AMPK Associates with Chromatin and Phosphorylates the TAF-1 Subunit of the Transcription Initiation Complex to Regulate Histone Gene Expression in ALL Cells.

Unlabelled: The survival rates for relapsed/refractory acute lymphoblastic leukemia (ALL) remain poor. We and others have reported that ALL cells are vulnerable to conditions inducing energy/ER-stress mediated by AMP-activated protein kinase (AMPK). To identify the target genes directly regulated by AMPKα2, we performed genome-wide RNA-seq and ChIP-seq in CCRF-CEM (T-ALL) cells expressing HA-AMPKα2 (CN2) under normal and energy/metabolic stress conditions.

Protein Kinase D-Dependent Downregulation of Immediate Early Genes through Class IIA Histone Deacetylases in Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is a leading cause of cancer-related death in children and adolescents, and cure rates for relapsed/refractory ALL remain dismal, highlighting the need for novel targeted therapies. To identify genome-wide metabolic-stress regulated genes, we used RNA-sequencing in ALL cells treated with AICAR, an AMPK activator. RNA-sequencing identified the immediate early genes (IEGs) as a subset of genes downregulated by AICAR.

The NEDD8-activating enzyme inhibitor pevonedistat activates the eIF2α and mTOR pathways inducing UPR-mediated cell death in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the leading cause of cancer-related death in children, and cure rates for adults remain dismal. Further, effective treatment strategies for relapsed/refractory ALL remain elusive. We previously uncovered that ALL cells are prone to apoptosis via endoplasmic reticulum (ER) stress/unfolded protein response (UPR)-mediated mechanisms.

Mcl-1 downregulation leads to the heightened sensitivity exhibited by BCR-ABL positive ALL to induction of energy and ER-stress.

BCR-ABL positive (+) acute lymphoblastic leukemia (ALL) accounts for ∼30% of cases of ALL. We recently demonstrated that 2-deoxy-d-glucose (2-DG), a dual energy (glycolysis inhibition) and ER-stress (N-linked-glycosylation inhibition) inducer, leads to cell death in ALL via ER-stress/UPR-mediated apoptosis. Among ALL subtypes, BCR-ABL+ ALL cells exhibited the highest sensitivity to 2-DG suggesting BCR-ABL expression may be linked to this increased vulnerability.

Metformin induces apoptosis through AMPK-dependent inhibition of UPR signaling in ALL lymphoblasts.

The outcome of patients with resistant phenotypes of acute lymphoblastic leukemia (ALL) or those who relapse remains poor. We investigated the mechanism of cell death induced by metformin in Bp- and T-ALL cell models and primary cells, and show that metformin effectively induces apoptosis in ALL cells. Metformin activated AMPK, down-regulated the unfolded protein response (UPR) demonstrated by significant decrease in the main UPR regulator GRP78, and led to UPR-mediated cell death via up-regulation of the ER stress/UPR cell death mediators IRE1α and CHOP.

Inhibition of Akt potentiates 2-DG-induced apoptosis via downregulation of UPR in acute lymphoblastic leukemia.

The ability to pair the regulation of metabolism and cellular energetics with oncogenes and tumor suppressor genes provides cancer cells with a growth and survival advantage over normal cells. We investigated the mechanism of cell death induced by 2-deoxy-D-glucose (2-DG), a sugar analog with dual activity of inhibiting glycolysis and N-linked glycosylation, in acute lymphoblastic leukemia (ALL). We found that, unlike most other cancer phenotypes in which 2-DG only inhibits cell proliferation under normoxic conditions, ALL lymphoblasts undergo apoptosis.

AMPK and Akt determine apoptotic cell death following perturbations of one-carbon metabolism by regulating ER stress in acute lymphoblastic leukemia.

AICAr is a cell-permeable nucleotide that has been used in vivo and in vitro to activate AMPK. Our previous findings have shown that AICAr as a single agent induces dose- and time-dependent growth inhibition in acute lymphoblastic leukemia (ALL) cell lines. In addition, the combination of AICAr with antifolates [methotrexate (MTX) or pemetrexed] has been shown to further potentiate AMPK activation and to lead to greater cytotoxicity and growth inhibition in leukemia and other malignant cell types.

AMPK-induced activation of Akt by AICAR is mediated by IGF-1R dependent and independent mechanisms in acute lymphoblastic leukemia.

Background: Children with Acute Lymphoblastic Leukemia (ALL) diagnosed with resistant phenotypes and those who relapse have a dismal prognosis for cure. In search for novel treatment strategies, we identified the AMP activated protein kinase (AMPK) as a potential drug target based on its effects on cell growth and survival. We have shown previously that AICAR-induced AMPK activation also induced a compensatory survival mechanism via PI3K/Akt signaling.

Folylpolyglutamate synthetase gene transcription is regulated by a multiprotein complex that binds the TEL-AML1 fusion in acute lymphoblastic leukemia.

Acute Lymphoblastic Leukemia (ALL) non-random fusions influence clinical outcome and alter the accumulation of MTX-PGs in vivo. Analysis of primary ALL samples uncovered subtype-specific patterns of folate gene expression. Using an FPGS-luciferase reporter gene assay, we determined that E2A-PBX1 and TEL-AML1 expression decreased FPGS transcription.

Cytotoxic effect of 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR) on childhood acute lymphoblastic leukemia (ALL) cells: implication for targeted therapy.

Background: Acute lymphoblastic leukemia (ALL) is the most common hematological malignancy affecting children. Despite significant progress and success in the treatment of ALL, a significant number of children continue to relapse and for them, outcome remains poor. Therefore, the search for novel therapeutic approaches is warranted.

Analysis of folylpoly-gamma-glutamate synthetase gene expression in human B-precursor ALL and T-lineage ALL cells.

Background: Expression of folylpoly-gamma-glutamate synthetase (FPGS) gene is two- to three-fold higher in B-precursor ALL (Bp- ALL) than in T-lineage ALL (T-ALL) and correlates with intracellular accumulation of methotrexate (MTX) polyglutamates and lymphoblast sensitivity to MTX. In this report, we investigated the molecular regulatory mechanisms directing FPGS gene expression in Bp-ALL and T-ALL cells.

Methods: To determine FPGS transcription rate in Bp-ALL and T-ALL we used nuclear run-on assays.

Cloning and mRNA expression of the Ca2+-binding DREAM protein in the pituitary.

It is well recognized that the level of intracellular calcium governs several cellular processes such as gene expression and secretion in the pituitary. Recently, a novel gene has been identified in neuroendocrine cells that encodes DREAM, a calcium-binding protein that acts as a transcriptional repressor by binding specific downstream regulatory elements (DRE) on DNA. To explore the possibility that DREAM may be expressed in the rat pituitary and may function in endocrine activity, we analyzed its mRNA expression by RT-PCR.

Real-time RT-PCR analysis of mRNA decay: half-life of Beta-actin mRNA in human leukemia CCRF-CEM and Nalm-6 cell lines.

BACKGROUND: We describe an alternative method to determine mRNA half-life (t1/2) based on the Real-Time RT-PCR procedure. This approach was evaluated by using the beta-actin gene as a reference molecule for measuring of mRNA stability. RESULTS: Human leukemia Nalm-6 and CCRF-CEM cells were treated with various concentrations of Actinomycin D to block transcription and aliquots were removed periodically.