Methods for diagnosis of low grade astrocytoma

Abstract

A method for identifying low grade astrocytoma cells in a sample is provided, wherein the method distinguishes between low grade astrocytoma cells and normal astrocytes, thus permitting early diagnosis of astrocytoma. The method uses antibody directed against JI-31 to test astrocytes in the sample for the presence or absence of JI-31 polypeptide, the low grade astrocytoma cells being characterized by the absence of JI-31 while normal astrocytes are characterized by the presence of JI-31.

What is claimed is:  
     
         1 . A method for identifying low grade astrocytoma cells in a sample containing astrocytes, comprising testing the astrocytes in the sample for the presence or absence of JI-31 polypeptide, the low grade astrocytoma cells being characterized by the absence of JI-31 and the normal astrocytes being characterized by the presence of JI-31.  
     
     
         2 . A method for distinguishing low grade astrocytoma cells from normal astrocytes, the method comprising the steps of: 
 providing a tissue sample from a site of a suspected astrocytoma;    contacting the sample with antibody molecules immunoreactive with JI-31 protein, under conditions wherein the antibody molecules can form an immune complex with JI-31 antigen in the sample;    detecting cells in the sample in which the immune complex is present, thereby identifying cells expressing the JI-31 antigen; and    detecting astrocytes present in the sample in which the immune complex is absent, thereby identifying low-grade astrocytoma cells.    
     
     
         3 . The method of  claim 2 , wherein the antibody molecules are selected from the group consisting of monoclonal antibodies, recombinant antibodies, and monoclonal antibody fragments.  
     
     
         4 . The method of  claim 3 , wherein the antibodies are monoclonal antibodies.  
     
     
         5 . The method of  claim 4 , wherein the antibody is the anti-JI-31 monoclonal antibody produced by the hybridoma cell line JI-31, ATCC designation number CRL-2253.  
     
     
         6 . The method of  claim 2 , further comprising the step of contacting the sample with antibody molecules immunoreactive with glial fibrillary acidic protein (GFAP), under conditions wherein the anti-GFAP antibody molecules can form an immune complex with GFAP antigen in the sample.  
     
     
         7 . A method for identifying low grade astrocytoma cells in a biological sample, comprising the steps of: 
 contacting the biological sample with anti-JI-31 antibody under conditions in which the antibody binds to JI-31 antigen in the sample;    contacting the biological sample with a secondary antibody selected so as to form an immune complex with the anti-JI-31 antibody bound to JI-31 antigen;    detecting cells expressing the JI-31 antigen by detecting the immune complex; and    detecting astrocytes in the sample in which the immune complex is not present, to thereby identify low-grade astrocytoma cells.    
     
     
         8 . The method of  claim 7 , wherein the secondary antibody is biotinylated.  
     
     
         9 . The method of  claim 8 , wherein the immune complex is detected by contacting the sample with an avidin-peroxidase conjugate, followed by a chromagen suitable for use as a peroxidase substrate.  
     
     
         10 . The method of  claim 7 , wherein the secondary antibody is labeled with a fluorescent dye.  
     
     
         11 . The method of  claim 7 , wherein the secondary antibody is labeled with a metal particle.  
     
     
         12 . The method of  claim 7 , further comprising the step of contacting the sample with anti-GFAP antibody under conditions in which the anti-GFAP antibody binds to GFAP antigen in the sample.  
     
     
         13 . The method of  claim 7 , wherein the anti-JI-31 antibody is a monoclonal antibody.  
     
     
         14 . The method of  claim 13 , wherein the anti-JI-31 antibody is produced by the hybridoma cell line JI-31, ATCC designation number CRL-2253.  
     
     
         15 . A kit for in vitro diagnosis of low grade astrocytoma comprising: 
 anti-JI-31 antibody;    a medium suitable for formation of an antigen-antibody complex; and    reagents for detection of the antigen-antibody complex.    
     
     
         16 . The kit of  claim 15 , further comprising anti-GFAP antibody.  
     
     
         17 . The kit of  claim 15 , further comprising JI-31 antigen.  
     
     
         18 . A kit for in vitro diagnosis of low grade astrocytoma comprising anti-JI-31 antibody and instructions for performing the method of  claim 2 .  
     
     
         19 . The kit of  claim 18 , further comprising JI-31 antigen.  
     
     
         20 . A method for identifying low grade astrocytoma cells in a biological sample, comprising the steps of: 
 providing a biological sample comprising suspected low grade astrocytoma cells and other cells;    isolating at least one suspected low grade astrocytoma cell from the other cells in the sample;    extracting protein from the isolated cell;    contacting the protein extract with anti-JI-31 antibody under conditions in which the antibody binds to JI-31 antigen in the protein extract;    contacting the protein extract with a secondary antibody selected so as to form an immune complex with the anti-JI-31 antibody bound to JI-31 antigen; and    detecting the presence or absence of the immune complex in the protein extract.