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At least 19 recordsLinked to original sources
PubMed2026

First-in-Class Small Molecule Inhibitor of Oncogene AVIL in Glioblastoma.

Glioblastoma multiforme (GBM) is the most prevalent and aggressive malignant primary brain tumor, marked by rapid growth, extensive invasiveness, and a median survival of only ∼15 months despite current multimodal therapy. To identify new therapeutic vulnerabilities, we investigated the actin-regulatory protein AVIL, previously implicated through a MARS-AVIL gene fusion in rhabdomyosarcoma. Comprehensive genomic and transcriptomic analyses across REMBRANDT, TCGA, and CGGA datasets revealed recurrent AVIL amplification and consistently elevated AVIL expression in GBM compared with normal brain tissue. AVIL was overexpressed across all GBM molecular subtypes and glioma stem cell (GSC) states but was nearly undetectable in normal astrocytes, neural stem cells, and brain tissues. Functional studies demonstrated that AVIL is both necessary and sufficient for glioma genesis: AVIL silencing eradicated GBM cells in vitro and suppressed xenograft growth in vivo, while AVIL overexpression enhanced proliferation, migration, and transformation. Mechanistically, AVIL drives tumor progression through actin cytoskeleton remodeling and activation of the FOXM1-LIN28B oncogenic pathway. Using a small molecule microarray screen, we identified a selective AVIL-binding compound (compound A) that potently inhibited GBM cell growth with minimal toxicity to normal astrocytes. Gene expression changes induced by compound A mirrored those following AVIL knockdown, indicating on-target activity. Compound A demonstrated robust antitumor efficacy in multiple preclinical GBM models, including orthotopic xenografts, GSC-derived tumors, patient-derived xenografts, and temozolomide-resistant GBM with favorable pharmacokinetics and blood-brain barrier penetration. The minimal AVIL expression in normal tissues and lack of phenotype in AVIL-deficient mice underscore its potential as a low-toxicity therapeutic target. Together, these findings establish AVIL as a critical oncogenic driver in GBM and introduce a first-in-class AVIL inhibitor with strong translational promise for precision neuro-oncology.

Glioblastoma↗
PubMed2024

Identification of potent pan-ephrin receptor kinase inhibitors using DNA-encoded chemistry technology.

EPH receptors (EPHs), the largest family of tyrosine kinases, phosphorylate downstream substrates upon binding of ephrin cell surface-associated ligands. In a large cohort of endometriotic lesions from individuals with endometriosis, we found that EPHA2 and EPHA4 expressions are increased in endometriotic lesions relative to normal eutopic endometrium. Because signaling through EPHs is associated with increased cell migration and invasion, we hypothesized that chemical inhibition of EPHA2/4 could have therapeutic value. We screened DNA-encoded chemical libraries (DECL) to rapidly identify EPHA2/4 kinase inhibitors. Hit compound, CDD-2693, exhibited picomolar/nanomolar kinase activity against EPHA2 (Ki: 4.0 nM) and EPHA4 (Ki: 0.81 nM). Kinome profiling revealed that CDD-2693 bound to most EPH family and SRC family kinases. Using NanoBRET target engagement assays, CDD-2693 had nanomolar activity versus EPHA2 (IC50: 461 nM) and EPHA4 (IC50: 40 nM) but was a micromolar inhibitor of SRC, YES, and FGR. Chemical optimization produced CDD-3167, having picomolar biochemical activity toward EPHA2 (Ki: 0.13 nM) and EPHA4 (Ki: 0.38 nM) with excellent cell-based potency EPHA2 (IC50: 8.0 nM) and EPHA4 (IC50: 2.3 nM). Moreover, CDD-3167 maintained superior off-target cellular selectivity. In 12Z endometriotic epithelial cells, CDD-2693 and CDD-3167 significantly decreased EFNA5 (ligand) induced phosphorylation of EPHA2/4, decreased 12Z cell viability, and decreased IL-1β-mediated expression of prostaglandin synthase 2 (PTGS2). CDD-2693 and CDD-3167 decreased expansion of primary endometrial epithelial organoids from patients with endometriosis and decreased Ewing's sarcoma viability. Thus, using DECL, we identified potent pan-EPH inhibitors that show specificity and activity in cellular models of endometriosis and cancer.

Humans↗
PubMed2026

Small molecule inhibition of CPSF3 may impact R-loop distribution and abundance.

R-loops are three-stranded nucleic acid structures consisting of an RNA/DNA hybrid and a displaced strand of DNA. These structures have been implicated in a variety of regulatory cellular processes. Their untimed or excess accumulation, however, can cause genomic instability and induce DNA damage. Most R-loops form co-transcriptionally when the nascent transcript reanneals to unwound DNA duplex. Changes in transcription rates have the potential to impact R-loop formation, and compounds that modulate R-loop formation would be useful molecular tools and therapeutic leads. Cleavage and Polyadenylation Specific Factor 3 (CPSF3) recognizes the pre-mRNA 3' cleavage site, cleaves the transcript prior to polyadenylation, and has been linked to R-loop formation. Inhibition of CPSF3 has been found to induce transcriptional readthrough and cell proliferation defects. A previous report suggested that inhibition of CPSF3 with a small molecule causes a global increase in R-loop formation. Here, we test the impact of YT-II-100, a novel inhibitor of CPSF3. We find that addition of YT-II-100 increases global R-loop formation but does not change R-loop formation at specific genes that are normally used as positive controls for R-loop formation. We performed parallel assays using a previously reported compound, JTE-607, and observed similar results. Our data emphasize the need for cautious interpretation of experiments using JTE-607 and YT-II-100. There may be different mechanisms of R-loop formation depending on gene loci, where the control of R-loop formation by agonists at certain genes may differ from the trends observed for impacts on global R-loop formation.

R-Loop Structures↗
PubMed2017

Small-Molecule Inhibitors Targeting DNA Repair and DNA Repair Deficiency in Research and Cancer Therapy.

To maintain stable genomes and to avoid cancer and aging, cells need to repair a multitude of deleterious DNA lesions, which arise constantly in every cell. Processes that support genome integrity in normal cells, however, allow cancer cells to develop resistance to radiation and DNA-damaging chemotherapeutics. Chemical inhibition of the key DNA repair proteins and pharmacologically induced synthetic lethality have become instrumental in both dissecting the complex DNA repair networks and as promising anticancer agents. The difficulty in capitalizing on synthetically lethal interactions in cancer cells is that many potential targets do not possess well-defined small-molecule binding determinates. In this review, we discuss several successful campaigns to identify and leverage small-molecule inhibitors of the DNA repair proteins, from PARP1, a paradigm case for clinically successful small-molecule inhibitors, to coveted new targets, such as RAD51 recombinase, RAD52 DNA repair protein, MRE11 nuclease, and WRN DNA helicase.

DNA Helicases↗
PubMed2025

The limitations of small molecule and genetic screening in phenotypic drug discovery.

Phenotypic screens carried out with functional genomics or small molecules have led to novel biological insights, revealed previously unknown targets for drug discovery programs, and provided starting points for the development of first-in-class therapies. Despite being valuable research tools, genetic and compound screening also have significant limitations. This perspective aims to shed a light on those limitations and provide mitigation strategies when available, with a goal of helping phenotypic screening practitioners gain an understanding of how and when to best utilize either approach.

Drug Discovery↗
PubMed2025

ChemPerturb-seq screen identifies a small molecule cocktail enhancing human beta cell survival after subcutaneous transplantation.

Traditional chemical screens have focused on a single assay per screen, making them labor intensive and costly. Here, we combined a chemical screen with single-cell RNA sequencing (scRNA-seq) to perform Chemical Perturb-seq (ChemPerturb-seq), enabling a systematic analysis of the molecular changes of human beta cells upon individual small molecule treatments. Using this platform, we performed an in vivo barcoded screen and discovered a small molecule cocktail, including beta-lipotropin 61-91, insulin growth factor-1, and prostaglandin E2, with which preconditioning human beta cells and primary islets significantly enhanced function and survival when transplanted subcutaneously to female, but not to male, mice. We identified two additional molecules, serotonin and histamine, that promote islet function when transplanted subcutaneously to male mice using ChemPerturb-seq. Such small molecule cocktails could be applied to improve the current FDA-approved islet transplantation procedure. Finally, we developed an artificial intelligence (AI)-powered website, ChemPerturbDB, which provides user-friendly open access analysis of the extensive ChemPerturb-seq dataset.

Humans↗
PubMed2025

Chromatin Regulatory Targets for Anticancer Therapeutics.

Chromatin serves to organize and compact the genome but also functions as a signaling hub for the dynamic regulation of transcriptional programs that control cell type specification. The historical discovery that several pro-differentiation anti-cancer agents target chromatin regulatory enzymes buoyed early interest in developing drugs that modulate chromatin structure and function. Chromatin-based drug discovery has since flourished alongside major advances in discovery chemistry and target selection, producing a rich collection of chemical probes, drugs, and drug candidates targeting chromatin regulatory processes. The substantial growth and maturity of this field over the last several decades provides an opportunity to reflect on the successes and failures associated with translating chromatin regulatory targets into anti-cancer drugs. Taking a target-centric perspective, we discuss the motivation for pursuing specific chromatin regulatory proteins and review the chemistries that enabled small molecule discovery and development. In so doing, we hope to evaluate the strength of these targets, the agents that prosecute them, and the prospects for future efforts in this field.

Humans↗
PubMed2026

Structure-based drug design of small-molecule c-Myc G-quadruplex binders.

The c-Myc oncogene is crucial in tumorigenesis. Although it is a promising therapeutic target, its protein lacks a conventional drug-binding pocket, making it traditionally "undruggable". Recent studies show that the c-Myc promoter can form a G-quadruplex (G4) structure, which suppresses transcription and offers a new strategy for indirect inhibition. In this study, structure-based virtual screening was performed using the c-Myc G4 crystal structure to screen the ChemDiv compound library, aiming to identify small molecules that bind to the G4 structure. Candidate compounds were evaluated in preliminary in vitro assays for biological activity. The results showed that Y502-3888 binds to the c-Myc G4 and downregulates c-Myc expression at both mRNA and protein levels. Collectively, these findings support the potential of Y502-3888 as a c-Myc G4 binder for the treatment of multiple myeloma (MM), providing a foundation for future development of anticancer agents targeting the c-Myc G4.

G-Quadruplexes↗
PubMed1987

Sequence organization of repetitive sequences enriched in small polydisperse circular DNAs from HeLa cells.

A total of 36 clones were randomly selected from a recombinant DNA library of small polydisperse circular DNA (spcDNA) molecules from HeLa cells and were shown to contain repetitive sequences of different reiteration frequencies that ranged from several hundred to several hundred thousand per genome. Sequencing of representative clones revealed tandem repeats of alphoid (alpha) satellite DNA, clustered repeats of the Alu family, KpnI family sequences, tandem repeats of an alpha satellite DNA specific to the X chromosome (alpha X), and A + T-rich segments carrying short stretches of poly(A) or poly(T). DNA rearrangement was frequently found in the repetitive sequences enriched in these spcDNA clones. Short regions of homology that were patchy and inverted were often found, especially at the novel joint where spcDNA sequences are circularized. The presence of these inverted repeats suggests that HeLa spcDNAs are formed by a mechanism that involves looping out of the spcDNA region and joining of the flanking DNA by illegitimate recombination.

Base Sequence↗
PubMed1991

A new type of synthetic peptide library for identifying ligand-binding activity.

Our aim was to improve techniques for drug development by facilitating the identification of small molecules that bind with high affinity to acceptor molecules (for example, cell-surface receptors, enzymes, antibodies) and so to mimic or block their interaction with the natural ligand. Previously such small molecules have been characterized individually on a serial basis. The systematic synthesis and screening of peptide libraries of defined structure represents a new approach. For relatively small libraries, predetermined sequence variations on solid-phase supports have been used, and large libraries have been produced using a bacteriophage vector into which random oligodeoxynucleotide sequences have been introduced, but these techniques have severe limitations. Here we investigate an alternative approach to synthesis and screening of peptide libraries. Our simple methodology greatly enhances the production and rapid evaluation of random libraries of millions of peptides so that acceptor-binding ligands of high affinity can be rapidly identified and sequenced, on the basis of a 'one-bead, one-peptide' approach.

Amino Acid Sequence↗
PubMed1986

Identification and characterisation of PmaCI an endonuclease of novel specificity from Pseudomonas maltophila.

We report the use of MonoQ FPLC (Fast Protein Liquid Chromatography) for the rapid purification of a novel Type II restriction endonuclease PmaCI, from Pseudomonas maltophila, which recognises the sequence 5'-CAC decreases GTG-3'. The resulting enzyme is free of other nucleases to a level suitable for its characterisation by multiple-substrate digestion and DNA sequencing techniques. This method appears to be widely applicable and we have used it for the isolation of restriction endonucleases of comparable purity from a range of other organisms. Also described is a rapid method for screening a library of small inserted regions in recombinant M13 molecules for the presence and subsequent screening of restriction sites of interest.

Base Sequence↗
PubMed1990

Characterization of cDNA clones defining variant forms of human neural cell adhesion molecule N-CAM.

The neural cell adhesion molecule N-CAM has been identified in a number of species and comprises at least three major cell surface polypeptides of different molecular structures and tissue distributions. We report here the isolation and characterization of cDNA clones encoding two of the three major forms of N-CAM from a human neuroblastoma cDNA library. One of the clones, NII-6, provides the first complete sequence of a small cytoplasmic domain (140 kDa) form of the molecule in humans and differs in a number of respects from cDNA clones derived from human muscle. These differences include the presence of a 30-bp insert in the fourth immunoglobulin-like domain of N-CAM, a 3-bp insert in the extracellular portion of the molecule, and an additional 6 bp in the middle of the membrane-spanning segment. Based on the analysis of a genomic DNA clone spanning these regions of N-CAM, the first two differences arise by alternate splicing of RNA and occur in some, but not all clones; the additional 6 bp may reflect a genetic polymorphism. A second cDNA clone, NI-10, encodes the complete sequence of a segment that is specific to the large cytoplasmic domain (180 kDa) polypeptide of human N-CAM and is very similar to corresponding segments of mouse, chicken, and rat N-CAM. This sequence also arises by alternative splicing of RNA. In addition, we have identified a genomic DNA segment encoding sequences specific to the third, small surface domain (120 kDa) polypeptide of N-CAM. The data presented here and previously define the DNA sequences of the membrane-bound forms and known variants of human N-CAM. From these sequences, a wide variety of probes can be generated for investigating the expression of particular N-CAM polypeptides in normal and pathological tissues.

Amino Acid Sequence↗
PubMed1991

Agarose entrapment method for the production of SfiI linking library for Theileria parva.

We have developed a simple method for isolation of SfiI linking clones from a eukaryotic genomic DNA. The method involves the physical separation of the small proportion of plasmids in a plasmid genomic library that are linearized by SfiI digestion, from the bulk of molecules that remain circular, by ordinary electrophoresis through high-percentage gels of SeaPlaque agarose. Following the isolation of linearized molecules, their recircularization, and introduction into Escherichia coli, 55% of recovered plasmids contained inserts of the expected size, and 73% of these had SfiI sites. This represented a 25-fold enrichment of linking clones expected to be present at a frequency of 1/60 in the original library of 4- 6-kb fragments of genomic DNA of the protozoan parasite Theileria parva. This approach is rapid and obviates the need for introduction of a selectable marker. It is uniquely appropriate for linking clones spanning SfiI sites as this enzyme leaves degenerate 3' overhanging ends that preclude the direct ligation into vector sites required by most alternative strategies, but that favor the recircularization reactions used here.

Animals↗
PubMed1985

Nucleotide sequence of small polyadenylated B2 RNA.

Small poly(A)-containing RNA molecules which hybridize to the ubiquitous short repetitive sequence B2 and which are transcribed by RNA polymerase III have been identified in the cytoplasm of mouse cells. Here, we describe the structure of this small B2 RNA. A cDNA library was prepared from low-molecular-weight cytoplasmic poly(A)+RNA isolated from Ehrlich carcinoma cells and the clones which hybridized to B2 sequence were selected. The clones were sequenced and shown to contain B2 sequences followed by a poly(A) tract. The sequences of the cloned B2 RNAs different from each other by 3-10%, being similar in this respect to genomic B2 copies. Thus, B2 RNA is transcribed from many different B2 sequences in the genome. The 5'-ends of B2 RNA at least in most molecules coincide with the beginning of B2 genomic sequence. The poly(A) segments located at the 3'-end of small B2 RNA are the same size as in mRNA molecules, suggesting posttranscriptional formation. In some clones, additional sequences were detected between the 3'-end of B2 sequence and the poly(A) stretch. They seem to result from a lesion in the RNA polymerase III terminator in the corresponding B2 sequences. The possible significance of B2 sequences and small B2 RNA is discussed.

Animals↗
PubMedDate not supplied

[The structure of small polyadenylated B2-RNA].

Small poly(A)-containing RNA molecules which hybridize to the ubiquitous short repetitive sequence B2 and which are transcribed by RNA polymerase III have been identified in the cytoplasm of mouse cells. Here we describe the structure of this small B2 RNA. A cDNA library was prepared from low-molecular weight cytoplasmic poly(A)+RNA isolated from Ehrlich carcinoma cells and the clones which hybridized to B2 sequence were selected. The clones were sequenced and shown to contain B2 sequences followed by a poly(A) tract. The sequences of the cloned B2 RNAs differ from each other by 3-10%, being similar in this respect to genomic B2 copies. Thus, B2 RNA is transcribed from many different B2 sequences in the genome. The 5'-ends of B2 RNA at least in most molecules coincide with the beginning of B2 genomic sequence. The poly(A) segments located at the 3'-end of small B2 RNA are the same size as in mRNA molecules, suggesting posttranscriptional formation. In some clones additional sequences were detected between the 3'-end of B2 sequence and the poly(A) stretch. They seem to result from a lesion in the RNA polymerase III terminator in the corresponding B2 sequences. A model of B2 RNA secondary structure is suggested.

Animals↗
PubMed1992

CD24, a signal-transducing molecule expressed on human B cells, is a major surface antigen on small cell lung carcinomas.

Cell lines derived from human small cell carcinoma of the lung express high levels of a surface polypeptide termed the cluster-w4 antigen, which was previously identified as a potential target for toxin-based immunotherapy of lung cancer. We have cloned a complementary DNA encoding the cluster-w4 antigen from COS-1 fibroblasts transfected with a SW2 small cell carcinoma library, by panning with a mixture of the cluster-w4-specific monoclonal antibodies SWA11, SWA21, and SWA22. The sequence of the cluster-w4 complementary DNA encodes an unusually short (80-amino acid) protein identical to that recently reported for the leukocyte activation molecule CD24 except for a single valine-alanine substitution due to a single-base polymorphism within the region of the gene coding for the extracellular domain. Biochemical analyses of the cloned cluster-w4 antigen confirmed both the presence of the phosphatidylinositol tail and the extensive glycosylation reported for the CD24 molecule. Furthermore, the cloned cluster-w4 antigen expressed on COS cells was shown to react with a comprehensive panel of CD24-specific monoclonal antibodies, as assessed by indirect immunofluorescence staining. Northern blot hybridization indicated the presence of several transcript sizes for the cluster-w4 antigen that were greatly overexpressed in small cell carcinoma cell lines, compared with normal hemopoietic cells and CD24-positive cell lines. Southern blot hybridization of restriction digests of genomic DNA identified a complex pattern of bands consistent with either a complex gene structure containing many exons or the presence of a family of closely related genes.

Alanine↗
PubMed2026

Ligand-Mediated Reprogramming Redirects Liver-Tropic Ionizable Lipid Nanoparticles for Lung-Selective mRNA Delivery.

Systemic delivery of messenger RNA (mRNA) to target tissues and cells using lipid nanoparticles (LNPs) holds transformative potential for gene therapy. However, most clinically validated LNP exhibit strong liver tropism, and redirecting their organ specificity without redesigning entirely new chemistries remains challenging. Here we present a ligand-mediated lipid reprogramming approach that repurposes chemically defined, liver-tropic, ionizable lipids (lipidoids) for mRNA delivery beyond the liver. From a library of 90 degradable lipidoids, we identified 2-t6b as a potent liver-targeting platform. By site-specific displaying of small molecule ligands onto 2-t6b headgroup, we engineered a series of reconfigured lipidoids that achieve lung-specific targeting while retaining the parent delivery scaffold. Ligand7-2-t6b-lipid-functionalized LNP achieved over 200-fold higher mRNA translation in the lungs compared to the parent liver-tropic LNP. Proteomics and molecular docking analysis revealed enhanced binding of the modified lipid to vitronectin, a serum glycoprotein that improves integrin binding and thus promotes cellular uptake and translation efficiency. Ligand-mediated 2-t6b/ligand7 LNPs achieved outperformed efficacy and therapeutic potential in lung-specific genome editing relative to SORT-constructed 2-t6b LNP system. Our modular reprogramming strategy provides a generalizable framework to upgrade existing liver-biased LNPs into lung-selective mRNA carriers, advancing next-generation tissue-specific mRNA therapies for gene editing, protein replacement therapy, and regenerative medicine.

RNA, Messenger↗
PubMed1985

cDNA cloning of a human autoimmune nuclear ribonucleoprotein antigen.

Sera from patients with systemic lupus erythematosus and other autoimmune disorders contain antibodies against nuclear proteins. One such autoantibody system, known as Sm, reacts with antigens associated with small nuclear RNA molecules. In this paper we report the use of Sm autoantibodies to isolate a cDNA clone for the mRNA of one of these nuclear antigens. A HeLa cell cDNA library was screened by message selection followed by autoantibody reaction of cell-free translation products. This led to the identification of a cDNA clone, p281, containing sequences complementary to mRNA for an Sm autoantibody-reactive, 11,000 Mr protein. This cloned Sm antigen comigrated with the small nuclear RNA-associated protein known as "E" and reacted with four out of four Sm autoantibodies that precipitate E protein from total mRNA translation products. RNA gel blot hybridization with clone p281 DNA revealed a poly(A)+ mRNA of approximately equal to 600 nucleotides in human and marmoset (New World primate) cells. Southern blot hybridization of HeLa cell and human lymphocyte DNA indicated the presence of 6-10 copies of p281-homologous sequences. Similar copy numbers were observed with genomic DNA from baboon, cat, and mouse, indicating that the Sm antigen mRNA sequence represented in p281 is conserved across three classes of the Mammalia (primates, carnivores, and rodents). However, no cross-hybridization of p281 was observed with frog or Drosophila DNA. In light of existing evidence that the mammalian Sm antigen E is a weaker autoantigen than other small nuclear RNA-associated proteins, these results suggest a possible correlation between a protein's capacity to serve as an autoantigen during breakdown of the host's immunological tolerance and its extent of evolutionary conservation, whereas the inverse relationship applies to conventional immunity. We suspect, as have others, that this is a clue to the mechanism of autoimmunity.

Antigens↗