Project description:MiRNAs differentially expressed in normal pancreatic cell line (Human Pancreatic Ductal Epithelial cell line) vs MIA PaCa-2 (Pancreatic cancer cell line) were first identified by profiling >1900 miRNAs using an array approach. Subsequently, miRNAs differentially expressed in DZNep treated cells (as compared to untreated) were also identified. We also checked for miRNA changes with gemcitabine treatment as well as combination treatment.
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:Purpose: Radiotherapy is useful for non-small cell lung cancer (NSCLC) patients who cannot be treated surgically. Modification of histone proteins occurs during radiotherapy, and affects gene expression.In this study, we assessed the effects of radiotherapy on histone modification via 3-deazaneplanocin A (DZNep) in NSCLC cells. Methods: NCI-H460 NSCLC cell line were subjected to gamma irradiation. To reveal histone modification reagent DZNep targeted genes, we conducted mRNA-sequencing. Results: We evaluated the epigenetic regulation of autophagy-related genes by DZNep through mRNA-sequencing, and we identified genes that are differentially expressed upon irradiation, including a candidate histone modification target gene.
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:DNA methylation, histone modifications, and nucleosomal occupancy collaborate to cause silencing of tumor related genes in cancer. The development of drugs that target these processes is therefore important for cancer therapy. Inhibitors of DNA methylation and histone deacetylation have already been approved by the FDA for the treatment of hematologic malignancies. However, drugs that target the other mechanisms still need to be developed. Recently, 3-deazaneplanocin A (DZNep) was reported to selectively inhibit the trimethylation of lysine 27 on histone H3 (H3K27me3) and lysine 20 on histone H4 (H4K20me3) as well as re-activate silenced genes in cancer cells. This finding opens the door to pharmacological inhibition of histone methylation and we therefore wanted to further study the mechanism of action of 3-deazaneplanocin A in cancer cells. Western blot analysis showed that two other drugs, sinefungin and adenosine-dialdehyde (Adox), have similar effects on the trimethylation H3K27 as 3-deazaneplanocin A and that DZNep is not selective, but globally inhibits histone methylation. Intriguingly, chromatin immunoprecipitation of various histone modifications and microarray analysis show DZNep acts via a different pathway to 5-aza-2´-deoxycytidine (5-azaCdR), a DNA methyltransferase inhibitor and gives us an interesting insight into how chromatin structure effects gene expression. We also determine the kinetics of gene activation in order to understand if the induced changes were somatically heritable. We have found that upon removal of DZNep, gene expression is reduced to its original state suggesting that there is a homeostatic mechanism which returns the histone modifications to their “ground state” after DZNep treatment. Not only do these studies show the strong need for further development of histone methylation inhibitors but also allow us to better understand how chromatin structure affects gene expression.
Project description:DNA methylation, histone modifications, and nucleosomal occupancy collaborate to cause silencing of tumor related genes in cancer. The development of drugs that target these processes is therefore important for cancer therapy. Inhibitors of DNA methylation and histone deacetylation have already been approved by the FDA for the treatment of hematologic malignancies. However, drugs that target the other mechanisms still need to be developed. Recently, 3-deazaneplanocin A (DZNep) was reported to selectively inhibit the trimethylation of lysine 27 on histone H3 (H3K27me3) and lysine 20 on histone H4 (H4K20me3) as well as re-activate silenced genes in cancer cells. This finding opens the door to pharmacological inhibition of histone methylation and we therefore wanted to further study the mechanism of action of 3-deazaneplanocin A in cancer cells. Western blot analysis showed that two other drugs, sinefungin and adenosine-dialdehyde (Adox), have similar effects on the trimethylation H3K27 as 3-deazaneplanocin A and that DZNep is not selective, but globally inhibits histone methylation. Intriguingly, chromatin immunoprecipitation of various histone modifications and microarray analysis show DZNep acts via a different pathway to 5-aza-2´-deoxycytidine (5-azaCdR), a DNA methyltransferase inhibitor and gives us an interesting insight into how chromatin structure effects gene expression. We also determine the kinetics of gene activation in order to understand if the induced changes were somatically heritable. We have found that upon removal of DZNep, gene expression is reduced to its original state suggesting that there is a homeostatic mechanism which returns the histone modifications to their “ground state” after DZNep treatment. Not only do these studies show the strong need for further development of histone methylation inhibitors but also allow us to better understand how chromatin structure affects gene expression.
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.
Project description:3-deazaneplanocin A (DZNeP) is a promising cancer drug affecting the methylation status of histone lysine residues. To investigate the specificity and mode of action of DZNeP, zebrafish embryos displaying high histone methyltransferase activity were cultured with DZNeP and histone methylation (H3K4me3, H3K9me3, H3K27me3) was mapped by ChIP-chip genome-wide promoter at post-MBT stage (5.3 hpf) . We used a custom 2.1M probe HD promoter array (Nimblegen) for ChIP and input DNA hybridization. Peak detection was done using MA2C with P=10e-4 as cutoff.
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.