Mda-7 proteins and methods of use thereof

Abstract

This invention provides a method of generating a subtracted cDNA library of a cell comprising: a) generating a cDNA library of the cell; b) isolating double-stranded DNAs from the cDNA library; c) releasing the double-stranded cDNA inserts from the double-stranded DNAs; d) denaturing the isolated double-stranded cDNA inserts; e) hybridizing the denatured double-stranded cDNA inserts with a labelled single-stranded nucleic acid molecules which are to be subtracted from the cDNA library; and f) separating the hybridized labeled single-stranded nucleic acid molecule from the double-stranded cDNA inserts, thereby generating a subtracted cDNA library of a cell. This invention also provides different uses of the subtracted library.

1 . A nucleic acid selected from the group consisting of:
 (a) a mda-7 nucleic acid that specifically hybridizes to a nucleic acid having a sequence as set forth in  FIG. 38A-B , and that encodes a MDA-7 protein, wherein said MDA-7 protein, in an effective concentration, suppresses the proliferation of HO-1 cells; and   (b) a nucleic acid of at least 15 nucleotides which is capable of specifically hybridizing under stringent conditions to a nucleic acid having a sequence as set forth in  FIG. 38A-B .   
     
     
         2 . The nucleic acid of  claim 1 , which is a cDNA. 
     
     
         3 . The nucleic acid of  claim 1 , further comprising a promoter wherein the promoter controls the expression of the nucleic acid. 
     
     
         4 . The nucleic acid of  claim 3 , wherein the promoter is an inducible promoter, a tissue-specific promoter, or a bacteriophage promoter. 
     
     
         5 . The nucleic acid of  claim 4 , wherein the bacteriophage promoter is T3, T7 or SP6. 
     
     
         6 . A pharmaceutical composition which comprises the nucleic acid of  claim 1  or the encoded MDA-7 protein. 
     
     
         7 . The pharmaceutical composition of  claim 6 , wherein the nucleic acid is combined with a liposome. 
     
     
         8 . A vector comprising the nucleic acid of  claim 1 . 
     
     
         9 . The vector of  claim 8 , wherein the vector is a plasmid, a bacteriophage, a cosmid or a retroviral vector. 
     
     
         10 . A host cell comprising the vector of  claim 9 . 
     
     
         11 . A method for reversing the malignant phenotype of a malignant cell comprising introducing a nucleic acid comprising the mda-7 gene linked to a regulatory element such that the expression of the mda-7 gene is under the control of the regulatory element into the malignant cell under conditions permitting the expression of the mda-7 gene, whereby the transforming phenotype of the malignant cell is reversed. 
     
     
         12 . A method for inducing growth suppression in a tumorigenic and metastatic cell comprising introducing a nucleic acid comprising the mda-7 gene linked to a regulatory element such that the expression of the mda-7 gene is under the control of the regulatory element into the tumorigenic and metastatic cell, wherein growth suppression is induced. 
     
     
         13 . A method for inducing terminal differentiation in a tumorigenic and metastatic cell comprising introducing a nucleic acid comprising the mda-7 gene linked to a regulatory element such that the expression of the mda-7 gene is under the control of the regulatory element into the tumorigenic and metastatic cell, wherein terminal differentiation is induced. 
     
     
         14 . The method of  claim 11 , wherein the cell is a melanoma cell, a leukemia cell, a lymphoma cell, a neuroblastoma cell, or a glioblastoma multiforme cell. 
     
     
         15 . The method of  claim 11 , wherein the regulatory element is a promoter. 
     
     
         16 . The method of  claim 15 , wherein the promoter is a tissue-specific promoter or an inducible promoter. 
     
     
         17 . The method of  claim 11 , wherein the nucleic acid is introduced into the cell by naked DNA technology, retroviral vectors, antibody-coated liposomes, mechanical or electrical means.