The pathological characteristics of glioma stem cell niches.

Brain tumor stem cells (BTSC) are predicted to be critical drivers of tumor progression due to their self-renewal capacity and limitless proliferative potential. Recent studies suggest that stem cells are controlled by a particular microenvironment known as a "niche". We therefore analysed human glioma tissues and found that the CD133(+) and nestin(+) niches are perivascularly localized in all glioma tissues. Furthermore, there is a positive correlation between the CD133(+) niches and CD133(+) blood vessels, which is similar to the correlation between the nestin(+) niches and nestin(+) blood vessels. We demonstrate that both CD133(+) blood vessels and nestin(+) blood vessels have an important role in maintaining the structure of the glioma stem cell niche. Moreover, the abundance of CD133(+) niches and nestin(+) niches increases significantly as tumor grade increases. These findings provide a new insight into the biology of BTSC and open a new perspective for targeted therapy against the brain tumors.