Elimination of residual tumor cells after radiotherapy with zinc oxide nanoparticles

Radiotherapy still represents an important pillar of therapy for head and neck cancer (HNSCC). However, locoregional recurrences are seen in 15-50% of patients with HNSCC. In the course of radiotherapy, there is a risk that single cells survive treatment and proliferate again after a period of dormancy. There is increasing evidence that mechanisms of senescence play an important role in this context. Thus, the question comes into focus how residual, senescent tumor cells can be eliminated after radiotherapy in order to be able to prevent the development of a recurrence at an early stage.

The study aimed to investigate in vitro how senescent cells develop after radiotherapy, what properties they possess, and whether they can be attacked with zinc oxide nanoparticles to eliminate them and prevent the possibility of renewed proliferation.

In the study, it was shown that after treatment with 16 Gray, quiescent tumor cells emerged that exhibited properties typical of senescent cells. This was accompanied by the fact that these cells did not respond to a new cycle of irradiation with 16 Gray and that there was no increased cell death compared to untreated comparison cells. At the same time, we demonstrated that these cells were vulnerable to treatment with zinc oxide nanoparticles and could thus be driven into cell death.

The study reveals that radiotherapy-induced senescence in tumor cells could well be a therapeutic problem. At the same time, we showed that zinc oxide nanoparticles could represent a therapeutic possibility to eliminate these residual tumor cells.

Die Studie wurde von der Stiftung Tumorforschung Kopf-Hals, Wiesbaden gefördert.

Publication History

Article published online:
24 May 2022