RÉSUMÉ
@#[Abstract] Objective: To investigate the molecular mechanism of microRNA-101 (miR-101) inhibiting the migration and invasion of non-small cell lung cancer (NSCLC) via targeting fibroblast growth factor 2 (FGF2). Methods: qPCR was used to detect the expression levels of miR-101 and FGF2 in human normal lung epithelial BEAS-2B cells and NSCLC cell lines (A549, H661 and SK-MES-1) as well as A549 cells after transfection. MiR-NC, miR-101 mimics, miR-IN-NC, miR-101 inhibitor or pcDNA-3.1 empty plasmid, pcDNA-FGF2 were respectively transfected into A549 cells. Wound healing assay and Transwell assay were used to examine the effects of overexpression of miR-101 and FGF2 on the migration and invasion of A549 cells. Western blotting(WB) was used to detect the expression levels of FGF2, E-cadherin, N-cadherin, Vimentin, ERK1/2 and p-ERK1/2 in A549 cells in each group. Results: The expression level of miR-101 in NSCLC cell lines were significantly lower than that in normal lung epithelial cells (all P<0.05), while the expression level in A549 cells was the lowest. Overexpression of miR-101 significantly inhibited the migration (P<0.05) and invasion (P<0.01) of A549 cells, increased the expression level of E-cadherin but decreased the expression level of Vimentin (P<0.05),N-cadherin (P<0.01) and p-ERK1/2 (P<0.05). Inhibition of miR-101 significantly enhanced the invasion and migration of A549 cells (all P<0.05), decreased the expression level of E-cadherin but increased the expression levels of Vimentin, N-cadherin and p-ERK1/2 (all P<0.05). The results of WB and Dual-luciferase reporter gene assay verified that FGF2 is a direct target gene of miR-101, and over‐expression of FGF2 significantly enhanced the invasion and migration of A549 cells (all P<0.01), decreased the expression of E-cadherin (P<0.01) but increased the expressions of Vimentin (P<0.01), N-cadherin (P<0.05) and p-ERK1/2 (P<0.01). Compared with the FGF2 overexpression alone group, co-overexpression of miR-101 and FGF2 significantly reduced the invasion and migration of A549 cells (all P<0.01), increased the expression of E-cadherin (P<0.01), and decreased the expressions of Vimentin (P<0.01), N-cadherin (P<0.05) and p-ERK1/2 (P<0.01). Conclusion: By targeting FGF2, miR-101 inhibits the invasion and migration of NSCLC cells through suppressing the epithelial-mesenchymal transition (EMT) and ERK signaling pathway.
RÉSUMÉ
The VPl gene of enterovirus 71 (EV71) was synthesized, construct a recombinant plasmid pET15b/VP1 and expressed in E. coli BL21. The recombinant VP1 protein could specifically react with EV71-infected patient sera without the cross-reaction with serum antibodies of coxsackievirus A16 (CA16), A4, A5, B3 and B5 as well as echovirus 6. In acute and convalescent phases, IgM and IgG antibodies of 182 serum samples were detected by ELISA with recombinant VP1 protein as a coated antigen. The results showed that the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IgM antibodies in serum samples for the diagnosis of EV71 infection were 90.1, 98.4, 98.8 and 88.7%, respectively; similarly, those of IgG antibodies in serum samples were 82.4, 89.1, 91.5 and 78.1%, respectively. Five of 80 samples (6.25%) from CA16infected patients were detected positive by ELISA with recombinant VP1 protein in which indicated the cross reactions and 0 of 5 samples from patients infected with other enteroviruses including CA4, CA5, CB3, CB5 and echovirus 6. Therefore, the recombinant VP1 protein of EV7l may provide a theoretical reference for establishing an effective antibody screening of IgM for EV71-infected patients with clinically suspected hand, foot, and mouth disease (HFMD).