The structure–activity relationships of T0901317 analogs were explored as RORc inverse agonists using the principles of property- and structure-based drug design. An X-ray co-crystal structure of ...T0901317 and RORc was obtained and provided molecular insight into why T0901317 functioned as an inverse agonist of RORc; whereas, the same ligand functioned as an agonist of FXR, LXR, and PXR. The structural data was also used to design inhibitors with improved RORc biochemical and cellular activities. The improved inhibitors possessed enhanced selectivity profiles (rationalized using the X-ray crystallographic data) against other nuclear receptors.
Diffuse intrinsic pontine glioma (DIPG) remains a fatal brainstem tumor demanding innovative therapies. As B7-H3 (CD276) is expressed on central nervous system (CNS) tumors, we designed ...B7-H3-specific chimeric antigen receptor (CAR) T cells, confirmed their preclinical efficacy, and opened BrainChild-03 (NCT04185038), a first-in-human phase I trial administering repeated locoregional B7-H3 CAR T cells to children with recurrent/refractory CNS tumors and DIPG. Here, we report the results of the first three evaluable patients with DIPG (including two who enrolled after progression), who received 40 infusions with no dose-limiting toxicities. One patient had sustained clinical and radiographic improvement through 12 months on study. Patients exhibited correlative evidence of local immune activation and persistent cerebrospinal fluid (CSF) B7-H3 CAR T cells. Targeted mass spectrometry of CSF biospecimens revealed modulation of B7-H3 and critical immune analytes (CD14, CD163, CSF-1, CXCL13, and VCAM-1). Our data suggest the feasibility of repeated intracranial B7-H3 CAR T-cell dosing and that intracranial delivery may induce local immune activation.
This is the first report of repeatedly dosed intracranial B7-H3 CAR T cells for patients with DIPG and includes preliminary tolerability, the detection of CAR T cells in the CSF, CSF cytokine elevations supporting locoregional immune activation, and the feasibility of serial mass spectrometry from both serum and CSF. This article is highlighted in the In This Issue feature, p. 1.
Summary
Whether errors in protein synthesis play a role in aging has been a subject of intense debate. It has been suggested that rare mistakes in protein synthesis in young organisms may result in ...errors in the protein synthesis machinery, eventually leading to an increasing cascade of errors as organisms age. Studies that followed generally failed to identify a dramatic increase in translation errors with aging. However, whether translation fidelity plays a role in aging remained an open question. To address this issue, we examined the relationship between translation fidelity and maximum lifespan across 17 rodent species with diverse lifespans. To measure translation fidelity, we utilized sensitive luciferase‐based reporter constructs with mutations in an amino acid residue critical to luciferase activity, wherein misincorporation of amino acids at this mutated codon re‐activated the luciferase. The frequency of amino acid misincorporation at the first and second codon positions showed strong negative correlation with maximum lifespan. This correlation remained significant after phylogenetic correction, indicating that translation fidelity coevolves with longevity. These results give new life to the role of protein synthesis errors in aging: Although the error rate may not significantly change with age, the basal rate of translation errors is important in defining lifespan across mammals.
The Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib has shown impressive clinical efficacy in a range of B-cell malignancies. However, acquired resistance has emerged, and second generation ...therapies are now being sought. Ibrutinib is a covalent, irreversible inhibitor that modifies Cys481 in the ATP binding site of Btk and renders the enzyme inactive, thereby blocking B-cell receptor signal transduction. Not surprisingly, Cys481 is the most commonly mutated Btk residue in cases of acquired resistance to ibrutinib. Mutations at other sites, including Thr474, a gatekeeper residue, have also been detected. Herein, we describe noncovalent Btk inhibitors that differ from covalent inhibitors like ibrutinib in that they do not interact with Cys481, they potently inhibit the ibrutinib-resistant Btk C481S mutant in vitro and in cells, and they are exquisitely selective for Btk. Noncovalent inhibitors such as GNE-431 also show excellent potency against the C481R, T474I, and T474M mutants. X-ray crystallographic analysis of Btk provides insight into the unique mode of binding of these inhibitors that explains their high selectivity for Btk and their retained activity against mutant forms of Btk. This class of noncovalent Btk inhibitors may provide a treatment option to patients, especially those who have acquired resistance to ibrutinib by mutation of Cys481 or Thr474.
Tebipenem pivoxil HBr (TBPM-PI-HBr) is a novel orally bioavailable carbapenem. The active moiety is tebipenem. Tebipenem pivoxil is licensed for use in Japan in children with ear, nose, and throat ...infections and respiratory infections. The HBr salt was designed to improve drug substance and drug product properties, including stability. TBPM-PI-HBr is now being developed as an agent for the treatment of complicated urinary tract infections (cUTI) in adults. The pharmacokinetics-pharmacodynamics of tebipenem were studied in a well-characterized neutropenic murine thigh infection model. Plasma drug concentrations were measured using liquid chromatography-tandem mass spectrometry. Dose fractionation experiments were performed after establishing dose-response relationships. The magnitude of drug exposure required for stasis was established using 11 strains of
(
,
= 6;
,
= 5) with a variety of resistance mechanisms. The relationship between drug exposure and the emergence of resistance was established in a hollow-fiber infection model (HFIM). Tebipenem exhibited time-dependent pharmacodynamics that were best described by the free drug area under the concentration-time curve (
AUC
)/MIC corrected for the length of the dosing interval (
AUC
/MIC · 1/tau). The pharmacodynamics of tebipenem versus
and
were comparable, as was the response of strains possessing extended-spectrum β-lactamases versus the wild type. The median
AUC
/MIC · 1/tau value for the achievement of stasis in the 11 strains was 23. Progressively more fractionated regimens in the HFIM resulted in the suppression of resistance. An
AUC
/MIC · 1/tau value of 34.58 to 51.87 resulted in logarithmic killing and the suppression of resistance. These data and analyses will be used to define the regimen for a phase III study of adult patients with cUTI.
Dosage compensation, the equalized X chromosome gene expression between males and females in Drosophila , has also been found in triple X metafemales. Inverse dosage effects, produced by genomic ...imbalance, are believed to account for this modulated expression, but they have not been studied on a global level. Here, we show a global expression comparison of metafemales (XXX; AA) with normal females (XX; AA) with high-throughput RNA-sequencing. We found that the majority of the X-linked genes in metafemales exhibit dosage compensation with an expression level similar to that of normal diploid females. In parallel, most of the autosomal genes were expressed at about two-thirds the level of normal females, the ratio of inverse dosage effects produced by the extra X chromosome. Both compensation and inverse effects were further confirmed by combination of X-linked and autosomally located miniwhite reporter genes in metafemales and relative quantitative PCR of selected genes. These data provide evidence for an inverse dosage component to X chromosome compensation.
Aneuploidy, the presence of chromosome gains or losses, is a hallmark of cancer. Here, we describe KaryoCreate (karyotype CRISPR-engineered aneuploidy technology), a system that enables the ...generation of chromosome-specific aneuploidies by co-expression of an sgRNA targeting chromosome-specific CENPA-binding ɑ-satellite repeats together with dCas9 fused to mutant KNL1. We design unique and highly specific sgRNAs for 19 of the 24 chromosomes. Expression of these constructs leads to missegregation and induction of gains or losses of the targeted chromosome in cellular progeny, with an average efficiency of 8% for gains and 12% for losses (up to 20%) validated across 10 chromosomes. Using KaryoCreate in colon epithelial cells, we show that chromosome 18q loss, frequent in gastrointestinal cancers, promotes resistance to TGF-β, likely due to synergistic hemizygous deletion of multiple genes. Altogether, we describe an innovative technology to create and study chromosome missegregation and aneuploidy in the context of cancer and beyond.
Display omitted
•We designed chromosome-specific sgRNAs for targeting 19 of 24 human chromosomes•KaryoCreate facilitates sgRNA-dCas9 mediated recruitment of mutant kinetochore proteins•KaryoCreate enables the creation of human cells with distinct karyotypes•Engineered 18q loss promotes tumor-associated phenotypes in colon epithelial cells
A method for engineering human cells with distinct karyotypes of interest enables interrogation of a specific aneuploidy in the context of cancer.
Surgical Considerations in Vascular Malformations Johnson, Adam B.; Richter, Gresham T.
Techniques in vascular and interventional radiology,
December 2019, 2019-Dec, 2019-12-00, 20191201, Letnik:
22, Številka:
4
Journal Article
Recenzirano
Vascular malformations are generally congenital benign lesions that have multiple variations in treatment algorithms. Surgery can be used as a single modality or as an adjunct in multimodal therapy ...to treat these lesions. Here we discuss surgical treatment of the major vascular malformations, including lymphatic, venous, and arteriovenous malformations. We explain some of the basic principles to resection of simple and complex lesions and adjunctive therapies. These adjunct therapies include chemotherapeutic injections, embolization, and laser therapy. Surgical resection of complex lesions should only be performed by an experienced vascular anomalies surgeon. A team approach is generally necessary to provide safe and effective treatment. While surgery for these complex lesions is an option, the most important principle to adhere to when treating any of these lesions is that the treatment should be no worse than the disease.
Atheist moral philosopher Erik Wielenberg recently argued that Divine Command Theory is implausible as an explanation of objective morality because it fails to explain how psychopaths have moral ...obligations. In this paper I explain that everyone agrees the consciences of psychopaths don’t work as they should, but there’s disagreement among experts as to whether: A. The consciences of psychopaths don’t inform them of what’s right and wrong and that they should do what’s right or B. The consciences of psychopaths do inform them of these things but merely don’t generate the appropriate moral emotions. I argue that, based on the psychological research, a strong case can be made for B and thus under DCT psychopaths do have moral obligations because their consciences inform them of what’s right from wrong and that they should do what’s right. I also argue that even if A is true, God can, and does, make psychopaths aware of what’s right and wrong and that they should do what’s right through other means such as rationality, society, parents, culture, direct verbal commands, etc. Therefore, even if A is true, then psychopaths still have moral obligations under DCT because they do know what’s right from wrong and that they should do what’s right. Lastly, I turn the tables on Wielenberg and point out that his theory is even worse than DCT when it comes to providing an explanation for the moral rights and obligations of psychopaths
PDF
