TI - Net1 regulates cell survival in response to DNA damage . AB - Activation of RhoA promotes the survival of cells exposed to CDT [6] . In order to investigate whether Net1 is required for this RhoA mediated response , Net1 expression was inhibited by RNAi prior to intoxication and cell death was assessed by monitoring chromatin condensation . Down-regulation of Net1 resulted in a 4 - to 5-fold increase in the number of cells presenting chromatin condensation 48h after intoxication ( Figure 4A ) . Similar results were obtained in cells expressing the dominant negative Net1DeltaDH ( data not shown ) . Induction of cell death upon Net1 knock down was confirmed by cleavage of the caspase-3 SUBstrate PARP , as detected by western-blot analysis ( Figure 4B ) , and activation of the pro-apoptotic protein Bax , as detected by immunostaining using the conformation -dependent antibody 6A7 ( Figures 4C and 4D ) . The effect was already observed after 24h and became highly significant within 48h of treatment . The late occurrence of CDT -induced cell death observed upon Net1 knock down was similar to that observed in cells expressing a dominant negative RhoA ( RhoAN19 ) [6] . These results indicate that Net1 is an essential component in the survival response to DNA damage .