Scientists Plan to Use Electric Fields to Restrain Cancer Growth

In the August issue of Physics Today, scientists report on a novel electrical method to stem the growth and uncontrolled division of cancer cells.

The research is based on one of the key properties of cancer cells: their unfettered ability to divide and grow without restraint. In this context, bioelectrical research experts are now focusing their efforts in preventing malignant cell division through the use of electrical impulses.

Under normal conditions, cells have self-regulating mechanisms that keeps their growth in check. This process is variable depending on the type and needs of each cell. Skin cells, for example, divide every 30 days, but can accelerate their growth in response to a wound or a new external stimulus.

This growth mechanism is linked to a cycle that is present in all cells. If more cells are needed within a specific area, the cycle (of each cell) will advance into a 'division phase' and the cells will start to divide. Otherwise, cells will remain in a quiescent (inactive) state until there is an increase demand. Most cancer cells, however, lose this regulatory balance and stay in the division phase regardless of their external environment.

To try to exploit the mechanisms within the cell cycle, Yoram Paltin and colleagues at the Technion-Israel Insitute of Technology in Haifa, started using low-intensity (1-2 V/cm) electrical fields on tumor cells. These low-power fields (in the hundreds of kilohertz) were previously believed only to heat the cells without causing any other alterations. Palti's team, however, discovered that these electrical impulses could significantly diminish the growth of tumors when tested in cell cultures and animals.

Their prevailing theory is that the small electrical fields impede the assembly of the mitotic spindle. This is a network of fibers that is used by chromosomes to navigate to their new daughter cells during the cell division process. It is believed that the units of this network (tubulin dimmers) have specific polarities that are affected by the electrical current.