of B-ALL progress, and finely targeting both PMN-MDSCs and Tregs may be a promising approach for the treatment of B-ALL.


2021 ◽  
Vol 22 (3) ◽  
pp. 1388
Author(s):  
Natalia Maćkowska ◽  
Monika Drobna-Śledzińska ◽  
Michał Witt ◽  
Małgorzata Dawidowska

Distinct DNA methylation signatures, related to different prognosis, have been observed across many cancers, including T-cell acute lymphoblastic leukemia (T-ALL), an aggressive hematological neoplasm. By global methylation analysis, two major phenotypes might be observed in T-ALL: hypermethylation related to better outcome and hypomethylation, which is a candidate marker of poor prognosis. Moreover, DNA methylation holds more than a clinical meaning. It reflects the replicative history of leukemic cells and most likely different mechanisms underlying leukemia development in these T-ALL subtypes. The elucidation of the mechanisms and aberrations specific to (epi-)genomic subtypes might pave the way towards predictive diagnostics and precision medicine in T-ALL. We present the current state of knowledge on the role of DNA methylation in T-ALL. We describe the involvement of DNA methylation in normal hematopoiesis and T-cell development, focusing on epigenetic aberrations contributing to this leukemia. We further review the research investigating distinct methylation phenotypes in T-ALL, related to different outcomes, pointing to the most recent research aimed to unravel the biological mechanisms behind differential methylation. We highlight how technological advancements facilitated broadening the perspective of the investigation into DNA methylation and how this has changed our understanding of the roles of this epigenetic modification in T-ALL.


Blood ◽  
1993 ◽  
Vol 82 (2) ◽  
pp. 343-362 ◽  
Author(s):  
CH Pui ◽  
FG Behm ◽  
WM Crist

Abstract Immunologic marker studies of the lymphoid leukemias have greatly improved the precision of diagnosis of these disorders by providing specific information regarding the lineage and stage of maturation of the malignant cells. Such studies have also enhanced our understanding of normal lymphocyte development, permitting reproducible identification of lymphoid cells in discrete developmental stages. By elucidating the functions of lymphoid cell differentiation antigens, it has been possible to gain insight into the signal transduction mechanisms by which these cells interact among themselves and with other cell types. Similar studies have shown that ALL is an immunophenotypically heterogeneous disease with clinically important subtypes representing clonal expansions of lymphoblasts at different stages of maturation. Furthermore, successful correlation of immunophenotype with certain karyotypic and molecular abnormalities, which appear to underlie most or all leukemias, were made possible by the inclusion of immunologic marker assessment. Interestingly, many of these phenotype-related abnormalities have involved either the Ig or TCR genes, thus providing additional clues to the mechanisms of leukemogenesis. Knowledge of the immunologic features of leukemic cells has been essential for the generation of phenotype-specific response data in the context of modern therapy for ALL. With wider use of intensive treatment, the traditional prognostic distinctions among immunophenotypes have begun to disappear; however, certain classes of agents have more favorable toxicity/efficacy ratios against some immunophenotypes than others, justifying continued efforts to target therapy by immunologic species of ALL. Antibody-toxin conjugates, or immunotoxins, have induced complete responses in preliminary trials and may prove clinically useful, perhaps in combination with chemotherapy, if their toxic side effects can be controlled. Finally, immunologic markers may serve as sensitive targets for the detection of minimal residual disease; the clinical usefulness of this approach will depend on prospective comparisons with molecular methods.


Sign in / Sign up

Export Citation Format

Share Document