miR-640 exerts a promoting effect on glioblastoma cells by inhibiting SLIT1 expression. (A) miR-640 and (B) SLIT1 expression was detected in the transfected A172 and U251 cells via reverse transcription-quantitative PCR analysis. (C) Western blot analysis was performed to detect SLIT1 protein expression in A172 and U251 cells transfected with miR-640 mimic or OE-SLIT1. (D) The Cell Counting Kit-8 assay was performed to assess the viability of transfected A172 and U251 cells. (E) The BrdU ELISA assay was performed to assess the proliferation of transfected A172 and U251 cells. (F) The cell adhesion assay was performed to assess the adhesive ability of transfected A172 and U251 cells. (G) The caspase-3 activity assay was performed to assess apoptosis of transfected A172 and U251 cells. Data are presented as the mean ± standard deviation (n=3). *P<0.05, **P<0.001 vs. the control group; #P<0.05, ##P<0.001 vs. control co-transfection with mimic and the OE-SLIT1 group. miR, microRNA; SLIT1, Slit guidance ligand 1; OE, overexpression vector; NC, negative control; OD, optical density.