Uses of diterpenoid triepoxides as an antiproliferative agent

Abstract

Combinations of diterpenoid triepoxides and anti-proliferative agents are used in a combination therapy to treat hyperproliferative disorders. Anti-proliferative agents of interest include agents active in killing tumor cells, as well as immunosuppressants, and a variety of other agents that reduce cellular proliferation in targeted tissues. Synergistic combinations provide for comparable or improved therapeutic effects, while lowering adverse side effects.

What is claimed is:  
     
         1 . A method for treatment of a hyperproliferative disorder, the method comprising: 
 contacting a targeted cell population with a combination of an anti-proliferative agent; and a diterpenoid triepoxide having the structure:                        wherein X 1  is OH, ═O; or OR 1 ;    X 2  and X 3  are independently OH, OR 1  or H;    R 1  is —C(O)—Y-Z, wherein Y is a branched or unbranched C 1  to C 6  alkyl or alkenyl group; and    Z is COOR 2 , NR 3 R 3′ , or +NR 4 R 4′ , R 4″ , where R 2  is a cation; R 3  and R 3′  are independently H or branched or unbranched C 1  to C 6  alkyl, hydroxyalkyl, or alkoxyalkyl, or R 3  and R 3′  taken together form a 5- to 7-member heterocyclic ring whose ring atoms are selected from the group consisting of carbon, nitrogen, oxygen and sulfur, wherein the ring atoms include 2 to 6 carbon atoms, or more nitrogen atoms, and optionally one or more oxygen or sulfur atoms, and wherein the ring is unsubstituted or is substituted with one or more groups selected from R 5 , OR 5 , NR 5 R 6 , SR 5 , NO 2 , CN, C(O)R 5 , C(O)NR 5 R 6 , and halogen (fluoro, chloro, bromo, or iodo), where R 5  and R 6  are independently hydrogen, lower alkyl or lower alkenyl; and R 4 , R 4′  and R 4″  are independently branched or unbranched C, to C 6  alkyl, hydroxyalkyl or alkoxyalkyl;      in a combined dosage effective to substantially reduce the numbers of said targeted cell population.    
     
     
         2 . The method of  claim 1 , wherein said diterpenoid triepoxide is selected from the group consisting of triptolide, tripdiolide, 16-hydroxytriptolide; triptolide succinate, an ester derivative of, triptolide, an ester derivative of tripdiolide, and an ester derivative of 16-hydroxytriptolide.  
     
     
         3 . The method of  claim 1 , wherein said hyperproliferative disorder is selected from the group consisting of cancer, restenosis, atherosclerosis, in-stent stenosis, vascular graft restenosis, fibrotic disorders, psoriasis, inflammatory disorders, arthritis, glomerular nephritis, endometriosis, macular degenerative disorders, and autoimmune disorders.  
     
     
         4 . The method of  claim 1 , wherein said hyperproliferative disorder is a cancer.  
     
     
         5 . The method of  claim 1 , wherein said tumor is a human tumor.  
     
     
         6 . The method of  claim 5 , wherein said tumor is a solid tumor.  
     
     
         7 . The method of  claim 6 , wherein said tumor is a carcinoma.  
     
     
         8 . The method of  claim 4 , wherein said cancer is multi-drug resistant.  
     
     
         9 . The method of  claim 4 , wherein said cancer expresses functional p53 protein.  
     
     
         10 . The method of  claim 4 , wherein said cancer expresses p21 waf1/cip1 .  
     
     
         11 . The method according to  claim 10 , wherein said expression of p21 waf1/cip1  is upregulated in response to said anti-proliferative agent.  
     
     
         12 . The method of  claim 4 , wherein said anti-proliferative agent is a topoisomerase inhibitor.  
     
     
         13 . The method of  claim 12 , wherein said topoisomerase inhibitor is an anthracycline.  
     
     
         14 . The method according to  claim 13 , wherein said anthracycline is selected from the group consisting of doxorubicin, daunorubicin, epirubicin, idarubicin, anamycin, and MEN 10755.  
     
     
         15 . The method of  claim 1 , wherein said diterpenoid triepoxide and said anti-proliferative agent are administered in a co-formulation.  
     
     
         16 . The method of  claim 1 , wherein said diterpenoid triepoxide and said anti-proliferative agent are separately formulated.  
     
     
         17 . The method according to  claim 1 , wherein said combination of an anti-proliferative agent; and a diterpenoid triepoxide provide for a synergistic response.  
     
     
         18 . The method of  claim 1 , wherein said anti-proliferative agent is a DNA-damaging compound.  
     
     
         19 . The method of  claim 17 , wherein said anti-proliferative agent is taxol.  
     
     
         20 . A method of screening a tumor for benefit from a combination therapy comprising an anti-proliferative agent and a diterpenoid triepoxide, the method comprising: 
 obtaining a sample of cells from said tumor;    determining if said cells express p21 waf1/cip1 ;    wherein tumors comprising cells that express said p21 waf1/cip1  benefit from said combination therapy.    
     
     
         21 . The method according to  claim 20 , wherein said determining step comprises combining said sample of cells with a binding agent that specifically recognizes p21 waf1/cip1  protein.  
     
     
         22 . The method according to  claim 21 , wherein said binding agent is an antibody.  
     
     
         23 . The method according to  claim 20 , wherein said determining step comprises combining said sample of cells with a binding agent that specifically recognizes p21 waf1/cip1  mRNA or a cDNA derived therefrom.  
     
     
         24 . The method according to  claim 20 , further comprises the step of exposing said cells to a candidate anti-proliferative agent, and wherein said determining step compares expression of p21 waf1/cip1  in the absence and presence of said agent.  
     
     
         25 . The method of  claim 24 , wherein said anti-proliferative agent is a topoisomerase inhibitor.  
     
     
         26 . The method of  claim 25 , wherein said topoisomerase inhibitor is an anthracycline.  
     
     
         27 . The method according to  claim 26 , wherein said anthracycline is selected from the group consisting of doxorubicin, daunorubicin, epirubicin, idarubicin, anamycin, and MEN 10755.  
     
     
         28 . The method according to  claim 24 , wherein said anti-proliferative agent is CPT-11 (Irinotecan).  
     
     
         29 . The method according to  claim 24 , wherein said anti-proliferative agent is vinorelbine.