Profile of rolipram treated B-CLL, normal B, and normal T cells

PDE4 inhibitors, which activate cAMP signaling by reducing cAMP catabolism, are known to induce apoptosis in B lineage chronic lymphocytic leukemia (CLL) cells but not normal human T cells. The explanation for such differential sensitivity remains unknown. Here, we report studies contrasting the response to PDE4 inhibitor treatment in CLL cells and normal human T and B cells. Affymetrix gene chip analysis in the three cell populations following treatment with the PDE4 inhibitor rolipram identified a set of up-regulated transcripts with unusually high fold-changes in the CLL samples, several of which are likely part of compensatory negative feedback loops. The high fold-change were due to low basal transcript levels in CLL cells, suggesting that cAMP-mediated signaling may be unusually tightly regulated in this cell type. Keywords: drug response Four sets of primary B-CLL, normal B, or normal T cells were each treated with rolipram (20 uM) or vehicle and cultured for 4 hours. RNA was extracted and subjected to GeneChip analaysis.