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Technology in Cancer Research &... 2021Human umbilical endothelial cells (HUVECs) have been proved to be an effective whole-cell vaccine inhibiting tumor angiogenesis. In this study, we fused HUVECs with...
PURPOSE
Human umbilical endothelial cells (HUVECs) have been proved to be an effective whole-cell vaccine inhibiting tumor angiogenesis. In this study, we fused HUVECs with human lung adenocarcinoma cells A549 s, aiming at preparing lung cancer vaccine to achieve dual effects of anti-tumor angiogenesis and specific immunity to tumor cells.
METHODS
A549 cells were induced by ethyl methane sulfonate (EMS) and 8-azaguanine (8-AG) to get hypoxanthine guanine phosphoribosyl transferase (HGPRT) auxotrophic A549 cells. Then Fused HGPRT auxotrophic A549 cells with primary HUVEC cells by combining electrofusion with polyethylene glycol (PEG). Afterward the fusion cells were screened by HAT and HT selective medium and sorted by flow cell sorter to obtain high-purity HUVEC-A549 cells. Finally, HUVEC-A549 cells were identified by karyotype analysis and western blotting.
RESULTS
The fusion efficiency of HUVEC-A549 cells prepared by combining electrofusion with polyethylene glycol (PEG) was significantly higher than that of electrofusion and PEG (43.0% vs 17.60% vs 2.71%, < 0.05). After screened by HAT and HT selective medium and sorted by flow cell sorter, the proportion of HUVEC-A549 cells can count for 71.2% ± 3.2%. The mode of chromosomes in HUVEC-A549 cells was 68, and the chromosome was triploid. VE-cadherin and platelet endothelial cell adhesion molecule-1 (CD31) were highly expressed in HUVECs and HUVEC-A549 cells, but not in A549 cells.
CONCLUSIONS
These results indicate that HUVEC-A549 cells retain the biological characteristics of human umbilical vein endothelial cells and A549 cells. It can be used in the experimental study of lung cancer cell vaccine.
Topics: A549 Cells; Cancer Vaccines; Carcinoma, Non-Small-Cell Lung; Cell Fusion; Human Umbilical Vein Endothelial Cells; Humans; Immunotherapy; Karyotype; Lung Neoplasms; Neovascularization, Pathologic; Polyethylene Glycols
PubMed: 34318732
DOI: 10.1177/15330338211034260 -
Plant Communications Apr 2024Cytokinins are a type of mobile phytohormone that regulate plant growth, development, and environmental adaptability. The major cytokinin species include isopentenyl... (Review)
Review
Cytokinins are a type of mobile phytohormone that regulate plant growth, development, and environmental adaptability. The major cytokinin species include isopentenyl adenine (iP), trans-zeatin (tZ), cis-zeatin (cZ), and dihydrozeatin (DZ). The spatial distributions of different cytokinin species in different organelles, cells, tissues, and organs are primarily shaped by biosynthesis via isopentenyltransferases (IPT), cytochrome P450 monooxygenase, and 5'-ribonucleotide phosphohydrolase, and by conjugation or catabolism via glycosyltransferase or cytokinin oxidase/dehydrogenase (CKX). Cytokinins bind to histidine receptor kinases (HKs) in the endoplasmic reticulum (ER) or plasma membrane (PM) and relay signals to response regulators (RRs) in the nucleus by shuttle proteins known as histidine phosphotransfer proteins (HPs). The movements of cytokinins from sites of biosynthesis to signal perception sites usually require long-distance, intercellular, and intracellular transport. In the past decade, ATP-binding cassette (ABC) transporters, purine permeases (PUP), AZA-GUANINE RESISTANT (AZG) transporters, equilibrative nucleoside transporters (ENT), and Sugars Will Eventually be Exported Transporters (SWEET) have been characterized as involved in cytokinin transport processes. This review begins by introducing the spatial distributions of various cytokinins and the subcellular localizations of the proteins involved in cytokinin metabolism and signaling. Highlights focus on an inventory of the characterized transporters involved in cytokinin compartmentalization, including long-distance, intercellular, and intracellular transport, and the regulation of spatial distributions of cytokinins by environmental cues. Future directions for cytokinin research are also discussed.
PubMed: 38689499
DOI: 10.1016/j.xplc.2024.100936 -
Antimicrobial Agents and Chemotherapy Apr 2018The high acquisition rate of drug resistance by necessitates the ongoing search for new drugs to be incorporated in the tuberculosis (TB) regimen. Compounds used for...
The high acquisition rate of drug resistance by necessitates the ongoing search for new drugs to be incorporated in the tuberculosis (TB) regimen. Compounds used for the treatment of other diseases have the potential to be repurposed for the treatment of TB. In this study, a high-throughput screening of compounds against thiol-deficient strains and subsequent validation with thiol-deficient strains revealed that and mutants had increased susceptibility to azaguanine (Aza) and sulfaguanidine (Su); and mutants had increased susceptibility to bacitracin (Ba); and , , and mutants had increased susceptibility to fusaric acid (Fu). Further analyses revealed that some of these compounds were able to modulate the levels of thiols and oxidative stress in This study reports the activities of Aza, Su, Fu, and Ba against and provides a rationale for further investigations.
Topics: Antitubercular Agents; Azaguanine; Mutation; Mycobacterium tuberculosis; Oxidative Stress; Sulfaguanidine; Sulfhydryl Compounds
PubMed: 29437626
DOI: 10.1128/AAC.02236-17 -
Life Sciences Jan 2022Sjögren's syndrome (SjS) is an autoimmune disease with a strong genetic association. To date, no vaccine or therapeutic agent exists to cure SjS, and patients must rely...
BACKGROUND
Sjögren's syndrome (SjS) is an autoimmune disease with a strong genetic association. To date, no vaccine or therapeutic agent exists to cure SjS, and patients must rely on lifelong therapies to treat symptoms. Human leukocyte antigens (HLA) are primary susceptibility loci that form the genetic basis for many autoimmune diseases, including SjS. In this study, we sought to determine whether blocking MHC class II IAg antigen presentation in the NOD mouse would alleviate SjS by preventing the recognition of autoantigens by pathogenic T cells.
METHODS
Mapping of the antigenic epitopes of Ro60 autoantigen to IAg of the NOD mice was performed using structural modeling and in-vitro stimulation. Tetraazatricyclo-dodecane (TATD) and 8-Azaguanine (8-Aza) were previously identified as potential binders to IA of the NOD mice using in silico drug screening. Mice were treated with 20mgs/kg via IP every day five days/week for 23 weeks. Disease profiling was conducted.
FINDINGS
Specific peptides of Ro60 autoantigen were identified to bind to IAg and stimulated splenocytes of the NOD mice. Treating NOD mice with TATD or 8-Azaguanine alleviated SjS symptoms by improving salivary and lacrimal gland secretory function, decreasing the levels of autoantibodies, and reducing the severity of lymphocytic infiltration in the salivary and lacrimal glands.
INTERPRETATION
This study presents a novel therapeutic approach for SjS by identifying small molecules capable of inhibiting T cell response via antigen-specific presentation.
FUNDING
CQN is supported financially in part by PHS grants AI130561, DE026450, and DE028544 from the National Institutes of Health.
Topics: Alkanes; Animals; Antigen Presentation; Antimetabolites, Antineoplastic; Azaguanine; Female; Histocompatibility Antigens Class II; Mice; Mice, Inbred NOD; Polycyclic Compounds; Sjogren's Syndrome
PubMed: 34843735
DOI: 10.1016/j.lfs.2021.120182 -
European Biophysics Journal : EBJ Oct 20238-azaguanine is a triazolopyrimidine nucleobase analog possessing potent antibacterial and antitumor activities, and it has been implicated as a lead molecule in cancer...
8-azaguanine is a triazolopyrimidine nucleobase analog possessing potent antibacterial and antitumor activities, and it has been implicated as a lead molecule in cancer and malaria therapy. Its intrinsic fluorescence properties can be utilized for monitoring its interactions with biological polymers like proteins or nucleic acids. In order to better understand these interactions, it is important to know the tautomeric equilibrium of this compound. In this work, the tautomeric equilibrium of all natural neutral and anionic compound forms (except highly improbable imino-enol tautomers) as well as their methyl derivatives and ribosides was revealed by quantum chemistry methods. It was shown that, as expected, tautomers protonated at positions 1 and 9 dominate neutral forms both in gas phase and in aqueous solution. 8-azaguanines methylated at any position of the triazole ring are protonated at position 1. The computed vertical absorption and emission energies are in very good agreement with the experimental data. They confirm the validity of the assumption that replacing the proton with the methyl group does not significantly change the positions of absorption and fluorescence peaks.
Topics: Azaguanine; Spectrum Analysis; Protons; Proteins; Quantum Theory
PubMed: 37507591
DOI: 10.1007/s00249-023-01672-x -
Frontiers in Chemistry 2022DNA-encoded libraries are a prime technology for target-based small molecule screening. Native DNA used as genetic compound barcode is chemically vulnerable under many...
DNA-encoded libraries are a prime technology for target-based small molecule screening. Native DNA used as genetic compound barcode is chemically vulnerable under many reaction conditions. DNA barcodes that are composed of pyrimidine nucleobases, 7-deazaadenine, and 7-deaza-8-azaguanine have been investigated for their suitability for encoded chemistry both experimentally and computationally. These four-letter barcodes were readily ligated by T4 ligation, amplifiable by Taq polymerase, and the resultant amplicons were correctly sequenced. Chemical stability profiling showed a superior chemical stability compared to native DNA, though higher susceptibility to depurination than a three-letter code based on pyrimidine DNA and 7-deazaadenine.
PubMed: 35755251
DOI: 10.3389/fchem.2022.894563 -
International Journal of Clinical and... 2021In recent years, studies have shown that , as an oncogene, is involved in progression of cancers. However, its relationship with prognosis in glioma patients is rarely...
In recent years, studies have shown that , as an oncogene, is involved in progression of cancers. However, its relationship with prognosis in glioma patients is rarely reported. Our purpose was to explore the role of in glioma. Based on 1814 glioma samples from multiple databases such as The Cancer Genome Atlas (TCGA), The Chinese Glioma Genome Atlas (CGGA), and The Gene Expression Omnibus (GEO), we use a variety of bioinformatics methods to verify the mechanism of action of in glioma from mRNA to protein, from appearance to mechanism analysis, from clinical features to prognosis. Then, the connectivity map (CMap) tool was used to predict drugs that inhibit the expression of . First, we found is highly expressed in glioma at mRNA and protein levels. Second, is an independent risk factor in prognosis and has suitable clinical diagnostic value in glioma. It was also positively correlated with World Health Organization (WHO) grade, age, and histology, and negatively correlated with mutation and codeletion. Third, base excision, cell cycle, and mismatch repair pathway were activated by in glioma. We predict small molecules to inhibit such as 8-azaguanine, gw8510, 6-thioguanosine, and ursodeoxycholic acid. This study is the first comprehensive analysis of , revealing a relationship between this novel oncogene, clinical characteristics of patients with glioma, and a mechanism leading to poor prognosis. It also provides a biomarker for diagnosis and treatment of glioma and reveal the pathologic progress of glioma at the genetic level.
PubMed: 34646412
DOI: No ID Found -
Frontiers in Bioengineering and... 20208-Azaguanine (1) is a special 1,2,3-triazole containing natural product that possesses potent antibacterial and antitumor activities. In the present study, the entire...
8-Azaguanine (1) is a special 1,2,3-triazole containing natural product that possesses potent antibacterial and antitumor activities. In the present study, the entire 8-azaguanine biosynthetic gene cluster was located from CGMCC4.1633. Targeted gene disruption, heterologous expression analysis, and feeding experiments identified crucial genes for 8-azaguanine production. Moreover, we characterized the structure of two novel metabolites, analyzed NO (or reactive nitrogen species) related genes 8-azgA/B and radical SAM enzyme homologous 8-AzgG, and verified the non-enzymatic ring formation reaction of 8-azaguanine 1,2,3-triazole. All of the data and presumptions provide insight into the timing and mechanism of the enzymatic and non-enzymatic pathway that produce 8-azaguanine-type 1,2,3-triazole.
PubMed: 33251204
DOI: 10.3389/fbioe.2020.603514 -
The Journal of Biological Chemistry Aug 1975Adenine, guanine, and hypoxanthine were rapidly incorporated into the acid-soluble nucleotide pool and nucleic acids by wild type Novikoff cells. Incorporation followed...
Adenine, guanine, and hypoxanthine were rapidly incorporated into the acid-soluble nucleotide pool and nucleic acids by wild type Novikoff cells. Incorporation followed normal Michaelis-Menten kinetics, but the following evidence indicates that specific transport processes precede the phosphoribosyltransferase reactions and are the rate-limiting step in purine incorporation by whole cells. Cells of an azaguanine-resistant subline of Novikoff cells which lacked hypoxanthine-guanine phosphoribosyltransferase activity and failed to incorporate guanine or hypoxanthine into the nucleotide pool, exhibited uptake of guanine and hypoxanthine by a saturable process. Similarly, wild type cells which had been preincubated in a glucose-free basal medium containing KCN and iodoacetate transported guanine and hypoxanthine normally, although a conversion of these purines to nucleotides did not occur in these cells. The mutant and KCN-iodoacetate treated wild type cells also exhibited countertransport of guanine and hypoxanthine when preloaded with various purines, uracil, and pyrimidine nucleosides. The cells also possess a saturable transport system for uracil although they lack phosphoribosyltransferase activity for uracil. In the absence of phosphoribosylation, none of the substrates was accumulated against a concentration gradient. Thus transport is by facilitated diffusion (nonconcentrative transport). Furthermore, the apparent Km values for purine uptake by untreated wild type and azaguanine-resistant cells were higher and the apparent Vmax values were lower than those for the corresponding phosphoribosyltransferases...
Topics: Adenine; Animals; Biological Transport, Active; Calorimetry; Carcinoma, Hepatocellular; Cell Line; Centrifugation, Density Gradient; Chloromercuribenzoates; Cytochalasin B; Cytosine; Dipyridamole; Dithiothreitol; Guanine; Hypoxanthine Phosphoribosyltransferase; Hypoxanthines; Kinetics; Liver Neoplasms; Neoplasms, Experimental; Pentosyltransferases; Purines; Pyrimidines; Rats; Thermodynamics; Time Factors; Uracil
PubMed: 168203
DOI: No ID Found -
Biochemistry Jul 2019Guanine deaminase is a metabolic enzyme, found in all forms of life, which catalyzes the conversion of guanine to xanthine. Despite the availability of several crystal...
Guanine deaminase is a metabolic enzyme, found in all forms of life, which catalyzes the conversion of guanine to xanthine. Despite the availability of several crystal structures, the molecular determinants of substrate orientation and mechanism remain to be elucidated for the amidohydrolase family of guanine deaminase enzymes. Here, we report the crystal structures of and guanine deaminase enzymes (EcGuaD and Gud1, respectively), both members of the amidohydrolase superfamily. EcGuaD and Gud1 retain the overall TIM barrel tertiary structure conserved among amidohydrolase enzymes. Both proteins also possess a single zinc cation with trigonal bipyrimidal coordination geometry within their active sites. We also determined a liganded structure of Gud1 bound to the product, xanthine. Analysis of this structure, along with kinetic data of native and site-directed mutants of EcGuaD, identifies several key residues that are responsible for substrate recognition and catalysis. In addition, after a small library of compounds had been screened, two guanine derivatives, 8-azaguanine and 1-methylguanine, were identified as EcGuaD substrates. Interestingly, both EcGuaD and Gud1 also exhibit secondary ammeline deaminase activity. Overall, this work details key structural features of substrate recognition and catalysis of the amidohydrolase family of guanine deaminase enzymes in support of our long-term goal to engineer these enzymes with altered activity and substrate specificity.
Topics: Amidohydrolases; Catalytic Domain; Escherichia coli Proteins; Guanine Deaminase; Protein Binding; Protein Structure, Secondary; Saccharomyces cerevisiae Proteins; Substrate Specificity
PubMed: 31283204
DOI: 10.1021/acs.biochem.9b00341