Improved specificity of ribozyme-mediated cleavage of bcr-abl mRNA.
Ribozyme-mediated cleavage of bcr-abl mRNA has been shown to be associated with the concomitant cleavage of bcr mRNA. The possible role of this ribozyme as a clinical therapeutic constrained us to improve its target specificity. Consequently, three modified ribozymes (Rz7-9) were created, each carrying a single base mismatch in the sequence immediately 5' of the cleavage site, while a fourth ribozyme (Rz10) was targeted to a nearby site. Each was compared with the parent ribozyme for its ability to cleave synthetic bcr-abl and bcr substrates, and it was shown that alteration of the second base 5' of the cleavage site created a ribozyme with significantly improved specificity for its substrate. Rz10 was shown to exclusively act on bcr-abl, but the efficiency of cleavage was reduced compared to that shown by ribozymes 6, 8, and 9.
Kearney
P
P
Haematology Department, St Vincent's Hospital, Sydney, Australia.
Wright
L A
LA
Milliken
S
S
Biggs
J C
JC
D001483:Base Sequence; D016044:Fusion Proteins, bcr-abl / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D015513:Oncogene Proteins / Q000096:biosynthesis; D010957:Plasmids; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D016315:Proto-Oncogene Proteins c-abl / Q000096:biosynthesis; D051562:Proto-Oncogene Proteins c-bcr; D012313:RNA / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D016337:RNA, Catalytic / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D015183:Restriction Mapping; D013379:Substrate Specificity
D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins; D016337:RNA, Catalytic; D012333:RNA, Messenger; C039919:RNA, recombinant; D012313:RNA; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl; D016315:Proto-Oncogene Proteins c-abl; D051562:Proto-Oncogene Proteins c-bcr