bix-01294 and 3-deazaneplanocin

Monocytes play a key role in immune system function. Chromatin remodeling is crucial for various differentiation and gene regulation processes and is rather well studied in T cells. However, for monocytes not much is known regarding how the epigenetic machinery influences the differentiation into various effector cell types. In the work presented here, we explore the epigenetic underpinnings of monocyte differentiation. By transcriptional profiling we show that transcription of lysine methyltransferases (KMTs) and in particular KMT1c is markedly up regulated after differentiation of monocytes into immature dendritic cells (iDCs). Specifically inhibiting KMT1c function, using the small-molecule inhibitor BIX-01294, changes the transcription levels of the DC marker DC-SIGN, but does not affect surface protein expression. Blocking global KMT activity, using DZNep, does influence monocyte differentiation into iDCs, indicated by a loss of DC-SIGN surface expression. When BIX-01294 and DZNep treatment was combined DC-SIGN expression was almost lost completely. This work shows that the activities of KMTs are required for successful differentiation of monocyte-derived dendritic cells. Furthermore it shows the importance of KMT inhibitors in the field of epigenetic immune therapy, which is still much focused around HDAC inhibitors.

Topics: Acetylation; Adenosine; Azepines; Cell Adhesion Molecules; Cell Differentiation; Chromatin; Chromatin Assembly and Disassembly; Dendritic Cells; Epigenesis, Genetic; Gene Expression Profiling; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Lectins, C-Type; Methylation; Monocytes; Primary Cell Culture; Quinazolines; Receptors, Cell Surface; Signal Transduction; Transcription, Genetic

Aberrant epigenetic histone modifications are implicated in cancer pathobiology, therefore histone modifying enzymes are emerging targets for anti-cancer therapy. There is a few evidence for deregulation of the histone modifying enzymes in glioblastomas. Glioma treatment is a clinical challenge due to its resistance to current therapies.. The effect of selected inhibitors on epigenetic modifications and viability of glioma C6 cells were studied using immunofluorescence and MTT metabolism test.. We found that VPA and TSA increase histone H4 acetylation in glioma cells, while chaetocin and BIX01294 at low concentrations reduce H3K9me3, and 3DZNep decreases H3K27me3. Long-term treatment with some epigenetic inhibitors affects viability of glioma cells.. We established the concentrations of selected inhibitors which in C6 glioma cells inhibit the enzyme activity, but do not decrease cell viability, hence allow to study the role of histone modifications in C6 glioma biology.

Topics: Acetylation; Adenosine; Animals; Azepines; Brain Neoplasms; Cell Line, Tumor; Cell Survival; Enzyme Inhibitors; Epigenesis, Genetic; Glioma; Histones; Hydroxamic Acids; Piperazines; Quinazolines; Rats; Valproic Acid