Optogenetics as a Possible Cancer Treatment Technique

Author:  Julie Spitzer

Institution:  University of Wisconsin-Madison


Chemotherapy, hormone therapy, biological therapies including vaccines and antibodies, painkillers and other drug cocktails produce an array of unwanted side effects to an already ill person. Such side effects often make the disease feel as if it is dragging on longer and longer.

This is a paradox. Packing an ailing body with poison and calling it treatment, all while harming the already pained and sick individual more.

There are many treatment techniques for cancer, but many of them involve prescription drugs that are often harmful to the body. The side effects they produce can be worse than the actual cancer, ranging from hair loss to infertility to organ damage. Drug-free treatments and therapies are now being developed as alternatives to drug treatments.

In hopes of eventually developing new cancer treatment techniques, Michael Levin and his lab at Tufts University in Massachusetts are using optogenetics, which is a technique in which light is used to control cells, to reverse cancerous tumor growth in frogs.

This is the first time optogenetics has been used to target cancer cells. While this technique will likely not be used in human cells for quite some time, it paves the way for treatment methods that do not involve drug therapy.

“We hope we have a new strategy for reprogramming cell activity – we’re cracking the bioelectric code,” Levin told New Scientist.

Normal cancer treatment involves drugs that are often harmful to the body. The optogenetics technique involves injecting a gene into cells that make a light-sensitive protein. Next, they shine a laser on these cells to alter their behaviors. Different proteins will result in different behaviors. The ultimate goal in Levin’s experiment is to see if optogenetics will change the flow of ions into a cell to revert it to a non-dividing state.

Non-dividing states are ideal for cell communication. Nerve cells communicate through electrical signals. Ions travel into or out of the cell through channels in their membranes. This can trigger similar reactions in other surrounding cells. Often, the messages they transmit include information about their functions or movements. When cells divide to repair themselves, this communication is particularly important. Uncontrolled cell division, however, can lead to cancer. As a cell loses some of its negative charge, tumors spread easier. This is why a non-dividing state is ideal.  

Levin and his team of scientists studied frog embryos for this technique as they are easy to manipulate, according to Levin. They added a gene that predisposed the frog to cancer, as well as a gene that acted as the light activated channel. Once the embryos grew into tadpoles, they developed tumors. The tumors were similar to human tumors, with many of the same properties and behaviors.

After a laser had been shone at the tadpoles’ tumors, roughly a third of the tumors stopped developing.

“They’ve reprogrammed the cancer cells, by altering the electrical status of the cell. They are not cancer cells anymore,” Saverio Gentile of Loyola University Chicago told New Scientist. Essentially, the cells were reverted back to non-dividing states.

Breast and skin cancers may be most ideal for this kind of treatment because they are easy to target with a laser, according to Levin.

If this approach works on humans, it would place scientists closer to developing alternative drug-free treatment methods. Similarly, this method works differently than many cancer drugs, which commonly kill cells.

“Levin has shown that you don’t need to kill the cells – you can take them back to a normal state,” Gentile told New Scientist.

Reverting the cell back to its original state by hitting it with light may be the cancer treatment of the future. Optogenetics merely reverts the cell back to its normal, or non-dividing, state. Standard cancer drugs that target dividing cells are not 100 percent effective, and they often have harsh side effects. This drug-free treatment technique may be a healthier alternative to treating a volatile disease.