Cancer cells cannibalise healthy cells after chemotherapy
Cancerous cells will consume nearby cells in order to regrow after chemotherapy, new research suggests. This ‘cannibalism’ was discovered by scientists at the Tulane University School of Medicine in New Orleans, who identified whole cells engulfed within cancer cells in mice.
Chemotherapy drugs target the DNA of a cancer cell, the destruction of which, in most cases, causes the cell to die.
But certain breast cancer cells are only stunned by chemotherapy, lying dormant instead of dead, in a state referred to as ‘senescence’. These senescent cancer cells can then give rise to relapse tumours, and as such the survival rates of these breast cancers are low.
James Jackson, one of the researchers on the study, had previously identified that breast cancers with a gene called TP53 responded to chemotherapy with senescence. The team wanted to better understand how the senescent cells were able to regrow even after entering their dormant state.
“Understanding the properties of these senescent cancer cells that allow their survival after chemotherapy treatment is extremely important,” said Crystal A. Tonnessen-Murray, who took part in the research.
In the lab, researchers saw whole tumour cells being engulfed by the senescent cancer cells. Once ‘eaten’, the cell would be digested, providing the cancer with the nutrients and energy it needed to regrow into a tumour.
These Hannibal cells survived longer than those that did not cannibalise their neighbouring cells. The cannibalism was found in cells kept in cultures, as well as in tumours grown in mice. The researchers also found lung and bone cancers were capable of engulfing nearby cells.
“Inhibiting this process may provide new therapeutic opportunities, because we know that it is the breast cancer patients with tumours that undergo TP53-mediated senescence in response to chemotherapy that have poor response and poor survival rates,” said Jackson.