Cancer cells resistant to drugs can and do emerge at random by natural selection in a population. But they may also have tricks that speed up mutation and boost the chances of resistant strains appearing. And they seem able to generate dormant, spore-like forms, as Dictyostelium discoideum does, that produce “time-bomb” relapses even after cancer traces have disappeared in scans and blood tests.
So what’s to be done? Ben-Jacob and colleagues say that if we can crack the code of how cancer cells communicate, we might be able to subvert it. These cells seem to exchange chemical signals, including short strands of the nucleic acid RNA which is known to control genes. They can even genetically modify and reprogramme healthy cells by dispatching segments of DNA. The researchers think that it might be possible to turn this crosstalk of tumour cells against them, inducing the cells to die or split apart spontaneously.
Meanwhile, if we can figure out what triggers the “awakening” of dormant cancer cells, they might be tricked into revealing themselves at the wrong time, after the immune system has been boosted to destroy them in their vulnerable, newly aroused state. Ben-Jacob and colleagues suggest experiments that could probe how this switch from dormant to active cells comes about. Beyond this, perhaps we might commandeer harmless or even indigenous bacteria to act as spies and agent provocateurs, using their proven smartness to outwit and undermine that of cancer cells.
The “warfare” analogy in cancer treatment is widely overplayed and potentially misleading, but in this case it has some value. It is often said that the nature of war has changed over the past several decades: it’s no longer about armies, superior firepower, and battlefield strategy, but about grappling with a more diffuse foe – indeed one loosely organized into “cells” – by identifying and undermining channels of recruitment, communication and interaction. If it means anything to talk of a “war on cancer”, then perhaps here too we need to think about warfare in this new way.