Matrigel Invasion Assay for Glioma Cells

In vitro analysis of invasion was assessed using Matrigel (BD Biosciences, Frankling Lakes, NJ, USA) and 8-µm Transwell inserts (BD Biosciences). The cell invasion assay was performed as previously described (18 (link)). Briefly, 50 µl Matrigel (diluted 1:5 with serum-free DMEM) was plated onto the Transwell insert. Then a cell suspension of 5×10³ U251MG or U-87MG ATCC cells was added. Treatments of 10 µM apatinib and 20 µM TMZ were made for 24 h at 37°C. The invasive cells were fixed with 4% paraformaldehyde (Beyotime Institute of Biotechnology) and stained with 10% crystal violet (Beyotime Institute of Biotechnology) at room temperature (from 22 to 25°C) for 15 mins. The invasive cells were photographed by light microscopy (DTX500; Nikon Corporation, Tokyo, Japan) with a magnification of ×40 and the cells in three random fields of view were counted.