Discovery and Structure-Activity Relationship Study of ()-5-Methylenethiazolidin-4-one Derivatives as Potent and Selective Pan-phosphatidylinositol 5-Phosphate 4-Kinase Inhibitors.

Due to their role in many important signaling pathways, phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) are attractive targets for the development of experimental therapeutics for cancer, metabolic, and immunological disorders. Recent efforts to develop small molecule inhibitors for these lipid kinases resulted in compounds with low- to sub-micromolar potencies. Here, we report the identification of CVM-05-002 using a high-throughput screen of PI5P4Kα against our in-house kinase inhibitor library.

Chemical interrogation of the malaria kinome.

Malaria, an infectious disease caused by eukaryotic parasites of the genus Plasmodium, afflicts hundreds of millions of people every year. Both the parasite and its host utilize protein kinases to regulate essential cellular processes. Bioinformatic analyses of parasite genomes predict at least 65 protein kinases, but their biological functions and therapeutic potential are largely unknown.

PIM kinases are essential for chronic lymphocytic leukemia cell survival (PIM2/3) and CXCR4-mediated microenvironmental interactions (PIM1).

Overexpression of the CXCR4 receptor is a hallmark of chronic lymphocytic leukemia (CLL) and is important for CLL cell survival, migration, and interaction with their protective microenvironment. In acute myelogenous leukemia (AML), PIM1 was shown to regulate the surface expression of the CXCR4 receptor. Here, we show that PIM (proviral integration site for Moloney murine leukemia virus) kinases 1-3 are overexpressed and that the CXCR4 receptor is hyperphosphorylated on Ser339 in CLL compared with normal lymphocytes.

High-throughput kinase profiling: a more efficient approach toward the discovery of new kinase inhibitors.

Selective protein kinase inhibitors have only been developed against a small number of kinase targets. Here we demonstrate that "high-throughput kinase profiling" is an efficient method for the discovery of lead compounds for established as well as unexplored kinase targets. We screened a library of 118 compounds constituting two distinct scaffolds (furan-thiazolidinediones and pyrimido-diazepines) against a panel of 353 kinases.

Microenvironmental influence on pre-clinical activity of polo-like kinase inhibition in multiple myeloma: implications for clinical translation.

Polo-like kinases (PLKs) play an important role in cell cycle progression, checkpoint control and mitosis. The high mitotic index and chromosomal instability of advanced cancers suggest that PLK inhibitors may be an attractive therapeutic option for presently incurable advanced neoplasias with systemic involvement, such as multiple myeloma (MM). We studied the PLK 1, 2, 3 inhibitor BI 2536 and observed potent (IC50<40 nM) and rapid (commitment to cell death <24 hrs) in vitro activity against MM cells in isolation, as well as in vivo activity against a traditional subcutaneous xenograft mouse model.

Selective stabilization of natively folded RNA structure by DNA constraints.

Learning how native RNA conformations can be stabilized relative to unfolded states is an important objective, for both understanding natural RNAs and improving the design of artificial functional RNAs. Here we show that covalently attached double-stranded DNA constraints (ca. 14 base pairs in length) can significantly stabilize the native conformation of an RNA molecule.

Synthesis and application of a 5'-aldehyde phosphoramidite for covalent attachment of DNA to biomolecules.

We recently reported the use of covalently attached DNA as a structural constraint for rational control of macromolecular conformation. Reductive amination was employed to attach each strand of the duplex DNA constraint to RNA, utilizing an aldehyde tethered to the 5'-terminus of the DNA. Here we describe the synthesis of a thymidine phosphoramidite that has the 5'-tethered aldehyde masked as a 1,2-diol.

DNA constraints allow rational control of macromolecular conformation.

We report that double-helical DNA constraints can be used to control the conformation of another molecule, RNA. When a covalently attached DNA constraint is structurally incompatible with the native Mg2+-dependent RNA conformation, RNA folding is disrupted, as revealed by nondenaturing gel electrophoresis and independently by chemical probing. Our approach is distinct from other efforts in DNA nanotechnology, which have prepared DNA objects by self-assembly, built static DNA lattices for assembly of other objects, and created nanomachines made solely of DNA.

Synthesis of amine- and thiol-modified nucleoside phosphoramidites for site-specific introduction of biophysical probes into RNA.

For studies of RNA structure, folding, and catalysis, site-specific modifications are typically introduced by solid-phase synthesis of RNA oligonucleotides using nucleoside phosphoramidites. Here, we report the preparation of two complete series of RNA nucleoside phosphoramidites; each has an appropriately protected amine or thiol functional group. The first series includes each of the four common RNA nucleotides, U, C, A, and G, with a 2'-(2-aminoethoxy)-2'-deoxy substitution (i.