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1.
Orphanet J Rare Dis ; 19(1): 186, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38702811

ABSTRACT

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder, leading to various complications and impairments in patients' health-related quality of life (HRQOL). Limited research has been conducted to evaluate the HRQOL of Chinese patients with PNH. Understanding the HRQOL in this specific population is crucial for providing effective healthcare interventions and improving patient' health outcomes. This study aimed to assess HRQOL of Chinese patients with PNH, and identify key determinants. METHODS: A cross-sectional study was conducted during 2022 to recruit patients with PNH in China. The study population was recruited from PNH China, one of the largest public welfare PNH patient mutual aid organization in China. Data were collected via an online questionnaire including the EQ-5D-5L (5L), and social-demographic and clinical characteristics. Descriptive statistics were employed to summarize the characteristics of the participants and their HRQOL. Multiple linear and logistic regression analyses were adopted to explore key factors affecting HRQOL. RESULTS: A total of 329 valid questionnaires were collected. The mean (SD) age of the patients was 35.3 (10.0) years, with 52.3% of them being male. The patients reported more problems in Anxiety/Depression (81.5%) and Pain/Discomfort (69.9%) dimensions compared to the other three 5L dimensions. The mean (SD) of 5L health utility score (HUS) and EQ-VAS score were 0.76 (0.21) and 62.61 (19.20), respectively. According to multiple linear regression, initial symptoms (i.e., Anemia [fatigue, tachycardia, shortness of breath, headache] and back pain) and complication of thrombosis were significant influencing factors affecting 5L HUS. Total personal income of the past year, initial symptom of hemoglobinuria and complication of thrombosis were significantly influencing factors of VAS score. Social-demographic and clinical characteristics, such as gender, income, and thrombosis, were also found to be significantly related to certain 5L health problems as well. CONCLUSION: Our study manifested the HRQOL of PNH patients in China was markedly compromised, especially in two mental-health related dimensions, and revealed several socio-demographic and clinical factors of their HRQOL. These findings could be used as empirical evidence for enhancing the HRQOL of PNH patients in China.


Subject(s)
Hemoglobinuria, Paroxysmal , Quality of Life , Humans , Male , Female , China/epidemiology , Adult , Cross-Sectional Studies , Middle Aged , Surveys and Questionnaires , Young Adult , Adolescent
2.
Eur J Med Chem ; 268: 116285, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38428273

ABSTRACT

Biological studies on the endocannabinoid system (ECS) have suggested that monoacylglycerol lipase (MAGL), an essential enzyme responsible for the hydrolysis of 2-arachidonoylglycerol (2-AG), is a novel target for developing antidepressants. A decrease of 2-AG levels in the hippocampus of the brain has been observed in depressive-like models induced by chronic stress. Herein, employing a structure-based approach, we designed and synthesized a new class of (piperazine-1-carbonyl) quinolin-2(1H)-one derivatives as potent, reversible and selective MAGL inhibitors. And detailed structure-activity relationships (SAR) studies were discussed. Compound 27 (IC50 = 10.3 nM) exhibited high bioavailability (92.7%) and 2-AG elevation effect in vivo. Additionally, compound 27 exerted rapid antidepressant effects caused by chronic restraint stress (CRS) and didn't show signs of addictive properties in the conditioned place preference (CPP) assays. Our study is the first to report that reversible MAGL inhibitors can treat chronic stress-induced depression effectively, which may provide a new potential therapeutic strategy for the discovery of an original class of safe, rapid antidepressant drugs.


Subject(s)
Enzyme Inhibitors , Monoacylglycerol Lipases , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Monoacylglycerol Lipases/metabolism , Depression/drug therapy , Monoglycerides , Structure-Activity Relationship , Antidepressive Agents/pharmacology , Antidepressive Agents/therapeutic use , Endocannabinoids
3.
Heliyon ; 10(5): e26344, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38439830

ABSTRACT

As coal mines shift from shallow to deeper excavation, the number of mines facing the risk of rock burst disasters is gradually increasing. Rockburst, with their characteristics of vibration, suddenness, complexity, and unpredictability, make it increasingly difficult to prevent and control these disasters. Therefore, the challenges of preventing and controlling rock burst disasters are becoming more and more severe. This paper, based on the system-theoretic accident model and processes (STAMP) theory, extracts the causal factors affecting coal mine rock burst accidents. Using the interpretative structural modeling (ISM) and decision-making trial and evaluation laboratory (DEMATEL) method, the accident-causing factors are quantitatively assigned. By constructing model equations and drawing causal loop diagrams and stock-flow diagrams, the event is dynamically simulated and early warnings are issued. The results show that the control defects leading to the accident are analyzed from the perspectives of the government level, management level, grassroots level, physical layer, and the dynamic process of the accident. In the short term, safety investment in grassroots operations is the most effective control. In the long run, the most effective measure is for the management level to strengthen its supervisory work. By changing the input ratios of various variables, it can be seen that different variables in the system dynamics (SD) model have different impacts on coal mine rock burst accidents. It is necessary to continuously strengthen the implementation of the safety responsibility system, improve the work efficiency of the government and management level, and enhance the timeliness of emergency decision-making.

4.
Blood ; 143(19): 1980-1991, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38364109

ABSTRACT

ABSTRACT: The switch from fetal hemoglobin (γ-globin, HBG) to adult hemoglobin (ß-globin, HBB) gene transcription in erythroid cells serves as a paradigm for a complex and clinically relevant developmental gene regulatory program. We previously identified HIC2 as a regulator of the switch by inhibiting the transcription of BCL11A, a key repressor of HBG production. HIC2 is highly expressed in fetal cells, but the mechanism of its regulation is unclear. Here we report that HIC2 developmental expression is controlled by microRNAs (miRNAs), as loss of global miRNA biogenesis through DICER1 depletion leads to upregulation of HIC2 and HBG messenger RNA. We identified the adult-expressed let-7 miRNA family as a direct posttranscriptional regulator of HIC2. Ectopic expression of let-7 in fetal cells lowered HIC2 levels, whereas inhibition of let-7 in adult erythroblasts increased HIC2 production, culminating in decommissioning of a BCL11A erythroid enhancer and reduced BCL11A transcription. HIC2 depletion in let-7-inhibited cells restored BCL11A-mediated repression of HBG. Together, these data establish that fetal hemoglobin silencing in adult erythroid cells is under the control of a miRNA-mediated inhibitory pathway (let-7 ⊣ HIC2 ⊣ BCL11A ⊣ HBG).


Subject(s)
Carrier Proteins , MicroRNAs , Nuclear Proteins , Repressor Proteins , MicroRNAs/genetics , MicroRNAs/metabolism , Humans , Repressor Proteins/genetics , Repressor Proteins/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Transcription, Genetic , Kruppel-Like Transcription Factors/genetics , Kruppel-Like Transcription Factors/metabolism , Fetal Hemoglobin/genetics , Fetal Hemoglobin/metabolism , Ribonuclease III/genetics , Ribonuclease III/metabolism , beta-Globins/genetics , beta-Globins/metabolism , Gene Expression Regulation , Erythroblasts/metabolism , Erythroblasts/cytology , gamma-Globins/genetics , gamma-Globins/metabolism , DEAD-box RNA Helicases/genetics , DEAD-box RNA Helicases/metabolism
5.
J Am Chem Soc ; 146(7): 4913-4921, 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38319594

ABSTRACT

Colloidal quantum dots with lower surface ligand density are desired for preparing the active layer for photovoltaic, lighting, and other potential optoelectronic applications. In emerging perovskite quantum dots (PQDs), the diffusion of cations is thought to have a high energy barrier, relative to that of halide anions. Herein, we investigate the fast cross cation exchange approach in colloidal lead triiodide PQDs containing methylammonium (MA+) and formamidinium (FA+) organic cations, which exhibits a significantly lower exchange barrier than inorganic cesium (Cs+)-FA+ and Cs+-MA+ systems. First-principles calculations further suggest that the fast internal cation diffusion arises due to a lowering in structural distortions and the consequent decline in attractive cation-cation and cation-anion interactions in the presence of organic cation vacancies in mixed MA+-FA+ PQDs. Combining both experimental and theoretical evidence, we propose a vacancy-assisted exchange model to understand the impact of structural features and intermolecular interaction in PQDs with fewer surface ligands. Finally, for a realistic outcome, the as-prepared mixed-cation PQDs display better photostability and can be directly applied for one-step coated photovoltaic and photodetector devices, achieving a high photovoltaic efficiency of 15.05% using MA0.5FA0.5PbI3 PQDs and more precisely tunable detective spectral response from visible to near-infrared regions.

6.
Nucleic Acids Res ; 52(4): 2078-2090, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38261989

ABSTRACT

The partnership of DNA deaminase enzymes with CRISPR-Cas nucleases is now a well-established method to enable targeted genomic base editing. However, an understanding of how Cas9 and DNA deaminases collaborate to shape base editor (BE) outcomes has been lacking. Here, we support a novel mechanistic model of base editing by deriving a range of hyperactive activation-induced deaminase (AID) base editors (hBEs) and exploiting their characteristic diversifying activity. Our model involves multiple layers of previously underappreciated cooperativity in BE steps including: (i) Cas9 binding can potentially expose both DNA strands for 'capture' by the deaminase, a feature that is enhanced by guide RNA mismatches; (ii) after strand capture, the intrinsic activity of the DNA deaminase can tune window size and base editing efficiency; (iii) Cas9 defines the boundaries of editing on each strand, with deamination blocked by Cas9 binding to either the PAM or the protospacer and (iv) non-canonical edits on the guide RNA bound strand can be further elicited by changing which strand is nicked by Cas9. Leveraging insights from our mechanistic model, we create novel hBEs that can remarkably generate simultaneous C > T and G > A transitions over >65 bp with significant potential for targeted gene diversification.


Subject(s)
CRISPR-Associated Protein 9 , Cytidine Deaminase , Escherichia coli , Gene Editing , CRISPR-Associated Protein 9/metabolism , CRISPR-Cas Systems , Cytidine Deaminase/metabolism , DNA/genetics , Escherichia coli/metabolism , Mutation , RNA, Guide, CRISPR-Cas Systems , Humans , Animals
7.
Nat Biotechnol ; 42(2): 305-315, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37095348

ABSTRACT

Simple, efficient and well-tolerated delivery of CRISPR genome editing systems into primary cells remains a major challenge. Here we describe an engineered Peptide-Assisted Genome Editing (PAGE) CRISPR-Cas system for rapid and robust editing of primary cells with minimal toxicity. The PAGE system requires only a 30-min incubation with a cell-penetrating Cas9 or Cas12a and a cell-penetrating endosomal escape peptide to achieve robust single and multiplex genome editing. Unlike electroporation-based methods, PAGE gene editing has low cellular toxicity and shows no significant transcriptional perturbation. We demonstrate rapid and efficient editing of primary cells, including human and mouse T cells, as well as human hematopoietic progenitor cells, with editing efficiencies upwards of 98%. PAGE provides a broadly generalizable platform for next-generation genome engineering in primary cells.


Subject(s)
CRISPR-Cas Systems , Gene Editing , Humans , Animals , Mice , Gene Editing/methods , CRISPR-Cas Systems/genetics , Electroporation , Hematopoietic Stem Cells
8.
Sci Immunol ; 8(86): eade3369, 2023 08 25.
Article in English | MEDLINE | ID: mdl-37595022

ABSTRACT

Identifying molecular mechanisms of exhausted CD8 T cells (Tex) is a key goal of improving immunotherapy of cancer and other diseases. However, high-throughput interrogation of in vivo Tex can be costly and inefficient. In vitro models of Tex are easily customizable and quickly generate high cellular yield, enabling CRISPR screening and other high-throughput assays. We established an in vitro model of chronic stimulation and benchmarked key phenotypic, functional, transcriptional, and epigenetic features against bona fide in vivo Tex. We leveraged this model of in vitro chronic stimulation in combination with CRISPR screening to identify transcriptional regulators of T cell exhaustion. This approach identified several transcription factors, including BHLHE40. In vitro and in vivo validation defined a role for BHLHE40 in regulating a key differentiation checkpoint between progenitor and intermediate Tex subsets. By developing and benchmarking an in vitro model of Tex, then applying high-throughput CRISPR screening, we demonstrate the utility of mechanistically annotated in vitro models of Tex.


Subject(s)
Clustered Regularly Interspaced Short Palindromic Repeats , T-Cell Exhaustion , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , CD8-Positive T-Lymphocytes , Cell Differentiation , Epigenomics
9.
Proc Natl Acad Sci U S A ; 120(36): e2303859120, 2023 09 05.
Article in English | MEDLINE | ID: mdl-37639593

ABSTRACT

Recurrent chromosomal rearrangements found in rhabdomyosarcoma (RMS) produce the PAX3-FOXO1 fusion protein, which is an oncogenic driver and a dependency in this disease. One important function of PAX3-FOXO1 is to arrest myogenic differentiation, which is linked to the ability of RMS cells to gain an unlimited proliferation potential. Here, we developed a phenotypic screening strategy for identifying factors that collaborate with PAX3-FOXO1 to block myo-differentiation in RMS. Unlike most genes evaluated in our screen, we found that loss of any of the three subunits of the Nuclear Factor Y (NF-Y) complex leads to a myo-differentiation phenotype that resembles the effect of inactivating PAX3-FOXO1. While the transcriptomes of NF-Y- and PAX3-FOXO1-deficient RMS cells bear remarkable similarity to one another, we found that these two transcription factors occupy nonoverlapping sites along the genome: NF-Y preferentially occupies promoters, whereas PAX3-FOXO1 primarily binds to distal enhancers. By integrating multiple functional approaches, we map the PAX3 promoter as the point of intersection between these two regulators. We show that NF-Y occupies CCAAT motifs present upstream of PAX3 to function as a transcriptional activator of PAX3-FOXO1 expression in RMS. These findings reveal a critical upstream role of NF-Y in the oncogenic PAX3-FOXO1 pathway, highlighting how a broadly essential transcription factor can perform tumor-specific roles in governing cellular state.


Subject(s)
Rhabdomyosarcoma , CCAAT-Binding Factor/genetics , Cell Differentiation/genetics , Chromosome Aberrations , Rhabdomyosarcoma/genetics , Transcription Factors
10.
Adv Mater ; 35(38): e2302839, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37391877

ABSTRACT

Dual-interface modulation including buried interface as well as the top surface has recently been proven to be crucial for obtaining high photovoltaic performance in lead halide perovskite solar cells (PSCs). Herein, for the first time, the strategy of using functional covalent organic frameworks (COFs), namely HS-COFs for dual-interface modulation, is reported to further understand its intrinsic mechanisms in optimizing the bottom and top surfaces. Specifically, the buried HS-COFs layer can enhance the resistance against ultraviolet radiation, and more importantly, release the tensile strain, which is beneficial for enhancing device stability and improving the order of perovskite crystal growth. Furthermore, the detailed characterization results reveal that the HS-COFs on the top surface can effectively passivate the surface defects and suppress non-radiation recombination, as well as optimize the crystallization and growth of the perovskite film. Benefiting from the synergistic effects, the dual-interface modified devices deliver champion efficiencies of 24.26% and 21.30% for 0.0725 cm2 and 1 cm2 -sized devices, respectively. Moreover, they retain 88% and 84% of their initial efficiencies after aging for 2000 h under the ambient conditions (25 °C, relative humidity: 35-45%) and a nitrogen atmosphere with heating at 65 °C, respectively.

12.
Small ; 19(47): e2302383, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37501318

ABSTRACT

Lead halide perovskite solar cells (PSCs) have made unprecedented progress, exhibiting great potential for commercialization. Among them, inverted p-i-n PSCs provide outstanding compatibility with flexible substrates, more importantly, with silicon (Si) bottom devices for higher efficiency perovskite-Si tandem solar cells. However, even with recently obtained efficiency over 25%, the investigation of inverted p-i-n PSCs is still behind the n-i-p counterpart so far. Recent progress has demonstrated that the fill factor (FF) in inverted PSCs currently still underperforms relative to open-circuit voltage and short-circuit current density, which requires an in-depth understanding of the mechanism and further research. In this review article, the recent advancements in high FF inverted PSCs by adopting the approaches of interfacial optimization, precursor engineering as well as fabrication techniques to minimize undesirable recombination are summarized. Insufficient carrier extraction and transport efficiency are found to be the main factors that hinder the current FF of inverted PSCs. In addition, insights into the main factors limiting FF and strategies for minimizing series resistance in inverted PSCs are presented. The continuous efforts dedicated to the FF of high-performance inverted devices may pave the way toward commercial applications of PSCs in the near future.

13.
Radiother Oncol ; 187: 109813, 2023 10.
Article in English | MEDLINE | ID: mdl-37468066

ABSTRACT

BACKGROUND: Radiation nephropathy (RN) can be a severe late complication for patients treated with radiotherapy (RT) targeting abdominal and paraspinal tumors. Recent studies investigating the mechanisms of RT-mediated injury in the kidney have demonstrated that RT disrupts the cellular integrity of renal podocytes leading to cell death and loss of renal function. AIM: To determine if RT-induced renal dysfunction is associated with alterations in podocyte and glomerular function, and whether RT-induced podocyte alterations were associated with changes in the glomerular basement membrane (GBM). METHODS: C57BL/6 mice were treated with focal bilateral X-irradiation using a single dose (SD) of 4 Gy, 10 Gy, or 14 Gy or fractionated dosing (FD) of 5x6Gy or 24x2Gy. Then, 10-40 weeks after RT parameters of renal function were measured, along with glomerular filtration rate (GFR) and glomerular histology, as well as ultrastructural changes in GBM by transmission electron microscopy. RESULTS: RT treatment resulted in persistent changes in renal function beginning at 10 weeks with little recovery up to 40 weeks post RT. Dose dependent changes were seen with increasing SD but no functional sparing was evident after FD. RT-induced loss of renal function was associated with expansion of the GBM and significant increases in foot process width, and associated with significant reduction in GFR, podocyte loss, and renal fibrosis. CONCLUSION: For the first time, these data show that expansion of the GBM is one consequence of radiation injury, and disarrangement of the GBM might be associated with the death of podocytes. These data shed new light on the role podocyte injury and GBM in RT-induced renal dysfunction.


Subject(s)
Kidney Diseases , Podocytes , Radiation Injuries , Mice , Animals , Disease Models, Animal , Mice, Inbred C57BL , Kidney Glomerulus/pathology , Kidney Glomerulus/ultrastructure , Kidney Diseases/etiology , Kidney Diseases/metabolism , Kidney Diseases/pathology , Podocytes/metabolism , Podocytes/pathology , Podocytes/ultrastructure , Radiation Injuries/pathology
14.
Immunity ; 56(6): 1320-1340.e10, 2023 06 13.
Article in English | MEDLINE | ID: mdl-37315535

ABSTRACT

CD8+ T cell exhaustion (Tex) limits disease control during chronic viral infections and cancer. Here, we investigated the epigenetic factors mediating major chromatin-remodeling events in Tex-cell development. A protein-domain-focused in vivo CRISPR screen identified distinct functions for two versions of the SWI/SNF chromatin-remodeling complex in Tex-cell differentiation. Depletion of the canonical SWI/SNF form, BAF, impaired initial CD8+ T cell responses in acute and chronic infection. In contrast, disruption of PBAF enhanced Tex-cell proliferation and survival. Mechanistically, PBAF regulated the epigenetic and transcriptional transition from TCF-1+ progenitor Tex cells to more differentiated TCF-1- Tex subsets. Whereas PBAF acted to preserve Tex progenitor biology, BAF was required to generate effector-like Tex cells, suggesting that the balance of these factors coordinates Tex-cell subset differentiation. Targeting PBAF improved tumor control both alone and in combination with anti-PD-L1 immunotherapy. Thus, PBAF may present a therapeutic target in cancer immunotherapy.


Subject(s)
CD8-Positive T-Lymphocytes , Chromatin Assembly and Disassembly , Chromatin , Cell Differentiation , Epigenesis, Genetic
16.
Trends Pharmacol Sci ; 44(9): 555-557, 2023 09.
Article in English | MEDLINE | ID: mdl-37328396

ABSTRACT

CRISPR tiling screens offer an efficient way to identify gain-of-function mutations in targets of cancer therapy. Recently, by utilizing these screens, Kwok et al. unexpectedly discovered mutations conferring drug addiction in lymphoma, revealing a requirement for a 'just right' window of histone methylation crucial for cancer survival.


Subject(s)
Clustered Regularly Interspaced Short Palindromic Repeats , Neoplasms , Humans , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Neoplasms/genetics , Epigenomics , Epigenesis, Genetic , CRISPR-Cas Systems
17.
bioRxiv ; 2023 Apr 17.
Article in English | MEDLINE | ID: mdl-37131713

ABSTRACT

Identifying novel molecular mechanisms of exhausted CD8 T cells (T ex ) is a key goal of improving immunotherapy of cancer and other diseases. However, high-throughput interrogation of in vivo T ex can be costly and inefficient. In vitro models of T ex are easily customizable and quickly generate high cellular yield, offering an opportunity to perform CRISPR screening and other high-throughput assays. We established an in vitro model of chronic stimulation and benchmarked key phenotypic, functional, transcriptional, and epigenetic features against bona fide in vivo T ex . We leveraged this model of in vitro chronic stimulation in combination with pooled CRISPR screening to uncover transcriptional regulators of T cell exhaustion. This approach identified several transcription factors, including BHLHE40. In vitro and in vivo validation defined a role for BHLHE40 in regulating a key differentiation checkpoint between progenitor and intermediate subsets of T ex . By developing and benchmarking an in vitro model of T ex , we demonstrate the utility of mechanistically annotated in vitro models of T ex , in combination with high-throughput approaches, as a discovery pipeline to uncover novel T ex biology.

18.
Analyst ; 148(11): 2511-2517, 2023 May 30.
Article in English | MEDLINE | ID: mdl-37191134

ABSTRACT

Histopathological molecular testing of tissue sections is an essential step in tumor diagnosis; however, the commonly used immunohistochemical methods have problems such as low specificity and the subjective bias of the observer. Here, we report an electrochemiluminescence (ECL) imaging method to detect a membrane carcinoembryonic antigen (CEA) at the single tissue sections of cancer patients. By permeabilizing the tissue attached to a glassy carbon electrode, Ru(bpy)32+ tagged at the membrane CEA of the tissue could electrochemically react with TPrA in solution to emit ECL that has near-zero background and an extremely high signal-to-background ratio. Using the established ECL method, the expression differences and distribution characteristics of the CEA protein in the carcinoma and paracancerous tissues of pancreatic ductal carcinoma (PDAC) and lung adenocarcinoma (LUAD) patients are investigated. The images reveal that CEA proteins are mostly distributed in the acini and surrounding areas both in PDAC and LUAD tissues. Therefore, the presented approach could be able to provide a new molecular recognition method for the diagnosis of adenocarcinoma and other tumors.


Subject(s)
Electrochemical Techniques , Luminescent Measurements , Humans , Electrochemical Techniques/methods , Luminescent Measurements/methods , Carcinoembryonic Antigen/analysis , Carcinoembryonic Antigen/metabolism , Adenocarcinoma/chemistry , Adenocarcinoma/metabolism , Pancreatic Neoplasms/chemistry , Pancreatic Neoplasms/metabolism , Cell Membrane/chemistry , Cell Membrane/metabolism
19.
Blood ; 142(11): 973-988, 2023 09 14.
Article in English | MEDLINE | ID: mdl-37235754

ABSTRACT

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Up to 40% of patients with DLBCL display refractory disease or relapse after standard chemotherapy treatment (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone [R-CHOP]), leading to significant morbidity and mortality. The molecular mechanisms of chemoresistance in DLBCL remain incompletely understood. Using a cullin-really interesting new gene (RING) ligase-based CRISPR-Cas9 library, we identify that inactivation of the E3 ubiquitin ligase KLHL6 promotes DLBCL chemoresistance. Furthermore, proteomic approaches helped identify KLHL6 as a novel master regulator of plasma membrane-associated NOTCH2 via proteasome-dependent degradation. In CHOP-resistant DLBCL tumors, mutations of NOTCH2 result in a protein that escapes the mechanism of ubiquitin-dependent proteolysis, leading to protein stabilization and activation of the oncogenic RAS signaling pathway. Targeting CHOP-resistant DLBCL tumors with the phase 3 clinical trial molecules nirogacestat, a selective γ-secretase inhibitor, and ipatasertib, a pan-AKT inhibitor, synergistically promotes DLBCL destruction. These findings establish the rationale for therapeutic strategies aimed at targeting the oncogenic pathway activated in KLHL6- or NOTCH2-mutated DLBCL.


Subject(s)
Drug Resistance, Neoplasm , Lymphoma, Large B-Cell, Diffuse , Humans , Drug Resistance, Neoplasm/genetics , Ubiquitin , Proteomics , Neoplasm Recurrence, Local/drug therapy , Rituximab/therapeutic use , Vincristine , Cyclophosphamide , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/genetics , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Prednisone , Mutation , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Receptor, Notch2/genetics
20.
Genes Dev ; 37(7-8): 321-335, 2023 04 01.
Article in English | MEDLINE | ID: mdl-37024283

ABSTRACT

Several rRNA-modifying enzymes install rRNA modifications while participating in ribosome assembly. Here, we show that 18S rRNA methyltransferase DIMT1 is essential for acute myeloid leukemia (AML) proliferation through a noncatalytic function. We reveal that targeting a positively charged cleft of DIMT1, remote from the catalytic site, weakens the binding of DIMT1 to rRNA and mislocalizes DIMT1 to the nucleoplasm, in contrast to the primarily nucleolar localization of wild-type DIMT1. Mechanistically, rRNA binding is required for DIMT1 to undergo liquid-liquid phase separation, which explains the distinct nucleoplasm localization of the rRNA binding-deficient DIMT1. Re-expression of wild-type or a catalytically inactive mutant E85A, but not the rRNA binding-deficient DIMT1, supports AML cell proliferation. This study provides a new strategy to target DIMT1-regulated AML proliferation via targeting this essential noncatalytic region.


Subject(s)
Leukemia, Myeloid, Acute , Methyltransferases , Humans , Cell Nucleolus/metabolism , Cell Nucleus/metabolism , Leukemia, Myeloid, Acute/genetics , Methyltransferases/metabolism , RNA Processing, Post-Transcriptional , RNA, Ribosomal, 18S/metabolism
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