The molecular target of rapamycin (mTOR) is up-regulated in glioblastoma (GBM) 
and this is associated with the rate of cell growth, stem cell proliferation and 
disease relapse. Rapamycin is a powerful mTOR inhibitor and strong autophagy 
inducer. Previous studies analyzed the effects of rapamycin in GBM cell lines. 
However, to our knowledge, no experiment was carried out to evaluate the effects 
of rapamycin neither in primary cells derived from GBM patients nor in vivo in 
brain GBM xenograft. These data are critical to get a deeper insight into the 
effects of such adjuvant therapy in GBM patients. In the present study, various 
doses of rapamycin were tested in primary cell cultures from GBM patients. These 
effects were compared with that obtained by the same doses of rapamycin in GBM 
cell lines (U87Mg). The effects of rapamycin were also evaluated in vivo, in 
brain tumors developed from mouse xenografts. Rapamycin, starting at the dose of 
10nm inhibited cell growth both in U87Mg cell line and primary cell cultures 
derived from various GBM patients. When administered in vivo to brain xenografts 
in nude mice rapamycin almost doubled the survival time of mice and inhibited by 
more than 95% of tumor volume.