600 million year old cancer gene discovered
15 February 2010
Biochemists and biologists at the University of Innsbruck,
Austria, have retraced the function of an important human cancer gene
600 million years back in time.
For the first time, they have identified the oncogene 'myc' in a
freshwater microorganism and have shown that this oncogene has
similar biochemical functions in ancestral metazoan and in humans.
The scientists published their findings in PNAS.
The myc gene plays an important role in the growth of organisms.
It produces a protein that acts as a gene regulator, which controls
the expression of up to 15 % of all human genes. This means that it
controls whether these genes are activated or deactivated.
A deregulation of the myc gene leads to uncontrolled cell
proliferation and to cancer; a deregulated myc gene occurs in about
30% of all human cancers.
Structure of a stem cell of an ancestral
metazoan.
The insert shows the activity of the cancer gene myc
in these cells.
Photo credit: University of Innsbruck.
“To get a better understanding of the deregulation process caused
by the oncogene, we would have to know which genes are regulated by
myc and which of these are important for cancers“, says Klaus Bister
from the Institute of Biochemistry at the University of Innsbruck.
Due to the complexity of the human organism, researchers use
simpler model systems for their experiments, whose results may then
be translated to humans. The Innsbruck scientific teams of Klaus
Bister, Markus Hartl and Bert Hobmayer have, for the first time,
identified the oncogene in a fresh water polyp (Hydra) and they have
shown that it has very similar functions when compared with humans.
Expression of a cancer gene (blue) in an
ancestral metazoan (the metazoan is about 2mm long). Photo credit: University of Innsbruck.
Oncogene found in stem cell
The two millimeter long Hydra were one of the first metazoans
that developed on the earth about 600 million years ago and can
still be found in many waters.
"It is amazing that we have been able to find this oncogene in
such a simple organism", says Hydra expert Hobmayer from the
Institute of Zoology. "Because the gene has been conserved in
evolution all the way from Hydra to humans, we are now able to
analyze biological and biochemical functions of the myc gene in
detail and draw conclusions for the human organism," adds Klaus
Bister.
The findings of the researchers from Innsbruck are particularly
interesting because they identified the oncogene in the stem cell
system of Hydra.
“Our experiments are bound to uncover interesting findings about
stem cells“, says Prof. Bister. The stem cells in the fresh water
polyp strongly indicate its regenerative ability — the polyp
completely regenerates within five days and, thus, it could
theoretically age ad infinitum.
Success for research focus
Scientists from the Institute of Biochemistry, Institute of
Zoology and the Institute of Organic Chemistry of the University of
Innsbruck cooperated in this research work, which is a research
focus of the University’s Centre for Molecular Biosciences (CMBI).
The results have been published at the online edition of
the journal Proceedings of the National Academy of Sciences
(PNAS). The researchers are supported by the Austrian Science Funds
(FWF).