PARP degradation in apoptotic Syrian hamster embryo (SHE) cells compared to HL60 cell line

In this study, we attempted to identify apoptotic Syrian hamster embryo (SI -IE) cells by detecting the specific cleavage of poly(ADP-ribose)polymerase (PARP). Apoptosis was unequivocally identified in serum-deprived SHE cells . After protein electrophoresis and transfer, the anti-PARP antibody (C-2-1 0) was applied in order to visualize PARP degradation and the anti-polymer antibody (LP96-10) was used to identify PARP and its expected 89-kDa fragme nt on the membrane after renaturation and NAD(+) addition. Results showed t hat PARP rapidly disappeared during apoptosis in SHE cells, but the resulti ng fragment remained undetectable with the anti-PARP antibody and no stable polymerase activity of this fragment was measured using anti-polymer antib ody. Serum-starved SHE cells were compared to the etoposide-treated HL60 ce ll line as a control for typical apoptosis-related PARP cleavage. These res ults underline the fact that while PARR degradation is a criterion for apop tosis, the diagnosis of apoptosis can not rely exclusively on the appearanc e of its 89-kDa fragment as this signal may fail to appear in some cell sys tems. (C) 2000 Societe francaise de biochimie et biologie moleculaire / Edi tions scientifiques et medicales Elsevier SAS.