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1.
bioRxiv ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38746434

RESUMO

Proteins harboring intrinsically disordered regions (IDRs) that lack regular secondary or tertiary structure are abundant across three domains of life. Here, using a deep neural network (DNN)-based method we predict IDRs in the extracytoplasmic proteome of Streptococcus mutans , Streptococcus pyogenes and Streptococcus pneumoniae . We identify a subset of the serine/threonine-rich IDRs and demonstrate that they are O -glycosylated with glucose by a GtrB-like glucosyltransferase in S. pyogenes and S. pneumoniae , and N-acetylgalactosamine by a Pgf-dependent mechanism in S. mutans . Loss of glycosylation leads to a defect in biofilm formation under ethanol-stressed conditions in S. mutans . We link this phenotype to a C-terminal IDR of peptidyl-prolyl isomerase PrsA which is protected from proteolytic degradation by O -glycosylation. The IDR length attenuates the efficiency of glycosylation and expression of PrsA. Taken together, our data support a model in which extracytoplasmic IDRs function as dynamic switches of protein homeostasis in streptococci.

2.
bioRxiv ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38766245

RESUMO

Streptococcus mutans, the causative agent of human dental caries, expresses a cell wall attached Serotype c- specific Carbohydrate (SCC) that is critical for cell viability. SCC consists of a repeating →3)α-Rha(1→2)α-Rha(1→ polyrhamnose backbone, with glucose (Glc) side-chains and glycerol phosphate (GroP) decorations. This study reveals that SCC has one major and two minor Glc modifications. The major Glc modification, α-Glc, attached to position 2 of 3-rhamnose, is installed by SccN and SccM glycosyltransferases and is the site of the GroP addition. The minor Glc modifications are ß-Glc linked to position 4 of 3-rhamnose installed by SccP and SccQ glycosyltransferases, and α-Glc attached to position 4 of 2-rhamnose installed by SccN working in tandem with an unknown enzyme. Both the major and the minor ß-Glc modifications control bacterial morphology, but only the GroP and major Glc modifications are critical for biofilm formation.

3.
bioRxiv ; 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38617328

RESUMO

In adult stem cell lineages, the cellular microenvironment plays essential roles to ensure the proper balance of self-renewal, differentiation and regulated elimination of differentiating cells. Although regulated death of progenitor cells undergoing proliferation or early differentiation is a feature of many tissues, mechanisms that initiate this pruning remain unexplored, particularly in the male germline, where up to 30% of the germline is eliminated before the meiotic divisions. We conducted a targeted screen to identify functional regulators required in somatic support cells for survival or differentiation at early steps in the male germ line stem cell lineage. Cell type-specific knockdown in cyst cells uncovered novel roles of genes in germline stem cell differentiation, including a previously unappreciated role of the Septate Junction (SJ) in preventing cell death of differentiating germline progenitors. Loss of the SJ in the somatic cyst cells resulted in elimination of transit-amplifying spermatogonia by the 8-cell stage. Germ cell death was spared in males mutant for the differentiation factor bam indicating that intact barriers surrounding transit amplifying progenitors are required to ensure germline survival once differentiation has initiated.

4.
Cancers (Basel) ; 16(5)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38473335

RESUMO

Forchlorfenuron (FCF) is a widely used plant cytokinin that enhances fruit quality and size in agriculture. It also serves as a crucial pharmacological tool for the inhibition of septins. However, the precise target of FCF has not yet been fully determined. This study reveals a novel target of FCF and elucidates its downstream signaling events. FCF significantly impairs mitochondrial respiration and mediates metabolic shift toward glycolysis, thus making cells more vulnerable to glycolysis inhibition. Interestingly, FCF's impact on mitochondrial function persists, even in cells lacking septins. Furthermore, the impaired mitochondrial function leads to the degradation of HIF-1α, facilitated by increased cellular oxygen. FCF also induces AMPK activation, suppresses Erk1/2 phosphorylation, and reduces the expression of HER2, ß-catenin, and PD-L1. Endometrial cancer is characterized by metabolic disorders such as diabetes and aberrant HER2/Ras-Erk1/2/ß-catenin signaling. Thus, FCF may hold promise as a potential therapeutic in endometrial cancer.

5.
Genome Res ; 34(2): 217-230, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38355305

RESUMO

Secondary structure is a principal determinant of lncRNA function, predominantly regarding scaffold formation and interfaces with target molecules. Noncanonical secondary structures that form in nucleic acids have known roles in regulating gene expression and include G-quadruplexes (G4s), intercalated motifs (iMs), and R-loops (RLs). In this paper, we used the computational tools G4-iM Grinder and QmRLFS-finder to predict the formation of each of these structures throughout the lncRNA transcriptome in comparison to protein-coding transcripts. The importance of the predicted structures in lncRNAs in biological contexts was assessed by combining our results with publicly available lncRNA tissue expression data followed by pathway analysis. The formation of predicted G4 (pG4) and iM (piM) structures in select lncRNA sequences was confirmed in vitro using biophysical experiments under near-physiological conditions. We find that the majority of the tested pG4s form highly stable G4 structures, and identify many previously unreported G4s in biologically important lncRNAs. In contrast, none of the piM sequences are able to form iM structures, consistent with the idea that RNA is unable to form stable iMs. Unexpectedly, these C-rich sequences instead form Z-RNA structures, which have not been previously observed in regions containing cytosine repeats and represent an interesting and underexplored target for protein-RNA interactions. Our results highlight the prevalence and potential structure-associated functions of noncanonical secondary structures in lncRNAs, and show G4 and Z-RNA structure formation in many lncRNA sequences for the first time, furthering the understanding of the structure-function relationship in lncRNAs.


Assuntos
Quadruplex G , RNA Longo não Codificante , RNA , RNA Longo não Codificante/genética , Proteínas/genética
6.
J Prof Nurs ; 50: 83-94, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38369377

RESUMO

Electronic health records are integral to the advanced practice registered nurse role, yet access and training during academic preparation are profoundly limited. Lack of exposure to electronic health records prevents students from becoming fully prepared for the responsibilities of clinical practice and potentially impacts quality of care, patient safety, and communication among patients and providers. This scoping review of 20 articles on electronic health record use in advanced practice registered nursing student education shows significant gaps in current research. Nine articles were classified as research. The remaining 11 were non-research reports of teaching innovations describing the use of simulated electronic health records in graduate nursing education or the use of an electronic health record in interprofessional education activities. Most of the limited research did not use valid and reliable instruments or robust designs, employed disparate approaches and tools to study the phenomenon, and measured low-level outcomes such as student navigation and confidence in using electronic health records. The non-research literature draws attention to the deficits in educational resources, including unaffordable electronic health records for academic use. Although rigorous evidence is lacking, a common theme throughout the reviewed literature was the benefit of simulation to develop electronic health record skills.


Assuntos
Prática Avançada de Enfermagem , Educação de Pós-Graduação em Enfermagem , Educação em Enfermagem , Estudantes de Enfermagem , Humanos , Registros Eletrônicos de Saúde
7.
Immunohorizons ; 8(1): 74-88, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38226924

RESUMO

Chronic alcohol use increases morbidity and mortality in the setting of sepsis. Both chronic alcohol use and sepsis are characterized by immune dysregulation, including overexpression of T cell coinhibitory molecules. We sought to characterize the role of CTLA-4 during sepsis in the setting of chronic alcohol exposure using a murine model of chronic alcohol ingestion followed by cecal ligation and puncture. Results indicated that CTLA-4 expression is increased on CD4+ T cells isolated from alcohol-drinking septic mice as compared with either alcohol-drinking sham controls or water-drinking septic mice. Moreover, checkpoint inhibition of CTLA-4 improved sepsis survival in alcohol-drinking septic mice, but not water-drinking septic mice. Interrogation of the T cell compartments in these animals following pharmacologic CTLA-4 blockade, as well as following conditional Ctla4 deletion in CD4+ T cells, revealed that CTLA-4 deficiency promoted the activation and proliferation of effector regulatory T cells and the generation of conventional effector memory CD4+ T cells. These data highlight an important role for CTLA-4 in mediating mortality during sepsis in the setting of chronic alcohol exposure and may inform future approaches to develop targeted therapies for this patient population.


Assuntos
Etanol , Inibidores de Checkpoint Imunológico , Sepse , Animais , Camundongos , Linfócitos T CD4-Positivos , Antígeno CTLA-4 , Etanol/efeitos adversos , Células T de Memória , Sepse/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico
8.
Mol Pharm ; 21(1): 53-61, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38029291

RESUMO

Epithelial-mesenchymal transition (EMT) is a reversible and dynamic biological process in which epithelial cells acquire mesenchymal characteristics including enhanced stemness and migratory ability. EMT can facilitate cancer metastasis and is a known driver of cellular resistance to common chemotherapeutic drugs, such as docetaxel. Current chemotherapeutic practices such as docetaxel treatment can promote EMT and increase the chance of tumor recurrence and resistance, calling for new approaches in cancer treatment. Here we show that prolonged docetaxel treatment at a sub-IC50 concentration inhibits EMT in immortalized human mammary epithelial (HMLE) cells. Using immunofluorescence, flow cytometry, and bulk transcriptomic sequencing to assess EMT progression, we analyzed a range of cellular markers of EMT in docetaxel-treated cells and observed an upregulation of epithelial markers and downregulation of mesenchymal markers in the presence of docetaxel. This finding suggests that docetaxel may have clinical applications not only as a cytotoxic drug but also as an inhibitor of EMT-driven metastasis and multidrug resistance depending on the concentration of its use.


Assuntos
Antineoplásicos , Transição Epitelial-Mesenquimal , Humanos , Docetaxel/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Células Epiteliais
9.
J Am Pharm Assoc (2003) ; 64(1): 104-110, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37940102

RESUMO

BACKGROUND: Pharmacists' and pharmacy technicians' stress and job turnover are at an all-time high. Both intrinsic motivations and extrinsic rewards play key roles in workplace satisfaction. Differences in workplace satisfaction have been identified when comparing chain pharmacies, independent pharmacies, and health systems work settings. OBJECTIVES: Cognitive evaluation theory was applied to explore the influence of intrinsic motivations and extrinsic rewards on both pharmacists' and pharmacy technicians' perceptions of motivations and rewards across various workplace settings. METHODS: A 92-item questionnaire was administered to 129 pharmacists and 111 pharmacy technicians. Participants were primarily recruited at a state pharmacy association annual meeting and via online forums. The questionnaire captured participant demographics including role and work setting (i.e., chain, independent, or health systems), demographic variables, and perceptions about work including autonomy, competence, relationships, pay satisfaction, and benefit satisfaction. RESULTS: A 2-way multivariate analysis of covariance was conducted to test hypothesized differences by role (pharmacist or pharmacy technician) and setting (chain, independent, or health systems). Results show pharmacy personnel in independent and hospital systems settings felt more positive about relationships, competence, pay satisfaction, and benefit satisfaction than those in chain settings. There were no role differences between pharmacists and pharmacy technicians on these outcomes. DISCUSSION: These findings highlight challenges of working in chain pharmacy environments. Results reveal that although pay does not differ across work settings, feelings about both the work and compensation satisfaction do vary across settings. Because role did not drive these relationships, this suggests a need to attend to working conditions for pharmacy personnel. CONCLUSION: Intrinsic motivation elements of competence and relationships are statistically different among employment settings. Relationships and feelings of competence are perceived more favorably in independent and health systems, rather than chain settings. More studies on intrinsic motivations of pharmacy employees within these settings are needed.


Assuntos
Assistência Farmacêutica , Farmácias , Farmácia , Humanos , Motivação , Farmacêuticos/psicologia , Técnicos em Farmácia/psicologia , Satisfação no Emprego
10.
PLoS One ; 18(12): e0295893, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38085734

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0173335.].

11.
Int J Part Ther ; 10(2): 85-93, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38075486

RESUMO

Purpose: Many patients with metastatic cancer live years beyond diagnosis, and there remains a need to improve the therapeutic ratio of metastasis-directed radiation for these patients. This study aimed to assess a process for delivering cost-effective palliative proton therapy to the spine using diagnostic scan-based planning (DSBP) and prefabricated treatment delivery devices. Materials and Methods: We designed and characterized a reusable proton aperture system that adjusts to multiple lengths for spine treatment. Next, we retrospectively identified 10 patients scan treated with thoracic proton therapy who also had a diagnostic computed tomography within 4 months of simulation. We contoured a T6-T9 target volume on both the diagnostic scans (DS) and simulation scans (SS). Using the aperture system, we generated proton plans on the DS using a posterior-anterior beam with no custom range compensator to treat T6-T9 to 8 Gy × 1. Plans were transferred to the SS to compare coverage and normal tissue doses, followed by robustness analysis. Finally, we compared normal tissue doses and costs between proton and photon plans. Results were compared using the Wilcoxon signed-rank test. Results: Median D95% on the DS plans was 101% (range, 100%-102%) of the prescription dose. Median Dmax was 107% (range, 105%-108%). When transferred to SS, coverage and hot spots remained acceptable for all cases. Heart and esophagus doses did not vary between the DS and SS proton plans (P >.2). Robustness analysis with 5 mm X/Y/Z shifts showed acceptable coverage (D95% > 98%) for all cases. Compared with the proton plans, the mean heart dose was higher for both anterior-posterior/posterior-anterior and volumetric modulated arc therapy plans (P < .01). Cost for proton DSBP was comparable to more commonly used photon regimens. Conclusion: Proton DSBP is technically feasible and robust, with superior sparing of the heart compared with photons. Eliminating simulation and custom devices increases the value of this approach in carefully selected patients.

12.
RNA Biol ; 20(1): 908-925, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-37906624

RESUMO

Alternative processing of nascent mRNAs is widespread in eukaryotic organisms and greatly impacts the output of gene expression. Specifically, alternative cleavage and polyadenylation (APA) is a co-transcriptional molecular process that switches the polyadenylation site (PAS) at which a nascent mRNA is cleaved, resulting in mRNA isoforms with different 3'UTR length and content. APA can potentially affect mRNA translation efficiency, localization, stability, and mRNA seeded protein-protein interactions. APA naturally occurs during development and cellular differentiation, with around 70% of human genes displaying APA in particular tissues and cell types. For example, neurons tend to express mRNAs with long 3'UTRs due to preferential processing at PASs more distal than other PASs used in other cell types. In addition, changes in APA mark a variety of pathological states, including many types of cancer, in which mRNAs are preferentially cleaved at more proximal PASs, causing expression of mRNA isoforms with short 3'UTRs. Although APA has been widely reported, both the function of APA in development and the mechanisms that regulate the choice of 3'end cut sites in normal and pathogenic conditions are still poorly understood. In this review, we summarize current understanding of how APA is regulated during development and cellular differentiation and how the resulting change in 3'UTR content affects multiple aspects of gene expression. With APA being a widespread phenomenon, the advent of cutting-edge scientific techniques and the pressing need for in-vivo studies, there has never been a better time to delve into the intricate mechanisms of alternative cleavage and polyadenylation.


Assuntos
Regulação da Expressão Gênica , Poliadenilação , Humanos , Regiões 3' não Traduzidas , Isoformas de RNA/genética , Isoformas de RNA/metabolismo , Diferenciação Celular/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
JAMA Netw Open ; 6(10): e2340654, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37906192

RESUMO

Importance: Adjuvant stereotactic radiosurgery (SRS) enhances the local control of resected brain metastases (BrM). However, the risks of local failure (LF) and potential for posttreatment adverse radiation effects (PTRE) after early postoperative adjuvant SRS have not yet been established. Objective: To evaluate whether adjuvant SRS delivered within a median of 14 days after surgery is associated with improved LF without a concomitant increase in PTRE. Design, Setting, and Participants: This prospective cohort study examines a clinical workflow (RapidRT) that was implemented from 2019 to 2022 to deliver SRS to surgical patients within a median of 14 days, ensuring all patients were treated within 30 days postoperatively. This prospective cohort was compared with a historical cohort (StanRT) of patients with BrM resected between 2013 and 2019 to assess the association of the RapidRT workflow with LF and PTRE. The 2 cohorts were combined to identify optimal SRS timing, with a median follow-up of 3.3 years for survivors. Exposure: Timing of adjuvant SRS (14, 21, and 30 days postoperatively). Main Outcomes and Measures: LF and PTRE, according to modified Response Assessment in Neuro-Oncology Brain Metastases criteria. Results: There were 438 patients (265 [60.5%] female patients; 23 [5.3%] Asian, 27 [6.2%] Black, and 364 [83.1%] White patients) with a mean (SD) age of 62 (13) years; 377 were in the StanRT cohort and 61 in the RapidRT cohort. LF and PTRE rates at 1 year were not significantly different between RapidRT and StanRT cohorts. Timing of SRS was associated with radiographic PTRE. Patients receiving radiation within 14 days had the highest 1-year PTRE rate (18.08%; 95% CI, 8.31%-30.86%), and patients receiving radiation between 22 and 30 days had the lowest 1-year PTRE rate (4.10%; 95% CI, 1.52%-8.73%; P = .03). LF rates were highest for patients receiving radiation more than 30 days from surgery (10.65%; 95% CI, 6.90%-15.32%) but comparable for patients receiving radiation within 14 days, between 15 and 21 days, and between 22 and 30 days (≤14 days: 5.12%; 95% CI, 0.86%-15.60%; 15 to ≤21 days: 3.21%; 95% CI, 0.59%-9.99%; 22 to ≤30 days: 6.58%; 95% CI, 3.06%-11.94%; P = .20). Conclusions and Relevance: In this cohort study of adjuvant SRS timing following surgical resection of BrM, the optimal timing for adjuvant SRS appears to be within 22 to 30 days following surgery. The findings of this study suggest that this timing allows for a balanced approach that minimizes the risks associated with LF and PTRE.


Assuntos
Neoplasias Encefálicas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Radiocirurgia , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Estudos Prospectivos , Estudos de Coortes , Adjuvantes Imunológicos , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia
14.
ACS Chem Neurosci ; 14(18): 3518-3527, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37695072

RESUMO

Understanding the chemical events following trauma to the central nervous system could assist in identifying causative mechanisms and potential interventions to protect neural tissue. Here, we apply a partial optic nerve transection model of injury in rats and use synchrotron X-ray fluorescence microscopy (XFM) to perform elemental mapping of metals (K, Ca, Fe, Cu, Zn) and other related elements (P, S, Cl) in white matter tracts. The partial optic nerve injury model and spatial precision of microscopy allow us to obtain previously unattained resolution in mapping elemental changes in response to a primary injury and subsequent secondary effects. We observed significant elevation of Cu levels at multiple time points following the injury, both at the primary injury site and in neural tissue near the injury site vulnerable to secondary damage, as well as significant changes in Cl, K, P, S, and Ca. Our results suggest widespread metal dyshomeostasis in response to central nervous system trauma and that altered Cu homeostasis may be a specific secondary event in response to white matter injury. The findings highlight metal homeostasis as a potential point of intervention in limiting damage following nervous system injury.


Assuntos
Traumatismos do Sistema Nervoso , Substância Branca , Animais , Ratos , Cobre , Homeostase , Modelos Animais
15.
Microsc Microanal ; 29(Supplement_1): 374-375, 2023 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-37613622
16.
J Arthroplasty ; 38(12): 2526-2530.e1, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37595766

RESUMO

BACKGROUND: The Index of Concentration at the Extremes (ICE), a measure of geographic socioeconomic polarization, predicts several health outcomes but has not been evaluated concerning total knee arthroplasty (TKA). This study evaluates ICE as a predictor of post-TKA resource utilization. METHODS: Using the Healthcare Cost and Utilization Project's New York State database from 2016 to 2017, we retrospectively evaluated 57,426 patients ≥50 years undergoing primary TKA. The ICE values for extreme concentrations of income and race were calculated using United States Census Bureau data with the formula ICEi = (Pi-Di)/Ti where Pi, Di, and Ti are the number of households in the most privileged extreme, disadvantaged extreme, and total population in zip code i, respectively. Extremes of privilege and disadvantage were defined as ≥$150,000 versus <$25,000 for income and non-Hispanic White versus non-Hispanic Black for race. Association of ICE values, demographics, and comorbidities with 90-day readmission and 90-day emergency department (ED) visits was examined using multivariable analysis. RESULTS: Overall 90-day readmission and ED visit rates were 12.8% and 9.4%, respectively. On multivariable analysis, the lowest ICEIncome quintile (concentrated poverty) predicted 90-day readmission (odds ratio 1.17, 95% confidence interval 1.05 to 1.30, P = .005) and 90-day ED visit (odds ratio 1.22, 95% confidence interval 1.08 to 1.38, P = .001). The ICERace was not predictive of either outcome. CONCLUSION: Patients in communities with the lowest ICEIncome values use more inpatient and ED resources after primary TKA. Incorporating ICEIncome into risk-adjusted payment models may help align incentives for equitable care.


Assuntos
Artroplastia de Quadril , Artroplastia do Joelho , Humanos , Estados Unidos , Artroplastia do Joelho/efeitos adversos , Fatores de Risco , Estudos Retrospectivos , Etnicidade , Comorbidade , Artroplastia de Quadril/efeitos adversos , Readmissão do Paciente , Complicações Pós-Operatórias/etiologia
17.
Cell Rep Med ; 4(7): 101113, 2023 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-37467718

RESUMO

Recurrences frequently occur following surgical removal of primary tumors. In many cancers, adjuvant therapies have limited efficacy. Surgery provides access to the tumor microenvironment, creating an opportunity for local therapy, in particular immunotherapy, which can induce local and systemic anti-cancer effects. Here, we develop a surgically optimized biodegradable hyaluronic acid-based hydrogel for sustained intraoperative delivery of Toll-like receptor 3 agonist poly(I:C) and demonstrate that it significantly reduces tumor recurrence after surgery in multiple mouse models. Mechanistically, poly(I:C) induces a transient interferon alpha (IFNα) response, reshaping the tumor/wound microenvironment by attracting inflammatory monocytes and depleting regulatory T cells. We demonstrate that a pre-existing IFN signature predicts response to the poly(I:C) hydrogel, which sensitizes tumors to immune checkpoint therapy. The safety, immunogenicity, and surgical feasibility are confirmed in a veterinary trial in canine soft tissue tumors. The surgically optimized poly(I:C)-loaded hydrogel provides a safe and effective approach to prevent cancer recurrence.


Assuntos
Hidrogéis , Recidiva Local de Neoplasia , Camundongos , Animais , Cães , Hidrogéis/uso terapêutico , Recidiva Local de Neoplasia/prevenção & controle , Imunoterapia , Modelos Animais de Doenças , Microambiente Tumoral
18.
Cancers (Basel) ; 15(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37444542

RESUMO

Small-molecule inhibitors of PD-L1 are postulated to control immune evasion in tumors similar to antibodies that target the PD-L1/PD-1 immune checkpoint axis. However, the identity of targetable PD-L1 inducers is required to develop small-molecule PD-L1 inhibitors. In this study, using chromatin immunoprecipitation (ChIP) assay and siRNA, we demonstrate that vitamin D/VDR regulates PD-L1 expression in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) cells. We have examined whether a VDR antagonist, MeTC7, can inhibit PD-L1. To ensure that MeTC7 inhibits VDR/PD-L1 without off-target effects, we examined competitive inhibition of VDR by MeTC7, utilizing ligand-dependent dimerization of VDR-RXR, RXR-RXR, and VDR-coactivators in a mammalian 2-hybrid (M2H) assay. MeTC7 inhibits VDR selectively, suppresses PD-L1 expression sparing PD-L2, and inhibits the cell viability, clonogenicity, and xenograft growth of AML cells. MeTC7 blocks AML/mesenchymal stem cells (MSCs) adhesion and increases the efferocytotic efficiency of THP-1 AML cells. Additionally, utilizing a syngeneic colorectal cancer model in which VDR/PD-L1 co-upregulation occurs in vivo under radiation therapy (RT), MeTC7 inhibits PD-L1 and enhances intra-tumoral CD8+T cells expressing lymphoid activation antigen-CD69. Taken together, MeTC7 is a promising small-molecule inhibitor of PD-L1 with clinical potential.

19.
Chem Sci ; 14(28): 7681-7687, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37476710

RESUMO

DNA G-quadruplexes (G4s) have been identified as important biological targets for transcriptional, translational, and epigenetic regulation. The stabilisation of G4s with small molecule ligands has emerged as a technique to regulate gene expression and as a potential therapeutic approach for human diseases. Here, we demonstrate that ligand stabilisation of G4s causes altered chromatin accessibility dependent on the targeting specificity of the molecule. In particular, stabilisation of a target G4 using the highly specific GTC365 ligand resulted in differential accessibility of 61 genomic regions, while the broad-targeting G4 ligand, GQC-05, stabilised many G4s and induced a global shift towards increased accessibility of gene promoter regions. Interestingly, while we observed distinct effects of each ligand on RNA expression levels and the induction of DNA double-stranded breaks, both ligands modified DNA damage response pathways. Our work represents the dual possibility of G4-stabilising ligands for specific or global chromatin modulation via unique targeting characteristics.

20.
Proc Natl Acad Sci U S A ; 120(20): e2210991120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155843

RESUMO

In 2021, the World Health Organization reclassified glioblastoma, the most common form of adult brain cancer, into isocitrate dehydrogenase (IDH)-wild-type glioblastomas and grade IV IDH mutant (G4 IDHm) astrocytomas. For both tumor types, intratumoral heterogeneity is a key contributor to therapeutic failure. To better define this heterogeneity, genome-wide chromatin accessibility and transcription profiles of clinical samples of glioblastomas and G4 IDHm astrocytomas were analyzed at single-cell resolution. These profiles afforded resolution of intratumoral genetic heterogeneity, including delineation of cell-to-cell variations in distinct cell states, focal gene amplifications, as well as extrachromosomal circular DNAs. Despite differences in IDH mutation status and significant intratumoral heterogeneity, the profiled tumor cells shared a common chromatin structure defined by open regions enriched for nuclear factor 1 transcription factors (NFIA and NFIB). Silencing of NFIA or NFIB suppressed in vitro and in vivo growths of patient-derived glioblastomas and G4 IDHm astrocytoma models. These findings suggest that despite distinct genotypes and cell states, glioblastoma/G4 astrocytoma cells share dependency on core transcriptional programs, yielding an attractive platform for addressing therapeutic challenges associated with intratumoral heterogeneity.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioblastoma , Adulto , Humanos , Glioblastoma/genética , Glioblastoma/patologia , Cromatina/genética , Transcriptoma , Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Mutação , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo
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