Epigenetics
Epigenetics research delves into the molecular mechanisms that control gene expression and cellular traits without altering the underlying DNA sequence. One crucial aspect of this field is the role of small molecules, which act as powerful regulators of epigenetic modifications. These small compounds, typically comprising a few dozen to a few hundred atoms, have emerged as essential tools in understanding and manipulating the epigenome.
- DNA Methylation Inhibitors: Small molecules like 5-azacytidine and 5-aza-2'-deoxycytidine are DNA methyltransferase inhibitors. They block the addition of methyl groups to DNA, leading to DNA demethylation. This can reactivate silenced genes, potentially offering therapeutic avenues for conditions like cancer.
- HDAC inhibitors: HDACs remove acetyl groups from histone proteins, contributing to gene repression. Small molecule HDAC inhibitors, such as Vorinostat and Romidepsin, can reverse this process by increasing histone acetylation, allowing genes to be more accessible for transcription. These inhibitors are being explored for cancer therapy and other conditions.
- Histone Methyltransferase Inhibitors: Small molecules like GSK126 inhibit specific histone methyltransferases, affecting histone methylation patterns. This can alter gene expression, making them promising candidates for cancer and other diseases with epigenetic dysregulation.
- RNA Modulators: Small molecules can also target non-coding RNAs involved in epigenetic regulation. For instance, small molecules called small interfering RNAs (siRNAs) can be designed to target and degrade specific long non-coding RNAs, influencing gene expression.
- Epigenetic Reader Domain Inhibitors: These small molecules target proteins that recognize and bind to specific epigenetic marks. Examples include inhibitors of bromodomain-containing proteins (BET inhibitors), which can disrupt gene regulation by interfering with protein-DNA interactions.
Small molecules in epigenetics research not only provide insights into the fundamental biology of gene regulation but also hold immense promise for developing novel therapeutics. Their ability to selectively modulate specific epigenetic marks and pathways has led to ongoing clinical trials and drug development efforts for various diseases, including cancer, neurological disorders, and inflammatory conditions. Understanding and harnessing the power of these small molecules is at the forefront of modern epigenetics research, offering new hope for precision medicine and targeted therapies.
3 key components involved in the regulation of epigenetic modifications
Epigenetics Writer
Epigenetics writers are enzymes responsible for adding chemical marks or modifications to DNA or histone proteins. These marks include DNA methylation (addition of methyl groups to DNA) and histone modifications (such as acetylation, methylation, phosphorylation, etc.).
Epigenetics Reader
Function: Epigenetics readers are proteins that can recognize and bind to specific epigenetic marks on DNA or histones. These reader proteins interpret the epigenetic code and facilitate downstream cellular processes, such as gene activation or repression.
Epigenetics Eraser
Function: Epigenetics erasers are enzymes responsible for removing or reversing epigenetic marks on DNA or histones. This process allows for the dynamic regulation of gene expression and the resetting of epigenetic states during various stages of development and in response to environmental changes.
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Dot1L inhibitor
Dot1L-IN-2 is a potent, selective and orally bioavailable inhibitor of Dot1L (a histone methyltransferase), with an IC50 and Ki of 0.4 nM and 0.08 nM, respectively. -
PARP-2 inhibitor
PARP-2-IN-1 is a potent and selective PARP-2 inhibitor with an IC50 of 11.5 nM. -
pan HDAC inhibitor
Tefinostat (CHR-2845) is a monocyte/macrophage-targeted pan HDAC inhibitor, cleaved into active acid CHR-2847 by the intracellular esterase human carboxylesterase-1 (hCE-1). Anti-monocytoid lineage leukaemias activity. -
HDAC inhibitor
Oxamflatin (Metacept-3) is a potent HDAC inhibitor with an IC50 of 15.7 nM. -
EZH1/2 dual inhibitor
Valemetostat (DS-3201) is a first-in-class EZH1/2 dual inhibitor, used in the research of relapsed/refractory peripheral T-cell lymphoma. -
PTP1B inhibitor
PTP1B-IN-2 is a potent protein tyrosine phosphatase 1B (PTP1B) inhibitor with an IC50 of 50 nM. -
KDM5 inhibitor
KDM5A-IN-1 is a potent, orally bioavailable pan-histone lysine demethylases 5 (KDM5) inhibitor with IC50s of 45 nM, 56 nM and 55 nM for KDM5A, KDM5B and KDM5C, respectively, and with an EC50 value of 960 nM for PC9 H3K4Me3. -
BRCA1 inhibitor
BRCA1-IN-1 is a novel small-molecule-like BRCA1 inhibitor with IC50 and Ki of 0.53 μM and 0.71 μM, respecrively. -
PPI inhibitor
BRCA1-IN-2 (compound 15) is a cell-permeable protein-protein interaction (PPI) inhibitor for BRCA1 with an IC50 of 0.31 μM and a Kd of 0.3 μM, which shows antitumor activities via the disruption of BRCA1 (BRCT)2/protein interactions. -
p300/CBP histone acetyltransferase inhibitor
P300/CBP-IN-3, a p300/CBP histone acetyltransferase inhibitor. -
SMYD3 inhibitor
SMYD3-IN-1 (compound 29) is an irreversible and selective inhibitor of SMYD3 (SET and MYND domain containing 3), with an IC50 of 11.7 nM. -
PARP14 inhibitor
PARP14 inhibitor H10, compound H 10, is a selective inhibitor against PARP14 (IC50=490 nM), over other PARPs (??24 fold over PARP1). PARP14 inhibitor H10 induces caspase-3/7-mediated cell apoptosis. -
BRD4-BD1 inhibitor
BRD4 Inhibitor-10 is a potent BRD4-BD1 inhibitor extracted from patent WO2015022332A1, Compound II-25, has an IC50 of 8 nM. -
TYK2 Inhibitor
BMS-986165 is a Highly Potent and Selective Allosteric Inhibitor of TYK2. BMS-986165 Blocks Il-12, IL-23 and type I Interferon Signaling and Provides for Robust Efficacy in Preclinical Models of Inflammatory Bowel Disease. -
Bromodomain inhibitor
Bromodomain IN-1 is a Bromodomain inhibitor extracted from patent WO2016069578A1, compound 4 . -
HDAC inhibitor
CHDI-390576, a potent, cell permeable and CNS penetrant class IIa histonedeacetylase (HDAC) inhibitor with IC50s of 54 nM, 60 nM, 31 nM, 50 nM for class IIa HDAC4, HDAC5, HDAC7, HDAC9, respectively, shows >500-fold selectivity over class I HDACs (1, 2, 3) and ~150-fold selectivity over HDAC8 and the class IIb HDAC6 isoform. -
JAK3 covalent inhibitor
JAK3 covalent inhibitor-1 is a potent and selective janus kinase 3 (JAK3) covalent inhibitor with an IC50 of 11 nM and shows 246-fold selectivity vs other JAKs. -
pan-PAD inhibitor
Streptonigrin (Bruneomycin), a natural product produced by Streptomyces flocculus, possesses both anti-tumor and anti-bacterial activity. Streptonigrin acts as a pan-PAD inhibitor with IC50s of 48.3??34.2 ?M, 26.1??0.3 ?M, 0.43??0.03 ?M, and 2.5??0.4 ?M for PAD1, PAD2, PAD3, and PAD4, respectively. -
JAK2/STAT3 inhibitor
Protosappanin A is an immunosuppressive ingredient of the medicinal herb Caesalpinia sappan L.
