Detection of gleevec resistance

Abstract

The present invention relates to isolated polypeptides which comprise an amino acid sequence consisting of a mutated functional Abl kinase domain, said mutated functional kinase domain being resistant to inhibition of its tyrosine kinase activity by N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-4-(4-methyl-piperazin-1-ylmethyl)-benzamide or a salt thereof, to the use of such polypeptides to screen for compounds which inhibit the tyrosine kinase activity of such polypeptides, to nucleic acid molecules encoding such polypeptides, to recombinant vectors and host cells comprising such nucleic acid molecules and to the use of such nucleic acid molecules in the production of such polypeptides for use in screening for compounds which inhibit the tyrosine kinase activity of such polypeptides.

1 . A method of detecting STI571 resistance prior to clinical relapse of a subject during STI571 therapy, comprising:
 selecting a subject undergoing STI571 therapy;   obtaining a sample from the subject;   detecting a mutation in the amino acid sequence of an Abl kinase domain of a Bcr-Abl polypeptide in the sample obtained from the subject, wherein the mutation confers resistance to kinase inhibition by STI571, thereby detecting STI571 resistance prior to clinical relapse of the subject.   
     
     
         2 . The method of  claim 1 , wherein the difference in the amino acid sequence is an amino acid substitution at position 315. 
     
     
         3 . The method of  claim 2 , wherein the method comprises detection of a C to T point mutation that results in a substitution of isoleucine for threonine at position 315. 
     
     
         4 . The method of  claim 1 , wherein the difference in the amino acid sequence is an amino acid substitution at position 255. 
     
     
         5 . The method of  claim 4 , wherein the method comprises detection of an A to T point mutation that results in the substitution of valine for glutamic acid at position 255 or a G to A point mutation that results in the substitution of lysine for glutamic acid at position 255. 
     
     
         6 . The method of  claim 1 , wherein detecting a mutation in the Abl kinase domain of the Bcr-Abl polypeptide comprises:
 determining the sequence of a nucleic acid encoding the Abl kinase domain; and   comparing the amino acid sequence encoded by the nucleic acid with the amino acid sequence set forth as SEQ ID NO: 2,   
       wherein a difference in the amino acid sequence of the Abl kinase domain from the sample from the amino acid sequence set forth as SEQ ID NO: 2 detects an STI571 resistant Abl kinase domain polypeptide. 
     
     
         7 . The method of  claim 1 , wherein determining the nucleic acid sequence comprises reverse transcriptase polymerase chain reaction. 
     
     
         8 . The method of  claim 1 , wherein determining the nucleic acid sequence comprises DNA sequencing. 
     
     
         9 . The method of  claim 1  wherein the tumor is a leukemia. 
     
     
         10 . The method of  claim 9 , wherein the leukemia is myelogenous leukemia. 
     
     
         11 . The method of  claim 1 , wherein detecting a mutation in an Abl kinase domain of the Bcr-Abl polypeptide comprises:
 determining the sequence of an Abl kinase domain in a sample from the subject; and   comparing the amino acid sequence of the Abl kinase domain with the amino acid sequence set forth as SEQ ID NO: 2,   wherein a difference in the amino acid sequence of the Abl kinase domain from the sample from the amino acid sequence set forth as SEQ ID NO: 2 detects an STI571 resistant Abl kinase domain polypeptide.   
     
     
         12 . The method of  claim 11 , wherein the difference in the amino acid sequence is an amino acid substitution at position 315. 
     
     
         13 . The method of  claim 12 , wherein the substitution is a substitution of isoleucine for threonine at position 315. 
     
     
         14 . The method of  claim 11 , wherein the difference in the amino acid sequence is an amino acid substitution at position 255. 
     
     
         15 . The method of  claim 14 , wherein the substitution is a substitution of valine for glutamic acid or lysine for glutamic acid at position 255. 
     
     
         16 . The method of  claim 11 , wherein the tumor is a leukemia. 
     
     
         17 . The method of  claim 16 , wherein the leukemia is myelogenous leukemia. 
     
     
         18 . A method of detecting a STI571 resistant mutation in a subject, comprising:
 selecting a subject for possible treatment with STI571;   obtaining a sample from the subject;   detecting a mutation in an amino acid sequence of Abl kinase domain of a Bcr-Abl polypeptide in the sample obtained from the subject, wherein the mutation is an amino acid substitution at position 315, 248, 255, 271, 286, 290, 315, 320, 322, 373, 375 or 380 of the Abl kinase domain that confers resistance to kinase inhibition by STI571, thereby detecting an STI571 resistant mutation in the subject.   
     
     
         19 . The method of  claim 18 , wherein the substitution is a substitution of isoleucine for threonine at position 315. 
     
     
         20 . The method of  claim 18 , wherein the substitution is a substitution of valine for glutamic acid or lysine for glutamic acid at position 255. 
     
     
         21 . The method of  claim 18 , wherein detecting a mutation in an Abl kinase domain of the Bcr-Abl polypeptide, comprises:
 determining the sequence of the Abl kinase domain in the sample from the subject; and   comparing the amino acid sequence of the Abl kinase domain with the amino acid sequence set forth as SEQ ID NO: 2,   wherein a difference in the amino acid sequence of the Abl kinase domain from the sample from the amino acid sequence set forth as SEQ ID NO: 2 indicates the presence of mutant Abl kinase domain polypeptide in the subject.   
     
     
         22 . The method of  claim 18 , wherein the subject has a tumor. 
     
     
         23 . The method of  claim 22 , wherein the tumor is a leukemia. 
     
     
         24 . The method of  claim 23 , wherein the leukemia is myelogenous leukemia. 
     
     
         25 . The method of  claim 18 , wherein the subject is undergoing STI571 therapy and the method is used to detect the presence of the STI571 resistant Abl kinase domain mutation prior to clinical relapse.