bix-01294 and sinefungin

G9a is the primary enzyme for mono- and dimethylation at Lys 9 of histone H3 and forms predominantly the heteromeric complex as a G9a-GLP (G9a-like protein) that is a functional histone lysine methltransferase in vivo. Mounting evidence suggests that G9a catalyzes methylation of histone and nonhistone proteins, which plays a crucial role in diverse biological processes and human diseases.. In this study, the current knowledge on biological functions of G9a and inhibitors were summarized.. we review the current knowledge on biological functions of G9a, with particular emphasis on regulating gene expression and cell processes, and involvement in human diseases. We outline a perspective on various classes of G9a inhibitors to date from both articles and patents with an emphasis on their discovery, activity and the current research status.. We highlight the key knowledge on potential biological functions and various human diseases. We also reviewed the discovery and characterization of the reported G9a inhibitors. However, we also propose the challenges and future opportunities in study of G9a. This review could make a crucial contribution to the long journey to develop drug-like molecules targeting G9a.

Topics: Adenosine; Animals; Antineoplastic Agents; Azepines; Benzimidazoles; DNA Methylation; Enzyme Inhibitors; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Molecular Targeted Therapy; Quinazolines

A series of cycloalkyl substituted analogues of the natural product sinefungin lacking the amino-acid moiety was designed and synthesized. Two stereoisomers (6-R and 6-S) were separated and their bioactivities examined against EHMT1/2. Of which, compound 14d showed an inhibitory activity against EHMT1/2 (88.9%, IC

Topics: Adenosine; Alkanes; Cell Line, Tumor; Cell Proliferation; Enzyme Inhibitors; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Inhibitory Concentration 50; Structure-Activity Relationship

A homogeneous time-resolved fluorescence (HTRF)-based binding assay has been established to measure the binding of the histone methyltransferase (HMT) G9a to its inhibitor CJP702 (a biotin analog of the known peptide-pocket inhibitor, BIX-01294). This assay was used to characterize G9a inhibitors. As expected, the peptide-pocket inhibitors decreased the G9a-CJP702 binding signal in a concentration-dependent manner. In contrast, the S-adenosyl-L-methionine (SAM)-pocket compounds, SAM and sinefungin, significantly increased the G9a-CJP702 binding signal, whereas S-adenosyl-L-homocysteine (SAH) showed minimal effect. Enzyme kinetic studies showed that CJP702 is an uncompetitive inhibitor (vs. SAM) that has a strong preference for the E:SAM form of the enzyme. Other data presented suggest that the SAM/sinefungin-induced increase in the HTRF signal is secondary to an increased E:SAM or E:sinefungin concentration. Thus, the G9a-CJP702 binding assay not only can be used to characterize the peptide-pocket inhibitors but also can detect the subtle conformational differences induced by the binding of different SAM-pocket compounds. To our knowledge, this is the first demonstration of using an uncompetitive inhibitor as a probe to monitor the conformational change induced by compound binding with an HTRF assay.

Topics: Adenosine; Azepines; Catalytic Domain; Chromatography, High Pressure Liquid; Fluorescent Dyes; Histone Methyltransferases; Histone-Lysine N-Methyltransferase; Humans; Kinetics; Protein Binding; Quinazolines; Recombinant Proteins; S-Adenosylhomocysteine; Tandem Mass Spectrometry; Time Factors