Project description:We and others have previously reported that 3-Deazaneplanocin A (DZNep) is a histone methylation inhibitor that has a wide range anticancer effects in a variety of human cancers. Here, using acute myeloid leukemia as a model, we reported a less toxic analog of DZNep, named D9, that is shown to be efficacious in both cell lines and patient samples of AML. Gene expression analysis in a panel of AML cell lines treated with D9 identified a set of genes that is associated with D9 sensitivity and is implicated in multiple oncogenic signaling pathways. Moreover, we show that D9 is able to deplete the leukemia stem cells (LSC) and abolish chemotherapy-induced LSC enrichment, leading to dramatic elimination of AML cell survival and associated gene expression when combined with chemotherapy. Thus, D9 appears to be a robust epigenetic compound that may constitute a potential for AML therapy.
Project description:We and others have previously reported that 3-Deazaneplanocin A (DZNep) is a histone methylation inhibitor that has a wide range anticancer effects in a variety of human cancers. Here, using acute myeloid leukemia as a model, we reported a less toxic analog of DZNep, named D9, that is shown to be efficacious in both cell lines and patient samples of AML. Gene expression analysis in a panel of AML cell lines treated with D9 identified a set of genes that is associated with D9 sensitivity and is implicated in multiple oncogenic signaling pathways. Moreover, we show that D9 is able to deplete the leukemia stem cells (LSC) and abolish chemotherapy-induced LSC enrichment, leading to dramatic elimination of AML cell survival and associated gene expression when combined with chemotherapy. Thus, D9 appears to be a robust epigenetic compound that may constitute a potential for AML therapy.
Project description:We and others have previously reported that 3-Deazaneplanocin A (DZNep) is a histone methylation inhibitor that has a wide range anticancer effects in a variety of human cancers. Here, using acute myeloid leukemia as a model, we reported a less toxic analog of DZNep, named D9, that is shown to be efficacious in both cell lines and patient samples of AML. Gene expression analysis in a panel of AML cell lines treated with D9 identified a set of genes that is associated with D9 sensitivity and is implicated in multiple oncogenic signaling pathways. Moreover, we show that D9 is able to deplete the leukemia stem cells (LSC) and abolish chemotherapy-induced LSC enrichment, leading to dramatic elimination of AML cell survival and associated gene expression when combined with chemotherapy. Thus, D9 appears to be a robust epigenetic compound that may constitute a potential for AML therapy. We found D9 treatment depleted chemotherapy-induced LSC. We next sought to characterize the molecular changes induce by the chemotherapy that is antagonized by D9. To do this, TF-1a cells before and after Ara-C or ADR treatment or co-treated with D9 were harvested for RNA isolation and genome-wide transcription profilling.
Project description:We and others have previously reported that 3-Deazaneplanocin A (DZNep) is a histone methylation inhibitor that has a wide range anticancer effects in a variety of human cancers. Here, using acute myeloid leukemia as a model, we reported a less toxic analog of DZNep, named D9, that is shown to be efficacious in both cell lines and patient samples of AML. Gene expression analysis in a panel of AML cell lines treated with D9 identified a set of genes that is associated with D9 sensitivity and is implicated in multiple oncogenic signaling pathways. Moreover, we show that D9 is able to deplete the leukemia stem cells (LSC) and abolish chemotherapy-induced LSC enrichment, leading to dramatic elimination of AML cell survival and associated gene expression when combined with chemotherapy. Thus, D9 appears to be a robust epigenetic compound that may constitute a potential for AML therapy. We evaluated the overall effects of D9 on histone lysine methylations in AML cell lines and its relationship to apoptosis induction by D9. The results demonstrated that the both sensitive and resistant cell lines, treated with D9 for 48 and 72 hours, showed similar levels of suppression of histone lysine methylation. Thus, the differential sensitivities of AML cells to D9 is not due to its different ability to inhibit the bulk histone methylation but is more likely to be associated with the differential gene expression response to D9. To test this hypothesis, we treated three sensitive (MOLM-14, MV4-11 and TF-1) and three resistant (Mono-Mac-1, THP-1, and KG-1a) cell lines with D9 at 1 or 5 μM for 48 hours and performed Illumina BeadChip transcriptom profiling analysis. Significance Analysis of Microarrays (SAM) analysis shows that D9 treatment resulted in transcriptional changes of 547 genes, including 327 upregulated genes and 220 downregulated genes in sensitive cell lines but not in resistant cell lines.
Project description:The epigenetic treatment by 3-Deazaneplanocin A (DZNep), a histone methyltransferase inhibitor, shows great potential against acute myeloid leukemia (AML). However, the variant sensitivity and incomplete response to DZNep are commonly observed. We reveal that vitamin C (Vc) dramatically promotes DZNep response against leukemic cells in different cell lines and primary AML samples. To examine the molecular determinants underlying Vc enhanced anti-leukemia effect of DZNep, we conducted a genome-wide RNA sequencing and a gene ontology (GO) enrichment analysis of differentially expressed mRNAs in each group was performed.
Project description:We demonstrated that 3-Deazaneplanocin A (DZNep), a histone methyltransferase inhibitor, induce robust apoptosis in AML cells through increased ROS production and ER stress. We identified a core gene signature including TXNIP, a major redox control molecule which is crucial in DZNep-induced apoptosis. MOLM-14 cells were treated with DMSO and DZNep 2 µM for 24 hours
Project description:We demonstrated that 3-Deazaneplanocin A (DZNep), a histone methyltransferase inhibitor, induce robust apoptosis in AML cells through increased ROS production and ER stress. We identified a core gene signature including TXNIP, a major redox control molecule which is crucial in DZNep-induced apoptosis.
Project description:Background:Aberrant DNA methylation that silences tumor suppressor genes occurs frequently in patients with acute myeloid leukemia (AML). Treatment of AML patients with the inhibitor of DNA methylation, 5-aza-2'-deoxycytidine (5-AZA-CdR) can induce complete remissions, but most patients will relapse. The clinical efficacy of 5-AZA-CdR may be influenced by its limited capacity to activate tumor suppressor genes silenced by methylation of lysine 27 histone H3 (H3K27) by EZH2. In order to overcome this limitation, we investigated previously the antileukemic action of 5-AZA-CdR in combination with the EZH2 inhibitor, 3-deazaneplanocin A (DZNep) on HL-60 AML cells. We observed a remarkable synergistic interaction against these AML cells for this combination. In this study, we investigated in more depth the action of 5-AZA-CdR plus DZNep on gene expression in AML cells using RNA sequence analysis Result:In a colony assay, 5-AZA-CdR in combination with DZNep exhibited also a potent synergy against another human AML cell line: AML-3. The induction of apoptosis in HL-60 and AML3 leukemic cells by 5-AZA-CdR plus DZNep was also synergistic. RNA sequence analysis on HL-60 leukemic cells showed that the combination of 5-AZA-CdR plus DZNep increased the expression of thousands of genes. The genes upregulated by this combination included genes related to differentiation, development, senescence, apoptosis, and tumor suppressor function. Many of the genes activated by 5-AZA-CdR plus DZNep have the potential to suppress leukemogenesis. Conclusion: The activation of many genes by the combination of 5-AZA-CdR plus DZNep correlates with its synergistic antileukemic action. The block in differentiation is one of the hallmarks of AML.The activation of many genes that program differentiation and development by this combination of epigenetic agents has the potential to reverse this block. The reversal of these two epigenetic genesilencing mechanisms by 5-AZA-CdR plus DZNep merits clinical investigation in patients with AML
Project description:The 3-Deazaneplanocin A (DZNep), one of S-adenosylhomocysteine (AdoHcy) hydrolase inhibitors, has shown antitumor activities in a broad range of solid tumors and acute myeloid leukemia. Here, we examined its effects on multiple myeloma (MM) cells and found that, at 500 nM, it potently inhibited growth and induced apoptosis in 2 of 8 MM cell lines. RNA from un-treated and DZNep treated cells was profiled by Affymetrix HG-U133 Plus 2.0 microarray and genes with a significant change in gene expression were determined by significance analysis of microarray (SAM) testing. ALOX5 was the most down-regulated gene (5.8-fold) in sensitive cells and was expressed at low level in resistant cells. The results were corroborated by quantitative RT-PCR. Western-blot analysis indicated ALOX5 was highly expressed only in sensitive cell line H929 and greatly decreased upon DZNep treatment. Ectopic expression of ALOX5 reduced sensitivity to DZNep in H929 cells. Furthermore, down-regulation of ALOX5 by RNA interference could also induce apoptosis in H929. Gene expression analysis on MM patient dataset indicated ALOX5 expression was significantly higher in MM patients compared to normal plasma cells. We also found that Bcl-2 was overexpressed in DZNep insensitive cells, and cotreatment with DZNep and ABT-737, a Bcl-2 family inhibitor, synergistically inhibited growth and induced apoptosis of DZNep insensitive MM cells. Taken together, this study shows one of mechanisms of the DZNep efficacy on MM correlates with its ability to down-regulate the ALOX5 levels. In addition, DZNep insensitivity might be associated with overexpression of Bcl-2, and the combination of ABT-737 and DZNep could synergistically induced apoptosis. These results suggest that DZNep may be exploited therapeutically for a subset of MM. Cells were treated with 0.5 μmol/L DZNep for 48 h. Total RNA was extracted by using the Qiagen RNeasy Mini kit (Germany). Gene expression was performed using the GeneChip® Human Genome U133A Array (Affymetrix) following the manufacturer’s instructions. Data analysis was performed using GeneSpring software from Agilent Technologies.