Brca-1 regulators and methods of use

Abstract

The invention provides ribozymes and encoding nucleic acids having target recognition sequences that allow the ribozyme to target and cleave BRCA-1 regulators, resulting in upregulation of BRCA-1 in a cell. Also provided are nucleic acids encoding BRCA-1 regulators that contain the target sequences recognized by the ribozymes of the invention. Fragments of these nucleic acid and protein sequences also are provided. Further provided is a method for identifying a gene where the expression level is affected by a BRCA-1 regulator and the identity of several such affected genes. Still further provided is a method of identifying a compound that modulates the activity of a BRCA-1 regulator. Also provided is a method of treating cancer, comprising introducing a ribozyme selectively reactive with an RNA encoding a BRCA-1 regulator into a cancerous cell. The invention further comprises a method of detecting a neoplastic cell in a sample.

1 . A method for identifying a candidate gene for which the level of expression is affected by a BRCA-1 regulator, said method comprising: 
 a) hybridizing a first mRNA and a second mRNA to at least one candidate gene or portion thereof, wherein said first mRNA is obtained from cells expressing a ribozyme that targets and cleaves mRNA encoding a BRCA-1 regulator and wherein said second mRNA is obtained from control cells otherwise similar to those expressing the ribozyme except that the BRCA-1 regulator mRNA is not targeted by a ribozyme; and    b) comparing the relative amounts of the first and second mRNA that hybridizes to the gene, whereby a difference in the relative amounts of hybridization identifies a gene the level of expression of which is affected by a BRCA-1 regulator.    
     
     
         2 . The method of  claim 1 , wherein said first and second mRNA is reverse transcribed into DNA before hybridization.  
     
     
         3 . The method of  claim 1 , wherein said first and second mRNA or said gene is labeled with a detectable moiety.  
     
     
         4 . The method of  claim 3 , wherein said detectable moiety is a fluorescent dye.  
     
     
         5 . The method of  claim 1 , wherein two or more genes are hybridized to said first and second mRNA.  
     
     
         6 . The method of  claim 5 , wherein said two or more genes are arrayed on a solid support before hybridization.  
     
     
         7 . The method of  claim 1 , wherein said BRCA-1 regulator is selected from the group consisting of: BR1 (SEQ ID NO: 1), ID4 (GenBank Acc. No. NM — 001547), BBC1 (GenBank Acc. No. X64707), RH3 (GenBank Acc. No. AL045940), and RH6 (GenBank Acc. No. AI276397).  
     
     
         8 . The method of  claim 1 , wherein said BRCA-1 regulator is selected from the group consisting of: GenBank Acc. No. AA419229, GenBank Acc. No. HI 8950, GenBank Acc. No. H07920, GenBank Acc. No. H70047, GenBank Acc. No. H84815, GenBank Acc. No. AA757764, GenBank Acc. No. H19111, GenBank Acc. No. AA629897, GenBank Acc. No. AA663439, GenBank Acc. No. R15740, GenBank Acc. No. AA454570, GenBank Acc. No. AA485748, GenBank Acc. No. AA464601, GenBank Acc. No. AA102107: and GenBank Acc. No. Z49826.  
     
     
         9 . A method of identifying a compound that modulates the activity of a BRCA-1 regulator, said method comprising contacting a BRCA-1 regulator with a test compound and a target molecule responsive to the activity of the BRCA-1 regulator, wherein an increase or decrease in the activity of the BRCA-1 regulator for the target molecule in the presence of the test compound as compared to the absence of the test compound identifies a compound that modulates the activity of a BRCA-1 regulator.  
     
     
         10 . The method of  claim 9 , wherein said test compound increases the activity of the BRCA-1 regulator.  
     
     
         11 . The method of  claim 9 , wherein said test compound decreases the activity of the BRCA-1 regulator.  
     
     
         12 . The method of  claim 9 , wherein said BRCA-1 regulator is selected from the group consisting of BR1 (SEQ ID NO: 1), ID4 (GenBank Acc. No. NM — 001547), BBC1 (GenBank Acc. No. X64707), RH3 (GenBank Acc. No. AL045940), and RH6 (GenBank Acc. No. AI276397).  
     
     
         13 . The method of  claim 9 , wherein said BRCA-1 regulator is selected from the group consisting of: GenBank Acc. No. AA419229, GenBank Acc. No. H18950, GenBank Acc. No. H07920, GenBank Acc. No. H70047, GenBank Acc. No. H84815, GenBank Acc. No. AA757764, GenBank Acc. No. H19111, GenBank Acc. No. AA629897, GenBank Acc. No. AA663439, GenBank Acc. No. R15740, GenBank Acc. No. AA454570, GenBank Acc. No. AA485748, GenBank Acc. No. AA464601, GenBank Acc. No. AA102107: and GenBank Acc. No. Z49826.  
     
     
         14 . The method of  claim 9 , wherein said BRCA-1 regulator activity is DNA binding activity.  
     
     
         15 . The method of  claim 9 , wherein said activity measured is expression of the nucleic acid element or a gene through its operative linkage to a reporter gene.  
     
     
         16 . The method of  claim 9 , wherein said BRCA-1 regulator activity is protein kinase activity.  
     
     
         17 . The method of  claim 9 , wherein said BRCA-1 regulator activity is GTP binding activity.  
     
     
         18 . The method of  claim 9 , wherein said BRCA-1 regulator activity is protease activity.  
     
     
         19 . The method of  claim 9 , wherein said BRCA-1 regulator activity is protein binding activity.  
     
     
         20 . The method of  claim 9 , wherein said BRCA-1 regulator activity is hormone binding activity.