Different Mechanisms of Cell Death in Radiosensitive and Radioresistant P53 Mutated Head and Neck Squamous Cell Carcinoma Cell Lines Exposed to Carbon Ions and X-Rays

Combining ultrasmall gadolinium-based nanoparticles with photon irradiation overcomes radioresistance of head and neck squamous cell carcinoma

“…These morphological features are typical of mitotic catastrophe, 28 a preliminary step to later apoptosis. [29][30][31] Our findings are consistent with those of Morgan et al 32 showing that abrogation of the G2/M checkpoint by a Chk1 inhibitor radiosensitizes pancreatic tumor cells.…”

“…20,[34][35][36] The radiosensitizing properties of GBNs appear comparable to those of carbon ions, which are known to induce complex and irreversible DNA lesions, since the α parameter becomes predominant in the linear quadratic equation. 31 The combination of GBNs and carbon therapy may be of potential interest and may improve patient outcomes.…”

Cellular and molecular portrait of eleven human glioblastoma cell lines under photon and carbon ion irradiation

“…Firstly, the cell lines presented a massive G2/M arrest 24 h after photon or carbon ion irradiation. This event was chronologically correlated with the appearance of abnormal nuclei and of micronuclei which is consistent with mitotic catastrophe occurrence [12,14,22]. Moreover, we have shown that ceramide-induced apoptosis 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Table 2 Kinetics of cell distribution in the cell cycle for the 11 GBM cell lines after a 10 Gy photon or 5 Gy carbon ion irradiation.…”

“…However, despite this induction of cell death, some tumor cells are capable of survival by undergoing endomitosis and reentering the cell cycle [23], and therefore can acquire a resistant phenotype [12,24]. However, as we have demonstrated that ceramide is an essential mediator in the course of late apoptosis activated during mitotic catastrophe, the modulation of this pathway will therefore be of interest in the future development of drugs in association with radiotherapy [25].…”

“…The proportion of cells in each phase of the cell cycle was quantified after propidium iodide labeling [12]. Ten thousand events were analyzed using an LSRIIBeckman-Coulter flow cytometer.…”