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Cancers comprise heterogeneous cells, ranging from highly proliferative immature precursors to more differentiated cell lineages. In the last decade, several groups have demonstrated the existence of cancer stem cells in both nonsolid solid tumors, including some of the brain: glioblastoma multiforme (GBM), medulloblastoma, and ependymoma. These cells, like their normal counterpart in homologous tissues, are multipotent, undifferentiated, self-sustaining, yet transformed cells. In particular, glioblastoma-stem like cells (GBSCs) self-renew under clonal conditions and differentiate into neuron- and glia-like cells, with aberrant, mixed neuronal/astroglial phenotypes. Remarkably, upon subcutaneous and intracerebral transplantation in immunosuppressed mice, GBSCs are able to form secondary tumors that closely resemble the human pathology, a property retained also throughout serial transplantation. The search is up for the identification of the markers and the molecular mechanisms that underpin the tumorigenic potential of these cells. This is critical if we aim at defining new therapeutic approaches for the treatment of malignant brain tumors. Lately, it has been shown that some key regulatory system that plays pivotal roles in neural stem cell physiology can also regulate the tumorigenic ability of cancer stem cells in GBMs. This suggests that the study of cancer stem cells in brain tumors might help to identify new and more specific therapeutic molecular effectors, with the cancer stem cells themselves representing one of the main targets, in fact the Holy Grail, in cancer cell therapy. This review includes a summary review on brain cancer cells and their usefulness as emerging targets in cancer cell therapy. [ABSTRACT FROM AUTHOR]

The dogma that the genesis of new cells is a negligible event in the adult mammalian brain has long influenced our perception and understanding of the origin and development of CNS tumours. The discovery that new neurons and glia are produced throughout life from neural stem cells provides new possibilities for the candidate cells of origin of CNS neoplasias. The emerging hypothesis is that alterations in the cellular and genetic mechanisms that control adult neurogenesis might contribute to brain tumorigenesis, thereby allowing the identification of new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Widespread demyelination and axonal loss are the pathological hallmarks of multiple sclerosis. The multifocal nature of this chronic inflammatory disease of the central nervous system complicates cellular therapy and puts emphasis on both the donor cell origin and the route of cell transplantation. We established syngenic adult neural stem cell cultures and injected them into an animal model of multiple sclerosis-experimental autoimmune encephalomyelitis (EAE) in the mouse-either intravenously or intracerebroventricularly. In both cases, significant numbers of donor cells entered into demyelinating areas of the central nervous system and differentiated into mature brain cells. Within these areas, oligodendrocyte progenitors markedly increased, with many of them being of donor origin and actively remyelinating axons. Furthermore, a significant reduction of astrogliosis and a marked decrease in the extent of demyelination and axonal loss were observed in transplanted animals. The functional impairment caused by EAE was almost abolished in transplanted mice, both clinically and neurophysiologically. Thus, adult neural precursor cells promote multifocal remyelination and functional recovery after intravenous or intrathecal injection in a chronic model of multiple sclerosis. [ABSTRACT FROM AUTHOR]

Distinct cell lineages established early in development are usually maintained throughout adulthood. Thus, adult stem cells have been thought to generate differentiated cells specific to the tissue in which they reside. This view has been challenged; for example, neural stem cells can generate cells that normally originate from a different germ layer. Here we show that acutely isolated and clonally derived neural stem cells from mice and humans could produce skeletal myotubes in vitro and in vivo, the latter following transplantation into adult animals. Myogenic conversion in vitro required direct exposure to myoblasts, and was blocked if neural cells were clustered. Thus, a community effect between neural cells may override such myogenic induction. We conclude that neural stem cells, which generate neurons, glia and blood cells, can also produce skeletal muscle cells, and can undergo various patterns of differentiation depending on exposure to appropriate epigenetic signals in mature tissues. [ABSTRACT FROM AUTHOR]

Discusses that mammalian cells with exceptional and unanticipated capacities to mature into a broad range of phenotypes may be isolated from a variety of organs at multiple ages, grown to abundance in culture with apparent accomodation to the environment. Impact of gastrulation on embryonic stem cells; Consequences of injecting adult neural stem cells into the blastocytes.

A correction to the article "Glioblastoma cell growth is suppressed by disruption of fibroblast growth factor pathway signaling" which was published in a previous issue is presented.

A letter to the editor is presented in response to the article "The hard copy," published in the previous issue.

Discusses findings of a study conducted by Cindi M. Morshead et al. which opposes report of three other studies that neural stem cells (NSC) are capable of differentiating into hematopoietic cells. Explanation of study conducted to reconcile differences between findings of other three studies and findings of study conducted by Morshead et al.; Suggestion that cultured NSC are heterogeneous.