The PTPN2/PTPN1 inhibitor ABBV-CLS-484 unleashes potent anti-tumour immunity.

Immune checkpoint blockade is effective for some patients with cancer, but most are refractory to current immunotherapies and new approaches are needed to overcome resistance1,2. The protein tyrosine phosphatases PTPN2 and PTPN1 are central regulators of inflammation, and their genetic deletion in either tumour cells or immune cells promotes anti-tumour immunity3-6. However, phosphatases are challenging drug targets; in particular, the active site has been considered undruggable. Here we present the discovery and characterization of ABBV-CLS-484 (AC484), a first-in-class, orally bioavailable, potent PTPN2 and PTPN1 active-site inhibitor. AC484 treatment in vitro amplifies the response to interferon and promotes the activation and function of several immune cell subsets. In mouse models of cancer resistant to PD-1 blockade, AC484 monotherapy generates potent anti-tumour immunity. We show that AC484 inflames the tumour microenvironment and promotes natural killer cell and CD8+ T cell function by enhancing JAK-STAT signalling and reducing T cell dysfunction. Inhibitors of PTPN2 and PTPN1 offer a promising new strategy for cancer immunotherapy and are currently being evaluated in patients with advanced solid tumours (ClinicalTrials.gov identifier NCT04777994 ). More broadly, our study shows that small-molecule inhibitors of key intracellular immune regulators can achieve efficacy comparable to or exceeding that of antibody-based immune checkpoint blockade in preclinical models. Finally, to our knowledge, AC484 represents the first active-site phosphatase inhibitor to enter clinical evaluation for cancer immunotherapy and may pave the way for additional therapeutics that target this important class of enzymes.

Bone Marrow Mesenchymal Stem Cells Alleviate Acute Severe Pancreatitis and Promote Lung Repair via Inhibiting NLRP3 Inflammasome in Rat.

BACKGROUND: Acute severe pancreatitis (SAP) is a severe acute abdominal disease, which can lead to pancreatic infection and necrosis as well as distant organ damage. Bone marrow mesenchymal stem cells (BMSCs) can exert anti-inflammatory effect on SAP, while NLRP3 inflammasomes play an important role in the inflammatory response. This study aimed to investigate whether BMSCs exert anti-inflammatory effect on SAP by inhibiting NLRP3 inflammasome. METHODS: The rat SAP model was established. Serum amylase, lipase and inflammatory factor levels were measured by ELISA, and the level of tissue injury was assessed by HE staining. The expression of NLRP3 inflammasome was detected by PCR, Western Blot and immunohistochemistry. ML385 was used to block Nrf2 pathway, aiming to investigate whether Nrf2 pathway was involved in the therapeutic effect of BMSCs on SAP by regulating NLRP3 inflammasome expression. RESULTS: In SAP rats, NLRP3 inflammasome was activated, which became more evident over time. After transplantation of BMSCs, the NLRP3 inflammasome expression decreased at both mRNA and protein levels, the serum levels of amylase, lipase and inflammatory factors decreased, and the pathological scores of the pancreas and lung were both improved. After blocking the Nrf2 pathway, the NLRP3 inflammasome expression increased in the injured pancreas and lung, and the inflammation deteriorated, which inhibited the therapeutic effects of BMSCs on SAP. CONCLUSION: The therapeutic effect of BMSC on SAP is at least partially ascribed to the inhibition of NLRP3 inflammasome, and Nrf2 pathway mediates the therapeutic effect of BMSC on SAP by inhibiting NLRP3 inflammasome.

Quantitative assessment of the influence of cytochrome P450 2C19 gene polymorphisms and digestive tract cancer risk.

Cytochrome P450 (CYP) 2C19 metabolizes many promutagens and procarcinogens to biologically active metabolites, which strongly promote proliferation of cancer cells in vitro and in vivo. The CYP2C19 gene exhibits several genetic polymorphisms that are thought to play a major role in inter-individual variability in drug response, drug-xenobiotic interactions, and in cancer susceptibility. Two polymorphisms of the CYP2C19 gene (CYP2C19*2, CYP2C19*3) which was associated with reduced enzyme activity have been investigated extensively digestive tract cancer; however, these studies have yielded contradictory results. To clarify this inconsistency, we performed this meta-analysis including 15 case-control studies with a total of 3,252 cases and 6,269 controls. Overall, we found significant association between CYP2C19*2 and digestive tract cancer (OR = 1.27, 95 % CI, 1.07-1.51, P = 0.007) while no significant results were found for CYP2C19*3. Potential sources of heterogeneity including cancer types, ethnicity, source of control, and sample size of study were assessed. In the subgroup analyses by cancer types, significant association was detected only in esophagus cancer for CYP2C19*2. When stratified by ethnicity, significantly increased risks were found for the CYP2C19*2 polymorphism among Asians. This meta-analysis demonstrated that the CYP2C19*2 polymorphism is a risk factor for developing digestive tract cancer. However, additional very large-scale studies are warranted to provide conclusive evidence on the effects of the CYP2C19 gene on risk of digestive tract cancer.

Comparison of the diagnostic efficiency for breast cancer in Chinese women using mammography, ultrasound, MRI, and different combinations of these imaging modalities.

To compare the respective diagnostic efficiency for breast cancer in Chinese women with x-ray mammography (XRM), ultrasound (US), magnetic resonance imaging (MRI; standard dynamic contrasted-enhanced MRI with diffusion-weighted imaging), and different combinations of these imaging modalities, ninety Chinese women patients with clinically suspected breast cancer underwent prospective breast XRM, US, and MRI. The diagnostic performance of each imaging method and different combinations of methods was compared, with the pathological report serving as the gold standard. In this cohort study 54.4% cases with age of 53.2 ± 7.6 years old were categorized as ACR 3 or 4 tissue density. In the diagnosis of breast cancer, sensitivity and diagnostic accuracy [area under the Receiver Operating Characteristic curve (AUC)] were significantly higher for MRI alone than for either XRM alone or US alone (P< 0.05). Of the misdiagnosed cases on XRM, up to 86.7% cancers were located in dense breasts. US and MRI can play important role in screening young Chinese women. The diagnostic sensitivity was significantly higher for combined MRI+US+XRM (98.2%, χ2=25.9, P< 0.001), MRI+US (94.5%, χ2 53.3, P=0.002) and MRI+XRM (92.9%, χ2 = 41,9, P < 0.001). The combination of two or three methods significantly improved the diagnostic sensitivity for breast cancer in Chinese women. When the results based on different imaging modalities or their combinations are inconsistent, further pathological diagnosis is very important for arriving at a correct diagnosis.

Exploration of cathepsin S inhibitors characterized by a triazole P1-P2 amide replacement.

This paper details exploration of a class of triazole-based cathepsin S inhibitors originally reported by Ellman and co-workers. SAR studies involving modifications across the whole inhibitor provide a perspective on the strengths and weaknesses of this class of inhibitors. In addition, we put the unique characteristics of this class of compounds into perspective with other classes of cathepsin S inhibitors.

Indole RSK inhibitors. Part 1: discovery and initial SAR.

A series of inhibitors for the 90 kDa ribosomal S6 kinase (RSK) based on an 1-oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a]indole-8-carboxamide scaffold were identified through high throughput screening. An RSK crystal structure and exploratory SAR were used to define the series pharmacophore. Compounds with good cell potency, such as compounds 43, 44, and 55 were identified, and form the basis for subsequent kinase selectivity optimization.

Indole Inhibitors of MMP-13 for Arthritic Disorders.

Here, we described the design, by fragment merging and multiparameter optimization, of selective MMP-13 inhibitors that display an appropriate balance of potency and physicochemical properties to qualify as tool compounds suitable for in vivo testing. Optimization of potency was guided by structure-based insights, specifically to replace an ester moiety and introduce polar directional hydrogen bonding interactions in the core of the molecule. By introducing polar enthalpic interactions in this series of inhibitors, the overall beneficial physicochemical properties were maintained. These physicochemical properties translated to excellent drug-like properties beyond potency. In a murine model of rheumatoid arthritis, treatment of mice with selective inhibitors of MMP-13 resulted in a statistically significant reduction in the mean arthritic score vs control when dosed over a 14 day period.

SAR studies of non-zinc-chelating MMP-13 inhibitors: improving selectivity and metabolic stability.

SAR studies to improve the selectivity and metabolic stability of a class of recently discovered MMP-13 inhibitors are reported. Improved selectivity was achieved by modifying interactions with the S1' pocket. Metabolic stability was improved through reduction of inhibitor lipophilicity. This translated into lower in vivo clearance for the preferred compound.

Improving potency and selectivity of a new class of non-Zn-chelating MMP-13 inhibitors.

Discovery and optimization of potency and selectivity of a non-Zn-chelating MMP-13 inhibitor with the aid of protein co-crystal structural information is reported. This inhibitor was observed to have a binding mode distinct from previously published MMP-13 inhibitors. Potency and selectivity were improved by extending the hit structure out from the active site into the S1' pocket.

Discovery and characterization of the N-phenyl-N'-naphthylurea class of p38 kinase inhibitors.

An effort aimed at exploring structural diversity in the N-pyrazole-N'-naphthylurea class of p38 kinase inhibitors led to the synthesis and characterization of N-phenyl-N'-naphthylureas. Examples of these compounds displayed excellent inhibition of TNF-alpha production in vitro, as well as efficacy in a mouse model of lipopolysaccharide induced endotoxemia. In addition, perspective is provided on the role of a sulfonamide functionality in defining inhibitor potency.

Synthesis and SAR studies of indole-based MK2 inhibitors.

Chemistry has been developed to specifically functionalize two structurally similar classes of indole-based MK2 inhibitors at positions prompted by a combination of X-ray crystallographic and computer assisted drug design. A gain in molecular potency was obtained by introducing aminomethyl groups to the lactam rings of 6-arylcarbamoyl-tetrahydro-beta-carbolinone and 6-arylcarbamoyl-dihydropyrazino[1,2-a]indolone MK2 inhibitors. In addition, improvements in molecular potency were achieved by expansion of the lactam from a 6- to 7-membered ring leading to 7-arylcarbamoyl-tetrahydro-[1,4]diazepino[1,2-a]indolones.

Discovery and optimization of p38 inhibitors via computer-assisted drug design.

Integration of computational methods, X-ray crystallography, and structure-activity relationships will be disclosed, which lead to a new class of p38 inhibitors that bind to p38 MAP kinase in a Phe out conformation.

Fragment-based discovery of indole inhibitors of matrix metalloproteinase-13.

Matrix metalloproteases (MMPs) play an important role in cartilage homeostasis under both normal and inflamed disease states and, thus, have become attractive targets for the treatment of arthritic diseases. Herein, we describe the identification of a potent, selective MMP-13 inhibitor, developed using fragment-based structure-guided lead identification and optimization techniques. Virtual screening methods identified a novel, indole-based MMP-13 inhibitor that bound into the S1' pocket of the protein exhibiting a novel interaction pattern hitherto not observed in MMP-13 inhibitors. X-ray crystallographic structures were used to guide the elaboration of the fragment, ultimately leading to a potent inhibitor that was >100-fold selective over nine other MMP isoforms tested.

A short total synthesis of (+)-omaezakianol via an epoxide-initiated cationic cascade reaction.

(+)-Omaezakianol was synthesized in only three steps from racemic chlorohydrin 4 by Shi epoxidation followed by cascade cyclization and reduction.