Cellular ‘Cheaters’ Give Rise to Cancer

This unrestrained clumping on a cactus, called fasciation, is a cancerlike phenomenon.Credit

Maybe it was in “some warm little pond,”Charles Darwin speculated in 1871, that life on Earth began. A few simple chemicals sloshed together and formed complex molecules. These, over great stretches of time, joined in various combinations, eventually giving rise to the first living cell: a self-sustaining bag of chemistry capable of dividing and spawning copies of itself.

While scientists still debate the specifics, mostsubscribe to some version of what Darwin suggested — genesis as a fortuitous chemical happenstance. But the story of how living protoplasm emerged from lifeless matter may also help explain something darker: the origin ofcancer.

As the primordial cells mutated and evolved, ruthlessly competing for nutrients, some stumbled upon a different course. They cooperated instead, sharing resources and responsibilities and so giving rise to multicellular creatures — plants, animals and eventually us.Each of these collectives is held together by a delicate web of biological compromises. By surrendering some of its autonomy, each cell prospers with the whole.

But inevitably, there are cheaters: A cell breaks loose from the interlocking constraints and begins selfishly multiplying and expanding its territory, reverting to the free-for-all of Darwin’s pond. And so cancer begins.

Although we are getting better at preventing or controlling these rebellions, cancer is an inescapable consequence of multicellularity. A fascinating review, published last month in Philosophical Transactions B, shows how cancer and similar kinds of cellular cheating arise not only in mammals, birds, reptiles, fish, insects and other animals, but also in plants, fungi — in most, if not all, multicellular organisms.

In “Cancer Across the Tree of Life: Cooperation and Cheating in Multicellularity,” researchers at the Institute for Advanced Study in Berlin show how maverick cells in species after species engage in the kind of pathological behavior that can bring down any society.

In a healthy organism, a cell replicates only as frequently as needed to maintain the population and allow for modest growth. Cancer cells begin reproducing wildly, consuming more than their share of resources and spewing poisons that degrade the environment and reshape it to their own advantage.

Through a process called differentiation, normal cells specialize, becoming skin cells, nerve cells, bone cells and so forth. There is a division of labor. But cancer cells “dedifferentiate,” abandoning their assigned roles and pursuing a course beneficial only to themselves.

Under normal circumstances, a cell that goes berserk is quickly eliminated through a mechanism called programmed cell death, or cellular suicide. Cancer cells defeat this safeguard. They refuse to die.

No wonder cancer has become a metaphor for human excess — overpopulation and consumption, environmental pollution, the concentration of resources among a hyperacquisitive 1 percent.

The paper in Philosophical Transactions describes cancerlike phenomena in almost every niche of the biosphere.