Figure 5.

Temozolomide effects on HUVECs in vitro and in combination with bevacizumab in vivo in GBM models. (A) Graphical representation of the effects of GBM conditioned media, either from U373 GBM cells treated with TMZ or left untreated, on the global growth of HUVECs. These results were obtained with the MTT assay. The percentage of viable HUVEC control cells was arbitrarily reported as 100%. The gray zone corresponds to the SEM of the control condition. The control condition was HUVECs cultured in endothelial cell growth medium EGM-2 MV BulletKit. Minimum essential medium, 5%, was the culture medium for U373 cells. CH14 and HTG06 were two independent batches of HUVECs. These were cultured in mixtures of conditioned medium from U373 cells (either untreated: CH14 and HTG06 “cond”; or treated with TMZ: CH14 and HTG06 “cond with TMZ”) and endothelial cell growth medium EGM (x axis). Results are presented as mean ± SEM. (B) Typical illustrations of the capillary networks formed by HUVECs when cultured for 24 hours on Matrigel. Ba relates to HUVECs cultured with 90% untreated U373 conditioned medium mixed with 10% EGM medium. Bb relates to HUVECs cultured with 90% conditioned medium of TMZ-treated U373 cells mixed with 10% EGM medium. (C) Survival analysis graphs for the in vivo Hs683 orthotopic GBM model treated with either TMZ (open squares) or bevacizumab (open diamonds) compounds alone or a combination of both drugs (open circles). Control groups are represented by black circles. Temozolomide and bevacizumab were administered separately or in combination at 40 mg/kg p.o. and 10 mg/kg i.v., respectively, three times per week for three consecutive weeks. Drug administration began 5 days after GBM cell grafting.