RESUMO
Objective@#To explore the inhibitory effect and possible mechanism of Baicalin on the human tongue squamous cell carcinoma cell line SCC15 and to provide a new idea and experimental basis for the clinical prevention and treatment of tongue squamous cell carcinoma.@*Methods @#SCC15 cells cultured in DMEM alone were used as the control group, and SCC15 cells cultured in 20 mg/mL baicalin solution were used as the baicalin group. Scratch tests and Transwell migration tests were performed to detect changes in cell migration ability, and flow cytometry was used to detect changes in the cell cycle. Western blotting was used to detect differences in the phosphorylation levels of signal transduction and transcription activator 3 (STAT3).@*Results @# Compared with the control group, the scratch test and the Transwell migration test showed that the cell migration ability of cells in the baicalin group was significantly decreased (t=4.927, P=0.008); flow cytometry showed that the number of cells of the baicalin group increased in the G0/G1 phase (t=9.893, P=0.001), decreased in the S phase (t=8.528, P=0.001), and decreased in the G2/M phase (t=3.550, P=0.024); Western blotting results showed that the STAT3 protein of SCC15 cells in the baicalin group decreased (t=3.550, P=0.024), and the phosphorylation level significantly decreased (t=8.262, P=0.001).@*Conclusion @#Baicalin inhibits the human tongue squamous cell carcinoma cell line SCC15, and its mechanism may be related to a decrease in STAT3 pathway phosphorylation activity.
RESUMO
Fusarium graminearum is the fungal pathogen that causes globally important diseases of cereals and produces mycotoxins such as deoxynivalenol (DON). Owing to the dearth of available sources of resistance to Fusarium pathogens, characterization of novel genes that confer resistance to mycotoxins and mycotoxin-producing fungi is vitally important for breeding resistant crop varieties. In this study, a wheat methionyl-tRNA synthetase (TaMetRS) gene was identified from suspension cell cultures treated with DON. It shares conserved aminoacylation catalytic and tRNA anticodon binding domains with human MetRS and with the only previously characterized plant MetRS, suggesting that it functions in aminoacylation in the cytoplasm. However, the TaMetRS comprises a typical nuclear localization signal and cellular localization studies with a TaMetRS::GFP fusion protein showed that TaMetRS is localized in the nucleus. Expression of TaMetRS was activated by DON treatment and by infection with a DON-producing F. graminearum strain in wheat spikes. No such activation was observed following infection with a non-DON-producing F. graminearum strain. Expression of TaMetRS in Arabidopsis plants conferred significant resistance to DON and F. graminearum. These results indicated that this DON-activated TaMetRS gene may encode a novel type of MetRS in plants that has a role in defense and detoxification.
