Fig. 4

Vastatin synergized with temozolomide in GB chemoresistant model. a TMZ resistance of U87-ATR cells. U87-ATR had a much higher half inhibited dosage of TMZ (>800 μM) than U87MG (<50 μM) in the proliferation test (upper). More U87-ATR than U87MG cells survived the treatment of 100 μM TMZ and formed cell colonies (lower). b U87-ATR cells showed enhanced cancer stem cell property by expression of CSC marker CD133. U87-ATR’ were cells amplified from a single cell clone which was picked out from TMZ treated U87-ATR. c Survival curves showing that GB model established using U87-ATR had a much shorter survival time (25 days) than using U87MG cells (50 days, P < 0.05), and did not respond to TMZ treatment (n = 5). d Survival curves of TMZ resistance GB animals treated by H1-Vastatin and/or TMZ (n = 5). H1-Vastatin significantly prolonged the median survival of animals bearing U87-ATR xenografts to 34 days (P < 0.05). The combination of TMZ and H1-Vastatin showed even better therapeutic effects, with median survival extended to 54 days (P < 0.01 against H1-EGFP treated group; P < 0.05 against H1-Vastatin single treatment group). This result suggested Vastatin synergized with TMZ and restored the sensitivity of chemoresistant mice to TMZ treatments