Cancer cells use a method to survive life-threatening injuries. They eat a portion of the surrounding membrane. A team of Danish researchers has shown this for the first-time.
The new research reveals a new way cancer cells can repair damage that could otherwise cause death.
The cell membrane is the skin of cells in both cancer and normal cells. The membrane's damage can cause serious injury and even death. Cells' interior is fluid and, if there is a hole in the membrane, it will float out and then die -- much like a hole in an inflatable water balloon.
Damage to the cell membrane needs to be repaired quickly. A team of Danish researchers has now discovered that cancer cells use a technique known as macropinocytosis. This technique is well-known and used in other settings. It involves cancer cells pulling the intact cell membrane over the damaged area, sealing the hole within minutes. The damaged cell membrane is then separated into smaller spheres. These spheres are transported to the cells' "stomach" -- the so-called Lysosomes -- where they are further broken down.
The laser used by the researchers to damage the membranes of cancer cells was used in the laboratory. It shoots tiny holes through the membrane and triggers macropinocytosis. They can see that the cancer cells can't repair the damage if they are unable to form small membrane spheres.
"Our research has provided very basic information about how cancer cells survive. Our experiments have shown that cancer cells can die if this process is blocked. This points to macropinocytosis being a potential target for future treatments. It's a long-term view, but it's interesting," said Jesper Nylandsted, a group leader at the Danish Cancer Society Research Center and University of Copenhagen. Nylandsted has been involved in the new research for years and has studied how cancer cells repair their membranes.
Possibility to recycle
Spreading cancer in the body is one of the most serious consequences of cancer. The disease can spread to new areas of the body and is more difficult to treat. This usually requires more intensive treatment. They are also more likely to cause damage to their membranes when they spread through the body's tissues.
The Danish Cancer Society has previously demonstrated that cancer cells can be repaired using a different technique, which is to tie off the damaged area, much like a lizard throwing its tail.
The laboratory experiments could show that macropinocytosis is used by aggressive cancer cells. The cancer cells have the ability to reuse damaged membranes after they are destroyed in the lysosomes. Because cancer cells divide often, this type of recycling is beneficial.
Although the researchers have published their new findings, it is not the end of their work. Stine Lauritzen, a postdoc in the research team, explains this:
"We are continuing to investigate how cancer cells protect and preserve their membranes. It is particularly interesting to observe what happens after the membrane has been closed, especially in relation to macropinocytosis. The first patching can be a little rough so we recommend that you do a more extensive repair to the membrane. She says it could be another weakness in cancer cells and that is something she wants to investigate more.