Figure 9

Effects of CDX2 expression vector transfection in cultured BECs. Cultured BECs were transiently transfected with the CDX2 expression vector or control vector without a CDX2 sequence (empty vector). (a–c) BECs from PCK rats. (d) BECs from control rats. (a) Transfection of the CDX2 expression vector induced CDX2 and MUC2 mRNA expression in cultured BECs (right lane). CDX2 and MUC2 mRNA were not detected in BECs with no transfection (left lane), or in those transfected with empty vector (middle lane). The expression level of CK19, a marker of biliary epithelium, was almost immutable after transfection of the CDX2 expression vector, the same as the β-actin mRNA expression. RT-PCR for CDX2, MUC2, and CK19. (b) MUC2 protein was expressed in cultured BECs with transfection of the CDX2 expression vector. No positive band of MUC2 protein was found on transfection of empty vector or without transfection. Western blotting for MUC2. (c) Positive staining of CDX2 (red) in the nucleus (upper and middle) and MUC2 (green) in the cytoplasm (upper and right) were seen in cultured BECs transfected with the CDX2 expression vector, whereas such expression of CDX2 and MUC2 was absent in cultured BECs transfected with the empty vector (lower lane). The nucleus of cultured cells was visualized with DAPI (left lane) with no immunostaining of CDX2 or MUC2. Fluorescence immunohistochemistry for CDX2 and MUC2. Original magnification, × 400. (d) MUC2 protein was expressed in cultured BECs from control rats on transfection of the CDX2 expression vector as well as those from PCK rats. Western blotting for MUC2.