The value of cellular self-sacrifice

Scientists have uncovered how one of the oldest and simplest animals on Earth sacrifices its own cells for the benefit of the organism.

They say the similarities between altruistic cell death in Trichoplax adhaerens – a tiny marine invertebrate that resembles an irregular hairy plate – and a similar but defective process in human cancer cells provides insights into the development of a new generation of cancer drugs.

The international study, published in the journal Science Advances, used the Australian Synchrotron to characterise and image this ancient mechanism of cell self-sacrifice at the atomic level.

Research co-leader Marc Kvansakul, from Australia’s La Trobe University, says the team was able to decipher, for the first time, the origins of cell death in the small marine invertebrate.

“A major evolutionary advance at the dawn of prehistoric times was the gigantic leap from an organism with a single cell to an organism with multiple cells, enabling the creation of the first animal,” he says.

“Trichoplax Adhaerens is the living ancestor of one of the first multicellular animals on earth and still found all around the world…”

For multicellular animals to survive, the researchers say, they needed new ways to repair a whole tissue made of multiple cells.

The new study describes how these organisms evolved to use apoptosis, a survival tactic known as cell death, to essentially sacrifice themselves for the benefit of the whole organism’s health. The same system is also present in humans.

Kvansakul’s colleague and a study co-author, Patrick Humbert, says apoptosis is crucial to preventing human cancer and autoimmune diseases, and the study has provided new ideas for the design of cancer drugs based around mimicking the ancient molecules.

This research team also included scientists from France and Germany.