Figure 4.

Impact of treatments on aggressiveness and recurrence potential of invading tumor cells. (A-C) Gelatin zymography method was carried out to assess gelatinases (MMP2 and MMP9) secretion and activity in invading cells supernatant. (A) 4 µg of total proteins obtained from supernatant of escaped cells were deposited in a 10% polyacrylamide gel with 1% porcine gelatin. Image of gel was acquired after migration for 2 hours and Coomassie Blue staining using a Doc XR+ Gel (Bio Rad, France). For each treatment condition, densitometric quantification of the bands allowed to determine (B) MMP2 secretion that corresponds to the sum of signals for MMP2 proenzyme and for active MMP2, and (C) active MMP2. Results are presented as mean ± SD (n = 4 independent experiments) (D and E) Assessment of the stem-like features of invading cells by neurosphere assay. After trypsinization, invading cells were recovered and counted. 1×10⁵ invading cells were resuspended in appropriate serum-free culture medium for 4 days, allowing the formation of floating neurospheres. At the end of the experiment, (D) number and (E) size of neurospheres were measured using the GelCount^® device (Oxford Optronix, UK). Results are presented as mean ± SD (n ≥ 4 independent experiments). For graphs B, C, D and (E) # = significant difference between RT groups versus Ctrl group and * = significant difference between “with Au@DTDTPA(Gd) nanoparticles” groups versus “w/o nanoparticles” groups at p < 0.05 according to the Mann–Whitney U-test.