P2X7, Inhibition Of Epithelial Cancers And Papillomas

Abstract

The present invention demonstrates that P2X7 receptor induced apoptosis may be specific for cancerous cells. Treatment with the P2X7 ligand BzATP, increased cellular apoptosis with no associated inflammatory changes or abnormal skin or systemic effects. In mice treated with DMBA/TPA, BzATP decreased papilloma skin formation. BzATP also induced involution of developed papillomas and stimulated apoptosis in keratinocytes outgrowing at the base of developed papillomas. These data show that (a) P2X7 regulates apoptosis of epidermal cells; (b) in vivo, local administration of a drug that activates the P2X7 receptor can inhibit development and progression of epidermal premalignant lesions.

We claim: 
     
         1 . A method, comprising:
 a) providing;
 i) at least one cancer cell comprising at least one P2X7 receptor expression regulator protein and at least one P2X7 receptor gene promoter enhancer region; and 
 ii) a compound capable of binding to said P2X7 receptor gene promoter enhancer region; 
   b) binding said compound to said P2X7 receptor gene promoter enhancer region under conditions such that expression of said at least one P2X7 receptor expression regulator protein is increased;   c) increasing expression of a P2X7 receptor with said increased at least one P2X7 receptor expression regulator protein; and   d) inducing apoptosis of said at least one cancer cell by said increased P2X7 receptor.   
     
     
         2 . The method of  claim 1 , wherein said at least one cancer cell is derived from a mammalian tumor. 
     
     
         3 . The method of  claim 2 , wherein said apoptosis decreases the size of said mammalian tumor. 
     
     
         4 . The method of  claim 2 , wherein said mammalian tumor is an epithelial tumor. 
     
     
         5 . The method of  claim 4 , wherein said epithelial tumor is a papilloma. 
     
     
         6 . The method of  claim 1 , wherein said P2X7 gene promoter enhancer region comprises a binding site for said at least one P2X7 receptor expression regulator protein. 
     
     
         7 . The method of  claim 6 , wherein said binding site for said at least one P2X7 receptor gene promoter enhancer region comprises nucleotides +222 to +232. 
     
     
         8 . The method of  claim 6 , wherein said binding site for said at least one P2X7 receptor gene enhancer region comprises nucleotides +403 to +573. 
     
     
         9 . The method of  claim 1 , wherein said compound comprises a P2X7 receptor antisense oligonucleotide. 
     
     
         10 . The method of  claim 9 , wherein said P2X7 receptor antisense oligonucleotide binds to said gene promoter enhancer region. 
     
     
         11 . The method of  claim 10 , wherein said P2X7 receptor antisense oligonucleotide comprises a nucleic acid sequence selected from the group consisting of SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24 and SEQ ID NO:25. 
     
     
         12 . The method of  claim 1 , wherein said at least one P2X7 receptor expression regulator protein is selected from the group consisting of p300, Elk-1, E47, EIIaE, E2F and p53. 
     
     
         13 . The method of  claim 6 , wherein said binding site is selected from the group consisting of a p300 enhancer binding site, an Elk-1 enhancer binding site, an E47 enhancer binding site, an EIIaE enhancer binding site, an E2F enhancer binding site and a p53 enhancer binding site. 
     
     
         14 . The method of  claim 1 , wherein said at least one cancer cell is malignant. 
     
     
         15 . The method of  claim 1 , wherein said at least one cancer cell is premalignant. 
     
     
         16 . The method of  claim 2 , wherein said mammalian tumor is derived from a human patient. 
     
     
         17 . The method of  claim 16 , further comprising administering said compound to said patient. 
     
     
         18 . A method, comprising:
 a) providing;
 i) at least one malignant tumor in a patient, wherein said tumor comprises at least one cancer cell expressing at least one P2X7 receptor expression regulator protein and at least one P2X7 receptor gene promoter enhancer region; and 
 ii) a compound capable of binding to said P2X7 receptor gene promoter enhancer region; 
   b) administering said compound to said patient under conditions such the size of said at least one malignant tumor decreases.   
     
     
         19 . The method of  claim 18 , wherein said patient is a human patient. 
     
     
         20 . The method of  claim 18 , wherein said decreased size of said mammalian tumor is due to increased apoptosis. 
     
     
         21 . The method of  claim 18 , wherein said tumor is an epithelial tumor. 
     
     
         22 . The method of  claim 21 , wherein said epithelial tumor is a papilloma. 
     
     
         23 . The method of  claim 18 , wherein said compound comprises a P2X7 receptor antisense oligonucleotide. 
     
     
         24 . The method of  claim 23 , wherein said P2X7 receptor antisense oligonucleotide comprises a nucleic acid sequence selected from the group consisting of SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24 and SEQ ID NO:25. 
     
     
         25 . The method of  claim 18 , wherein said at least one P2X7 receptor expression regulator protein is selected from the group consisting of p300, Elk-1, E47, EIIaE, E2F and p53. 
     
     
         26 . The method of  claim 18 , wherein said administering is local. 
     
     
         27 . A method, comprising:
 a) providing;
 i) at least one premalignant lesion in a patient, wherein said lesion comprises at least one premalignant cell expressing at least one P2X7 receptor expression regulator protein and at least one P2X7 receptor gene promoter enhancer region; and 
 ii) a compound capable of binding to said P2X7 receptor gene promoter enhancer region; 
   b) administering said compound to said patient under conditions such the size of said at least one premalignant lesion decreases.   
     
     
         28 . The method of  claim 27 , wherein said patient is a human patient. 
     
     
         29 . The method of  claim 27 , wherein said decreased size of said premalignant lesion is due to increased apoptosis. 
     
     
         30 . The method of  claim 27 , wherein said lesion is an epithelial lesion. 
     
     
         31 . The method of  claim 27 , wherein said compound comprises a P2X7 receptor antisense oligonucleotide. 
     
     
         32 . The method of  claim 27 , wherein said P2X7 receptor antisense oligonucleotide comprises a nucleic acid sequence selected from the group consisting of SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24 and SEQ ID NO:25. 
     
     
         33 . The method of  claim 27 , wherein said at least one P2X7 receptor expression regulator protein is selected from the group consisting of p300, Elk-1, E47, EIIaE, E2F and p53. 
     
     
         34 . The method of  claim 27 , wherein said administering is local.