'Cell wars' that could boost cancer treatments

New lease of hope

Researchers at the University College London found for the first time the gladiatorial contests between normal cells and tumours in mammals and the losers were killed by a process of “induced biological suicide” called apoptosis.

If the balance is in favour of the cancer cells, they will cut a swathe through the healthy cells around them and spread. But, if the healthy cells get the upper hand, they will surround and eliminate the cancer cells, the scientists found.

Although such “cell wars” have been seen before in fruit flies, scientists did not know until now that they also occurred in mammals — presumably including humans.
In future, experts believe, it may be possible to “tip the balance” so that healthy cells win in the struggle with cancer, the “Daily Mail” reported.

Dr Yasuyuki Fujita, who led the research, said: “This is the first time that we have seen cancer cells being killed simply by being surrounded by healthy cells.

“If we can build on this knowledge and improve our understanding of how this happens, in the future we may be able to find a way to enhance this ability and develop a totally new way of preventing and treating cancer.” The research, reported in the journal Public Library of Science (PLoS) Biology, has implications for treating common solid tumours of the sort that form in the breast, prostate, lung, stomach and bowel, the researchers said.

In experiments on laboratory-cultured dog kidney cells, the scientists identified two key proteins that helped determine the outcome of the contest between ‘good’ and ‘bad’ cells.

They found that cancer cells that lacked the proteins called Lgl and Mahjong were likely to end up as the losers. The mutant cells then underwent cell suicide when they were surrounded by cells in which the proteins were active.

In cells without Mahjong, over-producing Lgl did not prevent apoptosis. But the same was not true in reverse - cells missing Lgl did not self-destruct when they had a surfeit of Mahjong, the scientists found.

The effects were thought to involve a well-known cell-signalling pathway called JNK, which is known to be linked to cancer. JNK signalling was raised in both Lgl and Mahjong mutants.

The scientists wrote: “The demonstration of cell competition in mammalian tissues is an exciting step forward into understanding the interaction between carcinogenic cells and their surrounds.