Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P16104 (H2AX)
 3,930 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the mechanism of action of LBH589, a novel broad-spectrum HDAC inhibitor belonging to the hydroxamate class, in Philadelphia chromosome-negative (Ph(-)) acute lymphoblastic leukemia (ALL). Two model human Ph(-) ALL cell lines (T-cell MOLT-4 and pre-B-cell Reh) were treated with LBH589 and evaluated for biologic and gene expression responses. Low nanomolar concentrations (IC(50): 5-20 nM) of LBH589 induced cell-cycle arrest, apoptosis, and histone (H3K9 and H4K8) hyperacetylation. LBH589 treatment increased mRNA levels of proapoptosis, growth arrest, and DNA damage repair genes including FANCG, FOXO3A, GADD45A, GADD45B, and GADD45G. The most dramatically expressed gene (up to 45-fold induction) observed after treatment with LBH589 is GADD45G. LBH589 treatment was associated with increased histone acetylation at the GADD45G promoter and phosphorylation of histone H2A.X. Furthermore, treatment with LBH589 was active against cultured primary Ph(-) ALL cells, including those from a relapsed patient, inducing loss of cell viability (up to 70%) and induction of GADD45G mRNA expression (up to 35-fold). Thus, LBH589 possesses potent growth inhibitory activity against including Ph(-) ALL cells associated with up-regulation of genes critical for DNA damage response and growth arrest. These findings provide a rationale for exploring the clinical activity of LBH589 in the treatment of patients with Ph(-) ALL.
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PMID:The novel histone deacetylase inhibitor, LBH589, induces expression of DNA damage response genes and apoptosis in Ph- acute lymphoblastic leukemia cells. 1834 21

The deregulation of the DNA damage response (DDR) can contribute to leukemogenesis and favor the progression from myelodysplastic syndrome (MDS) to acute myeloid leukemia (AML). Since hypomethylating agent, notably azacitidine, constitute an efficient therapy for patients with high-risk MDS, we assessed whether such compounds can activate the DDR in malignant blasts. While azacitidine and decitabine had moderate effects on apoptosis and cell cycle progression, both agents induced profound changes in the expression and functionality of DDR-related proteins. Decitabine, and to a lesser degree azacitidine, induced the activation of checkpoint kinases Chk-1 and Chk-2 and the phosphorylation of the DDR-sensor H2AX. In addition, hypomethylating agents were found to cause the dephosphorylation of the transcriptional regulator forkhead box O3, best known as FOXO3A, whose phosphorylation has been related to poor prognosis in AML. The dephoasphorylation of FOXO3A induced by azacitidine or decitabine in malignant blasts was accompanied by the translocation of FOXO3A from the cytoplasm to the nucleus. Upon stimulation with azacitidine, MDS/AML-derived, azacitidine-sensitive SKM-1S cells upregulated FOXO3A and the pro-apoptotic FOXO3A targets BIM and PUMA, and this effect was attenuated or abolished in azacitidine-resistant SMK-1R cells. Altogether, our results suggest that the reactivation of FOXO3A may contribute to the effects of hypomethylating agents in malignant blasts.
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PMID:Hypomethylating agents reactivate FOXO3A in acute myeloid leukemia. 2190 75

Schwann cells are the main source of paracrine support to motor neurons. Oxidative stress and mitochondrial dysfunction have been correlated to motor neuron death in Amyotrophic Lateral Sclerosis (ALS). Despite the involvement of Schwann cells in early neuromuscular disruption in ALS, detailed molecular events of a dying-back triggering are unknown. Sciatic nerves of presymptomatic (60-day-old) SOD1(G93A) mice were submitted to a high-density oligonucleotide microarray analysis. DAVID demonstrated the deregulated genes related to death, stress and mitochondrion, which allowed the identification of Cell cycle, ErbB signaling, Tryptophan metabolism and Rig-I-like receptor signaling as the most representative KEGG pathways. The protein-protein interaction networks based upon deregulated genes have identified the top hubs (TRAF2, H2AFX, E2F1, FOXO3, MSH2, NGFR, TGFBR1) and bottlenecks (TRAF2, E2F1, CDKN1B, TWIST1, FOXO3). Schwann cells were enriched from the sciatic nerve of presymptomatic mice using flow cytometry cell sorting. qPCR showed the up regulated (Ngfr, Cdnkn1b, E2f1, Traf2 and Erbb3, H2afx, Cdkn1a, Hspa1, Prdx, Mapk10) and down-regulated (Foxo3, Mtor) genes in the enriched Schwann cells. In conclusion, molecular analyses in the presymptomatic sciatic nerve demonstrated the involvement of death, oxidative stress, and mitochondrial pathways in the Schwann cell non-autonomous mechanisms in the early stages of ALS.
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PMID:Dysregulated expression of death, stress and mitochondrion related genes in the sciatic nerve of presymptomatic SOD1(G93A) mouse model of Amyotrophic Lateral Sclerosis. 2633 26

During colon cancer, epigenetic alterations contribute to the dysregulation of major cellular functions and signaling pathways. Modifications in chromatin signatures such as H3K4me3 and H3K9ac, which are associated with transcriptionally active genes, can lead to genomic instability and perturb the expression of gene sets associated with oncogenic processes. In order to further elucidate early pre-tumorigenic epigenetic molecular events driving CRC, we integrated diverse, genome-wide, epigenetic inputs (by high throughput sequencing of RNA, H3K4me3, and H3K9ac) and compared differentially expressed transcripts (DE) and enriched regions (DER) in an in-vivo rat colon cancer progression model. Carcinogen (AOM) effects were detected genome-wide at the RNA (116 DE genes), K9ac (49 DERs including 24 genes) and K4me3 (7678 DERs including 3792 genes) level. RNA-seq differential expression and pathway analysis indicated that interferon-associated innate immune responses were impacted by AOM exposure. Despite extensive associations between K4me3 DERs and colon tumorigenesis (1210 genes were linked to colorectal carcinoma) including FOXO3, GNAI2, H2AFX, MSH2, NR3C1, PDCD4 and VEGFA, these changes were not reflected at the RNA gene expression level during early cancer progression. Collectively, our results indicate that carcinogen-induced changes in gene K4me3 DERs are harbingers of future transcriptional events, which drive malignant transformation of the colon.
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PMID:Assessment of histone tail modifications and transcriptional profiling during colon cancer progression reveals a global decrease in H3K4me3 activity. 2831 75