Figure 3.

(A) Gap junction assay. Transfer of calcein AM from the donor cells to the recipient cells was observed only when donor cells and recipient cells were cocultured in direct contact. When cells were cultured in Transwell system, which inhibited direct cell contact between donor and recipient cells, gap junction was not established between them, and consequently, calcein AM was not transferred to the donor cells. (B and C) Effect of CBX on chemoprotection. Chemoprotection assay was performed by PI staining and FACS analysis. CBX significantly reversed the protective effects induced by astrocytes in MDA-MB-231 (B) and PC14Br4 (C). *P < .01.