Immune cells cast DNA ‘webs’ that may help ovarian cancer spread

Scientists have discovered that immune cells play a role in helping ovarian cancer cells spread in mice.

Researchers from the University of Texas found that ovarian cancer cells spread to new tissue in mice after being caught in DNA webs released by specialised immune cells, called neutrophils. 

Professor Victoria Sanz-Moreno, a cancer biology expert at Barts Cancer Institute says the research reinforces the idea that certain immune cells can play a role in stemming the spread of cancer.

“Previous studies have found a role for neutrophils in the spread of breast and prostate cancer to the lung, and now ovarian cancer can be added to this list,” said Sanz-Moreno.

“But the research has mainly looked in mice, and so the findings would need to be confirmed in more patient samples.”

It’s not yet known if these immune cells play the same supporting role to ovarian cancer cells in people.

Preventing cancer spread

Ovarian cancer is the fifth highest cause of cancer death in women. Advanced cases are characterised by cancer cells spreading to a fatty tissue near the stomach that contains a high number of immune cells, called the omentum.

To help the body fight off infections in the abdomen, these immune cells release DNA webs, called neutrophil extracellular traps (NETs), to catch invading microbes.

The new research, published in the Journal of Experimental Medicine, found that ovarian cancer cells release signals that cause more immune cells to gather in the omentum and release their DNA webs. These help to trap ovarian cancer cells that broken away from the original tumour and entered the bloodstream, helping them to colonise the omentum.

The US scientists found that preventing immune cells from forming the webs reduced the spread of cancer cells into the omentum of mice.

“What’s interesting is that blocking the formation of NETs in mice reduced ovarian cancer spread, shedding some hope for developing new treatments,” said Sanz-Moreno.

The omentum is often surgically removed from patients during the early stages of the cancer, to stop cancer cells from spreading into the tissue. This new research suggests that stopping DNA webs being released could help to reduce ovarian cancer spread without the need to remove this tissue.