Ex vivo drug testing of patient-derived lung organoids to predict treatment responses for personalized medicine.

Lung cancer is the leading cause of global cancer-related mortality resulting in âˆ¼ 1.8 million deaths annually. Systemic, molecular targeted, and immune therapies have provided significant improvements of survival outcomes for patients. However, drug resistance usually arises and there is an urgent need for novel therapy screening and personalized medicine. 3D patient-derived organoid (PDO) models have emerged as a more effective and efficient alternative for ex vivo drug screening than 2D cell culture and patient-derived xenograft (PDX) models. In this review, we performed an extensive search of lung cancer PDO-based ex vivo drug screening studies. Lung cancer PDOs were successfully established from fresh or bio-banked sections and/or biopsies, pleural effusions and PDX mouse models. PDOs were subject to ex vivo drug screening with chemotherapy, targeted therapy and/or immunotherapy. PDOs consistently recapitulated the genomic alterations and drug sensitivity of primary tumors. Although sample sizes of the previous studies were limited and some technical challenges remain, PDOs showed great promise in the screening of novel therapy drugs. With the technical advances of high throughput, tumor-on-chip, and combined microenvironment, the drug screening process using PDOs will enhance precision care of lung cancer patients.

Pharmacological characterization of a structural hybrid P2X7R antagonist using ATP and LL-37.

Antagonists of the P2X7 receptor (P2X7R) have the potential to treat diseases where neuroinflammation is present such as depression, chronic pain and Alzheimer's disease. We recently developed a structural hybrid (C1; 1-((adamantan-1-yl)methyl)-2-cyano-3-(quinolin-5-yl)guanidine) of a purported competitive P2X7R antagonist (C2; 2-cyano-1-((1S)-1-phenylethyl)-3-(quinolin-5-yl)guanidine) and a likely negative allosteric modulator (NAM) of the P2X7R (C3; N-((adamantan-1-yl)methyl)-2-chloro-5-methoxybenzamide). Here we aimed to pharmacologically characterize C1, to gain insights into how select structural components impact antagonist interaction with the P2X7R. A second aim was to examine the role of the peptide LL-37, an apparent activator of the P2X7R, and compare the ability of multiple P2X7R antagonists to block its effects. Compounds 1, 2 and 3 were characterised using washout, Schild and receptor protection studies, all using dye uptake assays in HEK293 cells expressing the P2X7R. LL-37 was examined in the same HEK293 cells and THP-1 monocytes. Compounds 2 and 3 acted as a BzATP-competitive antagonist and NAM of the P2X7R respectively. Compound 1 was a slowly reversible NAM of the P2X7R suggesting the incorporation of an appropriately positioned adamantane promotes binding to the allosteric site of the P2X7R. LL-37 was shown to potentiate the ability of ATP to induce dye uptake at low concentrations (1-3 µg mL-1) or induce dye uptake alone at higher concentrations (10-20 µg mL-1). None of the P2X7R antagonists studied were able to block LL-37-induced dye uptake bringing in to question the ability of current P2X7R antagonists to inhibit the inflammatory action of LL-37 in vivo.

A Series of 2-((1-Phenyl-1H-imidazol-5-yl)methyl)-1H-indoles as Indoleamine 2,3-Dioxygenase 1 (IDO1) Inhibitors.

Indoleamine 2,3-dioxygenase 1 (IDO1) is a promising therapeutic target in cancer immunotherapy and neurological disease. Thus, searching for highly active inhibitors for use in human cancers is now a focus of widespread research and development efforts. In this study, we report the structure-based design of 2-(5-imidazolyl)indole derivatives, a series of novel IDO1 inhibitors which have been designed and synthesized based on our previous study using N1-substituted 5-indoleimidazoles. Among these, we have identified one with a strong IDO1 inhibitory activity (IC50 =0.16 µM, EC50 =0.3 µM). Structural-activity relationship (SAR) and computational docking simulations suggest that a hydroxyl group favorably interacts with a proximal Ser167 residue in Pocket A, improving IDO1 inhibitory potency. The brain penetrance of potent compounds was estimated by calculation of the Blood Brain Barrier (BBB) Score and Brain Exposure Efficiency (BEE) Score. Many compounds had favorable scores and the two most promising compounds were advanced to a pharmacokinetic study which demonstrated that both compounds were brain penetrant. We have thus discovered a flexible scaffold for brain penetrant IDO1 inhibitors, exemplified by several potent, brain penetrant, agents. With this promising scaffold, we provide herein a basis for further development of brain penetrant IDO1 inhibitors.

Identification of Potent Indoleamine 2,3-Dioxygenase 1 (IDO1) Inhibitors Based on a Phenylimidazole Scaffold.

Inhibition of indoleamine 2,3-dioxygenase (IDO1) is an attractive immunotherapeutic approach for the treatment of a variety of cancers. Dysregulation of this enzyme has also been implicated in other disorders including Alzheimer's disease and arthritis. Herein, we report the structure-based design of two related series of molecules: N1-substituted 5-indoleimidazoles and N1-substituted 5-phenylimidazoles. The latter (and more potent) series was accessed through an unexpected rearrangement of an imine intermediate during a Van Leusen imidazole synthesis reaction. Evidence for the binding modes for both inhibitor series is supported by computational and structure-activity relationship studies.

Discovery and pharmacological evaluation of a novel series of adamantyl cyanoguanidines as P2X7 receptor antagonists.

Here we report adamantyl cyanoguanidine compounds based on hybrids of the adamantyl amide scaffold reported by AstraZeneca and cyanoguanidine scaffold reported by Abbott Laboratories. Compound 27 displayed five-fold greater inhibitory potency than the lead compound 2 in both pore-formation and interleukin-1ß release assays, while 35-treated mice displayed an antidepressant phenotype in behavioral studies. This SAR study provides a proof of concept for hybrid compounds, which will help in the further development of P2X7R antagonists.

Active Site Crowding of Cytochrome P450 3A4 as a Strategy To Alter Its Selectivity.

Substrate-promiscuous enzymes are a promising starting point for the development of versatile biocatalysts. In this study, human cytochrome P450 3A4, known for its ability to metabolise hundreds of drugs, was engineered to alter its regio- and stereoselectivity. Rational mutagenesis was used to introduce steric hindrance in a specific manner in the large active site of P450 3A4 and to favour oxidation at a more sterically accessible position on the substrate. Hydroxylation of a synthetic precursor of (R)-lisofylline, a compound under investigation for its anti-inflammatory properties, was chosen as a first proof-of-principle application of our protein engineering strategy. In a second example, increasing active site crowding led to an incremental shift in the selectivity of oxidation from an internal double bond to a terminal phenyl group in a derivative of theobromine. The same correlation between crowding and selectivity was found in a final case focused on the hydroxylation of the steroid sex hormone progesterone.

3-Oxo-hexahydro-1H-isoindole-4-carboxylic Acid as a Drug Chiral Bicyclic Scaffold: Structure-Based Design and Preparation of Conformationally Constrained Covalent and Noncovalent Prolyl Oligopeptidase Inhibitors.

Bicyclic chiral scaffolds are privileged motifs in medicinal chemistry. Over the years, we have reported covalent bicyclic prolyl oligopeptidase inhibitors that were highly selective for POP over a number of homologous proteins. Herein, we wish to report the structure-based design and synthesis of a novel class of POP inhibitors based on hexahydroisoindoles. A docking study guided the selection of structures for synthesis. The stereochemistry, decoration, and position within the molecule of the bicyclic scaffolds were assessed virtually. Following the synthesis of the best candidates, in vitro assays revealed that one member of this chemical series was more active than any of our previous inhibitors with a Ki of 1.0 nM. Additional assays also showed that the scaffold of this potent inhibitor, in contrast to one of our previously reported chemical series, is highly metabolically stable, despite the foreseen potential sites of metabolism. Interestingly, computer docking calculations accurately predicted the optimal features of the inhibitors.

Metabolic Instability of Cyanothiazolidine-Based Prolyl Oligopeptidase Inhibitors: a Structural Assignment Challenge and Potential Medicinal Chemistry Implications.

As part of the development of cyanothiazolidine-based prolyl oligopeptidase inhibitors, initial metabolism studies suggested multiple sites of oxidation by P450 enzymes. Surprisingly, in-depth investigations revealed that epimerization at multiple stereogenic centers was responsible for the conversion of the single primary metabolite into a panel of secondary metabolites. The rapid isomerization of all seven detected molecules precluded the use of NMR spectroscopy or X-ray crystallography for complete structural determination, presenting an interesting structure elucidation challenge. Through a combination of LC-MS analysis, synthetic work, deuterium exchange studies, and computational predictions, we were able to characterize all metabolites and to elucidate their dynamic behavior in solution. In the context of drug development, this study reveals that cyanothiazolidine moieties are problematic due to their rapid P450-mediated oxidation and the unpredictable stability of the corresponding metabolites.

Discovery of novel small-molecule antagonists for GluK2.

KA receptors have shown to be potential therapeutic targets in CNS diseases such as schizophrenia, depression, neuropathic pain and epilepsy. Through the use of our docking tool Fitted, we investigated the relationship between ligand activity towards GluK2 and the conformational state induced at the receptor level. By focusing our rational design on the interaction between the ligand and a tyrosine residue in the binding site, we synthesized a series of molecules based on a glutamate scaffold, and carried out electrophysiological recordings. The observed ability of some of these molecules to inhibit receptor activation shows the potential of our design for the development of effective antagonists with a molecular size comparable to that of the endogenous neurotransmitter L-glutamate.

Trishomocubane as a scaffold for the development of selective dopamine transporter (DAT) ligands.

In our continued exploration of trishomocubane derivatives with central nervous system (CNS) activity, N-arylalkyl-8-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecanes (10-13) displaying affinity for the sigma (σ) receptor were also found, in several cases, to interact with the dopamine transporter (DAT). Compound 12 was identified as the first trishomocubane-derived high affinity DAT ligand (K(i) = 1.2 nM), with greater than 8300-fold selectivity over the monoamine transporters NET and SERT, and only low to moderate affinity for σ(1) and σ(2) receptors.