By Purnendu Ghosh Dec 21 2009
The research conducted at the Israel (Novocure, Israel Institute of Technology, Weizmann Institute of Science and Elisha Medical Centre) indicate disruption of cancer cell replication by alternating electric fields. The effect is found to be selective, affecting only dividing cell lines and sparing the quiescent ones. The electric field arrests cell proliferation as well as destruction of cells while undergoing division. Just before a dividing cell splits in two, it briefly forms an hourglass shape before the two daughter cells pinch off, and this shape is particularly vulnerable to electricity. The current gets concentrated at the cell’s narrow waist, and at the very moment of division, the cell membrane is destroyed, and the cells disintegrate. The mechanism of action of the fields, researchers say, depends on disruption of the microtubules of the mitotic spindle and the electric forces resulting from focusing of the field in the dividing cells. The spindle is composed of cell components known as microtubules. The microtubules contain components that have high electric dipole moment, in which there is a large separation of opposite electric charges. Therefore, parts of the mitotic spindle are greatly influenced and apparently get disrupted by an electric field.
The cancer fighting abilities of this technique are being evaluated on human patients with recurrent glioblastoma multiforme (GBM); a fast growing, and difficult to treat form of brain cancer. This new technique exploits the difference between normal cells and cancer cells; it acts only on physically splitting cancer cells. The researchers are optimistic as they observed slower than usual progress in the development of brain tumour; in some cases even cell regression was observed. It is believed that this technique will work on all type of cancers and can possibly be applied to many different disease types. When the technique is applied in association with chemotherapy, its effect has been found more promising; the electric fields appear to make the cancer cells far more susceptible to chemotherapy without any additional increase in side effects and toxicity.