scholarly journals 8a, a New Acridine Antiproliferative and Pro-Apoptotic Agent Targeting HDAC1/DNMT1

2021 ◽  
Vol 22 (11) ◽  
pp. 5516
Author(s):  
Qiting Zhang ◽  
Ziyan Wang ◽  
Xinyuan Chen ◽  
Haoxiang Qiu ◽  
Yifan Gu ◽  
...  

Epigenetic therapy using histone deacetylase (HDAC) inhibitors has become an attractive project in new drug development. However, DNA methylation and histone acetylation are important epigenetic ways to regulate the occurrence and development of leukemia. Given previous studies, N-(2-aminophenyl)benzamide acridine (8a), as a histone deacetylase 1 (HDAC1) inhibitor, induces apoptosis and shows significant anti-proliferative activity against histiocytic lymphoma U937 cells. HDAC1 plays a role in the nucleus, which we confirmed by finding that 8a entered the nucleus. Subsequently, we verified that 8a mainly passes through the endogenous (mitochondrial) pathway to induce cell apoptosis. From the protein interaction data, we found that 8a also affected the expression of DNA methyltransferase 1 (DNMT1). Therefore, an experiment was performed to assess the binding of 8a to DNMT1 at the molecular and cellular levels. We found that the binding strength of 8a to DNMT1 enhanced in a dose-dependent manner. Additionally, 8a inhibits the expression of DNMT1 mRNA and its protein. These findings suggested that the anti-proliferative and pro-apoptotic activities of 8a against leukemia cells were achieved by targeting HDAC1 and DNMT1.

2014 ◽  
Vol 46 (7) ◽  
pp. 245-255 ◽  
Author(s):  
Pankaj Chaturvedi ◽  
Anuradha Kalani ◽  
Srikanth Givvimani ◽  
Pradip Kumar Kamat ◽  
Anastasia Familtseva ◽  
...  

The mechanisms of homocysteine-mediated cardiac threats are poorly understood. Homocysteine, being the precursor to S-adenosyl methionine (a methyl donor) through methionine, is indirectly involved in methylation phenomena for DNA, RNA, and protein. We reported previously that cardiac-specific deletion of N-methyl-d-aspartate receptor-1 (NMDAR1) ameliorates homocysteine-posed cardiac threats, and in this study, we aim to explore the role of NMDAR1 in epigenetic mechanisms of heart failure, using cardiomyocytes during hyperhomocysteinemia (HHcy). High homocysteine levels activate NMDAR1, which consequently leads to abnormal DNA methylation vs. histone acetylation through modulation of DNA methyltransferase 1 (DNMT1), HDAC1, miRNAs, and MMP9 in cardiomyocytes. HL-1 cardiomyocytes cultured in Claycomb media were treated with 100 μM homocysteine in a dose-dependent manner. NMDAR1 antagonist (MK801) was added in the absence and presence of homocysteine at 10 μM in a dose-dependent manner. The expression of DNMT1, histone deacetylase 1 (HDAC1), NMDAR1, microRNA (miR)-133a, and miR-499 was assessed by real-time PCR as well as Western blotting. Methylation and acetylation levels were determined by checking 5′-methylcytosine DNA methylation and chromatin immunoprecipitation. Hyperhomocysteinemic mouse models (CBS+/−) were used to confirm the results in vivo. In HHcy, the expression of NMDAR1, DNMT1, and matrix metalloproteinase 9 increased with increase in H3K9 acetylation, while HDAC1, miR-133a, and miR-499 decreased in cardiomyocytes. Similar results were obtained in heart tissue of CBS+/− mouse. High homocysteine levels instigate cardiovascular remodeling through NMDAR1, miR-133a, miR-499, and DNMT1. A decrease in HDAC1 and an increase in H3K9 acetylation and DNA methylation are suggestive of chromatin remodeling in HHcy.


Blood ◽  
2009 ◽  
Vol 114 (13) ◽  
pp. 2764-2773 ◽  
Author(s):  
Tamer E. Fandy ◽  
James G. Herman ◽  
Patrick Kerns ◽  
Anchalee Jiemjit ◽  
Elizabeth A. Sugar ◽  
...  

Abstract Sequential administration of DNA methyltransferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors has demonstrated clinical efficacy in patients with hematologic malignancies. However, the mechanism behind their clinical efficacy remains controversial. In this study, the methylation dynamics of 4 TSGs (p15INK4B, CDH-1, DAPK-1, and SOCS-1) were studied in sequential bone marrow samples from 30 patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) who completed a minimum of 4 cycles of therapy with 5-azacytidine and entinostat. Reversal of promoter methylation after therapy was observed in both clinical responders and nonresponders across all genes. There was no association between clinical response and either baseline methylation or methylation reversal in the bone marrow or purified CD34+ population, nor was there an association with change in gene expression. Transient global hypomethylation was observed in samples after treatment but was not associated with clinical response. Induction of histone H3/H4 acetylation and the DNA damage–associated variant histone γ-H2AX was observed in peripheral blood samples across all dose cohorts. In conclusion, methylation reversal of candidate TSGs during cycle 1 of therapy was not predictive of clinical response to combination “epigenetic” therapy. This trial is registered with http://www.clinicaltrials.gov under NCT00101179.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2418-2418 ◽  
Author(s):  
Angela Hatter ◽  
Purva Bali ◽  
Maria Balasis ◽  
Warren Fiskus ◽  
Sandhya Boyapalle ◽  
...  

Abstract We have previously reported that agents that inhibit ATP binding and chaperone function of hsp90 are highly active against wild type and mutant Bcr-Abl and mutant FLT-3 containing human acute leukemia cells. In the present studies, we determined the effects of a more soluble and potent geldanamycin analogue, DMAG (Kosan Biosciences Inc.), and/or hydroxamate histone deacetylase inhibitor (HHDI), vorinostat (Merck & Co., Inc.), against human MCL Jeko1 and MO2058 cells. These cells contain the characteristic MCL-associated chromosomal translocation t(11; 14)(q13;q32), which results in the overexpression of cyclin D1. Recently, HHDIs, such as vorinostat, have been shown to inhibit HDAC6, which results in the acetylation of hsp90 and inhibition of its ATP binding and chaperone function. Treatment with vorinostat (0.5 to 2.0 μM) induced the accumulation of the cells in the G1 and DMAG (0.1 to 0.5 μM) in the G2/M phase of the cell cycle. Both agents induced apoptosis in a dose-dependent manner (up to 50%). While vorinostat induced both p21 and p27 levels, DMAG only increased the intracellular levels of p21. Treatment with either agent depleted the intracellular levels of c-Myc, c-Raf, Akt and cdk4 in a dose dependent manner. It is well established that the chaperone association with hsp90 maintains Akt, c-Raf, cyclin D1 and cdk4 in the native and active conformation, and inhibition of hsp90 promotes their polyubiquitylation and proteasomal degradation. Notably, co-treatment with DMAG (e.g., 0.25 μM) and vorinostat (e.g., 2.0 μM), more than either agent alone, markedly attenuated the levels of cyclin D1 and cdk4, as well as the levels of c-Myc, c-Raf and Akt. The combination of DMAG and vorinostat also induced significantly more apoptosis of Jeko1 and MO2058 cells, as compared to the treatment with either agent alone (p < 0.01). These findings demonstrate that the combined treatment with vorinostat and DMAG is highly active against human MCL cells, and support the rationale to determine the in vivo efficacy and safety of the combination against human MCL.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5033-5033
Author(s):  
Quanyi Lu ◽  
Jane Feng ◽  
Karen Seiter ◽  
Tauseef Ahmed ◽  
Dicky J.W. Chiao ◽  
...  

Abstract Histone deacetylase (HDAC) inhibitors are emerging as a promising family of new agents in the therapy of hematologic malignancies. We have shown that phenyhexyl isothiocyanate(PHI) is a novel histone deacetylase inhibitor and can also modulate histone methylation in leukemia cells. In this study we investigated the effect of PHI on human myeloma cell line RPMI8226 in vitro. We have observed that cell proliferation was inhibited by PHI in a dose and time dependent manner. Cell cycle analysis indicated an arrest in G0/G1 phase, and significant apoptosis was detected in PHI treated RPMI8226 cells. The accumulation of P21 and reduced Levels of PCNA were detected. We also examined the effect of PHI on vascular endothelial growth factor (VEGF) production by the myeloma cells. Treatment with 20μM PHI for 24hrs led to a decrease of VEGF concentration by 50% of that secreted by the control cells. VEGF production further decreased to 25% when the cells were exposed to PHI for 48hrs. These data suggest that myeloma cells are sensitive to the novel HDAC inhibitor, and PHI may become a novel agent in multiple myeloma therapy. PHI Inhibit VEGF production by Myeloma Cells PHI Inhibit VEGF production by Myeloma Cells


Blood ◽  
2003 ◽  
Vol 102 (7) ◽  
pp. 2615-2622 ◽  
Author(s):  
Laurence Catley ◽  
Ellen Weisberg ◽  
Yu-Tzu Tai ◽  
Peter Atadja ◽  
Stacy Remiszewski ◽  
...  

Abstract Histone deacetylase (HDAC) inhibitors are emerging as a promising new treatment strategy in hematologic malignancies. Here we show that NVP-LAQ824, a novel hydroxamic acid derivative, induces apoptosis at physiologically achievable concentrations (median inhibitory concentration [IC50] of 100 nM at 24 hours) in multiple myeloma (MM) cell lines resistant to conventional therapies. MM.1S myeloma cell proliferation was also inhibited when cocultured with bone marrow stromal cells, demonstrating ability to overcome the stimulatory effects of the bone marrow microenvironment. Importantly, NVP-LAQ824 also inhibited patient MM cell growth in a dose- and time-dependent manner. NVP-LAQ824-induced apoptotic signaling includes up-regulation of p21, caspase cascade activation, and poly (adenosine diphosphate [ADP]) ribose (PARP) cleavage. Apoptosis was confirmed with cell cycle analysis and annexin-propidium iodide staining. Interestingly, treatment of MM cells with NVPLAQ824 also led to proteasome inhibition, as determined by reduced proteasome chymotrypsin-like activity and increased levels of cellular polyubiquitin conjugates. Finally, a study using NVP-LAQ824 in a preclinical murine myeloma model provides in vivo relevance to our in vitro studies. Taken together, these findings provide the framework for NVP-LAQ824 as a novel therapeutic in MM. (Blood. 2003;102:2615-2622)


2007 ◽  
Vol 27 (20) ◽  
pp. 7089-7101 ◽  
Author(s):  
Michael Schnekenburger ◽  
Glenn Talaska ◽  
Alvaro Puga

ABSTRACT Transcriptional regulation of gene expression requires posttranslational modification of histone proteins, which, in concert with chromatin-remodeling factors, modulate chromatin structure. Exposure to environmental agents may interfere with specific histone modifications and derail normal patterns of gene expression. To test this hypothesis, we coexposed cells to binary mixtures of benzo[a]pyrene (B[a]P), an environmental procarcinogen that activates Cyp1a1 transcriptional responses mediated by the aryl hydrocarbon receptor (AHR), and chromium, a carcinogenic heavy metal that represses B[a]P-inducible AHR-mediated gene expression. We show that chromium cross-links histone deacetylase 1-DNA methyltransferase 1 (HDAC1-DNMT1) complexes to Cyp1a1 promoter chromatin and inhibits histone marks induced by AHR-mediated gene transactivation, including phosphorylation of histone H3 Ser-10, trimethylation of H3 Lys-4, and various acetylation marks in histones H3 and H4. These changes inhibit RNA polymerase II recruitment without affecting the kinetics of AHR DNA binding. HDAC1 and DNMT1 inhibitors or depletion of HDAC1 or DNMT1 with siRNAs blocks chromium-induced transcriptional repression by decreasing the interaction of these proteins with the Cyp1a1 promoter and allowing histone acetylation to proceed. By inhibiting Cyp1a1 expression, chromium stimulates the formation of B[a]P DNA adducts. Epigenetic modification of gene expression patterns may be a key element of the developmental and carcinogenic outcomes of exposure to chromium and to other environmental agents.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2729-2729
Author(s):  
Yuan-I Chang ◽  
Guangyao Kong ◽  
Jing Zhang ◽  
Erik A. Ranheim

Abstract Recent whole genome/exome sequencing efforts in myeloid malignancies identified that mutations in DNA methyltransferase 3A (DNMT3A) are prevalent in acute myeloid leukemia (AML). In addition, DNMT3A mutations are also identified in various T cell malignancies. Of note, DNMT3A mutations are typically heterozygous and some WT DNMT3A functions thus remain in this state. However, the predominant DNMT3A R882 mutations, which locate in the catalytic domain, seem to inhibit the methyltransferase activity of the remaining WT DNMT3A due to its dominant-negative function (Yang L, Rau R, Goodell MA, Nat. Rev. Cancer 15: 152-165, 2015). COSMIC database analysis reveals different prevalence of DNMT3A R882 mutations in various hematopoietic malignancies. Approximately 60% of DNMT3A mutations in AML are R882 mutations, while the frequency of R882 mutations drops to ~40% in myelodysplastic syndrome (MDS) and myeloproliferative neoplasm (MPN). In contrast, the frequency of R882mutations is less than 25% in T-cell acute lymphoblastic leukemia (T-ALL). The significantly different frequencies of DNMT3A R882 mutations in AML versus T-ALL inspired us to investigate whether downregulation of DNMT3A regulates malignancies of different lineages in a dose-dependent manner. We previously showed that Dnmt3a-/- promotes MPN progression in KrasG12D/+ mice and ~1/3 compound mice develop AML-like disease (Chang et al. Leukemia 29: 1847-1856, 2015). Here, we generated KrasG12D/+; Dnmt3afl/+; Mx1-Cre mice to determine how Dnmt3a haploisufficiency affects KrasG12D/+-induced leukemogenesis. After pI-pC injections to induce Mx1-Cre expression, primary KrasG12D/+; Dnmt3a+/- mice died quickly as primary KrasG12D/+ mice; the survival rates of these two groups of animals were not significantly different. However, in a competitive transplant setting, recipients transplanted with KrasG12D/+; Dnmt3a+/- bone marrow cells displayed a significantly shortened survival than recipients with KrasG12D/+ cells. Moreover, all of the recipients with KrasG12D/+; Dnmt3a+/- cells developed a lethal T-ALL without significant MPN phenotypes, while ~20% of recipients with KrasG12D/+ cells developed MPN with or without T-ALL. This is in sharp contrast to the recipients with KrasG12D/+; Dnmt3a-/- cells, in which ~60% developed a lethal myeloid malignancy (MPN or AML). Our data suggest that in the context of oncogenic Kras, loss of Dnmt3a promotes myeloid malignancies, while Dnmt3a haploisufficiency induces T-ALL. This dose-dependent phenotype is highly consistent with the prevalence of DNMT3A R882 mutations in AML versus T-ALL in human. We are currently investigating the underlying mechanisms. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 25 (1) ◽  
pp. 173-191 ◽  
Author(s):  
Rachel Kuta ◽  
Nancy Larochelle ◽  
Mario Fernandez ◽  
Arun Pal ◽  
Sandra Minotti ◽  
...  

AbstractUpregulation of heat shock proteins (HSPs) is an approach to treatment of neurodegenerative disorders with impaired proteostasis. Many neurons, including motor neurons affected in amyotrophic lateral sclerosis (ALS), are relatively resistant to stress-induced upregulation of HSPs. This study demonstrated that histone deacetylase (HDAC) inhibitors enable the heat shock response in cultured spinal motor neurons, in a stress-dependent manner, and can improve the efficacy of HSP-inducing drugs in murine spinal cord cultures subjected to thermal or proteotoxic stress. The effect of particular HDAC inhibitors differed with the stress paradigm. The HDAC6 (class IIb) inhibitor, tubastatin A, acted as a co-inducer of Hsp70 (HSPA1A) expression with heat shock, but not with proteotoxic stress induced by expression of mutant SOD1 linked to familial ALS. Certain HDAC class I inhibitors (the pan inhibitor, SAHA, or the HDAC1/3 inhibitor, RGFP109) were HSP co-inducers comparable to the hydroxyamine arimoclomol in response to proteotoxic stress, but not thermal stress. Regardless, stress-induced Hsp70 expression could be enhanced by combining an HDAC inhibitor with either arimoclomol or with an HSP90 inhibitor that constitutively induced HSPs. HDAC inhibition failed to induce Hsp70 in motor neurons expressing ALS-linked mutant FUS, in which the heat shock response was suppressed; yet SAHA, RGFP109, and arimoclomol did reduce loss of nuclear FUS, a disease hallmark, and HDAC inhibition rescued the DNA repair response in iPSC-derived motor neurons carrying the FUSP525Lmutation, pointing to multiple mechanisms of neuroprotection by both HDAC inhibiting drugs and arimoclomol.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1994-1994
Author(s):  
Matthew C. Stubbs ◽  
Teresa Kim ◽  
Andrei Krivtsov ◽  
Peter Atadja ◽  
Scott A. Armstrong ◽  
...  

Abstract Lymphoblastic leukemias containing chromosomal translocations involving the Mixed Lineage Leukemia (MLL, HRX, ALL-1) gene, as well as most acute myeloid leukemias (AMLs) have relatively poor clinical prognoses due in part to intrinsic drug resistance. Therefore, new avenues are being explored for treatment of MLL-rearranged ALL and AMLs. One possible new therapeutic class currently being investigated is the histone deacetylase (HDAC) inhibitors. We utilized the histone deacetylase inhibitor NVP-LAQ824 (Novartis, Basel, Switzerland) and analyzed its effects on MLL rearranged and other myeloid leukemias. We also made use of an MLL-AF9 expressing myeloid leukemia cell line (AKLG) derived from purified murine leukemia stem cells to perform gene expression analysis on NVP-LAQ824 treated cells in order to further understand the mechanism of action of HDAC inhibitors, and to potentially identify cooperating therapeutics. NVP-LAQ824 inhibits cell growth at similar concentrations for all cell lines and primary patient samples tested (~25–50nM) as determined by MTT assay 48 hours after treatment. NVP-LAQ824 does not appear to induce apoptosis solely through inhibition of the HSP90/FLT3-ITD complex as cell lines possessing FLT3-ITD (a HSP90-chaperoned protein) and cells without this mutation have similar drug sensitivities. In fact, in cells overexpressing FLT3-ITD that are treated with NVP-LAQ824, phospho-FLT3-ITD levels do not diminish. Microarray data indicated that NVP-LAQ824 induces the BH3-only family member bim. This finding was verified by Western blotting in all cell lines and patient samples tested. Further, shRNA-mediated knockdown of Bim induced relative resistance of cells to NVP-LAQ824. The expression profile also showed similarities to gene expression patterns of dexamethasone treated cells, namely, increased bim levels and decreased expression of c-myc, raising the possibility of synergy between the two drugs. Using MTT assays, we discovered that NVP-LAQ824 in low doses (25nM) induces sensitivity to dexamethasone in glucocorticoid resistant cell lines in a glucocorticoid receptor (GR) dependent manner. Therefore, our data indicate that NVP-LAQ824 may reverse glucocorticoid resistance and may provide insight into glucocorticoid resistance in MLL rearranged leukemias. The biochemistry behind HDAC inhibitors merits further study.


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