24 results on '"Caligiuri M"'
Search Results
2. E3 ubiquitin ligase Cbl-b activates the p53 pathway by targeting Siva1, a negative regulator of ARF, in FLT3 inhibitor-resistant acute myeloid leukemia.
- Author
-
Park IK, Blum W, Baker SD, and Caligiuri MA
- Subjects
- Humans, Signal Transduction, Tumor Suppressor Protein p53 metabolism, Ubiquitin-Protein Ligases physiology, fms-Like Tyrosine Kinase 3 antagonists & inhibitors, Apoptosis Regulatory Proteins antagonists & inhibitors, Drug Resistance, Neoplasm, Leukemia, Myeloid, Acute metabolism, Proto-Oncogene Proteins c-cbl physiology
- Published
- 2017
- Full Text
- View/download PDF
3. The dual epigenetic role of PRMT5 in acute myeloid leukemia: gene activation and repression via histone arginine methylation.
- Author
-
Tarighat SS, Santhanam R, Frankhouser D, Radomska HS, Lai H, Anghelina M, Wang H, Huang X, Alinari L, Walker A, Caligiuri MA, Croce CM, Li L, Garzon R, Li C, Baiocchi RA, and Marcucci G
- Subjects
- Animals, Apoptosis, Blotting, Western, Cell Proliferation, Chromatin Immunoprecipitation, Down-Regulation, Flow Cytometry, Gene Expression Regulation, Leukemic, Humans, Immunoenzyme Techniques, Leukemia, Myeloid, Acute pathology, Mice, Mice, Inbred NOD, Mice, SCID, Protein-Arginine N-Methyltransferases antagonists & inhibitors, RNA, Messenger genetics, RNA, Small Interfering genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Transcriptional Activation, Tumor Cells, Cultured, Xenograft Model Antitumor Assays, Arginine chemistry, DNA Methylation, Epigenesis, Genetic genetics, Epigenomics, Histones chemistry, Leukemia, Myeloid, Acute genetics, MicroRNAs genetics, Protein-Arginine N-Methyltransferases genetics
- Abstract
Changes in the enzymatic activity of protein arginine methyltransferase (PRMT) 5 have been associated with cancer; however, the protein's role in acute myeloid leukemia (AML) has not been fully evaluated. Here, we show that increased PRMT5 activity enhanced AML growth in vitro and in vivo while PRMT5 downregulation reduced it. In AML cells, PRMT5 interacted with Sp1 in a transcription repressor complex and silenced miR-29b preferentially via dimethylation of histone 4 arginine residue H4R3. As Sp1 is also a bona fide target of miR-29b, the miR silencing resulted in increased Sp1. This event in turn led to transcription activation of FLT3, a gene that encodes a receptor tyrosine kinase. Inhibition of PRMT5 via sh/siRNA or a first-in-class small-molecule inhibitor (HLCL-61) resulted in significantly increased expression of miR-29b and consequent suppression of Sp1 and FLT3 in AML cells. As a result, significant antileukemic activity was achieved. Collectively, our data support a novel leukemogenic mechanism in AML where PRMT5 mediates both silencing and transcription of genes that participate in a 'yin-yang' functional network supporting leukemia growth. As FLT3 is often mutated in AML and pharmacologic inhibition of PRMT5 appears feasible, the PRMT5-miR-29b-FLT3 network should be further explored as a novel therapeutic target for AML.
- Published
- 2016
- Full Text
- View/download PDF
4. Somatic mutational landscape of AML with inv(16) or t(8;21) identifies patterns of clonal evolution in relapse leukemia.
- Author
-
Sood R, Hansen NF, Donovan FX, Carrington B, Bucci D, Maskeri B, Young A, Trivedi NS, Kohlschmidt J, Stone RM, Caligiuri MA, Chandrasekharappa SC, Marcucci G, Mullikin JC, Bloomfield CD, and Liu P
- Subjects
- Humans, Recurrence, Chromosome Inversion, Chromosomes, Human, Pair 16, Chromosomes, Human, Pair 21, Chromosomes, Human, Pair 8, Clonal Evolution, Leukemia, Myeloid, Acute genetics, Mutation, Translocation, Genetic
- Published
- 2016
- Full Text
- View/download PDF
5. Receptor tyrosine kinase Axl is required for resistance of leukemic cells to FLT3-targeted therapy in acute myeloid leukemia.
- Author
-
Park IK, Mundy-Bosse B, Whitman SP, Zhang X, Warner SL, Bearss DJ, Blum W, Marcucci G, and Caligiuri MA
- Subjects
- Cell Line, Tumor, Drug Resistance, Neoplasm, Humans, Phosphorylation, Axl Receptor Tyrosine Kinase, Leukemia, Myeloid, Acute drug therapy, Protein Kinase Inhibitors therapeutic use, Proto-Oncogene Proteins physiology, Receptor Protein-Tyrosine Kinases physiology, fms-Like Tyrosine Kinase 3 antagonists & inhibitors
- Abstract
In acute myeloid leukemia (AML), about 25-30% of patients harbor a constitutively active receptor tyrosine kinase (RTK) FLT3 encoded by a FLT3 allele harboring internal tandem duplication (FLT3-ITD) mutation. The presence of FLT3-ITD correlates with poor prognosis in AML and it makes FLT3 an attractive therapeutic target in AML. Unfortunately, to date small-molecule inhibitors of FLT3 have resulted in only partial and transient clinical responses with residual leukemic blasts resistant to FLT3 inhibitors detected in blood or bone marrow. In this study, we investigated whether the RTK Axl is responsible for resistance of FLT3-ITD(+) AML cells to PKC412 and AC220, FLT3 inhibitors currently under clinical trials for FLT3-ITD(+) AML patients. Upon treatment with PKC412 or AC220, phosphorylation of Axl was significantly enhanced in the FLT3-ITD(+) MV4-11 AML cell line and in primary blasts from a FLT3-ITD(+) AML patient. Consistently, a PKC412-resistant AML cell line and PKC412-resistant primary blasts from FLT3-ITD(+) AML patients had significantly higher levels of constitutively phosphorylated Axl and total Axl when compared with a PKC412-sensitive AML cell line and PKC412-sensitive primary blasts from FLT3-ITD(+) AML patients. We also found that resistance of AML cells against the FLT3 inhibitor PKC412 and AC220 was substantially diminished by the inhibition of Axl via a small-molecule inhibitor TP-0903, a soluble receptor Axl fusion protein Axl-Fc or knockdown of Axl gene expression by shRNA. Collectively, our study suggests that Axl is required for resistance of FLT3-ITD(+) AML cells against the FLT3 inhibitor PKC412 and AC220, and that inhibition of Axl activation may overcome resistance to FLT3-targeted therapy in FLT3-ITD(+) AML.
- Published
- 2015
- Full Text
- View/download PDF
6. Targeting leukemia stem cells in vivo with antagomiR-126 nanoparticles in acute myeloid leukemia.
- Author
-
Dorrance AM, Neviani P, Ferenchak GJ, Huang X, Nicolet D, Maharry KS, Ozer HG, Hoellarbauer P, Khalife J, Hill EB, Yadav M, Bolon BN, Lee RJ, Lee LJ, Croce CM, Garzon R, Caligiuri MA, Bloomfield CD, and Marcucci G
- Subjects
- Animals, DNA Methylation, Humans, Leukemia, Myeloid, Acute genetics, Leukemia, Myeloid, Acute mortality, Leukocyte Common Antigens antagonists & inhibitors, Mice, Mice, Inbred C57BL, MicroRNAs physiology, Neoplastic Stem Cells drug effects, Leukemia, Myeloid, Acute therapy, MicroRNAs antagonists & inhibitors, Nanoparticles administration & dosage, Neoplastic Stem Cells physiology
- Abstract
Current treatments for acute myeloid leukemia (AML) are designed to target rapidly dividing blast populations with limited success in eradicating the functionally distinct leukemia stem cell (LSC) population, which is postulated to be responsible for disease resistance and relapse. We have previously reported high miR-126 expression levels to be associated with a LSC-gene expression profile. Therefore, we hypothesized that miR-126 contributes to 'stemness' and is a viable target for eliminating the LSC in AML. Here we first validate the clinical relevance of miR-126 expression in AML by showing that higher expression of this microRNA (miR) is associated with worse outcome in a large cohort of older (⩾60 years) cytogenetically normal AML patients treated with conventional chemotherapy. We then show that miR-126 overexpression characterizes AML LSC-enriched cell subpopulations and contributes to LSC long-term maintenance and self-renewal. Finally, we demonstrate the feasibility of therapeutic targeting of miR-126 in LSCs with novel targeting nanoparticles containing antagomiR-126 resulting in in vivo reduction of LSCs likely by depletion of the quiescent cell subpopulation. Our findings suggest that by targeting a single miR, that is, miR-126, it is possible to interfere with LSC activity, thereby opening potentially novel therapeutic approaches to treat AML patients.
- Published
- 2015
- Full Text
- View/download PDF
7. Pharmacological targeting of miR-155 via the NEDD8-activating enzyme inhibitor MLN4924 (Pevonedistat) in FLT3-ITD acute myeloid leukemia.
- Author
-
Khalife J, Radomska HS, Santhanam R, Huang X, Neviani P, Saultz J, Wang H, Wu YZ, Alachkar H, Anghelina M, Dorrance A, Curfman J, Bloomfield CD, Medeiros BC, Perrotti D, Lee LJ, Lee RJ, Caligiuri MA, Pichiorri F, Croce CM, Garzon R, Guzman ML, Mendler JH, and Marcucci G
- Subjects
- Animals, Apoptosis drug effects, Blotting, Western, Cell Differentiation drug effects, Cell Proliferation drug effects, Chromatin Immunoprecipitation, Drug Resistance, Neoplasm, Female, Gene Expression Regulation, Leukemic drug effects, Humans, Leukemia, Myeloid, Acute pathology, Mice, Mice, Inbred NOD, Mice, SCID, Monocytes drug effects, Monocytes metabolism, Monocytes pathology, NEDD8 Protein, NF-kappa B genetics, NF-kappa B metabolism, Promoter Regions, Genetic, RNA, Messenger genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction drug effects, Tumor Cells, Cultured, Xenograft Model Antitumor Assays, Cyclopentanes pharmacology, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute genetics, MicroRNAs genetics, Pyrimidines pharmacology, Tandem Repeat Sequences genetics, Ubiquitins antagonists & inhibitors, fms-Like Tyrosine Kinase 3 genetics
- Abstract
High levels of microRNA-155 (miR-155) are associated with poor outcome in acute myeloid leukemia (AML). In AML, miR-155 is regulated by NF-κB, the activity of which is, in part, controlled by the NEDD8-dependent ubiquitin ligases. We demonstrate that MLN4924, an inhibitor of NEDD8-activating enzyme presently being evaluated in clinical trials, decreases binding of NF-κB to the miR-155 promoter and downregulates miR-155 in AML cells. This results in the upregulation of the miR-155 targets SHIP1, an inhibitor of the PI3K/Akt pathway, and PU.1, a transcription factor important for myeloid differentiation, leading to monocytic differentiation and apoptosis. Consistent with these results, overexpression of miR-155 diminishes MLN4924-induced antileukemic effects. In vivo, MLN4924 reduces miR-155 expression and prolongs the survival of mice engrafted with leukemic cells. Our study demonstrates the potential of miR-155 as a novel therapeutic target in AML via pharmacologic interference with NF-κB-dependent regulatory mechanisms. We show the targeting of this oncogenic microRNA with MLN4924, a compound presently being evaluated in clinical trials in AML. As high miR-155 levels have been consistently associated with aggressive clinical phenotypes, our work opens new avenues for microRNA-targeting therapeutic approaches to leukemia and cancer patients.
- Published
- 2015
- Full Text
- View/download PDF
8. Toward personalized therapy in AML: in vivo benefit of targeting aberrant epigenetics in MLL-PTD-associated AML.
- Author
-
Bernot KM, Siebenaler RF, Whitman SP, Zorko NA, Marcucci GG, Santhanam R, Ahmed EH, Ngangana M, McConnell KK, Nemer JS, Brook DL, Kulp SK, Chen CS, Frankhouser D, Yan P, Bundschuh R, Zhang X, Dorrance AM, Dickerson KE, Jarjoura D, Blum W, Marcucci G, and Caligiuri MA
- Subjects
- Animals, Histone-Lysine N-Methyltransferase, Humans, Leukemia, Myeloid, Acute genetics, Mice, Mice, Knockout, Epigenesis, Genetic, Leukemia, Myeloid, Acute therapy, Myeloid-Lymphoid Leukemia Protein genetics, Precision Medicine
- Published
- 2013
- Full Text
- View/download PDF
9. A stem cell-like gene expression signature associates with inferior outcomes and a distinct microRNA expression profile in adults with primary cytogenetically normal acute myeloid leukemia.
- Author
-
Metzeler KH, Maharry K, Kohlschmidt J, Volinia S, Mrózek K, Becker H, Nicolet D, Whitman SP, Mendler JH, Schwind S, Eisfeld AK, Wu YZ, Powell BL, Carter TH, Wetzler M, Kolitz JE, Baer MR, Carroll AJ, Stone RM, Caligiuri MA, Marcucci G, and Bloomfield CD
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cytogenetic Analysis, Female, Humans, Leukemia, Myeloid, Acute mortality, Leukemia, Myeloid, Acute therapy, Male, Middle Aged, Oligonucleotide Array Sequence Analysis, Prognosis, Remission Induction, Stem Cells pathology, Survival Rate, Young Adult, Biomarkers, Tumor genetics, Leukemia, Myeloid, Acute genetics, MicroRNAs genetics, Stem Cells metabolism, Transcriptome
- Abstract
Acute myeloid leukemia (AML) is hypothesized to be sustained by self-renewing leukemia stem cells (LSCs). Recently, gene expression signatures (GES) from functionally defined AML LSC populations were reported, and expression of a 'core enriched' (CE) GES, representing 44 genes activated in LCSs, conferred shorter survival in cytogenetically normal (CN) AML. The prognostic impact of the CE GES in the context of other molecular markers, including gene mutations and microRNA (miR) expression alterations, is unknown and its clinical utility is unclear. We studied associations of the CE GES with known molecular prognosticators, miR expression profiles, and outcomes in 364 well-characterized CN-AML patients. A high CE score (CE(high)) associated with FLT3-internal tandem duplication, WT1 and RUNX1 mutations, wild-type CEBPA and TET2, and high ERG, BAALC and miR-155 expression. CE(high) patients had a lower complete remission (CR) rate (P=0.003) and shorter disease-free (DFS, P<0.001) and overall survival (OS, P<0.001) than CE(low) patients. These associations persisted in multivariable analyses adjusting for other prognosticators (CR, P=0.02; DFS, P<0.001; and OS, P<0.001). CE(high) status was accompanied by a characteristic miR expression signature. Fifteen miRs were upregulated in both younger and older CE(high) patients, including miRs relevant for stem cell function. Our results support the clinical relevance of LSCs and improve risk stratification in AML.
- Published
- 2013
- Full Text
- View/download PDF
10. Increased anti-leukemic activity of decitabine via AR-42-induced upregulation of miR-29b: a novel epigenetic-targeting approach in acute myeloid leukemia.
- Author
-
Mims A, Walker AR, Huang X, Sun J, Wang H, Santhanam R, Dorrance AM, Walker C, Hoellerbauer P, Tarighat SS, Chan KK, Klisovic RB, Perrotti D, Caligiuri MA, Byrd JC, Chen CS, James Lee L, Jacob S, Mrózek K, Bloomfield CD, Blum W, Garzon R, Schwind S, and Marcucci G
- Subjects
- Animals, Azacitidine therapeutic use, Blotting, Western, Cell Line, Tumor, Decitabine, Histone Deacetylases metabolism, Humans, Leukemia, Myeloid, Acute enzymology, Leukemia, Myeloid, Acute genetics, Mice, Mice, Inbred NOD, Mice, SCID, Up-Regulation drug effects, Azacitidine analogs & derivatives, Epigenesis, Genetic, Histone Deacetylase Inhibitors therapeutic use, Leukemia, Myeloid, Acute drug therapy, MicroRNAs genetics, Phenylbutyrates therapeutic use
- Abstract
Histone deacetylase (HDAC) inhibitors either alone or in combination with hypomethylating agents have limited clinical effect in acute myeloid leukemia (AML). Previously, we demonstrated that AML patients with higher miR (microRNA)-29b expression had better response to the hypomethylating agent decitabine. Therefore, an increase in miR-29b expression preceding decitabine treatment may provide a therapeutic advantage. We previously showed that miR-29b expression is suppressed by a repressor complex that includes HDACs. Thus, HDAC inhibition may increase miR-29b expression. We hypothesized that priming AML cells with the novel HDAC inhibitor (HDACI) AR-42 would result in increased response to decitabine treatment via upregulation of miR-29b. Here, we show that AR-42 is a potent HDACI in AML, increasing miR-29b levels and leading to downregulation of known miR-29b targets (that is, SP1, DNMT1, DNMT3A and DNMT3B). We then demonstrated that the sequential administration of AR-42 followed by decitabine resulted in a stronger anti-leukemic activity in vitro and in vivo than decitabine followed by AR-42 or either drug alone. These preclinical results with AR-42 priming before decitabine administration represent a promising, novel treatment approach and a paradigm shift with regard to the combination of epigenetic-targeting compounds in AML, where decitabine has been traditionally given before HDACIs.
- Published
- 2013
- Full Text
- View/download PDF
11. The MLL partial tandem duplication in adults aged 60 years and older with de novo cytogenetically normal acute myeloid leukemia.
- Author
-
Whitman SP, Caligiuri MA, Maharry K, Radmacher MD, Kohlschmidt J, Becker H, Mrózek K, Wu YZ, Schwind S, Metzeler KH, Mendler JH, Wen J, Baer MR, Powell BL, Carter TH, Kolitz JE, Wetzler M, Carroll AJ, Larson RA, Marcucci G, and Bloomfield CD
- Subjects
- Adult, Aged, Cohort Studies, Cytogenetic Analysis, Female, Histone-Lysine N-Methyltransferase, Humans, Leukemia, Myeloid, Acute mortality, Male, Middle Aged, Prognosis, Survival Rate, Trisomy, Biomarkers, Tumor genetics, Leukemia, Myeloid, Acute genetics, MicroRNAs genetics, Myeloid-Lymphoid Leukemia Protein genetics, Tandem Repeat Sequences genetics
- Published
- 2012
- Full Text
- View/download PDF
12. Escalation of daunorubicin and addition of etoposide in the ADE regimen in acute myeloid leukemia patients aged 60 years and older: Cancer and Leukemia Group B Study 9720.
- Author
-
Baer MR, George SL, Sanford BL, Mrózek K, Kolitz JE, Moore JO, Stone RM, Powell BL, Caligiuri MA, Bloomfield CD, and Larson RA
- Subjects
- Aged, Aged, 80 and over, Cytarabine therapeutic use, Daunorubicin therapeutic use, Etoposide therapeutic use, Female, Humans, Karyotyping, Leukemia, Myeloid, Acute genetics, Leukemia, Myeloid, Acute mortality, Male, Middle Aged, Remission Induction, Survival Rate, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Leukemia, Myeloid, Acute drug therapy
- Abstract
Untreated de novo (n=421) and secondary (n=189) acute myeloid leukemia (AML) patients ≥60 years received intensified chemotherapy, including daunorubicin 60 mg/m(2) and etoposide 100 mg/m(2) during days 1, 2, 3 with cytarabine 100 mg/m(2) during days 1-7, with a second induction if needed and one consolidation course with these drugs and doses for 2, 2 and 5 days, respectively. In all, 287 (47%) achieved complete remission (CR), 136 (22%) died and 187 (31%) were non-responders. CR rates were 27, 44 and 52% for complex karyotypes, rare aberrations and neither (P<0.001), 52 and 37% for de novo and secondary AML (P=0.003), and 53 and 42% for age 60-69 and ≥70 years (P=0.015). In multivariable analysis, CR predictors included non-complex/non-rare karyotypes (P<0.001), de novo AML (P<0.001), better performance status (PS) (P<0.001) and younger age (P=0.001). Disease-free (DFS) and overall (OS) survival medians were 6.8 (95% CI: 6.2, 7.8) and 7.2 (95% CI: 6.4, 8.6) months. In multivariable analysis, DFS was shorter for complex karyotypes (P<0.001) and increasing white blood count (WBC) (P<0.001) and age (P=0.038), and OS for complex karyotypes (P<0.001), increasing WBC (P=0.001) and age (P<0.001), poorer PS (P<0.001) and secondary AML (P=0.010). Outcomes and prognostic factors were similar to those in previous Cancer and Leukemia Group B studies.
- Published
- 2011
- Full Text
- View/download PDF
13. G3139, a BCL-2 antisense oligo-nucleotide, in AML.
- Author
-
Marcucci G, Stock W, Dai G, Klisovic MI, Maharry K, Shen T, Liu S, Sher DA, Lucas D, Zwiebel A, Larson RA, Caligiuri MA, Bloomfield CD, Chan KK, Grever MR, and Byrd JC
- Subjects
- Humans, Leukemia, Myeloid, Acute genetics, Oligonucleotides, Antisense adverse effects, Oligonucleotides, Antisense pharmacokinetics, Oligonucleotides, Antisense therapeutic use, RNA, Messenger drug effects, RNA, Messenger genetics, Thionucleotides pharmacokinetics, Leukemia, Myeloid, Acute drug therapy, Thionucleotides adverse effects, Thionucleotides therapeutic use
- Published
- 2004
- Full Text
- View/download PDF
14. Immunologic manipulation in AML: from bench to bedside.
- Author
-
Cooper MA and Caligiuri MA
- Subjects
- Antigens, CD metabolism, Humans, Lymphocytes physiology, Molecular Biology, Killer Cells, Natural immunology, Leukemia, Myeloid, Acute immunology
- Published
- 2002
- Full Text
- View/download PDF
15. High affinity interleukin-3 receptor expression on blasts from patients with acute myelogenous leukemia correlates with cytotoxicity of a diphtheria toxin/IL-3 fusion protein.
- Author
-
Alexander RL, Ramage J, Kucera GL, Caligiuri MA, and Frankel AE
- Subjects
- Acute Disease, Humans, Leukemia, Myeloid metabolism, Leukemia, Myeloid pathology, Leukemia, Myeloid, Acute pathology, Protein Binding, Tumor Cells, Cultured, Antineoplastic Agents pharmacology, Cell Division drug effects, Diphtheria Toxin pharmacology, Interleukin-3 pharmacology, Leukemia, Myeloid, Acute metabolism, Receptors, Interleukin-3 metabolism, Recombinant Fusion Proteins pharmacology, Stem Cells drug effects
- Abstract
Diphtheria fusion proteins are a novel class of agents for the treatment of chemotherapy resistant AML. We prepared DT(388)IL3 composed of human interleukin-3 (IL3) fused to the catalytic and translocation domain of diphtheria toxin (DT(388)) and assessed its activity on patient AML blasts. The number and affinity of IL3 receptors in circulating blasts was measured using a radiolabeled IL3 agonist (SC-65461). Ninety-two percent of patients' blasts had both high and low affinity IL3 receptors. DT(388)IL3 cytotoxicity (>1 log cell kill) was seen in nine of 25 samples (36%). There was a significant correlation between DT(388)IL3 log cell kill and blast high affinity IL3 receptor density (P=0.0044). These results show that specific high affinity IL3 binding is one factor important in the sensitivity of patients' leukemic blasts to DT(388)IL3.
- Published
- 2001
- Full Text
- View/download PDF
16. Leukemia-associated Rho guanine nucleotide exchange factor, a Dbl family protein found mutated in leukemia, causes transformation by activation of RhoA.
- Author
-
Reuther GW, Lambert QT, Booden MA, Wennerberg K, Becknell B, Marcucci G, Sondek J, Caligiuri MA, and Der CJ
- Subjects
- DNA-Binding Proteins metabolism, Humans, Male, Nuclear Proteins metabolism, Rho Guanine Nucleotide Exchange Factors, Serum Response Factor, Cell Transformation, Neoplastic, Guanine Nucleotide Exchange Factors physiology, Leukemia, Myeloid, Acute physiopathology, rhoA GTP-Binding Protein metabolism
- Abstract
Leukemia-associated Rho guanine nucleotide exchange factor (LARG) was originally identified as a fusion partner with mixed-lineage leukemia in a patient with acute myeloid leukemia. LARG possesses a tandem Dbl homology and pleckstrin homology domain structure and, consequently, may function as an activator of Rho GTPases. In this study, we demonstrate that LARG is a functional Dbl protein. Expression of LARG in cells caused activation of the serum response factor, a known downstream target of Rho-mediated signaling pathways. Transient overexpression of LARG did not activate the extracellular signal-regulated kinase or c-Jun NH(2)-terminal kinase mitogen-activated protein kinase cascade, suggesting LARG is not an activator of Ras, Rac, or Cdc42. We performed in vitro exchange assays where the isolated Dbl homology (DH) or DH/pleckstrin homology domains of LARG functioned as a strong activator of RhoA, but exhibited no activity toward Rac1 or Cdc42. We found that LARG could complex with RhoA, but not Rac or Cdc42, in vitro, and that expression of LARG caused an increase in the levels of the activated GTP-bound form of RhoA, but not Rac1 or Cdc42, in vivo. Thus, we conclude that LARG is a RhoA-specific guanine nucleotide exchange factor. Finally, like activated RhoA, we determined that LARG cooperated with activated Raf-1 to transform NIH3T3 cells. These data demonstrate that LARG is the first functional Dbl protein mutated in cancer and indicate LARG-mediated activation of RhoA may play a role in the development of human leukemias.
- Published
- 2001
- Full Text
- View/download PDF
17. Quantification of CBFbeta/MYH11 fusion transcript by real time RT-PCR in patients with INV(16) acute myeloid leukemia.
- Author
-
Marcucci G, Caligiuri MA, Döhner H, Archer KJ, Schlenk RF, Döhner K, Maghraby EA, and Bloomfield CD
- Subjects
- Adolescent, Adult, Female, Follow-Up Studies, Humans, Male, Middle Aged, Transcription Factor AP-2, Chromosome Inversion, Chromosomes, Human, Pair 16, DNA Glycosylases, DNA-Binding Proteins genetics, Leukemia, Myeloid, Acute genetics, N-Glycosyl Hydrolases genetics, Recombinant Fusion Proteins genetics, Reverse Transcriptase Polymerase Chain Reaction, Transcription Factors genetics
- Abstract
Amplification of the CBFbeta/MYH11 fusion transcript by a qualitative reverse transcription-polymerase chain reaction (RT-PCR) has been used to detect minimal residual disease (MRD) and assess the risk for disease relapse in inv(16)(p13q22) acute myeloid leukemia (AML). This strategy has, however, produced conflicting results and because of an uncertain predictive value, its use in the clinical setting cannot be recommended. The objective of the current study was to evaluate if quantification by Real Time RT-PCR could be useful to determine levels of CBFbeta/MYH11 fusion transcripts predictive of clinical outcome in inv(16)(p13q22) AML at diagnosis or during remission. Bone marrow (BM) samples from 16 patients with inv(16) AML enrolled on a German multicenter trial (AML HD93) were analyzed for levels of CBFbeta/MYH11 fusion transcripts by Real Time RT-PCR at diagnosis (n= 14), during remission (n= 10) and at relapse (n=6). The CBFbeta/MYH11 transcript copy number in each sample was normalized to copies of an internal control housekeeping transcript (ie 18S). The copy number measured at diagnosis or relapse were 3 to 4 log higher that those measured during remission, following completion of induction treatment. A high CBFbeta/MYH11 transcript copy number at diagnosis had a significant correlation with a high percentage of BM blasts (Spearman's coefficient = -0.66; P= 0.03), and a borderline correlation with a short complete remission (CR) duration (Spearman's coefficient = -0.51; P= 0.07). No difference in levels of CBFbeta/MYH11 fusion transcripts measured during intensification therapy was found between patients destined to relapse and those who continued in CCR (P= 0.75). Following completion of the entire chemotherapy program, patients that during CR showed a CBFbeta/MYH11 fusion transcript copy number >10 had a significantly shorter CR duration (P= 0.002) and higher risk for disease relapse (P= 0.05) than patients with a CBFbeta/MYH11 fusion transcript copy number <10. The results of the current study, therefore, suggest that it is possible to determine in remission samples a threshold of CBFbeta/MYH11 transcript copy number above which relapse occurs and below which continuous CR is likely.
- Published
- 2001
- Full Text
- View/download PDF
18. Novel methylation targets in de novo acute myeloid leukemia with prevalence of chromosome 11 loci.
- Author
-
Rush LJ, Dai Z, Smiraglia DJ, Gao X, Wright FA, Frühwald M, Costello JF, Held WA, Yu L, Krahe R, Kolitz JE, Bloomfield CD, Caligiuri MA, and Plass C
- Subjects
- Adult, Blotting, Southern, Chromosome Mapping, Cloning, Molecular, Deoxyribonucleases, Type II Site-Specific, Female, Humans, Male, Middle Aged, Molecular Sequence Data, Polymerase Chain Reaction, Remission Induction, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Tumor Cells, Cultured, Chromosomes, Human, Pair 11, DNA Methylation, Leukemia, Myeloid, Acute genetics
- Abstract
Aberrant DNA methylation is believed to be important in tumorigenesis by causing either transcriptional inactivation of genes or chromosomal instability. Several laboratories have identified promoter hypermethylation of tumor suppressor genes in acute myeloid leukemia (AML). However, these studies do not provide a global assessment of overall methylation changes and do not allow the identification of novel methylated sequences. Previously, nonrandom CpG island methylation was reported in 17 adult de novo AML diagnostic samples when compared with the corresponding remission samples by means of restriction landmark genomic scanning (RLGS). That study has been expanded on by an analysis of a larger set of CpG islands (1740 vs 1184), which now provides details of 33 cloned methylated loci, including 21 known genes or expressed sequence tags. Five of these cloned loci appear to be methylated only in AML and not in the 6 solid tumors studied in this study (more than 98 samples analyzed). Chromosomal location was available for 30 of the 33 loci, and 5 of these 30 (17%) are localized to chromosome 11, suggesting a trend toward overrepresentation of methylation events on this chromosome. These results provide evidence for widespread aberrant methylation in AML, with identification of novel methylation targets, epigenetic changes that appear unique to AML, and apparent preferential methylation on chromosome 11.
- Published
- 2001
- Full Text
- View/download PDF
19. Expression profiling reveals fundamental biological differences in acute myeloid leukemia with isolated trisomy 8 and normal cytogenetics.
- Author
-
Virtaneva K, Wright FA, Tanner SM, Yuan B, Lemon WJ, Caligiuri MA, Bloomfield CD, de La Chapelle A, and Krahe R
- Subjects
- Acute Disease, Antigens, CD34 analysis, Bone Marrow Cells cytology, Bone Marrow Cells pathology, Chromosome Mapping, Female, Humans, Leukemia, Myeloid pathology, Leukemia, Myeloid, Acute pathology, Male, Oligonucleotide Array Sequence Analysis, Polymerase Chain Reaction, Reference Values, Chromosomes, Human, Pair 8, Gene Expression Profiling methods, Leukemia, Myeloid genetics, Leukemia, Myeloid, Acute genetics, Trisomy
- Abstract
Acute myeloid leukemia (AML) is a heterogeneous group of diseases. Normal cytogenetics (CN) constitutes the single largest group, while trisomy 8 (+8) as a sole abnormality is the most frequent trisomy. How trisomy contributes to tumorigenesis is unknown. We used oligonucleotide-based DNA microarrays to study global gene expression in AML+8 patients with +8 as the sole chromosomal abnormality and AML-CN patients. CD34(+) cells purified from normal bone marrow (BM) were also analyzed as a representative heterogeneous population of stem and progenitor cells. Expression patterns of AML patients were clearly distinct from those of CD34(+) cells of normal individuals. We show that AML+8 blasts overexpress genes on chromosome 8, estimated at 32% on average, suggesting gene-dosage effects underlying AML+8. Systematic analysis by cellular function indicated up-regulation of genes involved in cell adhesion in both groups of AML compared with CD34(+) blasts from normal individuals. Perhaps most interestingly, apoptosis-regulating genes were significantly down-regulated in AML+8 compared with AML-CN. We conclude that the clinical and cytogenetic heterogeneity of AML is due to fundamental biological differences.
- Published
- 2001
- Full Text
- View/download PDF
20. Molecular and clinical advances in core binding factor primary acute myeloid leukemia: a paradigm for translational research in malignant hematology.
- Author
-
Marcucci G, Caligiuri MA, and Bloomfield CD
- Subjects
- Animals, Antimetabolites, Antineoplastic administration & dosage, Chromosomes, Human, Pair 16 genetics, Chromosomes, Human, Pair 21 genetics, Chromosomes, Human, Pair 8 genetics, Core Binding Factor alpha Subunits, Cytarabine administration & dosage, Diagnosis, Differential, Humans, Leukemia, Myeloid, Acute diagnosis, Leukemia, Myeloid, Acute drug therapy, Neoplasm, Residual, Prognosis, Randomized Controlled Trials as Topic, Remission Induction, Retrospective Studies, Survival Analysis, Transcription Factor AP-2, Translocation, Genetic, Treatment Outcome, Antimetabolites, Antineoplastic therapeutic use, Cytarabine therapeutic use, DNA-Binding Proteins genetics, Leukemia, Myeloid, Acute genetics, Transcription Factors genetics
- Abstract
Clonal chromosomal abnormalities are the most important prognostic indicators in acute myeloid leukemia (AML). Recent advances in molecular biology have allowed structural and functional characterization of many of these genomic rearrangements and have provided evidence for their primary role in leukemogenesis. Two of the most prevalent cytogenetic subtypes of adult primary or de novo AML, t(8;21)(q22;q22) and inv(16)(p13q22), are characterized by disruption of the AML1(CBF alpha 2) gene at 21q22 and the CBF beta gene at 16q22, respectively. Both genes encode a subunit of core binding factor (CBF), a regulator of normal hematopoiesis. At the molecular level, t(8;21)(q22;q22) and inv(16)(p13q22) result in the creation of novel fusion genes, AML1/ETO and CBF beta/MYH11, whose structures and functions are being successfully characterized by in vitro studies and transgenic animal models. Detection of t(8;21)(q22;q22) or inv(16)(p13q22) in adult patients with primary AML is a favorable independent prognostic indicator for achievement of cure after intensive chemotherapy or bone marrow transplantation and may serve as a paradigm for risk-adapted treatment in AML. The purpose of this review is to summarize the recent advances in the molecular biology and clinical management of t(8;21)(q22;q22) and inv(16)(p13q22) primary AML, collectively referred to here as CBF AML.
- Published
- 2000
- Full Text
- View/download PDF
21. Detection of minimal residual disease in patients with AML1/ETO-associated acute myeloid leukemia using a novel quantitative reverse transcription polymerase chain reaction assay.
- Author
-
Marcucci G, Livak KJ, Bi W, Strout MP, Bloomfield CD, and Caligiuri MA
- Subjects
- Acute Disease, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Chromosomes, Human, Pair 21 genetics, Chromosomes, Human, Pair 8 genetics, Core Binding Factor Alpha 2 Subunit, Feasibility Studies, Humans, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute genetics, Neoplasm, Residual, RUNX1 Translocation Partner 1 Protein, Recombinant Fusion Proteins analysis, Remission Induction, Translocation, Genetic genetics, Leukemia, Myeloid, Acute diagnosis, Oncogene Proteins, Fusion, Polymerase Chain Reaction methods, Transcription Factors analysis
- Abstract
The AML1/ETO fusion transcript can be detected by reverse transcription polymerase chain reaction (RT-PCR) in patients with t(8;21)-associated acute myeloid leukemia (AML) in long-term complete remission (CR). Quantitation of the amount of the fusion transcript during CR may therefore be more predictive of cure or relapse than a simple qualitative assessment. Real Time PCR, a fluorometric-based technique, allows simple and rapid quantitation of a target sequence during the extension phase of PCR amplification, in contrast to end-point quantitative methods. Six patients with t(8;21)(q22;q22) AML, who achieved CR were studied by Real Time RT-PCR at different time intervals following diagnosis and high-dose cytarabine and anthracycline-based induction therapy. Five patients had a diagnostic bone marrow (BM) sample available for molecular analysis. Each patient showed > or = 10(3) copies of the AML1/ETO fusion transcript at diagnosis, and each showed a 2- to 4-log decrease in copy number following successful induction chemotherapy. This is comparable to the log-fold reduction in leukemic blasts that is thought to occur in patients successfully cytoreduced into CR by induction chemotherapy. The sixth patient showed a relatively high copy number immediately following successful remission induction chemotherapy, which continued to increase during early CR and was later followed by relapse. Real Time RT-PCR appears to offer advantages over previously used quantitative RT-PCR methods by providing absolute quantitation of the target sequence, expanding the dynamic range of quantitation to over six orders of magnitude, eliminating the post-PCR processing, and reducing labor and carryover contamination. These features make this an attractive method to prospectively evaluate the prognostic value of AML1/ETO fusion transcript quantitation in a larger patient population with t(8;21)(q22;q22) AML in CR.
- Published
- 1998
- Full Text
- View/download PDF
22. Defining the "absence" of the CBFbeta/MYH11 fusion transcript in patients with acute myeloid leukemia and inversion of chromosome 16 to predict long-term complete remission: a call for definitions.
- Author
-
Marcucci G, Caligiuri MA, and Bloomfield CD
- Subjects
- Humans, Polymerase Chain Reaction, Chromosome Inversion, Chromosomes, Human, Pair 16, Leukemia, Myeloid, Acute genetics, Oncogene Proteins, Fusion genetics, RNA, Messenger analysis
- Published
- 1997
23. The partial tandem duplication of ALL1 in acute myeloid leukemia with normal cytogenetics or trisomy 11 is restricted to one chromosome.
- Author
-
Caligiuri MA, Strout MP, Oberkircher AR, Yu F, de la Chapelle A, and Bloomfield CD
- Subjects
- Adult, Alleles, Gene Amplification, Histone-Lysine N-Methyltransferase, Humans, Myeloid-Lymphoid Leukemia Protein, Trisomy, Chromosomes, Human, Pair 11, DNA-Binding Proteins genetics, Leukemia, Myeloid, Acute genetics, Proto-Oncogenes, Transcription Factors
- Abstract
The molecular defects responsible for tumorigenesis in adult de novo acute myeloid leukemia (AML) with a normal karyotype or an additional copy of one chromosome (i.e., trisomy) remain largely unknown. We recently discovered that approximately 90% of adult patients with de novo AML and trisomy 11 (+11) as a sole abnormality and 11% of adult patients with de novo AML and normal cytogenetics carry a molecular rearrangement of the ALL1 (MLL, HRX, or HTRX) gene. The rearranged ALL1 gene has been shown to result from the direct tandem duplication of a portion of ALL1 itself. To better understand the underlying mechanisms of leukemogenesis, we asked whether in cytogenetically normal cases one or both chromosomes carry the mutated allele and whether in trisomic cases the mutation is present in one, two, or three chromosomes. Herein we show that in cytogenetically normal cases of AML and in cases with +11 as a sole cytogenetic abnormality, only one chromosome contains the mutated ALL1 allele. Thus a single mutated ALL1 allele with the partial tandem duplication is sufficient for ALL1-associated leukemogenesis, irrespective of the number of normal genes present. The frequently occurring specific association of +11 and ALL1 gene mutation in the leukemic clone remains unexplained.
- Published
- 1997
- Full Text
- View/download PDF
24. Acute nonlymphocytic leukemia in a glue sniffer.
- Author
-
Caligiuri MA, Early AP, Marinello MJ, and Preisler HD
- Subjects
- Adolescent, Humans, Male, Adhesives, Leukemia, Myeloid, Acute etiology, Substance-Related Disorders complications
- Abstract
A 17-year-old white male with a past history of chronic inhalational abuse of plastic glue was referred to our institution for sore throat, cervical adenopathy, and an abnormal peripheral blood smear. A diagnosis of acute myelomonocytic leukemia was made and abnormalities in cytogenetic studies were demonstrated. Specific inquiry regarding this form of drug exposure should be pursued when searching for possible etiologies of malignant disease.
- Published
- 1985
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.