ALDH1 As A Cancer Stem Cell Marker

Abstract

The present invention relates to compositions and methods for treating, characterizing, and diagnosing cancer. In particular, the present invention provides a novel stem cell cancer marker, ALDH1, useful for the diagnosis, characterization, and treatment of solid tumor stem cells.

1 . A method of detecting solid tumor stem cells comprising;
 a) contacting a tissue sample with an antibody or antibody fragment configured to detect ALDH1 expression in cells in said tissue sample; and   b) determining if said tissue sample contains solid tumor stem cells based on the presence or absence of ALDH1 expression in said tissue sample.   
     
     
         2 . The method of  claim 1 , wherein said tissue sample comprises breast cancer cells. 
     
     
         3 . The method of  claim 1 , wherein said tissue sample comprises colon cancer cells. 
     
     
         4 . The method of  claim 1 , wherein said tissue sample comprises inflammatory breast cancer cells. 
     
     
         5 . The method of  claim 1 , wherein said tissue sample is a parafin embedded sample. 
     
     
         6 . The method of  claim 1 , further comprising c) determining if said tissue sample contains low levels of BRCRA1 expression. 
     
     
         7 . A method for identifying a cancer patient with a poor prognosis, comprising:
 a) obtaining a biological sample from said cancer patient comprising cancer cells;   b) treating said biological sample to determine if a portion of said cancer cells are ALDH1 expressing solid tumor stem cells, and   c) identifying said cancer patient as having a poor prognosis, wherein said identifying comprises demonstrating the presence of said ALDH1 expressing solid tumor stem cells in said biological sample.   
     
     
         8 . The method of  claim 7 , wherein said treating comprises contacting said biological sample with an antibody or antibody fragment specific for ALDH1. 
     
     
         9 . The method of  claim 7 , wherein said treating comprises contacting said biological sample with reagents configured to detecting expression of ALDH1 mRNA. 
     
     
         10 . A method for killing or inhibiting the proliferation of solid tumor stem cells comprising contacting said solid tumor stem cells with a biologically effective amount of a composition comprising at least one agent targeted to ALDH1. 
     
     
         11 . The method of  claim 10 , further comprising identifying the death of or the prevention of the growth of said solid tumor stem cells following said contacting. 
     
     
         12 . The method of  claim 10 , wherein said cell death is apoptosis. 
     
     
         13 . An isolated solid tumor stem cell, wherein: (a) the solid tumor stem cell is derived from a solid tumor; (b) the solid tumor stem cell expresses ALDH1; and (c) the solid tumor stem cell is tumorogenic. 
     
     
         14 . The isolated solid tumor stem cell of  claim 13 , wherein (d) the solid tumor stem cell over-expresses ERB2. 
     
     
         15 . The isolated solid tumor stem cell of  claim 13 , further wherein: (d) the solid tumor stem cell expresses the cell surface marker epithelial specific antigen (ESA). 
     
     
         16 . The isolated solid tumor stem cell of  claim 13 , further wherein: (d) the solid tumor stem cell expresses the cell surface marker epithelial specific antigen (ESA) and CD10. 
     
     
         17 . The isolated solid tumor stem cell of  claim 13 , further wherein: (d) the solid tumor stem cell does not expresses the cell surface marker epithelial specific antigen (ESA) or CD10. 
     
     
         18 . The isolated solid tumor stem cell of  claim 13 , wherein the solid tumor is a sarcoma cell or an epithelial cancer. 
     
     
         19 . The isolated solid tumor stem cell of  claim 13 , wherein the epithelial cancer is a breast cancer or an ovarian cancer. 
     
     
         20 . The isolated solid tumor stem cell of  claim 13 , wherein the solid tumor stem cell forms a new tumor upon transplantation into the host animal.