Cancer cells become ‘cannibals’ and eat other tumor cells to beat chemotherapy, study finds
- Researchers at Tulane University discovered one way breast cancer cells may survive chemotherapy
- Some cells stop multiplying when treated with chemo – but don’t die
- Instead, they go dormant but ‘eat’ neighboring cells
- This gives them a surplus of energy to fight off chemo’s effects
Some cancer cells turn to cannibalism to dodge the effects of chemotherapy, leaving them to come back after treatment, according to new research.
Eating neighboring cancer cells helps them survive – providing the energy to resist chemotherapy, say Tulane University scientists.
The discovery, found in breast cancer, could lead to new treatments for the disease and other cancers where recurrence is frequent.
Preventing recurrence could bring relief from both the disease itself and from patients’ anxieties.
SCROLL FOR VIDEO
A photo taken through a microscope shows how ‘cannibalistic’ cancer cells (green) engulfing neighboring ones (red) to give them energy, as discovered by Tulane University scientists
It’s a foremost concern of patients and their families – with the constant fear affecting quality of life.
About seven percent of sufferers have intrusive thoughts – misinterpreting even mild and unrelated symptoms.
Now a study has discovered how cells not destroyed by initial treatment come back – even stronger than before.
Instead of dying due to DNA damage caused by medications such as doxorubicin they just stop proliferating.
This is a dormant but metabolically active state known as senescence – meaning they are still alive.
It’s a particular problem in breast cancers that retain a normal copy of a gene called TP53.
These cells produce large amounts of inflammatory molecules and other factors that can promote a tumor’s regrowth.
Patients are prone to relapse and have poor survival rates.
Lead author Dr Crystal Tonnessen-Murray, of Tulane University in New Orleans, said: ‘Understanding the properties of these senescent cancer cells that allow their survival after chemotherapy treatment is extremely important.’
Her team found breast tumors that became sensecent after exposure to doxorubicin or other chemotherapy drugs often engulfed neighboring cancer cells.
This surprising behavior was observed both in cancer cells grown in the lab and in tumors growing in mice.
Lung and bone cancer cells are also capable of gobbling up their neighbors after becoming senescent, reports the Journal of Cell Biology.
The senescent cells triggered a group of genes that are normally active in white blood cells that destroy invading microbes or cellular debris.
After ‘eating’ their neighbors, they digested them by delivering them to cellular compartments called lysosomes.
Importantly, the researchers determined this process helps senescent cancer cells stay alive. They survived in culture for longer than those that didn’t.
It may provide them with the energy and materials they need to tough it out and produce the factors that fuel cancer relapse.
Lab head Dr James Jackson said: ‘Inhibiting this process may provide new therapeutic opportunities.
‘We know it’s the breast cancer patients with tumors that undergo TP53-mediated senescence in response to chemotherapy that have poor response and poor survival rates.’
Dr Tonnessen-Murray said the evidence from her laboratory and other studies that these tumors are more likely to have residual disease is compelling.
The senescent cells result in dramatically worse survival and the latest findings reveal for the first time how this happens.
Dr Tonnesen-Murray said: ‘Engulfment by senescent cells increased their survival and could provide building blocks that drive relapse.
‘These factors suggest immediate clinical relevance as senescence contributes to poor response and poor survival of breast cancer patients.’