2D and 3Din vitroassays to quantify the invasive behavior of glioblastoma stem cells in response to SDF-1α

Invasion is a hallmark of cancer and thereforein vitroinvasion assays are important tools in cancer research. We aimed to describein vitro2D transwell assays and 3D spheroid assays to quantitatively determine the invasive behavior of glioblastoma stem cells in response to the chemoattractant SDF-1 alpha. Matrigel was used as a matrix in both assays. We demonstrated quantitatively that SDF-1 alpha increased invasive behavior of glioblastoma stem cells in both assays. We conclude that the 2D transwell invasion assay is easy to perform, fast and less complex whereas the more time-consuming 3D spheroid invasion assay is physiologically closer to thein vivosituation. METHOD SUMMARY We describe 2D transwell invasion assays and 3D spheroid invasion assays for the investigation of effects of the chemoattractant SDF-1 alpha on human glioblastoma stem cellsin vitroin a quantitative manner using image analysis. In bothin vitroinvasion assays, Matrigel was used as the matrix that glioblastoma stem cells invade. The 2D assay is easy to perform, fast and less complex whereas the 3D assay models thein vivosituation more closely.