Dominant negative hsp110 mutant and its use in prognosing and treating cancers

Abstract

The present invention relates to a mutated heat-shock protein 110 (HSP110) lacking its substrate binding domain, which does not exhibit its chaperone activity and/or is not capable of binding to heat-shock protein 70 (HSP70) and/or to heat-shock protein 27 (HSP27), but which is capable of binding to a wild-type HSP 110. Such a mutated heat-shock protein 110 can be used (i) in methods for prognosing survival and/or the response to a treatment of a patient suffering from a cancer, more particularly from a cancer liable to have a microsatellite instability (MSI) phenotype, such as colorectal cancer (CRC), and (ii) for treating cancers.

1 . An isolated mutated heat-shock protein 110 (HSP110), wherein said protein:
 a) does not exhibit chaperone activity and/or is not capable of binding to heat-shock protein 70 (HSP70) and/or to heat-shock protein 27 (HSP27); and   b) is capable of binding to a wild-type HSP110 protein of SEQ ID NO: 2.   
     
     
         2 . An isolated mutated HSP110 according to  claim 1 , wherein said mutated HSP110 protein lacks the domain consisting of amino acids 381 to 858 of SEQ ID NO: 2. 
     
     
         3 . An isolated mutated HSP110 protein according to  claim 1 , wherein said protein consists of an amino acid sequence at least 80% identical to SEQ ID NO: 1. 
     
     
         4 . An isolated mutated HSP110 protein according to  claim 1 , wherein said protein consists of an amino acid sequence of SEQ ID NO: 1. 
     
     
         5 . An isolated nucleic acid comprising a sequence encoding the mutated HSP110 according to  claim 2 . 
     
     
         6 . A method for treating cancer, comprising the administration to an individual in need thereof, a compound selected from the group consisting of:
 a) the mutated HSP110 according to  claim 1 ; and/or   b) a fragment of at least 5 consecutive amino acids of the mutated HSP110, wherein said mutated HSP110 consists of: i) an amino acid sequence at least 80% identical to SEQ ID NO: 1 or ii) an amino acid sequence of SEQ ID NO: 1; and/or   c) a peptido-mimetic of the mutated HSP110 of a) or of the fragment of b); and/or   d) a nucleic acid encoding a mutated HSP110 of a) or a fragment of b); and/or   e) a Nonsense Mediated-mRNA Decay (NMD) inhibitor.   
     
     
         7 . The method according to  claim 6 , wherein said compound is a NMD inhibitor that is 6-Chloro-5,10-dimethyl-11H-pyrido[3′,2′:4,5]pyrrolo[3,2-g]isoquinolin. 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . An in vitro method for prognosing survival or and/or response to a treatment of a patient suffering from a cancer, said method comprising the steps of:
 a) measuring the expression of a mutated HSP110 according to  claim 2  in a biological sample of said patient; and/or   b) determining the length of thymidine repetition of a microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110;   c) and correlating the level of expression measured at step a) and/or the length of the thymidine deletion identified at step b) with the prognosis of said patient, thereby deducing the prognosis of said patient.   
     
     
         11 . An in vitro method according to  claim 10 , wherein said method comprising the steps of:
 a) determining the length of thymidine deletion of a microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110;   b) and correlating the length of the thymidine repetition identified at step a) with the prognosis of said patient, thereby deducing the prognosis of said patient.   
     
     
         12 . An in vitro method according to  claim 10 , wherein a deletion of at least 5 thymidines within the repetition is indicative of a good prognosis of survival and/or of response to the treatment. 
     
     
         13 . An in vitro method according to  claim 10 , wherein said method comprises the steps of:
 a) measuring the expression of a mutated HSP110 according to  claim 2  in a biological sample of said patient;   b) measuring the expression of a mutated HSP110 according to  claim 2  in a negative control sample;   
       wherein an significantly higher expression of mutated HSP measured at step a) in comparison to the expression measured at step b) is indicative of a good prognosis of survival and/or that the patient is likely to respond to the treatment. 
     
     
         14 . An in vitro method according to  claim 10 , wherein said method comprises the steps of:
 a) measuring the expression of a mutated HSP110 according to  claim 2  in a biological sample of said patient;   b) measuring the expression of wild-type HSP110 in said biological sample;   c) comparing the expression measured at steps a) and b), thereby deducing the prognosis of said patient.   
     
     
         15 . An in vitro method according to  claim 10 , wherein said method comprises the steps of:
 a) measuring the expression of mutated HSP110 and of wild-type HSP110 in a biological sample of said patient;   b) analyzing expression values obtained at step a) to generate an expression ratio;   c) measuring the expression of mutated HSP110 and wild-type HSP110 in a negative control sample;   d) analyzing expression values obtained at step c) to generate an expression ratio;   
       wherein a significantly higher expression ratio generated at step b) in comparison to the expression ratio generated at step d) indicates that the patient has a good prognosis and/or that the patient is likely to respond to the treatment. 
     
     
         16 . An in vitro method for diagnosing the MSI phenotype of a tumor, said method comprising the steps of:
 a) genotyping or sequencing the microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110 in a biological sample of a patient likely to be affected by a cancer with MSI phenotype;   b) detecting the presence or absence of instability on said microsatellite repeat,   
       wherein the detection of instability on said microsatellite repeat in the biological sample of the patient indicates that the patient suffers from a cancer with MSI phenotype. 
     
     
         17 . A kit comprising or consisting of:
 a) means for detecting the presence of mutated HSP110 according to the invention, and/or   b) means for detecting detect wild-type HSP110, and/or   c) means for detecting the length of a microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110.   
     
     
         18 . An in vitro method for determining a therapeutic regimen suitable for treating a subject suffering from a cancer liable to have a MSI phenotype, wherein said method comprises the steps of:
 a) determining the length of thymidine repetition of a microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding heat-shock protein 110 (HSP110) in a biological sample of said patient, and   b) deducing a suitable therapeutic regimen for the subject based on the length of said thymidine repetition.   
     
     
         19 . An in vitro method for prognosing survival and/or response to a treatment of a patient suffering from a cancer, said method comprising the steps of:
 a) detecting a nucleic acid according to  claim 5  in a biological sample of said patient; and   b) correlating the detection of a nucleic acid measured at step a) with the prognosis of said patient, thereby deducing the prognosis of said patient.   
     
     
         20 . A method for treating cancer in an individual in need thereof, said method comprising the steps of:
 a) measuring the expression of a mutated HSP110 according to  claim 2  in a biological sample of said patient; and/or   b) determining the length of thymidine repetition of a microsatellite repeat of 17 thimidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110;   c) correlating the level of expression measured at step a) and/or the length of the thymidine deletion identified at step b) with the prognosis of said patient, thereby deducing the prognosis of said patient,   d) administering to said individual a chemotherapeutic drug.   
     
     
         21 . A method for treating cancer in a patient likely to be affected by a cancer with MSI phenotype, said method comprising the steps of:
 a) genotyping or sequencing the microsatellite repeat of 17 thymidine nucleotides localized in the splicing acceptor site of intron 8 of the gene encoding HSP110 in a biological sample of said patient,   b) detecting the presence or absence of instability on said microsatellite repeat,   c) if an instability is detected on said microsatellite repeat, administering to said patient a suitable therapeutic regimen.   
     
     
         22 . An in vitro method according to  claim 10 , wherein said cancer is selected from the group consisting of colorectal cancer, stomach cancer, endometrial cancer, bladder cancer, urinary tract cancer, ovary cancer, prostate cancer, lymphomas, leukemias, glioblastoma, astrocytoma, and neuroblastoma.