Mechanistic basis for inhibition of the extended‐spectrum β‐lactamase GES ‐1 by enmetazobactam and tazobactam

β‐Lactamase‐catalysed hydrolysis is the primary form of β‐lactam antibiotic resistance in Gram‐negative bacteria. The penicillanic acid sulfone (PAS) enmetazobactam is thought to inhibit extended‐spectrum β‐lactamases (ESBLs) by fragmentation of an initial acyl‐enzyme to form an active‐site lysinoalanine cross link. We investigate interactions of enmetazobactam and its congener tazobactam with GES‐1, an ESBL with structural features of carbapenem‐hydrolysing β‐lactamases. Crystal structures show different breakdown products of the two inhibitors covalently bound to the catalytic Ser70, assigned using quantum mechanics/molecular mechanics (QM/MM) calculations. We find no evidence for lysinoalanine formation, with mass spectrometry indicating active enzyme regeneration, behaviour previously observed for carbapenem‐hydrolysing enzymes, but not ESBLs. This work establishes that PAS inhibitors interact with diverse β‐lactamases by differing mechanisms, which should inform development of future compounds.

Surfaceome: a new era in the discovery of immune evasion mechanisms of circulating tumor cells

Circulating tumor cells (CTCs) are cancer cells that detach from the original site and reach the bloodstream. The most aggressive CTCs survive various immune system attacks and initiate metastasis formation. Importantly, CTCs are not specifically targeted by the current immunotherapies due to the limited knowledge on specific targets. Proteomic profiling can be a powerful tool for understanding some of the immune evasion mechanisms used by cancer cells and particularly CTCs. These mechanisms are generally linked to the expression of specific surface proteins/peptides (i.e. the surfaceome). The study of the peptides that bind to class I molecules of the major histocompatibility complex (MHC‐I) and of the various glycoproteins expressed on CTC surface may open a completely new avenue for the discovery of novel mechanisms of immune evasion. In this review, we discuss how immunopeptidomic and glycoproteomic studies of CTCs that interact with immune cells could help to better understand how metastasis‐initiator CTCs escape the host immune response. We also describe how immunopeptidomic and glycoproteomic studies are carried out.

Cellular liquid biopsy provides unique chances for disease monitoring, preclinical model generation and therapy adjustment in rare salivary gland cancer patients

While cell‐free liquid biopsy (cfLB) approaches provide simple and inexpensive disease monitoring, cell‐based liquid biopsy (cLB) may enable additional molecular genetic assessment of systemic disease heterogeneity and preclinical model development. We investigated 71 blood samples of 62 patients with various advanced cancer types and subjected enriched circulating tumor cells (CTCs) to organoid culture conditions. CTC‐derived tumoroid models were characterized by DNA/RNA sequencing and immunohistochemistry, as well as functional drug testing. Results were linked to molecular features of primary tumors, metastases, and CTCs; CTC enumeration was linked to disease progression. Of 52 samples with positive CTC counts (≥1) from eight different cancer types, only CTCs from two salivary gland cancer (SGC) patients formed tumoroid cultures ( P  = 0.0005). Longitudinal CTC enumeration of one SGC patient closely reflected disease progression during treatment and revealed metastatic relapse earlier than clinical imaging. Multiomics analysis and functional in vitro drug testing identified potential resistance mechanisms and drug vulnerabilities. We conclude that cLB might add a functional dimension (to the genetic approaches) in the personalized management of rare, difficult‐to‐treat cancers such as SGC.

Targeting the AKT /m TOR pathway attenuates the metastatic potential of colorectal carcinoma circulating tumor cells in a murine xenotransplantation model

Circulating tumor cells (CTCs) play an important role in metastasis formation. Aberrant signaling of oncogenic pathways (e.g., PI3K/AKT/mTOR pathway) drives tumor progression. In this work, the susceptibility of the colon cancer CTC‐derived cell line CTC‐MCC‐41 to AKT and mammalian target of rapamycin (mTOR) inhibitors was evaluated. Additionally, the functional role of the expressed AKT isoforms was characterized in this cell line. The efficacy of the AKT inhibitor MK2206, the mTOR inhibitor RAD001, and the combination was examined in CTC‐MCC‐41 cells in a murine intracardiac xenotransplantation model. Furthermore, stable isoform‐specific AKT1 or AKT2 knockdowns (KDs) as well as AKT1/AKT2 double‐KD cells were generated. Differentially regulated proteins and phospho‐peptides were identified using liquid chromatography coupled mass spectrometry (LC–MS). CTC‐MCC‐41 cells showed a high susceptibility for dual targeting of AKT and mTOR in vivo , indicating that selective eradication of CTCs by AKT/mTOR inhibitors may be considered a new treatment option in cancer. KD of AKT1 or AKT2 significantly reduced the proliferation of CTC‐MCC‐41 cells. AKT KDs share commonly regulated proteins and phospho‐proteins, but also regulate a large number uniquely. AKT1/AKT2 double‐KD cells show a strongly dysregulated replication machinery, as well as a decrease in cell cycle activity and stem‐cell‐associated processes, underlining the non‐redundant role of AKT isoforms.

A DIA ‐ MS ‐based proteomics approach to find potential serum prognostic biomarkers in glioblastoma patients

No blood‐based protein biomarkers are currently available for routine clinical use to determine the prognosis of patients with glioblastoma (GB). We performed data‐independent acquisition mass spectrometry (DIA‐MS)‐based proteomics on 96 presurgical serum samples from patients with GB and 30 serum samples from healthy controls to identify such markers. Among the 622 serum proteins differentially expressed between the GB and control groups, 191 had a |log 2 (fold change)| ≥ 0.58 and an area under the curve ≥ 0.75. An analysis of their prognostic value revealed that high levels of IL1R2 and low levels of CRTAC1 and HRG were associated with poor survival. Multivariate Cox regression analysis identified IL1R2 as an independent prognostic factor for PFS and CRTAC1 as an independent prognostic factor for OS. The concentration of CRTAC1 in serum samples from an independent cohort of short‐ and long‐term survivors of GB (STS and LTS, respectively) by ELISA was shown to be lower in the STS than in the LTS group. CRTAC1, HRG, and IL1R2 could potentially be used to better inform prognosis and predict treatment response in GB patients.

Unique pharmacological properties of etrasimod among S1P receptor modulators

Etrasimod (ADP334) is an oral, once‐daily, selective sphingosine 1‐phosphate (S1P) 1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis and in development for the treatment of immune‐mediated inflammatory diseases. Interaction between S1P and its five receptor subtypes (S1P 1 –S1P 5 ) plays a role in several physiologic systems, including the cardiovascular and immune systems. Since differences in S1PR binding and downstream intracellular signaling could contribute to distinct profiles of drug efficacy and safety, we directly compared the S1P 1–5 selectivity profile of etrasimod to three marketed S1PR modulators: fingolimod, ozanimod, and siponimod. Using both heterologous expression systems and human umbilical vein endothelial cells that spontaneously express S1P 1 , we profiled key S1P 1 downstream signaling pathways and found that etrasimod had similar potency to the other tested S1PR modulators in promoting β‐arrestin recruitment and S1P 1 internalization. However, etrasimod was notably less potent than other S1PR modulators in assays measuring S1P 1 ‐mediated G protein activation (GTPγS binding and cAMP inhibition). Relatively lower potency of etrasimod in inducing G protein signaling corresponded to significantly diminished activation of human cardiac G protein‐coupled inwardly rectifying potassium channels when compared to ozanimod. Together with pharmacokinetic properties, this pharmacologic profile of etrasimod may contribute to the positive benefit risk profile of etrasimod observed during the phase III ELEVATE UC 52 and ELEVATE UC 12 trials in patients with moderately to severely active ulcerative colitis.

Wolf reintroduction to Scotland could support substantial native woodland expansion and associated carbon sequestration

Snakes and Lizards (Squamates)

Ethics, Rights, and Cybersecurity

Inflammation Promotes Aging‐Associated Oncogenesis in the Lung

ABSTRACT Background Lung cancer is the leading cause of cancer death in the world. While cigarette smoking is the major preventable factor for cancers in general and lung cancer in particular, old age is also a major risk factor. Aging‐related chronic, low‐level inflammation, termed inflammaging, has been widely documented; however, it remains unclear how inflammaging contributes to increased lung cancer incidence. Aim The aim of this study was to establish connections between aging‐associated changes in the lungs and cancer risk. Methods We analyzed public databases of gene expression for normal and cancerous human lungs and used mouse models to understand which changes were dependent on inflammation, as well as to assess the impact on oncogenesis. Results Analyses of GTEx and TCGA databases comparing gene expression profiles from normal lungs, lung adenocarcinoma, and lung squamous cell carcinoma of subjects across age groups revealed upregulated pathways such as inflammatory response, TNFA signaling via NFκB, and interferon‐gamma response. Similar pathways were identified comparing the gene expression profiles of young and old mouse lungs. Transgenic expression of alpha 1 antitrypsin (AAT) partially reverses increases in markers of aging‐associated inflammation and immune deregulation. Using an orthotopic model of lung cancer using cells derived from EML4‐ALK fusion‐induced adenomas, we demonstrated an increased tumor outgrowth in lungs of old mice while NLRP3 knockout in old mice decreased tumor volumes, suggesting that inflammation contributes to increased lung cancer development in aging organisms. Conclusions These studies reveal how expression of an anti‐inflammatory mediator (AAT) can reduce some but not all aging‐associated changes in mRNA and protein expression in the lungs. We further show that aging is associated with increased tumor outgrowth in the lungs, which may relate to an increased inflammatory microenvironment.