E-Paper
Mice hibernation gives hope in cancer fight
Scientists have succeeded in placing mice in a state of reversible metabolic hibernation, sparking hopes of inducing the same in humans and leading to new ways to treat cancer.
Scientists have succeeded in placing mice in a state of reversible metabolic hibernation, sparking hopes of inducing the same in humans and leading to new ways to treat cancer.
The landmark first demonstration of "hibernation on demand" in a mammal could also prevent death from insufficient blood supply to organs and help astronauts while travelling to space, reports Internet portal Astrobiology.
In the experiment, scientists at the US-based Fred Hutchinson Cancer Research Centre were reported inducing a state of clinical torpor in mice for up to six hours before restoring their normal metabolic function and activity.
In addition to mice, they have demonstrated the ability to metabolically arrest - and subsequently re-animate - in yeast and worms as well as the embryos of fruit flies and zebra fish.
"We are, in essence, temporarily converting mice from warm-blooded to cold-blooded creatures, which is exactly the same thing that happens naturally when mammals hibernate," lead investigator Mark Roth said.
"We think this may be a latent ability that all mammals have - potentially even humans - and we're just harnessing it and turning it on and off, inducing a state of hibernation on demand."
During a hibernation-like state, cellular activity slows to a near standstill, which reduces dramatically an organism's need for oxygen.
If such temporary metabolic inactivity - and subsequent freedom from oxygen dependence - could be replicated in humans, it could help buy time for critically ill patients on organ-transplant lists and in operating rooms, emergency wards and battlefields, Roth said.
Clinical applications of induced metabolic hibernation could include treating severe blood-loss injury, hypothermia, malignant fever, cardiac arrest and stroke.
Potential medical benefits also include improving cancer treatment by allowing patients to tolerate higher radiation doses without damaging healthy tissue, extending the time organs and tissues could be preserved outside the body prior to transplantation, accelerating wound healing in diabetics etc.
As of now, since cancer cells aren't dependent on oxygen to grow, they are more resistant to radiation than surrounding healthy cells, which need oxygen to live, Roth explained.
In their demonstration, scientists placed the mice in a chamber filled with normal room air laced with 80 parts per million of hydrogen sulfide - a chemical normally produced in humans and animals and believed to help regulate body temperature and metabolic activity.
Within minutes of breathing the hydrogen sulfide and room-air cocktail, the mice stopped moving and appeared to lose consciousness.
Their respiration dropped from the normal 120 breaths per minute to fewer than 10 breaths per minute and their core temperature dropped from the normal 37 degrees Celsius to as low as 11 degrees Celsius depending on the controlled ambient temperature within the chamber.
