Alpha 5 beta 1 and its ability to regulate the cell survival pathway

Abstract

The present invention provides for identification of agents that induce growth arrest and survival of cancer cells, which remain dormant in bone marrow, thus preventing their eradication through use of standard chemotherapy or radiation therapy. Basic fibroblast growth factor (FGF-2), a mammary differentiation factor abundant in the bone marrow stroma, induces growth arrest of relatively differentiated breast cancer cells and restricts their survival to fibronectin by upregulating integrin α5β1. Most of the FGF-2-arrested cells fail to establish optimal ligation to fibronectin and undergo cell death. Cells that do attach to fibronectin, another major constituent of the bone marrow microenvironment, stay alive and growth-arrested for many weeks. Using function-blocking antibodies and peptides, a specific contribution of α5β1-fibronectin interaction in maintaining survival of growth-arrested cells was demonstrated. The present invention thus allows for methods, agents and pharmaceutical compositions that can be used to potentiate the activity of chemotherapy or radiation therapy.

1 . A method for disrupting survival signaling from the microenvironment in cancer cells, wherein said disrupting results in sensitizing cells to chemotherapy, biological therapies or radiation therapy of primary tumors, cancer metastases or micrometastases and hyperproliferative disorders in a mammal. 
     
     
         2 . The method of  claim 1 , wherein said method comprises blocking the interaction of integrins with the extracellular matrix proteins of the microenvironment. 
     
     
         3 . The method of  claim 2 , wherein said integrins are alpha 5 and/or beta 1 integrins and wherein said extracellular matrix protein is fibronectin. 
     
     
         4 . The method of  claim 1 , wherein said cancer cell is a breast cancer cell or a prostate cancer cell. 
     
     
         5 . The method of  claim 2 , wherein said method comprises administration of an antibody specific for an integrin or a blocking peptide or modified peptide that disrupts interaction of the integrin with the extracellular matrix. 
     
     
         6 . The method of  claim 5 , wherein said integrin is an alpha 5 and/or a beta 1 integrin. 
     
     
         7 . A method of  claim 1 , said method comprising administration of all trans retinoic acid or a retinoic acid derivative. 
     
     
         8 . The method of  claim 1 , wherein said method comprises decreasing expression of cell surface integrins with a transcription inhibitor. 
     
     
         9 . The method of  claim 1 , wherein said method comprises blocking survival signaling initiated by ligation of integrins by microenvironment proteins. 
     
     
         10 . The method of  claim 1 , said method comprising treatment with an inhibitor of a kinase, said kinase selected from the group consisting of MEP/MAP kinase, p38, RhoA, Rho kinase, PI3 kinase, PKC, and PKA. 
     
     
         11 . The method of  claim 10 , wherein said inhibitor is selected from the group consisting of LY294002, UO 126, AG82, Y27632, SB203580, PD169316, PD98059, RO318220, and a C3 transferase inhibitor. 
     
     
         12 . A method for treating hyperproliferative disorders in a mammal, comprising administration of an agent capable of blocking the binding of integrins with the extracellular matrix. 
     
     
         13 . The method of  claim 12 , wherein said integrins comprise alpha 5 and/or beta 1 and wherein said matrix is fibronectin. 
     
     
         14 . The use of an agent for the preparation of a composition for treatment of hyperproliferative disorders, said agent capable of downregulation of the expression of alpha 5 and/or beta 1 integrins and their binding to the extracellular matrix. 
     
     
         15 . The use of kinase or transcription inhibitors as pre-treatment or concurrent treatment, to sensitize for or potentiate chemotherapy in the treatment of cancer or hyperproliferative disorders. 
     
     
         16 . The use of  claim 15 , wherein said cancer is a metastatic cancer. 
     
     
         17 . The use of  claim 15 , wherein said cancer is breast cancer. 
     
     
         18 . The use of kinase or transcription inhibitors as pre-treatment or concurrent treatment, to sensitize for or potentiate radiation therapy in the treatment of cancer or hyperproliferative disorders 
     
     
         19 . The use of  claim 18 , wherein said cancer is a metastatic cancer. 
     
     
         20 . The use of  claim 18 , wherein said cancer is breast cancer. 
     
     
         21 . The use of kinase or transcription inhibitors to downregulate expression of α5 integrins to treat cancer or hyperproliferative disorders. 
     
     
         22 . The use of  claim 21 , wherein said cancer is a metastatic cancer. 
     
     
         23 . The use of  claim 21 , wherein said cancer is breast cancer. 
     
     
         24 . The use of kinase or transcription inhibitors to downregulate expression of β1 integrins to treat cancer or hyperproliferative disorders. 
     
     
         25 . The use of  claim 24 , wherein said cancer is a metastatic cancer. 
     
     
         26 . The use of  claim 24 , wherein said cancer is breast cancer. 
     
     
         27 . The use of kinase or transcription inhibitors to decrease expression or phosphorylation of Akt in the treatment of cancer or hyperproliferative disorders. 
     
     
         28 . The use of  claim 27 , wherein said cancer is a metastatic cancer. 
     
     
         29 . The use of  claim 27 , wherein said cancer is breast cancer. 
     
     
         30 . The use of integrin alpha 5 or integrin beta 1 blocking antibodies or blocking peptides or modified peptides as pre-treatment or concurrent treatment, to sensitize for or potentiate chemotherapy in the treatment of cancer or hyperproliferative disorders. 
     
     
         31 . The use of  claim 30 , wherein said cancer is a metastatic cancer. 
     
     
         32 . The use of  claim 30 , wherein said cancer is breast cancer. 
     
     
         33 . The use of integrin alpha 5 or integrin beta 1 blocking antibodies as pre-treatment or concurrent treatment, to sensitize for or potentiate radiation therapy in the treatment of cancer or hyperproliferative disorders 
     
     
         34 . The use of  claim 33 , wherein said cancer is a metastatic cancer. 
     
     
         35 . The use of  claim 33 , wherein said cancer is breast cancer. 
     
     
         36 . The use of integrin alpha 5 or integrin beta 1 blocking antibodies or fibronectin blocking peptides or modified peptides as a pre-treatment or concurrent treatment, to sensitize for or potentiate radiation therapy or chemotherapy in the treatment of cancer. 
     
     
         37 . The method of  claim 36 , wherein said cancer is breast cancer. 
     
     
         38 . The use of fibronectin binding blocking peptides or modified peptides as pre-treatment or concurrent treatment, to sensitize for or potentiate chemotherapy in the treatment of cancer or hyperproliferative disorders. 
     
     
         39 . The use of  claim 38 , wherein said cancer is a metastatic cancer. 
     
     
         40 . The use of  claim 38 , wherein said cancer is breast cancer. 
     
     
         41 . The use of fibronectin binding blocking peptides or modified peptides as pre-treatment or concurrent treatment, to sensitize for or potentiate radiation therapy in the treatment of cancer or hyperproliferative disorders 
     
     
         42 . The use of  claim 41 , wherein said cancer is a metastatic cancer. 
     
     
         43 . The use of  claim 41 , wherein said cancer is breast cancer. 
     
     
         44 . The use of retinoids and/or retinoid derivatives to decrease expression or phosphorylation of Akt in the treatment of cancer or hyperproliferative disorders. 
     
     
         45 . The use of  claim 44 , wherein said cancer is a metastatic cancer. 
     
     
         46 . The use of  claim 44 , wherein said cancer is breast cancer. 
     
     
         47 . A method of inhibiting cellular proliferation or inducing cell death or cellular differentiation in a mammal suffering from a disease or a disorder characterized by cellular proliferation, said method comprising administering a therapeutically effective amount of a kinase or transcription inhibitor prior to, or concurrent with chemotherapy or radiation therapy. 
     
     
         48 . The method of  claim 47 , wherein said disease or disorder is cancer or a hyperproliferative disorder. 
     
     
         49 . The method of  claim 48 , wherein said cancer is breast cancer. 
     
     
         50 . The method of  claim 47 , wherein said kinase or transcription inhibitor downregulates expression of alpha 5 integrins or beta 1 integrins or phosphorylation of Akt to sensitize for or potentiate chemotherapy or radiation therapy in mammals in need thereof. 
     
     
         51 . The method of  claim 47 , wherein said kinase or transcription inhibitor is selected from the group consisting of inhibitors of MEP/MAP kinase, p38, RhoA, Rho kinase, PI3 kinase and/or PKC, and PKA. 
     
     
         52 . The method of  claim 51 , wherein said inhibitors are selected from the group consisting of LY294002, UO 126, AG82, Y27632, SB203580, PD169316, PD98059, RO318220, and a 3 transferase inhibitor. 
     
     
         53 . A method of treating cancer or a hyperproliferative disorder in a mammal, the method comprising administration of integrin alpha 5 or beta 1 blocking antibodies or fibronectin binding blocking peptides or modified peptides.