Method of inhibiting nonsense-mediated mRNA decay

1. A method for treating a NAD comprising administering to a patient suffering from a NAD a composition comprising an eIF5A inhibitor compound in an amount effective to prevent intracellular hypusination of eIF5A, whereby gene expression of NMD-susceptible mRNA is increased.

2. The method of claim 1 , wherein said eIF5A inhibitor compound is a compound of formula (I):

wherein

R 1 is (C 1 -C 6 ) alkyl;

R 2 is (C 1 -C 10 ) straight or branched alkyl, (C 3 -C 6 )cycloalkyl or phenoxy(C 1 -C 3 )alkyl, where the phenoxy group is substituted by substituted or unsubstituted phenoxy; and

R 3 is hydrogen or a pharmacologically acceptable salt.

3. The method of claim 2 , wherein R 1 is methyl, R 2 is cyclohexyl, and R 3 is hydrogen.

4. The method of claim 2 , wherein R 1 is methyl, R 2 is (CH 3 ) 3 CCH 2 (CH 3 )CH 2 —, and R 3 is + H 3 NCH 2 OH.

5. The method of claim 1 , wherein said eIF5A inhibitor compound is a compound of formula (II):

wherein

R 1 is hydrogen or a pharmacologically acceptable salt;

R 2 is ortho hydroxyl-substituted phenyl or pyridyl, where the phenyl or pyridyl group is otherwise unsubstituted or substituted with 1 to 3 additional substituents selected from the group consisting of (C 1 -C 6 ) alkyl, phenyl, (C 1 -C 6 )alkoxy, halogen, or hydroxyl;

A-B is —CH 2 —CR 3 — or —CH═CH—; and

R 3 is hydrogen or (C 1 -C 6 )alkyl.

6. The method of claim 5 , wherein R 1 is hydrogen, R 2 is phenyl, A-B is —CH═CR 3 —, and R 3 is hydrogen.

7. The method of claim 1 , wherein said eIF5A inhibitor compound is a compound of formula (III) or (IV):

wherein R 1 , R 2 , R 3 , and R 4 each individually represent a hydrogen, an alkyl, alkenyl, or alkoxy group containing 1 to 8 carbon atoms, an aryl, arylaklyl, or cycloalkyl group containing 5 to 12 carbon atoms, or a peptide or peptidomimetic moiety containing 10 to 30 carbon atoms.

8. The method of claim 7 , wherein said compound of formula (III) is deferiprone.

9. The method of claim 1 , wherein said NAD is selected from the group consisting of lysosomal disorders, metabolism disorders, familial cancer syndromes, neurodegenerative disorders, connective tissues disorders, hematologic diseases, and cardiovascular diseases.

10. The method of claim 9 , wherein said NAD is characterized by prematurely terminated proteins that are not harmful to biological functions.

11. The method of claim 1 , wherein said NAD is selected from the group consisting of collagenopathies, frontotemporal dementia, Tay-Sachs disease, Parkinson disease, Smith-Lemli-Opitz syndrome, Alagille syndrome, and Carney complex.

12. The method of claim 1 further comprising administering a composition comprising a nonsense codon suppression agent in an amount effective to inhibit translation termination at a misplaced nonsense mutation.

13. The method of claim 12 , wherein said nonsense codon suppression agent comprises a suppressor tRNA.

14. A method of treating a NAD comprising administering to a patient suffering from a NAD a composition comprising an eIF5A inhibitor compound, whereby gene expression of NMD-susceptible mRNA is increased, and wherein the eIF5A inhibitor compound is selected from an RNA interference agent targeting eIF5A mRNA, deoxyhypusine hydroxylase (DOHH) mRNA or deoxyhypusine synthase (DHS) mRNA.

15. The method of claim 14 , wherein said RNA interference agent is selected from an antisense oligonucleotide, siRNA, shRNA, or a vector comprising a DNA sequence encoding said antisense oligonucleotide, siRNA, or shRNA.

16. The method of claim 1 , wherein said NAD is selected from the group consisting of Niemann-Pick disease, familial hypercholesterolemia, McArdle disease, retinoblastoma, breast cancer, amyotrophic lateral sclerosis, spastic paraplegia, congenital muscular dystrophy, autosomal recessive proximal spinal muscular atrophy, Ehlers Danlos Syndrome, cystic fibrosis, thalassemia, ataxia-telangiectasia, long QT syndrome, ischemia syndrome and Duchene's muscular dystrophy.

17. The method of claim 1 , wherein said NAD is thalassemia.