Claudins as markers for early detection, diagnosis, prognosis and as targets of therapy for breast and metastatic brain or bone cancer

Abstract

Methods of diagnosis, prognosis, and treatment of breast cancer, and of metastatic brain cancer, are provided The diagnostic and prognostic methods involve the immunohistochemical detection of the level of expression of the proteins claudin 1, 3, 4, and 7 in tissue or cell samples. Claudins 1 and 7 are underexpressed in the majority of breast cancers, and claudins 3 and 4 are overexpressed. The methods of treatment involve the use of Clostridium perfringens enterotoxin (or a variant thereof) to lyse metastatic cancer cells in the brain and bone that overexpress claudins 3 and 4.

1 . A method for diagnosing cancer or metastasis in a patient in need thereof, comprising the steps of 
 determining a level of expression of at least one claudin in cells of interest, wherein said at least one claudin is selected from the group consisting of claudin 1, claudin 3, claudin 4, and claudin 7, and    assessing whether claudins 3 or 4 are expressed at a level which is higher than a predetermined level, or whether or not claudins 1 or 7 are expressed at a level which is lower than a predetermined level, where cancer or metastasis is implicated when claudins 3 or 4 are at or above said level which is higher that said predetermined level, or when claudins 1 or 7 are at or below said level which is lower than said predetermined level.    
     
     
         2 . The method of  claim 1 , wherein said cancer or metastasis is selected from the group consisting of breast cancer, lung cancer, colon cancer, kidney cancer, prostate cancer, pancreas cancer, ovarian cancer, thyroid cancer, gastric cancer, head and neck cancer, and skin cancer.  
     
     
         3 . The method of  claim 1  wherein said step of determining is carried out by exposing said cells of interest to at least one antibody recognizing a claudin.  
     
     
         4 . The method of  claim 3 , wherein said at least one antibody includes an antibody recognizing claudin 1, claudin 3, claudin 4, or combinations thereof.  
     
     
         5 . The method of  claim 3 , wherein said at least one antibody to a claudin includes an antibody recognizing a C-terminal region of CLDN-7.  
     
     
         6 . The method of  claim 3 , wherein said antibody is an antibody recognizing SEQ ID NO. 1.  
     
     
         7 . The method of  claim 1  further comprising the step of obtaining a sample of said cells of interest from said patient.  
     
     
         8 . The method of  claim 7 , wherein said sample is a biopsy tissue sample.  
     
     
         9 . The method of  claim 7 , wherein said sample comprises cells from ductal lavage fluid.  
     
     
         10 . The method of  claim 7 , wherein said at least one claudin is claudin 3 or claudin 4, or both claudins 3 and 4, and said sample is blood.  
     
     
         11 . The method of  claim 1 , further comprising the step of determining a grade of a sample containing said cells of interest based on an assessment made in said assessing step, and wherein said grade is high if claudin 7 expression is low, or low if claudin 7 expression is high.  
     
     
         12 . A method of killing cancer cells that express claudin-3 or claudin-4 or both claudin-3 and claudin-4, comprising the step of 
 exposing said cancer cells to molecules recognizing claudin-3 or claudin-4, wherein said molecules kill said cancer cells or deliver cytotoxic agents that kill said cancer cells.    
     
     
         13 . The method of  claim 12 , wherein said molecules include  Clostridium perfringens  enterotoxin in quantities sufficient to lyse said cancer cells.  
     
     
         14 . The method of  claim 13 , wherein said  Clostridium perfringens  enterotoxin is truncated by 45 amino acids at the amino terminus.  
     
     
         15 . The method of  claim 13 , wherein said  Clostridium perfringens  enterotoxin is encapsulated in vessels selected from the group consisting of liposomes, biodegradable synthetic polymer wafers, and micro-spheres.  
     
     
         16 . The method of  claim 13 , wherein said  Clostridium perfringens  enterotoxin is in the form of a chimeric protein comprising a matrix metalloprotease that is over-expressed by breast tumors.  
     
     
         17 . The method of  claim 12 , wherein said molecules include antibodies recognizing claudin-3 or claudin-4.  
     
     
         18 . The method of  claim 17 , wherein said antibodies recognizing claudin-3 or claudin-4 are attached to cytotoxic agents that kill cancer cells.  
     
     
         19 . The method of  claim 12  wherein said cytotoxic agents that kill cancer cells are contained in vessels selected from the group consisting of liposomes, biodegradable synthetic polymer wafers, and micro-spheres.  
     
     
         20 . The method of  claim 19 , wherein antibodies recognizing claudin-3 or claudin-4 are attached to said vessels.  
     
     
         21 . The method of  claim 12 , wherein said cancer cells are primary or metastatic cancer cells selected from the group consisting of breast cancer cells, lung cancer cells, colon cancer cells, kidney cancer cells, prostate cancer cells, pancreas cancer cells, ovarian cancer cells, thyroid cancer cells, gastric cancer cells, head and neck cancer cells, and skin cancer cells.  
     
     
         22 . The method of  claim 12 , wherein said cancer cells are metastatic cancer cells.  
     
     
         23 . The method of  claim 22 , wherein said metastatic cancer cells are located in a patient's brain or bone.