Materials

4T1E cells, which are the parent line of 4T1E/M3 cells, were established in our previous study [16]. RPMI-1640 supplemented with 4,500 mg/L glucose, L-glutamine, phenol red, HEPES, and sodium pyruvate was obtained from Wako Pure Chemical Industries, Ltd. (Tokyo, Japan) for culturing the 4T1E cells. Cell culture medium was prepared by adding 10 vol% heat-inactivated fetal bovine serum (HyClone Laboratories, Logan, UT, USA) and 1 vol% penicillin/streptomycin (Nacalai Tesque, Inc., Kyoto, Japan) to the RPMI-1640. Matrigel was obtained from Corning Inc. (Corning, NY, USA). SU-8 2075 negative photoresist was obtained from MicroChem (Newton, MA, USA). 1H,1H,2H,2H-Perfluorooctyltrichlorosilane was obtained from Wako Pure Chemical Industries, Ltd.