Identification of cancer stem cells markers and use of same for diagnosis and treatment

A method of identifying cancer stem cell markers in a human primary tumor selected from the group consisting of breast cancer, medulloblastoma, atypical teratoid/rhabdoid tumor (ATRT), Ewing's sarcoma, Pleuropulmonary Blastoma and Wilms' tumor, the method comprising:

• (a) in vivo passaging serial dilutions of the primary tumor for at least 10 passages to increase a tumor aggressiveness phenotype of the primary tumor, wherein cells of the primary tumor and passaged cells of the primary tumor are not subjected to immunoisolation and wherein said tumor aggressiveness phenotype is selected from the group consisting of time to tumor formation and amount of cells for tumor formation;
• and
• (b) isolating cells of the tumor following step (a) to generate a first population of passaged tumor cells;
• and
• (c) measuring a level of at least one antigen in said first population of passaged tumor cells of the primary tumor and measuring a level of said at least one antigen in a second population of tumor cells of the primary tumor, and wherein said second population of tumor cells are of are of a serial dilution of said first population of passaged tumor cells:
• (i) non-passaged cells of the human primary tumor;
• or
• (ii) in vivo passaged cells of the human primary tumor, wherein said second population of tumor cells has been in vivo passaged for at least one less number of passages than said first population of passaged tumor cell,
• wherein an increase in the amount of said antigen in said first population of tumor cells as compared to the amount of said antigen in said second population of tumor cells is indicative of a cancer stem cell marker in the human primary tumor.