ABSTRACT
@#[Abstract] Objective: To observe the effect of allogeneic platelets transfusion on the invasion and metastasis of human lung cancer A549 cells, and to preliminarily explore its mechanism of action. Methods: Eighty-nine patients with advanced lung cancer, who had received platelet transfusion in the Chemotherapy Department of Fourth Hospital of Hebei Medical University between January 2017 and December 2018, were enrolled in this study. The study cells were randomized into Ctrl group (A549 cells co-incubated with culture medium), Before group, and After group (A549 cells co-incubated with plasma Before and After platelet transfusion, respectively). The migration and invasion of A549 cells co-cultured with plasma before and after platelet transfection were detected by Scratch and Transwell experiments. The expression of MMPs, TIMPs and epithelial-mesenchymal transition (EMT) related proteins E-cadherin, N-cadherin and Vimentin, as well as vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2) were detected by Western blotting (WB) method. Results: The scratch healing ability of A549 cells in After group was significantly higher than that of Ctrl group and Before group [(73.67±2.60)% vs (58.33±2.33)%, (35.33±2.03) %; P<0.01, vs Ctrl group; P<0.05, vs Before group], and there was also a significant difference between Before group and Ctrl group (P<0.05). The results of cell migration experiment showed that the number of transmembrane cells in After group was significantly higher than that in Ctrl group and Before group [(69.67±7.84) vs (18±2.08) and (39.33±2.03), all P<0.01]. The cell invasion experiment showed that the number of transmembrane cells in After group was significantly higher than that in Ctrl group and Before group [(59.34±3.46) vs (18.34±1.56) and (37.58±2.79), all P<0.01]. When A549 cells were co-incubated with plasma before and after platelet transfusion for 48 h, it was found that the expressions of MMP9 and MMP2 were increased (P<0.05), while their inhibitors TIMP1 and TIMP2 were decreased (P<0.01); the expressions of EMT-related proteins N-cadherin and Vimentin were increased (P<0.05), but E-cadherin was decreased (P<0.01); the expressions of angiogenesis related proteins VEGF and VEGFR2 were increased (P<0.05). Conclusion: Alloplatelets transfusion can promote the invasion and metastasis of lung cancer A549 cells, which may be realized by regulation of the expressions of EMT, metallomatrix protease and vascular growth factor-related proteins.
ABSTRACT
Objective@#To investigate the duration of Norovirus (NoV) shedding among infected school children during a NoV outbreak in a kindergarten,and to provide scientitic basis for epidemic prevention and control.@*Methods@#Specimens and epidemiological data were collected from suspected cases, and specimens were detected using real-time RT-PCR to determine whether or not infecting with NoV. Specimens were collected every 3-7 days from NoV-infected children until specimens became negative for NoV.@*Results@#A total of 14 suspected cases were reported, and 12 of them were infected with NoV. The average duration of NoV shedding was (26.58±17.94)d. The specimens among 9 from 12 Nov-infected cases were positive at 7 days, 8 NoV-intected cased remained positive at 14 days and 7 Non-infected cased at least 21 days.@*Conclusion@#Since NoV shedding duration among NoV-infected children tends to longer than their isolation time during outbreaks, reinforcement of hygiene practices among these school children is especially necessary to reduce the risk of virus secondary transmissions after their return to school.