Discovery of 2-(3-Benzamidopropanamido)thiazole-5-carboxylate Inhibitors of the Kinesin HSET (KIFC1) and the Development of Cellular Target Engagement Probes.

The existence of multiple centrosomes in some cancer cells can lead to cell death through the formation of multipolar mitotic spindles and consequent aberrant cell division. Many cancer cells rely on HSET (KIFC1) to cluster the extra centrosomes into two groups to mimic the bipolar spindle formation of non-centrosome-amplified cells and ensure their survival. Here, we report the discovery of a novel 2-(3-benzamidopropanamido)thiazole-5-carboxylate with micromolar in vitro inhibition of HSET (KIFC1) through high-throughput screening and its progression to ATP-competitive compounds with nanomolar biochemical potency and high selectivity against the opposing mitotic kinesin Eg5.

Discovering cell-active BCL6 inhibitors: effectively combining biochemical HTS with multiple biophysical techniques, X-ray crystallography and cell-based assays.

By suppressing gene transcription through the recruitment of corepressor proteins, B-cell lymphoma 6 (BCL6) protein controls a transcriptional network required for the formation and maintenance of B-cell germinal centres. As BCL6 deregulation is implicated in the development of Diffuse Large B-Cell Lymphoma, we sought to discover novel small molecule inhibitors that disrupt the BCL6-corepressor protein-protein interaction (PPI). Here we report our hit finding and compound optimisation strategies, which provide insight into the multi-faceted orthogonal approaches that are needed to tackle this challenging PPI with small molecule inhibitors.

Privileged Structures and Polypharmacology within and between Protein Families.

Polypharmacology is often a key contributor to the efficacy of a drug, but is also a potential risk. We investigated two hits discovered via a cell-based phenotypic screen, the CDK9 inhibitor CCT250006 () and the pirin ligand CCT245232 (), to establish methodology to elucidate their secondary protein targets. Using computational pocket-based analysis, we discovered intrafamily polypharmacology for our kinase inhibitor, despite little overall sequence identity.

Femoral Nerve Block Intervention in Neck of Femur Fracture (FINOF): a randomised controlled trial.

Objective: Fractured neck of femur is a severely painful condition with significant mortality and morbidity. We investigated whether early and continuous use of femoral nerve block can improve pain on movement and mobility after surgery in older participants with fragility neck of femur fracture.

Design: Prospective single-centre, randomised controlled pragmatic trial.

Demonstrating In-Cell Target Engagement Using a Pirin Protein Degradation Probe (CCT367766).

Demonstrating intracellular protein target engagement is an essential step in the development and progression of new chemical probes and potential small molecule therapeutics. However, this can be particularly challenging for poorly studied and noncatalytic proteins, as robust proximal biomarkers are rarely known. To confirm that our recently discovered chemical probe 1 (CCT251236) binds the putative transcription factor regulator pirin in living cells, we developed a heterobifunctional protein degradation probe.

A fragment-based approach applied to a highly flexible target: Insights and challenges towards the inhibition of HSP70 isoforms.

The heat shock protein 70s (HSP70s) are molecular chaperones implicated in many cancers and of significant interest as targets for novel cancer therapies. Several HSP70 inhibitors have been reported, but because the majority have poor physicochemical properties and for many the exact mode of action is poorly understood, more detailed mechanistic and structural insight into ligand-binding to HSP70s is urgently needed. Here we describe the first comprehensive fragment-based inhibitor exploration of an HSP70 enzyme, which yielded an amino-quinazoline fragment that was elaborated to a novel ATP binding site ligand with different physicochemical properties to known adenosine-based HSP70 inhibitors.

Exploiting Protein Conformational Change to Optimize Adenosine-Derived Inhibitors of HSP70.

HSP70 is a molecular chaperone and a key component of the heat-shock response. Because of its proposed importance in oncology, this protein has become a popular target for drug discovery, efforts which have as yet brought little success. This study demonstrates that adenosine-derived HSP70 inhibitors potentially bind to the protein with a novel mechanism of action, the stabilization by desolvation of an intramolecular salt-bridge which induces a conformational change in the protein, leading to high affinity ligands.

Pre-Operative nutrition In Neck of femur Trial (POINT)--carbohydrate loading in patients with fragility hip fracture: study protocol for a randomised controlled trial.

Background: Trauma such as hip fracture initiates a neurohumoral stress response that changes the balance between anabolism and catabolism resulting in muscle breakdown and reduced mobilisation. Various studies have demonstrated a reduction in catabolism with pre-operative carbohydrate loading but only in an elective setting.

Methods/design: This is a two-centre, randomised double-blinded trial in the United Kingdom.

Femoral nerve block Intervention in Neck of Femur fracture (FINOF): study protocol for a randomized controlled trial.

Background: Hip fractures are very painful leading to lengthy hospital stays. Conventional methods of treating pain are limited. Non-steroidal anti-inflammatories are relatively contraindicated and opioids have significant side effects.

The effect of intravenous iron on postoperative transfusion requirements in hip fracture patients: study protocol for a randomized controlled trial.

Background: Anaemia following hip fracture is common. Approximately 30 to 45% of patients have haemoglobin concentrations below population norms on admission, and around 10% are severely anaemic. Anaemia on admission, and in the postoperative period, is associated with poor outcomes with regard to mobility, postoperative mortality and readmission.

Small-molecule inhibitors of the protein methyltransferase SET7/9 identified in a high-throughput screen.

Aberrant expression of chromatin-modifying enzymes (CMEs) is associated with a range of human diseases, including cancer. CMEs are now an important target area in drug discovery. Although the role that histone and protein (lysine) methyltransferases (PMTs) play in the regulation of transcription and cell growth is increasingly recognized, few small-molecule inhibitors of this class of enzyme have been reported.

Targeting the Hsp90 molecular chaperone with novel macrolactams. Synthesis, structural, binding, and cellular studies.

A series of resorcylic acid macrolactams, nitrogen analogues of the naturally occurring macrolactone radicicol, have been prepared by chemical synthesis and evaluated as inhibitors of heat shock protein 90 (Hsp90), an emerging attractive target for novel cancer therapeutic agents. The synthesis involves, as key steps, ring opening of an isocoumarin intermediate, followed by a ring-closing metathesis reaction to form the macrocycle. Subsequent manipulation of the ester group into a range of amides allows access to a range of new macrolactams following deprotection of the two phenolic groups.

Structure of the Ire1 autophosphorylation complex and implications for the unfolded protein response.

Ire1 (Ern1) is an unusual transmembrane protein kinase essential for the endoplasmic reticulum (ER) unfolded protein response (UPR). Activation of Ire1 by association of its N-terminal ER luminal domains promotes autophosphorylation by its cytoplasmic kinase domain, leading to activation of the C-terminal ribonuclease domain, which splices Xbp1 mRNA generating an active Xbp1s transcriptional activator. We have determined the crystal structure of the cytoplasmic portion of dephosphorylated human Ire1α bound to ADP, revealing the 'phosphoryl-transfer' competent dimeric face-to-face complex, which precedes and is distinct from the back-to-back RNase 'active' conformation described for yeast Ire1.

Discovery of 2-(6-{[(6-fluoroquinolin-2-yl)methyl]amino}bicyclo[3.1.0]hex-3-yl)-N-hydroxypyrimidine-5-carboxamide (CHR-3996), a class I selective orally active histone deacetylase inhibitor.

A novel series of HDAC inhibitors demonstrating class I subtype selectivity and good oral bioavailability is described. The compounds are potent enzyme inhibitors (IC₅₀ values less than 100 nM), and improved activity in cell proliferation assays was achieved by modulation of polar surface area (PSA) through the introduction of novel linking groups. Employing oral pharmacokinetic studies in mice, comparing drug levels in spleen to plasma, we selected compounds that were tested for efficacy in human tumor xenograft studies based on their potential to distribute into tumor.

Design and synthesis of novel pyrimidine hydroxamic acid inhibitors of histone deacetylases.

Inhibition of histone deacetylase activity represents a promising new modality in the treatment of a number of cancers. A novel HDAC series demonstrating inhibitory activity in cell proliferation assays is described. Optimisation based on the introduction of basic amine linkers to effect good drug distribution to tumour led to the identification of a compound with oral activity in a human colon cancer xenograft study associated with increased histone H3 acetylation in tumour tissue.

Inhibition of Hsp90 with resorcylic acid macrolactones: synthesis and binding studies.

A series of resorcylic acid macrolactones, analogues of the natural product radicicol has been prepared by chemical synthesis, and evaluated as inhibitors of heat shock protein 90 (Hsp90), an emerging attractive target for novel cancer therapeutic agents. The synthesis involves acylation of an ortho-toluic acid dianion, esterification, followed by a ring-closing metathesis to form the macrocycle. Subsequent manipulation of the protected hydroxymethyl side chain allows access to a range of new analogues following deprotection of the two phenolic groups.

Discovery of 4-amino-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamides as selective, orally active inhibitors of protein kinase B (Akt).

Protein kinase B (PKB or Akt) is an important component of intracellular signaling pathways regulating growth and survival. Signaling through PKB is frequently deregulated in cancer, and inhibitors of PKB therefore have potential as antitumor agents. The optimization of lipophilic substitution within a series of 4-benzyl-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-4-amines provided ATP-competitive, nanomolar inhibitors with up to 150-fold selectivity for inhibition of PKB over the closely related kinase PKA.

Detection of the ATPase activity of the molecular chaperones Hsp90 and Hsp72 using the TranscreenerTM ADP assay kit.

The molecular chaperone heat shock protein 90 (Hsp90) is required for the correct folding and stability of a number of client proteins that are important for the growth and maintenance of cancer cells. Heat shock protein 72 (Hsp72), a co-chaperone of Hsp90, is also emerging as an attractive cancer drug target. Both proteins bind and hydrolyze adenosine triphosphate (ATP), and ATPase activity is essential for their function.

Targeting the Hsp90 chaperone: synthesis of novel resorcylic acid macrolactone inhibitors of Hsp90.

A series of benzo-macrolactones has been prepared by chemical synthesis, and evaluated as inhibitors of heat shock protein 90 (Hsp90), an emerging attractive target for novel cancer therapeutic agents. A new synthesis of these resorcylic acid macrolactone analogues of the natural product radicicol is described in which the key steps are the acylation and ring opening of a homophthalic anhydride to give an isocoumarin, followed by a ring-closing metathesis to form the macrocycle. The methodology has been extended to a novel series of macrolactones incorporating a 1,2,3-triazole ring.

Synthesis of isothiazol-3-one derivatives as inhibitors of histone acetyltransferases (HATs).

High-throughput screening led to the identification of isothiazolones 1 and 2 as inhibitors of histone acetyltransferase (HAT) with IC50s of 3 microM and 5 microM, respectively. Analogues of these hit compounds with variations of the N-phenyl group, and with variety of substituents at C-4, C-5 of the thiazolone ring, were prepared and assayed for inhibition of the HAT enzyme PCAF. Potency is modestly favoured when the N-aryl group is electron deficient (4-pyridyl derivative 10 has IC(50)=1.

NVP-AUY922: a novel heat shock protein 90 inhibitor active against xenograft tumor growth, angiogenesis, and metastasis.

We describe the biological properties of NVP-AUY922, a novel resorcinylic isoxazole amide heat shock protein 90 (HSP90) inhibitor. NVP-AUY922 potently inhibits HSP90 (K(d) = 1.7 nmol/L) and proliferation of human tumor cells with GI(50) values of approximately 2 to 40 nmol/L, inducing G(1)-G(2) arrest and apoptosis.

Identification of 4-(4-aminopiperidin-1-yl)-7H-pyrrolo[2,3-d]pyrimidines as selective inhibitors of protein kinase B through fragment elaboration.

Fragment-based screening identified 7-azaindole as a protein kinase B inhibitor scaffold. Fragment elaboration using iterative crystallography of inhibitor-PKA-PKB chimera complexes efficiently guided improvements in the potency and selectivity of the compounds, resulting in the identification of nanomolar 6-(piperidin-1-yl)purine, 4-(piperidin-1-yl)-7-azaindole, and 4-(piperidin-1-yl)pyrrolo[2,3- d]pyrimidine inhibitors of PKBbeta with antiproliferative activity and showing pathway inhibition in cells. A divergence in the binding mode was seen between 4-aminomethylpiperidine and 4-aminopiperidine containing molecules.

Rapid evolution of 6-phenylpurine inhibitors of protein kinase B through structure-based design.

6-phenylpurines were identified as novel, ATP-competitive inhibitors of protein kinase B (PKB/Akt) from a fragment-based screen and were rapidly progressed to potent compounds using iterative protein-ligand crystallography with a PKA-PKB chimeric protein. An elaborated lead compound showed cell growth inhibition and effects on cellular signaling pathways characteristic of PKB inhibition.