CASP3 and infection: In particular, we found a significant decrease of PARP-1 cleavage in non-infected silenced cells (about 80% ± 0.01 and 40% ± 0.11) and an increase of caspase-3/pro-caspase-3 ratio (1.25 fold ± 0.12 and 1.46 fold ± 0.27) and of PARP-1 cleavage (1.46 fold ± 0.09 and twofold ± 0.15) in silenced NSC34 cells after infection (Fig. 8G, I).