Cancer stem cell in pediatric brain tumor

Cancers are formed by heterogeneous cell types from miniature highly proliferative cells to lineage-committed differentiated cells. Transplantation studies have suggest the existence of "cancer stein cells", individual cells capable of producing an entire tumor. Recent advances in stein cell research have allowed for the demonstration of the existence of cancer stein cells in acute myeloid leukemia, breast cancer, and, most recently, in pediatric brain tumors. Each of these has some similarities with the normal stein cells in the corresponding organs. For example, leukemia stem cells express some, but not all, markers of hematopoietic stein cells. Regarding pediatric brain tumors, putative cancer stein cells were identified from medulloblastoma and also from glioma. These tumor-derived cells self-renew under clonal conditions, and differentiate into neurons and glia as well as into abnormal cells with mixed phenotypes. Interestingly, the tumor stem/progenitors, enriched in culture, maintained proliferation after 4 weeks from transplantation into neonatal rat brain. In this review, we discuss the difference as well as the similarity between tumor and normal stem cells, and also the possible clinical implication of cancer stein cells.