In vitro investigations of the effects of Tumor-Treating Fields and Near-Infrared Photobiomodulation on cancer and normal cells

Electric fields (EFs) have a considerable influence in cell functions producing a wide selection of biological effects. Various combinations of EF frequency and intensity triggers different responses. EF may alter functionality and permeability of cell membrane, resulting in a higher flow of ions leading to membrane depolarization and intracellular calcium increase concentration, both features that could trigger apoptosis. This effects have been studied for decades achieving promising results in cancer treatment. The present work aims on the investigations of two different applications of EFs: a new promising therapy for cancer treatment using low-intensity (1--3 V/cm) alternating EFs with intermediate frequencies (100--500 kHz), named {Tumour-Treating Fields} (TTFields), observing delay in both mitosis and cytokinesis phases of the cell cycle and disrupting effects on the formation of the mitotic spindle during cell division leading to possible cell death. In order to have a more accurate understanding on the mechanism of the anti-tumor effects of TTFields, it has been performed {in vitro} LDH Cytotoxicity Assay and alamarBlue Cell Viability Assay which confirmed that cancer cells under TTFields treatment show higher cytotoxicity and lower viability. Next study concerns the application of {Photobiomodulation} (PBM) therapy using low level visible red to near infrared light (NIR) energy being absorbed by mitochondria enhancing ATP production and improving cell functions. It this work it is performed turbidity measurement during tubulin polymerization in buffer solution exposed to NIR light at different ranges of pulsed frequencies. Changing frequency lead to different turbidity results between exposed and unexposed tubulin samples, suggesting interesting new combinations to try investigate.