METHOD FOR DIAGNOSING NON-SMALL CELL LUNG CANCERS BY tRNA-DIHYDROURIDINE SYNTHASE ACTIVITY OF URLC8

Abstract

The present invention features a method for determining t-RNA dihydrouridine-synthase activity of a polypeptide and screening for modulators of t-RNA dihydrouridine-synthase activity. The present invention further provides methods or pharmaceutical compositions for preventing and/or treating non-small cell lung cancer (NSCLC) using such modulators. Furthermore, the present invention provides methods for diagnosing non-small cell lung cancer (NSCLC) using the t-RNA dihydrouridine-synthase activity of IMS-E21 (URLC8) protein as an index. The present invention further provides methods for predicting and prognosing lung squamous-cell carcinoma (SCC).

1 .- 9 . (canceled) 
     
     
         10 . A method of identifying an agent that modulates t-RNA dihydrouridine-synthase activity, said method comprising the steps of:
 a. incubating in the presence of a test compound under conditions suitable for the synthesis of t-RNA dihydrouridine a polypeptide selected from the group consisting of:
 i. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 (URLC8); 
 ii. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 wherein one or more amino acids are substituted, deleted, or inserted, provided said polypeptide has a biological activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2; 
 iii. a polypeptide encoded by a polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 1, provided the polypeptide has a biological activity equivalent to a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2; 
   b. detecting a t-RNA dihydrouridine synthesis level; and   c. comparing the t-RNA dihydrouridine synthesis level to a control level, wherein an increase or decrease in the t-RNA dihydrouridine synthesis level as compared to said control level indicates that the test compound modulates t-RNA dihydrouridine-synthase activity.   
     
     
         11 . A method of screening for a compound for treating and/or preventing non-small cell lung cancer (NSCLC), said method comprising the steps of:
 a. identifying a test compound that modulates t-RNA dihydrouridine-synthase activity by the method of  claim 10 , and   b. selecting a compound that decreases the t-RNA dihydrouridine synthesis level as compared to a control level.   
     
     
         12 .- 20 . (canceled) 
     
     
         21 . The method of  claim 10 , wherein the polypeptide comprising the amino acid sequence of SEQ ID NO:2 wherein 25 or less of amino acids are substituted, deleted, or inserted, provided said polypeptide has a t-RNA dihydrouridine-synthase activity. 
     
     
         22 . The method of  claim 21 , wherein DSRM (double-strand RNA binding motif) in the amino acid sequence of the polypeptide is conserved. 
     
     
         23 . The method of  claim 10 , wherein the polypeptide encoded by a polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 1, provided the polypeptide has a t-RNA dihydrouridine-synthase activity, wherein the stringent condition comprises washing 3 times in 2×SSC, 0.01% SDS at room temperature for 20 minutes, then washing 3 times in 1×SSC, 0.1% SDS at 37° C. for 20 minutes, and washing twice in 1×SSC, 0.1% SDS at 50° C. for 20 minutes. 
     
     
         24 . The method of  claim 23 , wherein DSRM (double-strand RNA binding motif) in the amino acid sequence of the polypeptide is conserved.