Efficient Apoptosis via Double-Strand Breaks of DNA in Breast Cancer Cells induced by Non-Thermal effect of High-Field Broadband Terahertz Waves

Induction of apoptosis is the main strategy of cancer therapies in clinical oncology. Chemical or biological stimuli generally result in drug or agent resistance and damage to the immune system. Current physical stimuli have strong side effects, such as radiation injury or collateral thermal damage, due to the inflammation from the necrosis. Therefore, a new physical non-inflammatory therapy based on a non-thermal effect is highly desirable. Here, we report highly efficient apoptosis, reaching nearly 99% in breast cancer cells, induced by the non-thermal effect, i.e. the nonlinear resonance effect of high-field (average field strength of ~5.87 MV/cm) broadband terahertz (THz) waves via double-strand breaks of DNA damage after 4 hours of irradiation. This is accompanied by 11 highly differentially expressed genes related to apoptosis and significant morphological changes in the cells. We speculate that a p53- and caspase-independent apoptotic signaling pathway might be activated. These results suggest that the non-thermal effect of high-field broadband THz waves could be used to develop a potential novel, noninvasive, and non-inflammatory therapy for human breast cancer or other superficial tumors. This economical, novel noninvasive therapy would be suitable for all people, especially for the elder patients or patients with low immunity and those people who are not suitable for surgery or other chemical and physical treatments.