Objective To investigate the effects of downregulating microRNA(miR)-550a-5p on the proliferation,migration and invasion of non-small cell lung cancer(NSCLC)and to explore its mo-lecular mechanisms.Methods The miR-550a-5p inhibitor and its negative control(inhibitor NC),as well as small interfering RNA targeting scavenger receptor class A member 3(si-SCARA3)and its negative control(si-NC)were individually or co-transfected into A549 cells.These cells were desig-nated as inhibitor NC group,miR-550a-5p inhibitor group,miR-550a-5p inhibitor+si-NC(co-trans-fection)group and miR-550a-5p inhibitor+si-SCARA3(co-transfection)group.Cell proliferation was assessed by CCK-8 assay;colony formation ability was evaluated using a plate cloning method;cell migration and invasion were detected by scratch assay and Transwell chamber assay,respectively;levels of matrix metalloproteinase(MMP)-2 and MMP-9 in the supernatant of A549 cells were measured by enzyme-linked immunosorbent assay(ELISA);apoptosis levels were determined by Annexin V/PI double staining.Results Compared with adjacent normal tissues,the expression level of miR-550a-5p was increased,while SCARA3 mRNA expression was decreased in NSCLC tissues(P＜0.05).Dual-luciferase reporter assays confirmed that miR-550a-5p directly targeted SCARA3.Compared with the inhibitor NC group,cell proliferation rate,colony formation number,migration and invasion ability of the miR-550a-5p inhibitor group decreased,apoptosis rate increased(P＜0.05).Compared with the inhibitor NC group,the expression levels of MMP-2 and MMP-9 in cell supernatant of the miR-550a-5p inhibitor group were decreased,and the expression levels of SCARA3 protein were increased(P＜0.05).Compared with the miR-550a-5p inhibitor group or the miR-550a-5p inhibitor+si-NC group,cell proliferation rate,clonal colony formation number,migration and invasion ability of the miR-550a-5p inhibitor+si-SCARA3 group were increased,and apoptosis rate was decreased(P＜0.05).Compared with the miR-550a-5p inhibitor group or the miR-550a-5p inhibitor+si-NC group,the miR-550a-5p inhibitor+si-SCARA3 group showed in-creased expression levels of MMP-2 and MMP-9 in the cell supernatant and decreased SCARA3 pro-tein expression levels(P＜0.05).Conclusion Downregulation of miR-550a-5p inhibits the prolif-eration,migration and invasion of NSCLC cells,and promotes apoptosis,possibly through upregulat-ing SC AR A3 expression.

Objective To study the relationship between injury site (right or left) or pathological type (hemorrhage or infarct) and atten-tion impairment in post stroke cognitive impairment (PSCI). Methods June, 2014 to June 2015, 49 patients with PSCI were assessed with Test of Attentional Performance (TAP) within 1 week of admission. The reaction time and the numbers of correct response were recorded. Results The reaction time of alertness (with or without alarm) was shorter in the patients with left infarction (Z=-2.32, t=-3.76, P<0.05), and the correct number of auditory was more (Z=2.42, P<0.05) than those with right infarction. The reaction time of incompatibility test and Go/Nogo test was shorter in patients with left hemorrhage than those with right hemorrhage (Z>2.32, t=-3.10, P<0.05). Conclusion A trend of lateralization was found in patients with PSCI, rather than in the pathology.