Influence on cell viability of PNA in combination with camptothecin (CPT). JAR cells were transfected with PNA (PNA2512 or its mismatch (mismatch, PNA2733) at 6 μM) in the presence of LFA2000 (8 μl/ml) and CPT at the indicated concentrations for 48 h and subjected to the MTS cellular viability assay (Promega). The obtained data are normalized to the non-treated sample and shown as relative cell viability (%). In the absence of CPT cell viability was 82% and 91% in the presence of PNA2512 and mismatch PNA2733, respectively (at 6 μM). Data are mean ± S.D. of four independent experiments.