Fig. 3.

Different mechanisms in which the immunotoxins induce apoptosis in cancer cells. a rGel as a RIP inhibits the protein synthesis by removing A⁴³²⁴ of eukaryotic 28 S ribosomal RNA. b hERB-hRNase induces the tRNA and mRNA degradation which followed by suppression of protein synthesis and induction of apoptosis. c–f GrB-4D5, e23sFv-TD-tBid, HER-PE-CP3, and immunocap-6 are immunoapoptotins which their effector moieties (i.e., GrB, tBid, CP3 and cap-6) mediate apoptosis in cancer cells directly. g KillerRed as a photosensitizer promotes the production of ROS under laser irradiation to induce apoptosis. CP3 caspase3, Cyt. C cytochrome C, GrB granzyme B, RIP ribosome inactivating proteins, ROS reactive oxygen species, tBid truncated Bid, TD diphtheria toxin linker