Figure 1.
A, Expression of β4 and α6 integrins in 4 human pancreatic cancer cell lines, namely BxPC-3 (lane 2), AsPC-1 (lane 3), MIAPaCa-2 (lane 4), and PANC-1 (lane 5), were examined by Western blotting. Mouse cell line A4 (lane 1) was used as a negative control. Expression of β4 and α6 was normalized to actin band, and relative cell line expression standardized against to A4 cell lysate were shown under the panels. B, Expression of α6β4 in these cell lines was compared by flow cytometric analysis. Percentages of α6β4-positive cells (numbers in the upper-right quadrant) are presented in a bar graph. C, BxPC-3 and A4 cells were incubated with fluorescein- or ICG-labeled anti-α6β4 antibody (ITGA6B4) for 18 hours and examined under a fluorescent microscope. Intense fluorescence signals in membrane and intracellular signals indicated the localization of each probe and confirmed the high α6β4 expression in BxPC-3 but not in the negative control A4 cells (scale bar = 100 µm). ICG indicates indocyanine green. DAPI, 4 ,6-diamidino-2-phenylindole.