The rapid annual regrowth of deer antlers is down to a combination of cancer-linked genes and tight regulation of them by tumour-suppressing genes, according to a new study. The results may offer a new avenue for cancer treatment research in humans.
'Deer antlers [are] using essentially a controlled form of bone cancer growth,' Dr Edward Davis, from the University of Oregon in the USA, who was not involved in the study, told Science magazine.
Deer and other ruminants are the only mammals that can rapidly regenerate bone to grow antlers and horns, achieving rates of up to an inch (2.5cm) a day. To find the genes responsible for this prolific growth, an international team lead by Chinese scientists sequenced 44 species of ruminants.
The researchers found that the gene-expression profile of growing antlers was more like bone cancer than normal bone tissue. However, in contrast to bone cancer, where tumours grow unchecked, antler growth appeared to be tightly regulated.
Some of the genes involved were related to a well-known tumour-suppressor gene, p53. One such gene, called PML, is expressed during antler growth and activates p53 to stop cell growth. Another, ADAMTS18, belongs to a family of genes also known to inhibit cancer cell growth. Together these cancer-suppressing genes help to keep the rapid bone growth in check.
This regulation of antler growth by tumour-suppressing genes may help protect ruminants against cancer, suggests senior author Dr Qiang Qiu, a geneticist from Northwestern Polytechnical University in Xi'an, China. It may also explain why ruminants in zoos develop cancer at rates five times lower than other mammals. It is hoped that understanding these genes further in ruminants could lead to developments in cancer research in humans.
'The significance [of the research] will be huge,' Dr Yunzhi Peter Yang of Stanford University told Wired magazine. Dr Yang was not involved in the ruminant genome project, but reviewed the research, which was published in Science, and wrote a perspective article on it in the same issue of the journal. 'Remember that a lot of genes that exist in cows and goats and deer and sheep also exist in humans.'