Objective: To study the effect of MNNG on inducement of non-targeted mutation and activation of several cellular signal transduction pathways, and to determine whether the activation of these signaling pathways was dependent on the DNA-damage.
Methods: Vero cells were enucleated by discontinuous density centrifugation. The PKA activities were measured by enzyme-linked immunosorbent assay. The status of cell membrane receptors was studied with immunofluorescent staining and confocal microscopy.
Result: In enucleated cytoplasts, MNNG-treatment increased PKA activity for about 2.3-fold in accordance with the 2.7-fold up-regulation of PKA activity in whole vero cells exposed to MNNG. The clustering of cell surface receptors of epidermal growth factor and tumor necrosis factor alpha was also observed in cells exposed to MNNG; this phenomenon was also found in enucleated cells.
Conclusion: The results indicate that the initiation of signal cascades induced by low concentration of MNNG might be associated with its interaction with cell surface receptors and/or direct activation of related signal proteins but not its DNA damage.
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http://dx.doi.org/10.3785/j.issn.1008-9292.2003.05.004 | DOI Listing |
Environ Health (Wash)
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School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, China.
To clarify the effect of the fluorine atom and piperazine ring on norfloxacin (NOR), NOR degradation products (NOR-DPs, P1-P8) were generated via UV combined with hydrogen peroxide (UV/HO) technology. NOR degradation did not significantly affect cytotoxicity of NOR against BV2, A549, HepG2, and Vero E6 cells. Compared with that of NOR, mutagenicity and median lethal concentration of P1-P8 in fathead minnow were increased, and bioaccumulation factor and oral median lethal dose of P1-P8 in rats were decreased.
View Article and Find Full Text PDFNat Prod Res
December 2024
School of Science, Walailak University, Thasala, Nakhonsithammarat, Thailand.
Two new compounds including one benzaldehyde () and one azaphilone () were isolated from the marine-derived fungus PSU-AMF89 together with nine known compounds (-). Their structures were determined by spectroscopic evidences. The absolute configuration of was established by comparison of the ECD data with those of the previously reported data of compound as well as the biosynthetic consideration.
View Article and Find Full Text PDFProtein Expr Purif
December 2024
Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Molecular and Cell Biology Research Center (MCBRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Electronic address:
Background: Tumor cells exploit epidermal growth factor receptor (EGFR) family to develop resistance against therapeutic antibodies, such as Herceptin. Upon ligand binding, dimerization between EGFR and HER2 is one of the most important causes of treatment failure in breast cancer and other cancers expressing EGFR and HER2. The aim of this study was to develop and evaluate the function of a human recombinant single-chain variable fragment (scFv) antibody against the dimerization domain of EGFR to inhibit its interaction with other members of the epidermal growth factor receptor family, especially HER2.
View Article and Find Full Text PDFCell Biochem Biophys
December 2024
Department of Biotechnology, Prathyusha Engineering College, Tiruvallur, Chennai, 602025, Tamilnadu, India.
The present study introduces a minimalistic and cost-effective approach to synthesising Gold nanoparticles (AuNPs) using aqueous leaf extracts of Andrographis paniculata. In this synthesis, bioactive metabolites in the leaf extract act as reducing agents, converting Au³⁺ ions to metallic Au⁰, while proteins in the extract form a stabilising layer around the nanoparticles to prevent agglomeration and maintain particle size stability. The synthesised AuNPs were systematically characterised using a range of analytical techniques.
View Article and Find Full Text PDFUnlabelled: Herpes simplex virus (HSV) infection has worldwide public health concerns and lifelong medical impacts. The standard therapy, acyclovir, has limited efficacy in preventing HSV subclinical virus shedding, and drug resistance occurs in immunocompromised patients, highlighting the need for novel therapeutics. HSV infection manifests in the skin epidermal layer, but current drug discovery utilizes Vero cells and fibroblasts monolayer cultures, capturing neither relevance nor tissue environment.
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