Caspase activation in response to cytotoxic Rana catesbeiana ribonuclease in MCF-7 cells.
Rana catesbeiana ribonuclease (RC-RNase) and onconase were proven to own anti-tumor activity. While molecular determinants of onconase-induced cell death have become more explicit, the RC-RNase-induced death pathway remains presently unknown. Here we demonstrated that RC-RNase-induced molecular cascades in caspase-3-deficient MCF-7 cells did not include activation of initiation caspase-8 and -9. Cleavage timing suggested that procaspase-2 and -6 might be processed by active caspase-7 in MCF-7 cells. Caspase-7 was also responsible for cleavage of the poly(ADP-ribose) polymerase. Furthermore, we reported that overexpression of Bcl-X(L) could raise the survival rates of MCF-7 cells treated with RC-RNase and onconase.
Hu
C C
CC
Institute of Biology and Anatomy, National Defense Medical Center, 161, Sec. 6, MinChuan E. Rd., 114, Taipei, Taiwan.
Tang
C H
CH
Wang
J J
JJ
D029845:Amphibian Proteins; D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism*; D004722:Endoribonucleases / Q000302:isolation & purification / Q000494:pharmacology*; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011892:Rana catesbeiana; D012260:Ribonucleases / Q000378:metabolism; D014407:Tumor Cells, Cultured; D051020:bcl-X Protein
D029845:Amphibian Proteins; D000970:Antineoplastic Agents; C494811:BCL2L1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; D004722:Endoribonucleases; D012260:Ribonucleases; C094067:pyrimidine-guanine sequence-specific ribonuclease, Rana catesbeiana; D020169:Caspases; C058703:ranpirnase