Transplantation of Defined Populations of Differentiated Human Neural Stem Cell Progeny.

Many neurological injuries are likely too extensive for the limited repair capacity of endogenous neural stem cells (NSCs). An alternative is to isolate NSCs from a donor, and expand them in vitro as transplantation material. Numerous groups have already transplanted neural stem and precursor cells. A caveat to this approach is the undefined phenotypic distribution of the donor cells, which has three principle drawbacks: (1) Stem-like cells retain the capacity to proliferate in vivo. (2) There is little control over the cells' terminal differentiation, e.g., a graft intended to replace neurons might choose a predominantly glial fate. (3) There is limited ability of researchers to alter the combination of cell types in pursuit of a precise treatment. We demonstrate a procedure for differentiating human neural precursor cells (hNPCs) in vitro, followed by isolation of the neuronal progeny. We transplanted undifferentiated hNPCs or a defined concentration of hNPC-derived neurons into mice, then compared these two groups with regard to their survival, proliferation and phenotypic fate. We present evidence suggesting that in vitro-differentiated-and-purified neurons survive as well in vivo as their undifferentiated progenitors, and undergo less proliferation and less astrocytic differentiation. We also describe techniques for optimizing low-temperature cell preservation and portability.

A Supplemented High-Fat Low-Carbohydrate Diet for the Treatment of Glioblastoma.

PURPOSE: Dysregulated energetics coupled with uncontrolled proliferation has become a hallmark of cancer, leading to increased interest in metabolic therapies. Glioblastoma (GB) is highly malignant, very metabolically active, and typically resistant to current therapies. Dietary treatment options based on glucose deprivation have been explored using a restrictive ketogenic diet (KD), with positive anticancer reports. However, negative side effects and a lack of palatability make the KD difficult to implement in an adult population. Hence, we developed a less stringent, supplemented high-fat low-carbohydrate (sHFLC) diet that mimics the metabolic and antitumor effects of the KD, maintains a stable nutritional profile, and presents an alternative clinical option for diverse patient populations. EXPERIMENTAL DESIGN: The dietary paradigm was tested in vitro and in vivo, utilizing multiple patient-derived gliomasphere lines. Cellular proliferation, clonogenic frequency, and tumor stem cell population effects were determined in vitro using the neurosphere assay (NSA). Antitumor efficacy was tested in vivo in preclinical xenograft models and mechanistic regulation via the mTOR pathway was explored. RESULTS: Reducing glucose in vitro to physiologic levels, coupled with ketone supplementation, inhibits proliferation of GB cells and reduces tumor stem cell expansion. In vivo, while maintaining animal health, the sHFLC diet significantly reduces the growth of tumor cells in a subcutaneous model of tumor progression and increases survival in an orthotopic xenograft model. Dietary-mediated anticancer effects correlate with the reduction of mTOR effector expression. CONCLUSIONS: We demonstrate that the sHFLC diet is a viable treatment alternative to the KD, and should be considered for clinical testing. Clin Cancer Res; 22(10); 2482-95. ©2015 AACR.