Discovery of a primordial cancer in a primitive animal

The research team led by the evolutionary biologist Professor Thomas Bosch from the Zoological Institute of Kiel University have now achieved an impressive understanding of the roots of cancer.

Bosch has been investigating stem cells and the regulation of tissue growth in Hydra, a phylogenetic old polyp, for many years. "Now we have discovered tumour-bearing polyps in two different species of Hydra, an organism very similar to corals", emphasises Bosch regarding the first result of the new study. This provides proof that tumours indeed exist in primitive and evolutionary old animals.

The team also tracked down the cellular cause of the tumours along the entire body axis. For the first time they were able to show that the stem cells, which are programmed for sex differentiation, accumulate in large quantities and are not removed naturally by programmed cell death. Interestingly, these tumours affect only female Hydra polyps and resemble ovarian cancers in humans.

"When undertaking more detailed molecular analyses of the tumours we found a gene that becomes active dramatically in tumour tissue and that normally prevents the programmed cell death", explains Alexander Klimovich, a scholarship student at the Alexander-von-Humboldt Foundation at the Zoological Institute of Kiel University and co-lead author of the current study regarding the second finding of the study. The third finding of the scientists was to show that tumour cells are invasive. This means that if tumour cells are introduced into a healthy organism, they can trigger tumour growth there.

According to the research team led by Bosch, the findings of primordial tumours in Hydra are a breakthrough step in that direction: "Our research reconfirms that primordial animals such as Hydra polyps provide an enormous amount of information to help us understand such complex problems as 'cancer'.