A tumor occurs when a cell starts rapidly replicating in an uncontrolled fashion. In some cancers in the body, as the tumor forms, the normal surrounding cells are just pushed to the side. While the patient may succumb to cancer because it metastasizes to too many areas, an individual tumor site may be amenable to complete surgical removal. The problem with brain cancer is that complete surgical removal is rarely achievable. The tumors seem to grow in an infiltrative manner, weaving amongst normal brain cells. A simple analogy is an octopus: there is a central portion of the tumor but also many tentacles of tumor cells extending out.
A recent article in Nature has given some new insight into the unique growth pattern of brain cancer. A Stanford research group discovered that about 5-10% of tumor cells hijack electrical signals from normal brain cells to drive their growth. This vampire-like activity, sucking the energy from the necks of normal brain cells, can be seen with an electron microscope.
This same Stanford group also discovered in 2017 that normal brain cells naturally produce a chemical called “neuroligin-3”, which may be responsible for a normal cell’s integration with a brain cancer cell. Neuroligin-3 maybe like pollen for a bee. This group found that when brain cancer cells are transplanted into genetically altered mice without neuroligin-3, there is no growth of the tumor. Unfortunately, knocking-out this gene in humans has not yet been accomplished.
A more readily available and novel treatment option may be interrupting these connections from the electrical perspective. Existing anti-epilepsy medications work by altering electrical-signaling pathways. One of these, perampanel, has already been showed to slow the growth of pediatric gliomas by about 50%.