(A–D) RFP-HUVEC and GFP-1205Lu metastatic melanoma cells were co-cultured in colonies separated by a precisely defined gap (method I), in random mixtures (method II) or with an RFP-HUVEC colony of precisely defined size and shape surrounded by GFP-1205Lu cells (method III); the phenotypes of cells co-cultured using method I (B), method II (C) and method III (D) were determined at 6 hrs. (upper panels) and 48 hrs. (lower panel).
(E–H) RFP-HUVECs alone were cultured for 48 hrs. in EGM-2 medium (E) or in conditioned medium (CM) from HUVECs (F), 1205Lu cells (G), or co-cultured RFP-HUVEC and GFP-1205Lu cells (H).