Targeting Lung Cancer Cell Motility Using Microbeam Radiation Therapy

Radiotherapy (RT) is currently among the standard treatments for lung cancer. However, in vitro studies have revealed that irradiation can increase lung cancer cell motility. This way, RT could potentially enhance the malignancy of solid tumors post-treatment, promoting metastasis. Therefore, there is a continued need to continue evolving RT modalities into safer and more effective treatments. The present study compares the impact of the broad beam (BB) and the spatially fractionated modality of microbeam radiation therapy (MRT) on the motility of A549 lung cancer cells. Our data corroborates previous findings that showed BB irradiation is a promoter of cell motility. For MRT, however, we observed a prevention of cellular migration. A significant reduction in NF-κB expression was observed only when A549 cells were irradiated with MRT, indicating a potential mechanism behind these findings. Finally, our data supports potential issues regarding MRT irradiation of key components of the tumor microenvironment, such as fibroblasts. Co-culturing A549 cells with MRT-irradiated MRC-5 lung fibroblasts led to increased tumor cell invasion, not observed when the fibroblasts received BB irradiation.