Nucleo-cytoplasmic shuttling of GFP-NFAT. A) GFP-NFAT expressing HeLa cells were grown on glass coverslips and either left untreated (control) or treated with ISIS 15534 or the mismatched control (ISIS 15521) as described in Materials and Methods. Twenty-four hours after oligonucleotide treatment, the cells were either directly fixed with paraformaldehyde (No ionomycin), or ionomycin was added to 1 μM for 30 minutes. After treatment with ionomycin, the cells were either fixed (+ ionomycin) or rinsed in PBS and grown for an additional 6 hours in medium in the absence of drug (washout) before fixing. Representative fields of cells were viewed by fluorescence microscopy and photographed. B). Northern analysis of HeLa cells following treatment with 500 nM ISIS 15534, 500 nM ISIS 155521 or lipofectin alone (control), probing for PP5 and GAPDH confirms that the antisense oligonucleotides are also effective HeLa cells.