International journal of cancer. Journal international du cancer
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The current study was designed to critically evaluate the notion that cancer stem cell (CSC)-like cells constitute a subpopulation of cells within experimental gliomas. Virtually all cells within the N29 and N32 rat glioma models homogenously expressed CD133, the stem/progenitor marker nestin as well as the neural lineage markers glial fibrillary acidic protein, betaIII-tubulin, and CNPase in vitro. The phenotype was largely retained on exposure to conditions promoting differentiation in vitro and after intracranial implantation of tumor cells into syngeneic hosts. ⋯ Single N29 and N32 tumor cells invariably formed clones in vitro, and intracerebral inoculation of as few as 10 adherently growing N29 and N32 tumor cells, respectively, gave rise to a tumor. These results provide an alternative view on CSC-like cells in glioma models: sphere-formation is not a prerequisite for accumulation of tumorigenic cells, and CSC-like cells do not reside within a rare subpopulation of cells in these glioma models. N29 and N32 gliomas may accordingly be used for the development of treatment strategies directed specifically against a practically pure population of brain tumor-initiating CSC-like cells.
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Comparative Study
Greater vegetable and fruit intake is associated with a lower risk of breast cancer among Chinese women.
The effect of vegetable and fruit consumption on breast cancer risk is controversial. We examined the association between vegetable and fruit intake and breast cancer risk in a hospital-based case-control study conducted in Guangdong, China. Four hundred and thirty-eight cases were frequency matched to 438 controls by age (5-year interval) and residence (rural/urban). ⋯ Consumption of individual vegetable and fruit groups such as dark green leafy vegetables, cruciferous vegetables, carrots and tomatoes, banana, watermelon/papaya/cantaloupe were all inversely and significantly related with breast cancer risk. An inverse association was also observed for vitamin A, carotene, vitamin C, vitamin E, and fiber intake. These data indicate that greater intake of vegetables and fruits is associated with a decreased risk of breast cancer among Chinese women residing in Guangdong.
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In human gliomas, self-renewing and tumor-initiating cells are characterized by the expression marker CD133. Although, widely used, the validity of CD133 is debated as recent data show that CD133(+) and CD133(-) cells share similar stemness and tumorigenic properties. To clarify this "CD133 controversy", we reexamined the methods of purification and the stem behavior of both CD133 compartments in fresh gliomas and gliomasphere cultures. ⋯ In contrast, when purified by fluorescence activating cell sorting, a specific expression and enrichment of CD133 was successfully observed in fresh human gliomas and gliomasphere cultures. However, neither the expression of stemness genes nor the long-term self-renewal capacities of CD133(+) and CD133(-) cells were significantly different, even after fresh isolation. Altogether, our data show that purification of CD133(+) glioma cells using hCD133-microbeads presents a lack of specificity and demonstrate that the use of CD133 as a unique glioma stem cell marker is likely not sufficient to tag the whole self-renewing tumor cell reservoir.