Radial Migration of Spheroids in 3D

Radial migration was performed in 3D cultures according to Vinci et al. [26 (link)]. Flat-bottomed, 24-well plates (Sarstedt, NC, USA) were coated with 0.01 mg/mL Poly-D-Lysine (Sigma-Aldrich^®, St. Louis, MO, USA) in sterile water for 2 h at room temperature, followed by 1:30 diluted Matrigel^TM coating for 30 min. Four-day spheroids were transferred to pre-coated plates and maintained in 500 μL of medium containing 10% FBS, 2% Matrigel^TM and the compounds, [15]pyN₅, [16]pyN₅ and ARP-100, in concentrations ranging from 5–40 µM. Images were captured at 5, 10 and 24 h using AE 2000 inverted microscope (Motic, Hong Kong, China) and the area between cells in the migration front and the perimeter of the spheroid measured. More than 10 spheroids per condition were analyzed.