Use of Hepatitis B X-Interacting Protein (HBXIP) in Modulation of Apoptosis

Abstract

Novel methods of regulating cellular apoptosis by affecting the interaction of hepatitis B X-interacting protein (HBXIP) with Survivin are described. More specifically, these novel methods of enhancing apoptosis of neoplastic cells comprises inhibiting interaction of hepatitis B X-interacting protein (HBXIP) with Survivin using siRNA or antisense compounds.

1 - 10 . (canceled) 
     
     
         11 . A method for identifying an agent that effectively inhibits the activity of Survivin, HBXIP or HBX, comprising:
 contacting Survivin, HBXIP or HBX with a cell extract containing HBXIP, Survivin and pro-Caspase-9 in the presence of a compound;   inducing activation of pro-Caspase-9 using cytochrome C; and   measuring the activation of pro-Caspase-9, thereby determining whether said compound is an agent that effectively inhibits the activity of Survivin, HBXIP or HBX.   
     
     
         12 - 13 . (canceled) 
     
     
         14 . A method for identifying an agent that effectively inhibits the activity of Survivin or HBXIP, comprising:
 contacting Survivin or HBXIP with purified pro-Caspase-9 and Apaf1 in the presence of HBXIP or Survivin and a compound;   inducing activation of pro-Caspase-9; and   measuring the activation of pro-Caspase-9, thereby determining whether said compound is an agent that effectively inhibits the activity of Survivin or HBXIP.   
     
     
         15 . (canceled) 
     
     
         16 . A method for identifying an effective agent that alters the association of Survivin and HBXIP comprising:
 contacting Survivin and HBXIP under conditions that allow Survivin and HBXIP to associate in the presence or absence of a compound, or in the presence or absence of a cell extract and the compound; and   detecting an altered association between Survivin and HBXIP, thereby determining whether said compound is an effective agent for altering association of Survivin with HBXIP.   
     
     
         17 . The method of  claim 16 , wherein said cell extract comprises pro-Caspase-9 and pro-Caspase-3. 
     
     
         18 . The method of  claim 16 , wherein the altered association between Survivin and HBXIP is detected by measuring the activation of pro-Caspase-3. 
     
     
         19 . The method of  claim 18 , wherein the activation of pro-Caspase-3 is measured by monitoring the cleavage of a caspase 3 substrate selected from the group consisting of DEVD-AFC, DEVD-pNA and DEVD-AMC. 
     
     
         20 . The method of  claim 16 , wherein Survivin and HBXIP associate in the presence of a compound and pro-Caspase-9. 
     
     
         21 . The method of  claim 16 , wherein the altered association between Survivin and HBXIP is detected by measuring the activation of pro-Caspase-9.