Abstract
Wheat germ lectin (WGA) is a cytotoxic lectin for many cell lines [Wang et al., 2000], but its underlying mechanism is not clear. In this report, we found that incubation of synchronized mouse L929 fibroblasts with WGA resulted in a dose-dependent reduction of intracellular incorporation of 3H-thymidine and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide)-conversion activity (IC50 congruent with 0.4 microM). Fluorescein-conjugated WGA was demonstrated to transport from the cell surface into the paranuclear region of cultured L929 cells within 30 min, and subsequently evoked lipid peroxidation of plasma membrane and vacuolation in the cytoplasm of these cells. Studies with tritiated thymidine incorporation, immunofluorescence microscopy, immunoblotting analysis and flow cytometry revealed that WGA inhibited cell cycle progression after one replication, resulting in G2/M arrest and alteration of cell cycle regulatory proteins, particularly activation of p21Cip1/WAF1 and suppression of cyclin B and cdc 2. Although there was an increase of cytosolic caspase 3 and bax protein expression, no apoptotic bodies were observed by both fluorescence and transmission electron microscopy. These results suggest that WGA arrested L929 proliferation after one cell cycle in the G2/M phase through activation of the p21Cip1/WAF1 and suppression of Cyclin B-Cdc2.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.