Fig. 2.

Adenosine deaminase-binding capacity and dipeptidyl peptidase IV activity increase in parallel with CD26 protein. Cells were treated with vehicle (light bars) or 2 μg/mL a 5-FU; b Cis; c Vin; or d MTX (hatched bars) and assayed when the maximal effect was attained, at 24 h (Vin) or 48 h (5-FU, Cis, MTX) for CD26 protein, ADA-binding capacity, and DPPIV activity. Mean ± SE (n = 4). *, P < 0.01 by Student’s t-test. e Decrease in CXCR4 due to 20 μg/mL 5-FU is maintained in the presence of the DPPIV enzyme inhibitor diprotin A (75 μM). f Increase in CD26 due to 20 μg/mL 5-FU is maintained in the presence of the DPPIV enzyme inhibitor diprotin A. Mean ± SE (n = 4). *, P < 0.01 by ANOVA