(c-e) EV and shRAB2AMDA-MB-231 cells were embedded in Spheroid Formation ECMR in the absence (-) or presence (+) of doxycycline and/or GM6001. After 3 days, the cells were transferred into Invasive MatrixR. Phase contrast light microscopy images of representative spheroids are shown after 9 days (c). Dashed circle indicates the size of spheroids at day 0. Bars, 500 µm. Invasive activity into ECM was expressed as total spheroid area (relative to control cells at day 0) quantified by ImageJ (d). The number of cells at the indicated days was quantified by CyQUANTR Cell Proliferation Assay Kit (e). Data are the mean ± SD (n=3 independent experiments). 