Compositions and methods for activating genes of interest

Abstract

Compositions and methods for activating genes of interest are provided. The compositions comprise a masked targeted expression cassette which expresses a gene product only in the presence of a target molecule. The cassettes are useful for the treatment of disease and for preventing the proliferation of neoplastic cells.

1 . A cell comprising a masked expression cassette comprising a double stranded nucleic acid molecule wherein a first strand comprises an RNA sequence which codes for a protein of interest linked downstream of a flanking sequence, and a eukaryotic translation initiation site operably inserted upstream of the RNA sequence; and, the second strand bound to the flanking sequence, wherein the second strand comprises a polynucleotide corresponding to the first strand and to a target molecule, further wherein the cell is a eukaryotic cell. 
     
     
         2 . The cell of  claim 1 , wherein the eukaryotic cell is selected from the group consisting of a plant cell and an animal cell. 
     
     
         3 . The cell of  claim 2 , wherein the cell is an animal cell, further wherein the cell is infected with HIV. 
     
     
         4 . The cell of  claim 1 , wherein the cell is neoplastic. 
     
     
         5 . The cell of  claim 1 , wherein the cassette further comprises a 7-methyl guanine cap linked to a 5′ end of the flanking sequence. 
     
     
         6 . The cell of  claim 1 , wherein the protein of interest comprises a toxin selected from the group consisting of Pseudomonas exotoxin A, ribonuclease, Barnase toxin, Pertussis toxin, and cholera toxin. 
     
     
         7 . A cell comprising a masked expression cassette comprising a double stranded nucleic acid molecule wherein a first strand comprises an RNA sequence which codes for a protein of interest linked downstream of a plurality of sense sequences, and a eukaryotic translation initiation site operably inserted upstream of the RNA sequence; and, a plurality of second strands, each bound to an individual sense sequence, wherein each of the second strands comprises a nucleotide sequence corresponding to one of the sense sequences and to a target molecule, further wherein the cell is a eukaryotic cell. 
     
     
         8 . The cell of  claim 7 , wherein the cell is selected from the group consisting of a plant cell and an animal cell. 
     
     
         9 . The cell of  claim 7 , wherein the cell is an animal cell, further wherein the cell is infected with HIV. 
     
     
         10 . The cell of  claim 7 , wherein the cell is neoplastic. 
     
     
         11 . The cell of  claim 7 , wherein the cassette further comprises a 7-methyl guanine cap linked to a 5′ end of the nucleic acid molecule. 
     
     
         12 . The cell of  claim 7 , wherein the protein of interest comprises a toxin selected from the group consisting of Pseudomonas exotoxin A, ribonuclease, Bamase toxin, Pertussis toxin, and cholera toxin. 
     
     
         13 . The cell of  claim 7 , wherein each of the sense sequences comprises a distinct nucleotide sequence and each of the second strands comprises a nucleotide sequence corresponding to one of the distinct sense sequences and to a distinct target molecule. 
     
     
         14 . The cell of  claim 7 , having two sense sequences and two second strands. 
     
     
         15 . The cell of  claim 7 , having three sense sequences and three second strands. 
     
     
         16 . A cell comprising a masked expression cassette comprising a double stranded nucleic acid molecule wherein a first strand comprises an RNA sequence having a translation initiation site operably inserted upstream of the RNA sequence, wherein the translation initiation site is inserted between a first flanking sequence and a second flanking sequence, further wherein the second strand is bound to the first flanking sequence and the second flanking sequence; wherein the second strand comprises a polynucleotide corresponding to the first strand and to a target molecule. 
     
     
         17 . The cell of  claim 16 , wherein the cell is selected from the group consisting of a plant cell and an animal cell. 
     
     
         18 . The cell of  claim 17 , wherein the cell is an animal cell, further wherein the cell is infected with HIV. 
     
     
         19 . The cell of  claim 16 , wherein the cell is neoplastic. 
     
     
         20 . The cell of  claim 16 , wherein the cassette further comprises a 7-methyl guanine cap linked to a 5′ end of the flanking sequence.