Human Cancer Stem Cell Culture Compositions Comprising ErbB2 Variants and Methods of Use

Abstract

The present invention provides compositions and methods for the culture and maintenance of cancer stem cells. More particularly, the present invention provides the identification of cancer stem cell specific markers and methods of recognizing the same for the detection of tumors, for facilitating the prognosis of a patient with a tumor, and for the treatment of various cancers. The invention also provides antibodies that specifically recognize the disulfide linked Erbb2Δ16 homodimer, an Erbb2Δ16/Erbb3 heterodimer, or post-translational modifications of Erbb2 that are specific to Erbb2 of variant hESCs, in addition, the invention provides a modified defined media useful in the absence of a feeder layer and in the absence of serum or serum replacement, that comprises a basal salt nutrient solution, bFGF, IGF-I, and Activin A, and wherein the composition does not comprise heregulin. The invention further relates to the use of an Erbb2 variant isoform to generate robust cell cultures that are independent of heregulin.

1 . A monoclonal antibody that selectively binds to an Erbb2 variant over an Erbb2 wild type isoform, wherein said Erbb2 variant comprises an amino acid sequence of SEQ ID NO:3 or an amino acid sequence having at least 99% amino acid sequence identity to full length SEQ ID NO:3, and wherein said Erbb2 variant has a deletion of an amino acid sequence encoded by exon 16 of SEQ ID NO:1. 
     
     
         2 . The monoclonal antibody of  claim 1 , wherein said Erbb2 variant comprises an amino acid sequence of SEQ ID NO:3. 
     
     
         3 . The monoclonal antibody of  claim 1 , wherein said Erbb2 variant comprises an amino acid sequence having at least 99% amino acid sequence identity to full length SEQ ID NO:3. 
     
     
         4 . The monoclonal antibody of  claim 3 , wherein the amino acid at position 1155 of SEQ ID NO:3 of said Erbb2 variant is not Proline. 
     
     
         5 . The monoclonal antibody of  claim 5 , wherein said amino acid at position 1155 of SEQ ID NO:3 of said Erbb2 variant is Alanine. 
     
     
         6 . The monoclonal antibody of  claim 1 , wherein said Erbb2 variant differs in its glycosylation profile from the wild type Erbb2 isoform encoded by SEQ ID NO:1. 
     
     
         7 . A monoclonal antibody that selectively binds to a domain of an Erbb2 variant over an Erbb2 wild type isomer, wherein said domain comprises an amino acid sequence of SEQ ID NO:5. 
     
     
         8 . The monoclonal antibody of  claim 7 , wherein said Erbb2 variant comprises an amino acid sequence of SEQ ID NO:3. 
     
     
         9 . The monoclonal antibody of  claim 7 , wherein said Erbb2 variant comprises an amino acid sequence having at least 99% amino acid sequence identity to full length SEQ ID NO:3. 
     
     
         10 . The monoclonal antibody of  claim 7 , wherein said Erbb2 variant has a deletion of an amino acid sequence encoded by exon 16 of SEQ ID NO:1. 
     
     
         11 . The monoclonal antibody of  claim 1  or  7 , wherein the antibody is a murine monoclonal antibody or a human monoclonal antibody. 
     
     
         12 . A hybridoma that produces the monoclonal antibody of  claim 1  or  7 .