SCDs As Modifiers of the p53 Pathway and Methods of Use

Abstract

Human SCD genes are identified as modulators of the p53 pathway, and thus are therapeutic targets for disorders associated with defective p53 function. Methods for identifying modulators of p53, comprising screening for agents that modulate the activity of SCD are provided.

1 . A method of identifying a candidate p53 pathway modulating agent, said method comprising the steps of: 
 (a) providing an assay system comprising a SCD polypeptide selected from the group consisting of SEQ ID NOs: 10-12, or a functionally active fragment or derivative thereof;    (b) contacting the assay system with a candidate test agent; and    (c) determining the expression or activity of the SCD polypeptide in the assay system, wherein a change in SCD polypeptide expression or activity between the presence and absence of said candidate test agent indicates the presence of a candidate p53 pathway modulating agent.    
     
     
         2 . The method of  claim 1 , wherein the assay system comprises cultured cells that express the SCD polypeptide.  
     
     
         3 . The method of  claim 2 , wherein the cultured cells additionally have defective p53 function.  
     
     
         4 . The method of  claim 1 , wherein the assay system includes a screening assay comprising a SCD polypeptide and the candidate test agent is a small molecule modulator.  
     
     
         5 . The method of  claim 4 , wherein the screening assay is a desaturase assay.  
     
     
         6 . The method of  claim 1 , wherein the assay system is selected from the group consisting of an apoptosis assay system, a cell proliferation assay system, an angiogenesis assay system, and a hypoxic induction assay system.  
     
     
         7 . The method of  claim 1 , wherein the assay system includes a binding assay comprising a SCD polypeptide and the candidate test agent is an antibody.  
     
     
         8 . The method of  claim 1 , wherein the assay system includes an expression assay comprising a SCD nucleic acid and the candidate test agent is a nucleic acid modulator.  
     
     
         9 . The method of  claim 8 , wherein the nucleic acid modulator is an antisense oligomer.  
     
     
         10 . The method of  claim 8 , wherein the nucleic acid modulator is a PMO.  
     
     
         11 . The method of  claim 1  additionally comprising: 
 (d) administering the candidate p53 pathway modulating agent identified in (c) to a model system comprising cells defective in p53 function and, detecting a phenotypic change in the model system that indicates that the p53 function is restored when compared relative to wild-type cells.    
     
     
         12 . The method of  claim 11 , wherein the model system is a mouse model with defective p53 function.  
     
     
         13 . A method for modulating a p53 pathway of a cell comprising contacting a cell defective in p53 function with a candidate modulator that specifically binds to a SCD polypeptide comprising an amino acid sequence selected from group consisting of SEQ ID NO: 10, 11, and 12, whereby p53 function is restored.  
     
     
         14 . The method of  claim 13 , wherein the candidate modulator is administered to a vertebrate animal predetermined to have a disease or disorder resulting from a defect in p53 function.  
     
     
         15 . The method of  claim 13 , wherein the candidate modulator is selected from the group consisting of an antibody and a small molecule.  
     
     
         16 . The method of  claim 1 , comprising the additional steps of: 
 (d) providing a secondary assay system comprising cultured cells or a non-human animal expressing SCD,    (e) contacting the secondary assay system with the test agent of (b) or an agent derived therefrom; and    (f) determining the expression or activity of SCD in the secondary assay system, wherein a change in SCD expression or activity between the presence and absence of said candidate test agent indicates the presence of a candidate p53 pathway modulating agent.    
     
     
         17 . The method of  claim 16 , wherein the secondary assay system comprises cultured cells.  
     
     
         18 . The method of  claim 16 , wherein the secondary assay system comprises a nonhuman animal.  
     
     
         19 . The method of  claim 18 , wherein the non-human animal mis-expresses a p53 pathway gene.  
     
     
         20 . A method of modulating p53 pathway in a mammalian cell comprising contacting the cell with an agent that specifically binds a SCD polypeptide or nucleic acid.  
     
     
         21 . The method of  claim 20 , wherein the agent is administered to a mammalian animal predetermined to have a pathology associated with the p53 pathway.  
     
     
         22 . The method of  claim 20 , wherein the agent is a small molecule modulator, a nucleic acid modulator, or an antibody.  
     
     
         23 . A method for diagnosing a disease in a patient comprising: 
 (a) obtaining a biological sample from the patient;    (b) contacting the sample with a probe for SCD expression;    (c) comparing results from step (b) with a control;    (d) determining whether step (c) indicates a likelihood of disease.    
     
     
         24 . The method of  claim 23 , wherein said disease is cancer.  
     
     
         25 . The method according to  claim 24 , wherein said cancer is a cancer as shown in Table 1 as having >25% expression level.