Polar intracellular structures

Polar intracellular structures refer to highly dipole-active components within a cell, most notably microtubules and septins, which possess significant electric charge distributions (Wikipedia). These structures are the primary targets of Tumor Treating Fields (TTFields), a non-invasive cancer therapy that utilizes alternating electric fields of intermediate frequency (NIH). During mitosis, the electric fields exert dielectrophoretic forces on these polar structures, disrupting the alignment of tubulin dimers and the localization of septins (Kirson et al., 2007). This interference leads to mitotic spindle instability, improper chromosome segregation, and ultimately, mitotic catastrophe or apoptosis in rapidly dividing cancer cells (Rominiyi et al., 2021). While not a single molecule, the collective targeting of these polar structures provides a unique biophysical mechanism for treating solid tumors like glioblastoma and malignant mesothelioma (Stupp et al., 2017). The efficacy of this approach depends on the high dielectric constant and dipole moment of the target structures compared to the surrounding cytoplasm. Clinical applications of targeting these structures have shown significant survival benefits in patients with recurrent and newly diagnosed glioblastoma when combined with standard chemotherapy.

Other names

Electrically polar intracellular structuresDipolar intracellular structuresMicrotubulesSeptin complexesMitotic spindle components

Inhibition of mitosis through dielectrophoretic forces and dipole alignment disruption of tubulin and septins (Kirson et al., 2007).