FIGURE 2.

IFN induction of MxA expression and inhibition of motility in PC-3 and PC-3M cells. A and B, fluorescence immunocytochemistry of MxA. PC-3 (panels A) and PC-3M (panels B) were grown for 24 h on coverslips in the presence or absence of 1000 international units (IU) of IFN-α/ml, fixed, permeabilized, stained with monoclonal anti-MxA and Cy-3-conjugated goat anti-mouse immunoglobulin, and counterstained with DAPI. Immunofluorescence was visualized with a Zeiss Axiophot microscope with a 40× objective, and the images were captured on an Optronics charge-coupled device camera. C, motility of PC-3 and PC-3M cells, with and without 24-h exposure to 1000 IU/ml IFN-α. Bars represent the percentage of control PC-3M mobility. Each bar represents the mean of two independent triplicate determinations ± S.E. D, MxA expression and motility. Motility of stable clones of PC-3M expressing β-galactosidase or two different levels of MxA was measured as above. To assess levels of expression in the cell lines being tested, Western blots of 50 μg of protein lysate per lane were probed with anti-MxA and shown in the inset. Each bar represents the mean ± S.E. of two independent experiments performed in triplicate. Wilcoxon rank sum test was used to compare the relative motility of control versus interferon-α-treated PC-3 and PC-3M cells (Fig. 2C) and β-gal-expressing versus two MxA-expressing PC-3M stable transfectants (Fig. 2D). ^*, p < 0.03.