“Big Bang” cancer growth

In the second of our guest blog posts, Dr Andrea Sottoriva describes how a comparison between the expanding universe and the growth of cancers led him to formulate his “Big Bang” theory of tumour growth – a model with novel treatment implications.

Image from Physicsworld.com

Image from Physicsworld.com

In 1929 Edward Hubble, sitting at the top of Mount Wilson, observed that stars and galaxies are moving away from each other. He reasoned that, if stars are continuously moving apart, they must have been closer together at earlier times, to the point that at the very beginning the entire cosmos would have been compressed into a tiny space. This led to the hypothesis that our universe could have originated from a cosmic explosion, “the Big Bang”. But where are the remnants of such an enormous blast? Surely such a phenomenon must have left its mark in today’s universe? In fact, it did. Radio astronomers, Arno Penzias and Robert Wilson, detected the Cosmic Microwave Background radiation in 1964. This is the glow of the Big Bang explosion, it permeates the whole universe at an almost uniform -270 degrees Celsius.

So, what does all of this have to do with cancer? Tumours are large collections of cancer cells that grow out of control and invade healthy tissue, thus becoming life-threatening. Like the universe, cancers expand from something tiny, a single tiny cell. By sequencing the DNA of tumours we discovered that each cancer is unique to a single patient, in the same way that the universe is unique, as far as we can tell.

Continue reading

Convergence in tumour evolution: singing the same tune

© Katerina Kousalova/ Dreamstime.com/ License: Royalty Free

© Katerina Kousalova/ Dreamstime.com/ License: Royalty Free

Cancer clone evolution, just like evolutionary speciation, is characterised by an extraordinary diversity of descendants derived from a common ancestor. Yet, paradoxically, some evolutionary trajectories are convergent on a common phenotype.

The classical examples of convergency from evolutionary biology include eyes, wings, big brains and social structures, all of which have been ‘invented’ multiple times, independently. We find that their genetic, developmental and biochemical details are often distinct but in the end, the functional result is very similar 1.

Continue reading