PARP1 and familial pancreatic carcinoma: PMN-Spt induced a potent apoptosis in human BxPC-3 pancreatic cancer cells (Fig. 3d), which was accompanied by a rapid caspase-3 activation and subsequent PARP-1 cleavage, a well-known caspase-3 substrate and a biochemical marker of apoptosis29, after only 3–6 h incubation (Fig. 5a).