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1.
Acta Pharmacol Sin ; 45(6): 1224-1236, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38467717

ABSTRACT

The root of Aconitum carmichaelii Debx. (Fuzi) is an herbal medicine used in China that exerts significant efficacy in rescuing patients from severe diseases. A key toxic compound in Fuzi, aconitine (AC), could trigger unpredictable cardiotoxicities with high-individualization, thus hinders safe application of Fuzi. In this study we investigated the individual differences of AC-induced cardiotoxicities, the biomarkers and underlying mechanisms. Diversity Outbred (DO) mice were used as a genetically heterogeneous model for mimicking individualization clinically. The mice were orally administered AC (0.3, 0.6, 0.9 mg· kg-1 ·d-1) for 7 d. We found that AC-triggered cardiotoxicities in DO mice shared similar characteristics to those observed in clinic patients. Most importantly, significant individual differences were found in DO mice (variation coefficients: 34.08%-53.17%). RNA-sequencing in AC-tolerant and AC-sensitive mice revealed that hemoglobin subunit beta (HBB), a toxic-responsive protein in blood with 89% homology to human, was specifically enriched in AC-sensitive mice. Moreover, we found that HBB overexpression could significantly exacerbate AC-induced cardiotoxicity while HBB knockdown markedly attenuated cell death of cardiomyocytes. We revealed that AC could trigger hemolysis, and specifically bind to HBB in cell-free hemoglobin (cf-Hb), which could excessively promote NO scavenge and decrease cardioprotective S-nitrosylation. Meanwhile, AC bound to HBB enhanced the binding of HBB to ABHD5 and AMPK, which correspondingly decreased HDAC-NT generation and led to cardiomyocytes death. This study not only demonstrates HBB achievement a novel target of AC in blood, but provides the first clue for HBB as a novel biomarker in determining the individual differences of Fuzi-triggered cardiotoxicity.


Subject(s)
AMP-Activated Protein Kinases , Aconitine , Cardiotoxicity , Histone Deacetylases , Animals , Mice , Cardiotoxicity/metabolism , Cardiotoxicity/etiology , Histone Deacetylases/metabolism , AMP-Activated Protein Kinases/metabolism , Male , Humans , Aconitum/chemistry , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Drugs, Chinese Herbal/pharmacology
2.
bioRxiv ; 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38464148

ABSTRACT

Nuclear speckles, a type of membraneless nuclear organelle in higher eukaryotic cells, play a vital role in gene expression regulation. Using the reverse transcription-based RNA-binding protein binding sites sequencing (ARTR-seq) method, we study human transcripts associated with nuclear speckles. We identify three gene groups whose transcripts demonstrate different speckle localization properties and dynamics: stably enriched in nuclear speckles, transiently enriched in speckles at the pre-mRNA stage, and not enriched in speckles. Specifically, we find that stably-enriched transcripts contain inefficiently spliced introns. We show that nuclear speckles specifically facilitate splicing of speckle-enriched transcripts. We further reveal RNA sequence features contributing to transcript speckle localization, underscoring a tight interplay between genome organization, RNA cis-elements, and transcript speckle enrichment, and connecting transcript speckle localization with splicing efficiency. Finally, we show that speckles can act as hubs for the regulated retention of introns during cellular stress. Collectively, our data highlight a role of nuclear speckles in both co- and post-transcriptional splicing regulation.

3.
Cell Rep ; 43(3): 113965, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38492217

ABSTRACT

G3BP1/2 are paralogous proteins that promote stress granule formation in response to cellular stresses, including viral infection. The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inhibits stress granule assembly and interacts with G3BP1/2 via an ITFG motif, including residue F17, in the N protein. Prior studies examining the impact of the G3PB1-N interaction on SARS-CoV-2 replication have produced inconsistent findings, and the role of this interaction in pathogenesis is unknown. Here, we use structural and biochemical analyses to define the residues required for G3BP1-N interaction and structure-guided mutagenesis to selectively disrupt this interaction. We find that N-F17A mutation causes highly specific loss of interaction with G3BP1/2. SARS-CoV-2 N-F17A fails to inhibit stress granule assembly in cells, has decreased viral replication, and causes decreased pathology in vivo. Further mechanistic studies indicate that the N-F17-mediated G3BP1-N interaction promotes infection by limiting sequestration of viral genomic RNA (gRNA) into stress granules.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , DNA Helicases/metabolism , RNA Helicases/metabolism , RNA Recognition Motif Proteins/metabolism , Poly-ADP-Ribose Binding Proteins/metabolism , Virulence , RNA, Guide, CRISPR-Cas Systems , Nucleocapsid Proteins , Virus Replication , RNA, Viral/genetics
4.
Molecules ; 29(4)2024 Feb 19.
Article in English | MEDLINE | ID: mdl-38398656

ABSTRACT

Melanoma is the most aggressive and difficult to treat of all skin cancers. Despite advances in the treatment of melanoma, the prognosis for melanoma patients remains poor, and the recurrence rate remains high. There is substantial evidence that Chinese herbals effectively prevent and treat melanoma. The bioactive ingredient Salvianolic acid B (SAB) found in Salvia miltiorrhiza, a well-known Chinese herbal with various biological functions, exhibits inhibitory activity against various cancers. A375 and mouse B16 cell lines were used to evaluate the main targets and mechanisms of SAB in inhibiting melanoma migration. Online bioinformatics analysis, Western blotting, immunofluorescence, molecular fishing, dot blot, and molecular docking assays were carried out to clarify the potential molecular mechanism. We found that SAB prevents the migration and invasion of melanoma cells by inhibiting the epithelial-mesenchymal transition (EMT) process of melanoma cells. As well as interacting directly with the N-terminal domain of ß-actin, SAB enhanced its compactness and stability, thereby inhibiting the migration of cells. Taken together, SAB could significantly suppress the migration of melanoma cells via direct binding with ß-actin, suggesting that SAB could be a helpful supplement that may enhance chemotherapeutic outcomes and benefit melanoma patients.


Subject(s)
Actins , Benzofurans , Melanoma , Animals , Mice , Humans , Actins/genetics , Melanoma/drug therapy , Molecular Docking Simulation , Depsides
5.
J Cell Biol ; 223(3)2024 03 04.
Article in English | MEDLINE | ID: mdl-38284934

ABSTRACT

Stress granule formation is triggered by the release of mRNAs from polysomes and is promoted by the action of the RNA-binding proteins G3BP1/2. Stress granules have been implicated in several disease states, including cancer and neurodegeneration. Consequently, compounds that limit stress granule formation or promote their dissolution have potential as both experimental tools and novel therapeutics. Herein, we describe two small molecules, G3BP inhibitor a and b (G3Ia and G3Ib), designed to bind to a specific pocket in G3BP1/2 that is targeted by viral inhibitors of G3BP1/2 function. In addition to disrupting the co-condensation of RNA, G3BP1, and caprin 1 in vitro, these compounds inhibit stress granule formation in cells treated prior to or concurrent with stress and dissolve pre-existing stress granules. These effects are consistent across multiple cell types and a variety of initiating stressors. Thus, these compounds represent powerful tools to probe the biology of stress granules and hold promise for therapeutic interventions designed to modulate stress granule formation.


Subject(s)
DNA Helicases , RNA Helicases , Stress Granules , DNA Helicases/genetics , Poly-ADP-Ribose Binding Proteins/genetics , RNA Helicases/genetics , RNA Recognition Motif Proteins/genetics
6.
Nat Biotechnol ; 2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38238480

ABSTRACT

RNA fate and function are affected by their structures and interactomes. However, how RNA and RNA-binding proteins (RBPs) assemble into higher-order structures and how RNA molecules may interact with each other to facilitate functions remain largely unknown. Here we present KARR-seq, which uses N3-kethoxal labeling and multifunctional chemical crosslinkers to covalently trap and determine RNA-RNA interactions and higher-order RNA structures inside cells, independent of local protein binding to RNA. KARR-seq depicts higher-order RNA structure and detects widespread intermolecular RNA-RNA interactions with high sensitivity and accuracy. Using KARR-seq, we show that translation represses mRNA compaction under native and stress conditions. We determined the higher-order RNA structures of respiratory syncytial virus (RSV) and vesicular stomatitis virus (VSV) and identified RNA-RNA interactions between the viruses and the host RNAs that potentially regulate viral replication.

7.
Nat Methods ; 21(2): 247-258, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38200227

ABSTRACT

RNA-binding proteins (RBPs) regulate diverse cellular processes by dynamically interacting with RNA targets. However, effective methods to capture both stable and transient interactions between RBPs and their RNA targets are still lacking, especially when the interaction is dynamic or samples are limited. Here we present an assay of reverse transcription-based RBP binding site sequencing (ARTR-seq), which relies on in situ reverse transcription of RBP-bound RNAs guided by antibodies to identify RBP binding sites. ARTR-seq avoids ultraviolet crosslinking and immunoprecipitation, allowing for efficient and specific identification of RBP binding sites from as few as 20 cells or a tissue section. Taking advantage of rapid formaldehyde fixation, ARTR-seq enables capturing the dynamic RNA binding by RBPs over a short period of time, as demonstrated by the profiling of dynamic RNA binding of G3BP1 during stress granule assembly on a timescale as short as 10 minutes.


Subject(s)
RNA , Reverse Transcription , RNA/genetics , RNA/metabolism , DNA Helicases/metabolism , Poly-ADP-Ribose Binding Proteins/genetics , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/genetics , RNA Helicases/metabolism , RNA Recognition Motif Proteins/genetics , RNA Recognition Motif Proteins/metabolism , RNA-Binding Proteins/metabolism , Binding Sites/genetics , Protein Binding
8.
J Ethnopharmacol ; 322: 117576, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38104880

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Type 1 diabetes mellitus (T1DM) results from insulin deficiency due to the destruction of pancreatic ß-cells. Previously, our studies showed that inhibition of Keap1/Nrf2 signaling pathway promoted the onset of T1DM, which suggests that finding drugs that can activate the Keap1/Nrf2 signaling may be a promising therapeutic strategy for the T1DM treatment. Astragalus membranaceus (Fisch.) Bunge is a common traditional Chinese medicine that has been frequently applied in Chinese clinics for the treatment of diabetes and other diseases. Formononetin (FMNT), one of the major isoflavonoid constituents isolated from this herbal medicine, possesses diverse pharmacological benefits and T1DM therapeutic potential. However, the exact molecular mechanisms underlying the action of FMNT in ameliorating T1DM have yet to be fully elucidated. AIMS OF THE STUDY: This study is to investigate the regulation of FMNT on the Keap1/Nrf2 signaling pathway to ameliorate T1DM based on network pharmacology approach combined with experimental validation. MATERIALS AND METHODS: A mouse-derived pancreatic islet ß-cell line (MIN6) was used for the in vitro studies. An alloxan (ALX)-induced T1DM model in wild-type and Nrf2 knockout (Nrf2-/-) C57BL/6J mice were established for the in vivo experiments. The protective effects of FMNT against ALX-stimulated MIN6 cell injury were evaluated using MTT, EdU, apoptosis and comet assays. The levels of blood glucose in mice were measured by using a blood monitor and test strips. The protein expression was detected by Western blot analysis. Furthermore, the binding affinity of FMNT to Keap1 was evaluated using cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, and solvent-induced protein precipitation (SIP) assay. The interaction pattern between FMNT and Keap1 was assessed by molecular docking and molecular dynamics simulation techniques. RESULTS: Network pharmacology analysis revealed that FMNT exerted its therapeutic effect against T1DM by mainly regulating oxidative stress response-associated signaling molecules and pathways, such as Nrf2 regulating anti-oxidant/detoxification enzymes and Keap1-Nrf2 signaling pathway. The in vivo results showed that FMNT significantly deceased the ALX-induced high blood glucose levels and conversely increased the ALX-induced low insulin contents. In vitro, FMNT markedly protected MIN6 cells from ALX-induced cytotoxicity, proliferation inhibition and DNA damage and reduced the ALX-stimulated cell apoptosis. FMNT also inhibited ALX-induced overproduction of intracellular ROS to alleviate oxidative stress. In addition, FMNT could bind to Keap1 to notably activate the Keap1/Nrf2 signaling to upregulate Nrf2 expression and promote the Nrf2 translocation from the cytoplasm to the nucleus, resulting in enhancing the expression of antioxidant proteins HO-1 and NQO1. Inhibition of Keap1/Nrf2 signaling by ALX was also markedly abolished in the cells and mice exposed to FMNT. Moreover, these effects of FMNT in ameliorating T1DM were not observed in Nrf2-/- mice. CONCLUSIONS: This study demonstrates that FMNT could bind to Keap1 to activate the Keap1/Nrf2 signaling to prevent intracellular ROS overproduction, thereby attenuating ALX-induced MIN6 cell injury and ameliorating ALX-stimulated T1DM. Results from this study might provide evidence and new insight into the therapeutic effect of FMNT and indicate that FMNT is a promising candidate agent for the treatment of T1DM in clinics.


Subject(s)
Diabetes Mellitus, Type 1 , Insulins , Isoflavones , Mice , Animals , Diabetes Mellitus, Type 1/drug therapy , Reactive Oxygen Species/metabolism , NF-E2-Related Factor 2/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Astragalus propinquus , Blood Glucose , Molecular Docking Simulation , Network Pharmacology , Mice, Inbred C57BL , Oxidative Stress , Signal Transduction , Insulins/metabolism , Insulins/pharmacology
9.
Free Radic Biol Med ; 208: 530-544, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37717793

ABSTRACT

Colon cancer continues to be a prevalent gastrointestinal malignancy with a bleak prognosis. The induction of ferroptosis, a new form of regulated cell death, has emerged as a potentially effective strategy for the treatment of colon cancer. However, numerous colon cancer cells display resistance to ferroptosis induced by erastin, a well-established ferroptosis inducer. Finding drugs that can enhance the susceptibility of colon cancer cells to erastin is of utmost importance. This study aimed to examine the synergistic therapeutic impact of combining erastin with a bioactive flavonoid compound luteolin on the ferroptosis-mediated suppression of colon cancer. Human colon cancer HCT116 and SW480 cells were used for the in vitro studies and a xenograft of colon cancer model in BALB/c nude mice was established for the in vivo experiments. The results showed that combinative treatment of luteolin and erastin effectively inhibited the viability and proliferation of colon cancer cells. Luteolin and erastin cotreatment synergistically induced ferroptosis, concomitant with a reduction in glutathione and an elevation in lipid peroxides. In vivo, combinative treatment of luteolin and erastin exhibited a pronounced therapeutic effect on xenografts of colon cancer, characterized by a significant induction of ferroptosis. Mechanistically, luteolin in combination with erastin synergistically reduced the expression of glutathione peroxidase 4 (GPX4), an antioxidase overexpressed in colon cancer cells. Furthermore, luteolin and erastin cotreatment significantly upregulated the expression of hypermethylated in cancer 1 gene (HIC1), a transcriptional repressor also recognized as a tumor suppressor. HIC1 overexpression notably augmented the suppression of GPX4 expression and facilitated ferroptotic cell death. In contrast, HIC1 silencing attenuated the inhibition of GPX4 expression and eliminated the ferroptosis. Conclusively, these results clearly demonstrated that luteolin acts synergistically with erastin and renders colon cancer cells vulnerable to ferroptosis through the HIC1-mediated inhibition of GPX4 expression, which may act as a promising therapeutic strategy.


Subject(s)
Colonic Neoplasms , Ferroptosis , Mice , Animals , Humans , Phospholipid Hydroperoxide Glutathione Peroxidase/genetics , Ferroptosis/genetics , Luteolin/pharmacology , Mice, Nude , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Kruppel-Like Transcription Factors
10.
bioRxiv ; 2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37425880

ABSTRACT

G3BP1/2 are paralogous proteins that promote stress granule formation in response to cellular stresses, including viral infection. G3BP1/2 are prominent interactors of the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the functional consequences of the G3BP1-N interaction in the context of viral infection remain unclear. Here we used structural and biochemical analyses to define the residues required for G3BP1-N interaction, followed by structure-guided mutagenesis of G3BP1 and N to selectively and reciprocally disrupt their interaction. We found that mutation of F17 within the N protein led to selective loss of interaction with G3BP1 and consequent failure of the N protein to disrupt stress granule assembly. Introduction of SARS-CoV-2 bearing an F17A mutation resulted in a significant decrease in viral replication and pathogenesis in vivo, indicating that the G3BP1-N interaction promotes infection by suppressing the ability of G3BP1 to form stress granules.

11.
bioRxiv ; 2023 Jun 28.
Article in English | MEDLINE | ID: mdl-37425931

ABSTRACT

Stress granule formation is triggered by the release of mRNAs from polysomes and is promoted by the action of the paralogs G3BP1 and G3BP2. G3BP1/2 proteins bind mRNAs and thereby promote the condensation of mRNPs into stress granules. Stress granules have been implicated in several disease states, including cancer and neurodegeneration. Consequently, compounds that limit stress granule formation or promote their dissolution have potential as both experimental tools and novel therapeutics. Herein, we describe two small molecules, referred to as G3BP inhibitor a and b (G3Ia and G3Ib), designed to bind to a specific pocket in G3BP1/2 that is known to be targeted by viral inhibitors of G3BP1/2 function. In addition to disrupting co-condensation of RNA, G3BP1, and caprin 1 in vitro, these compounds inhibit stress granule formation in cells treated prior to or concurrent with stress, and dissolve pre-existing stress granules when added to cells after stress granule formation. These effects are consistent across multiple cell types and a variety of initiating stressors. Thus, these compounds represent ideal tools to probe the biology of stress granules and hold promise for therapeutic interventions designed to modulate stress granule formation.

12.
Anal Chim Acta ; 1273: 341559, 2023 Sep 08.
Article in English | MEDLINE | ID: mdl-37423656

ABSTRACT

The measurement of DNA methyltransferase (MTase) activity and screening of DNA MTase inhibitors holds significant importance for the diagnosis and therapy of methylation-related illness. Herein, we developed a colorimetric biosensor (PER-FHGD nanodevice) to detect DNA MTase activity by integrating the primer exchange reaction (PER) amplification and functionalized hemin/G-quadruplex DNAzyme (FHGD). By replacing the native hemin cofactor into the functionalized cofactor mimics, FHGD has exhibited significantly improved catalytic efficiency, thereby enhancing the detection performance of the FHGD-based system. The proposed PER-FHGD system is capable of detecting Dam MTase with excellent sensitivity, exhibiting a limit of detection (LOD) as low as 0.3 U/mL. Additionally, this assay demonstrates remarkable selectivity and ability for Dam MTase inhibitors screening. Furthermore, using this assay, we successfully detect the Dam MTase activity both in serum and in E. coli cell extracts. Importantly, this system has the potential to serve as a universal strategy for FHGD-based diagnosis in point-of-care (POC) tests, by simply altering the recognition sequence of the substrate for other analytes.


Subject(s)
Biosensing Techniques , DNA, Catalytic , G-Quadruplexes , DNA, Catalytic/metabolism , Hemin , Colorimetry , Escherichia coli/genetics , DNA
13.
Exp Ther Med ; 25(4): 177, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37006876

ABSTRACT

Acyl-CoA medium-chain synthetase-3 (ACSM3) has been reported to be involved in the malignant progression of multiple types of human cancer. Nevertheless, the role of ACSM3 in acute myeloid leukemia (AML) and its exact mechanism of action are as yet undefined. In the present study, the expression levels of ACSM3 and IGF2 mRNA-binding protein 2 (IGF2BP2) were evaluated using the Gene Expression Profiling Interactive Analysis database and AML cells. The Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine staining were employed for the estimation of the cell proliferative activity. Induction of apoptosis and the assessment of the cell cycle were measured using flow cytometry and western blotting, respectively. The interaction of ACSM3 with IGF2BP2 was confirmed using an RNA immunoprecipitation assay. mRNA stabilization of ACSM3 following actinomycin D treatment was evaluated using reverse transcription-quantitative PCR analysis. The data indicated that the expression levels of ACSM3 were significantly downregulated, whereas those of IGF2BP2 were upregulated in tissues and AML cells. Downregulation of ACSM3 expression was closely associated with poor overall survival of patients with AML. ACSM3 overexpression repressed cell proliferative activity and induced apoptosis and cell cycle arrest. IGF2BP2 downregulated ACSM3 expression by reducing the stability of ACSM3 mRNA. In addition, IGF2BP2 overexpression counteracted the effects of ACSM3 overexpression noted on proliferation, induction of apoptosis and cell cycle arrest of HL-60 cells. In conclusion, ACSM3 repressed the cell proliferative activity and facilitated induction of apoptosis and cell cycle arrest in AML cells by modulating the expression of IGF2BP2.

14.
Front Pharmacol ; 14: 1111912, 2023.
Article in English | MEDLINE | ID: mdl-36755950

ABSTRACT

Colon cancer is a highly malignant cancer with poor prognosis. Astragalus membranaceus (Fisch.) Bunge (Huang Qi in Chinese, HQ), a well-known Chinese herbal medicine and a popular food additive, possesses various biological functions and has been frequently used for clinical treatment of colon cancer. However, the underlying mechanism is not fully understood. Isoflavonoids, including formononetin (FMNT) and calycosin (CS), are the main bioactive ingredients isolated from HQ. Thus, this study aimed to explore the inhibitory effects and mechanism of HQ, FMNT and CS against colon cancer by using network pharmacology coupled with experimental validation and molecular docking. The network pharmacology analysis revealed that FMNT and CS exerted their anticarcinogenic actions against colon cancer by regulating multiple signaling molecules and pathways, including MAPK and PI3K-Akt signaling pathways. The experimental validation data showed that HQ, FMNT and CS significantly suppressed the viability and proliferation, and promoted the apoptosis in colon cancer Caco2 and HT-29 cells. HQ, FMNT and CS also markedly inhibited the migration of Caco2 and HT-29 cells, accompanied by a marked increase in E-cadherin expression, and a notable decrease in N-cadherin and Vimentin expression. In addition, HQ, FMNT and CS strikingly decreased the expression of ERK1/2 phosphorylation (p-ERK1/2) without marked change in total ERK1/2 expression. They also slightly downregulated the p-Akt expression without significant alteration in total Akt expression. Pearson correlation analysis showed a significant positive correlation between the inactivation of ERK1/2 signaling pathway and the HQ, FMNT and CS-induced suppression of colon cancer. The molecular docking results indicated that FMNT and CS had a strong binding affinity for the key molecules of ERK1/2 signaling pathway. Conclusively, HQ, FMNT and CS exerted good therapeutic effects against colon cancer by mainly inhibiting the ERK1/2 signaling pathway, suggesting that HQ, FMNT and CS could be useful supplements that may enhance chemotherapeutic outcomes and benefit colon cancer patients.

15.
Chin J Nat Med ; 20(3): 202-209, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35369964

ABSTRACT

Two cardenolide glycosides, corotoxigenin 3-O-[ß-D-glucopyranosyl-(1→4)-6-deoxy-ß-D-glucopyranoside] (1) and coroglaucigenin 3-O-[ß-D-glucopyranosyl-(1→4)-6-deoxy-ß-D-glucopyranoside] (2), were isolated from the seed fairs of Asclepias curassavica. The structures of 1-2 were determined based on the combination of the analysis of their MS, NMR spectroscopic data and acid hydrolysis. The inhibitory effects of compounds 1 and 2 on human colorectal carcinoma cells (HCT116), non-small cell lung carcinoma cells (A549) and hepatic cancer cells (SMMC-7721) were evaluated. The results showed that both compounds 1 and 2 significantly inhibited the viability, proliferation, and migration of A549, HCT116 and SMMC-7721 cells, suggesting that compounds 1 and 2 can be applied in the treatment of lung, colon and liver cancers in clinical practice. This study may not only provide a scientific basis for clarifying the active ingredients in A. curassavica, but also help to understand its antitumor activity, which can promote the application of A. curassavica in clinical treatment of various cancers.


Subject(s)
Antineoplastic Agents , Asclepias , Antineoplastic Agents/pharmacology , Asclepias/chemistry , Cardenolides/chemistry , Cardenolides/pharmacology , Glycosides/chemistry , Glycosides/pharmacology , Humans , Seeds
16.
Nat Metab ; 4(2): 225-238, 2022 02.
Article in English | MEDLINE | ID: mdl-35228743

ABSTRACT

Many types of cancer feature TP53 mutations with oncogenic properties. However, whether the oncogenic activity of mutant p53 is affected by the cellular metabolic state is unknown. Here we show that cancer-associated mutant p53 protein is stabilized by 2-hydroxyglutarate generated by malic enzyme 2. Mechanistically, malic enzyme 2 promotes the production of 2-hydroxyglutarate by adjusting glutaminolysis, as well as through a reaction that requires pyruvate and NADPH. Malic enzyme 2 depletion decreases cellular 2-hydroxyglutarate levels in vitro and in vivo, whereas elevated malic enzyme 2 expression increases 2-hydroxyglutarate production. We further show that 2-hydroxyglutarate binds directly to mutant p53, which reduces Mdm2-mediated mutant p53 ubiquitination and degradation. 2-Hydroxyglutarate supplementation is sufficient for maintaining mutant p53 protein stability in malic enzyme 2-depleted cells, and restores tumour growth of malic enzyme 2-ablated cells, but not of cells that lack mutant p53. Our findings reveal the previously unrecognized versatility of malic enzyme 2 catalytic functions, and uncover a role for mutant p53 in sensing cellular 2-hydroxyglutarate levels, which contribute to the stabilization of mutant p53 and tumour growth.


Subject(s)
Neoplasms , Tumor Suppressor Protein p53 , Carcinogenesis , Glutarates , Humans , Malate Dehydrogenase , Neoplasms/genetics , Neoplasms/metabolism , Protein Stability , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
17.
Oncogene ; 41(4): 515-526, 2022 01.
Article in English | MEDLINE | ID: mdl-34782720

ABSTRACT

Metastasis is the leading cause of death of patients with esophageal squamous cell carcinoma (ESCC). Although an increasing number of studies have demonstrated the involvement of G3BP2 in several human cancers, how G3BP2 interacts with long noncoding RNAs and regulates mRNA transcripts in mediating ESCC metastasis remains unclear. In this study, we uncovered that G3BP2 was upregulated in ESCC. Further analysis revealed that upregulation of G3BP2 was significantly correlated with lymph node metastasis, depth of tumor invasion and unfavorable outcomes in ESCC patients. Both in vitro and in vivo functional assays demonstrated that G3BP2 dramatically enhanced ESCC cell migration and invasion. Mechanistically, LINC01554 maintained the high G3BP2 expression in ESCC by protecting G3BP2 from degradation through ubiquitination and the interaction domains within LINC01554 and G3BP2 were identified. In addition, RNA-seq revealed that HDGF was regulated by G3BP2. G3BP2 bound to HDGF mRNA transcript to stabilize its expression. Ectopic expression of HDGF effectively abolished the G3BP2 depletion-mediated inhibitory effect on tumor cell migration. Intriguingly, introduction of compound C108 which can inhibit G3BP2 remarkedly suppressed ESCC cell metastasis in vitro and in vivo. Collectively, this study describes a newly discovered regulatory axis, LINC01554/G3BP2/HDGF, that facilitates ESCC metastasis and will provide novel therapeutic strategies for ESCC.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Esophageal Squamous Cell Carcinoma/genetics , RNA, Long Noncoding/genetics , RNA-Binding Proteins/metabolism , Animals , Cell Line, Tumor , Cell Movement , Cell Proliferation , Disease Progression , Humans , Mice , Mice, Nude , Transfection , Up-Regulation
18.
Front Optoelectron ; 15(1): 38, 2022 Sep 19.
Article in English | MEDLINE | ID: mdl-36637691

ABSTRACT

Covalent organic frameworks (COFs) are one class of porous materials with permanent porosity and regular channels, and have a covalent bond structure. Due to their interesting characteristics, COFs have exhibited diverse potential applications in many fields. However, some applications require the frameworks to possess high structural stability, excellent crystallinity, and suitable pore size. COFs based on ß-ketoenamine and imines are prepared through the irreversible enol-to-keto tautomerization. These materials have high crystallinity and exhibit high stability in boiling water, with strong resistance to acids and bases, resulting in various possible applications. In this review, we first summarize the preparation methods for COFs based on ß-ketoenamine, in the form of powders, films and foams. Then, the effects of different synthetic methods on the crystallinity and pore structure of COFs based on ß-ketoenamine are analyzed and compared. The relationship between structures and different applications including fluorescence sensors, energy storage, photocatalysis, electrocatalysis, batteries and proton conduction are carefully summarized. Finally, the potential applications, large-scale industrial preparation and challenges in the future are presented.

19.
Chem Sci ; 12(13): 4683-4698, 2021 Mar 02.
Article in English | MEDLINE | ID: mdl-34163728

ABSTRACT

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) protein systems have transformed the field of genome editing and transcriptional modulation. Progress in CRISPR-Cas technology has also advanced molecular detection of diverse targets, ranging from nucleic acids to proteins. Incorporating CRISPR-Cas systems with various nucleic acid amplification strategies enables the generation of amplified detection signals, enrichment of low-abundance molecular targets, improvements in analytical specificity and sensitivity, and development of point-of-care (POC) diagnostic techniques. These systems take advantage of various Cas proteins for their particular features, including RNA-guided endonuclease activity, sequence-specific recognition, multiple turnover trans-cleavage activity of Cas12 and Cas13, and unwinding and nicking ability of Cas9. Integrating a CRISPR-Cas system after nucleic acid amplification improves detection specificity due to RNA-guided recognition of specific sequences of amplicons. Incorporating CRISPR-Cas before nucleic acid amplification enables enrichment of rare and low-abundance nucleic acid targets and depletion of unwanted abundant nucleic acids. Unwinding of dsDNA to ssDNA using CRISPR-Cas9 at a moderate temperature facilitates techniques for achieving isothermal exponential amplification of nucleic acids. A combination of CRISPR-Cas systems with functional nucleic acids (FNAs) and molecular translators enables the detection of non-nucleic acid targets, such as proteins, metal ions, and small molecules. Successful integrations of CRISPR technology with nucleic acid amplification techniques result in highly sensitive and rapid detection of SARS-CoV-2, the virus that causes the COVID-19 pandemic.

20.
Chem Commun (Camb) ; 57(56): 6871-6874, 2021 Jul 13.
Article in English | MEDLINE | ID: mdl-34169944

ABSTRACT

The trans-cleavage activity of the target-activated CRISPR/Cas12a liberated an RNA crosslinker from a molecular transducer, which facilitated the assembly of gold nanoparticles. Integration of the molecular transducer with isothermal amplification and CRISPR/Cas12a resulted in visual detection of the N gene and E gene of SARS-CoV-2 in 45 min.


Subject(s)
COVID-19/diagnosis , CRISPR-Cas Systems , Genes, Viral/genetics , Gold/chemistry , Metal Nanoparticles/chemistry , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , COVID-19/virology , Colorimetry , Cross-Linking Reagents , RNA/chemistry
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