Figure 3.

Detection of Cx40 and Cx37 within the vasculature of TC-1 tumors. Representative tumors (Ts) grown 16 days after the instillation into the mouse bladder of TC-1 cells. (M) Muscle, (LP) lamina propria, (L) lumen, (U) urothelium (upper left panel). Immunostaining for the endothelial cell marker Von Willebrand factor (vWF) reveals the microvessels of bladder and tumors (upper right panel). Higher magnification of the tumor area delimited by the blue square is shown. Immunostaining for different connexin isoforms (green), performed on consecutive sections, reveals Cx40 and Cx37 in the tumor vessels. The different distribution of Cx43 indicates that this connexin is expressed by tumor cells. No Cx26 was observed in the tumors (Cx26 is known to be expressed between normal bladder urothelial cells). The red background is produced by Evans blue counterstain when activated with green light (lower panels).