In vitro transcriptional and translational block of the bcl-2 gene operated by peptide nucleic acid.
The antisense and antigene activity of peptide nucleic acid (PNA) targeted to the human B-cell lymphoma (bcl)-2 gene was evaluated in vitro. Several PNAs complementary to different sequences of bcl-2, including the start codon and the 5'-untranslated region (5'-UTR), were tested. One PNA directed against the AUG start codon and another recognizing the 5'-UTR were able to specifically reduce Bcl-2 protein synthesis in a cell-free system; however, only partial inhibition (80 and 54%, respectively) was obtained when they were used singularly. Complete translation block was obtained with the simultaneous presence of both PNAs. A triplex-forming bis-PNA was targeted to a homopurine sequence on the coding strand of the bcl-2 cDNA. In an in vitro transcription assay this PNA specifically inhibited the transcription of bcl-2 at concentrations as low as 300 nM, with the concomitant appearance of a truncated 200-base-long product. These results demonstrate the ability of PNA to selectively modulate both translation and transcription of bcl-2 in vitro and suggest its potential use as an antisense and an antigene agent in order to downregulate bcl-2 expression in tumors.
Mologni
L
L
Department of Experimental Oncology, Istituto Nazionale Tumori, via Venezian 1, Milan, 20133, Italy. luca.mologni@helsinki.fi
Nielsen
P E
PE
Gambacorti-Passerini
C
C
D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D019254:Genes, bcl-2 / Q000187:drug effects*; D016376:Oligonucleotides, Antisense; D020135:Peptide Nucleic Acids / Q000494:pharmacology*; D010957:Plasmids; D014176:Protein Biosynthesis / Q000187:drug effects*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects*
D016376:Oligonucleotides, Antisense; D020135:Peptide Nucleic Acids; D019253:Proto-Oncogene Proteins c-bcl-2