Scientists from La Trobe University have uncovered how one of the oldest and simplest animals on earth sacrifices its own cells for the benefit of the organism

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 unexpected insights into the development of a new generation of cancer drugs.

The international research project, co-led by Professor Marc Kvansakul from the La Trobe Institute for Molecular Science and published in Science Advances, used the Australian Synchrotron to characterise and image this ancient mechanism of cell self-sacrifice at the atomic level.

Professor Kvansakul said researchers were able to decipher, for the first time, the origins of cell death in this 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,” Professor Kvansakul said.

“Trichoplax Adhaerens is the living ancestor of one of the first multicellular animals on earth and still found all around the world, including Australia.

“For multicellular animals like the Trichoplax Adhaerens to survive, they needed new ways to repair a whole tissue made of multiple cells. Our study describes how these organisms evolved to use apoptosis, a survival tactic known as cell death, to ‘take a hit for the team’ and sacrifice themselves for the benefit of the whole organism’s health.”

Apoptosis is a self-sacrifice mechanism that allows unhealthy cells to remove themselves from the population, making way for new healthy cells. This same system is also present in humans.

Study co-author, La Trobe’s Professor Patrick Humbert, said apoptosis is crucial to preventing human cancer and autoimmune diseases.

“By understanding how this self-sacrifice switch first appeared many millions of years ago, this curious little sea creature has provided us with new ideas for the design of the next generation of cancer drugs based around mimicking these ancient molecules,” Professor Humbert said.

This international research team included scientists from France (Lyon, Bordeaux) and Germany (Hannover). It was partly funded by a La Trobe University Research Focus Area Seed Grant to Professors Kvansakul and Humbert.