The Naked (Mole Rat) Approach to Cancer Therapy
By Kalil Menezes, Biochemistry, 2018
Naked mole rats are the superstars of the rodent family with regards to health and longevity. Not only can they live to be over 30 years old (almost twice as long as any other member of the rodent family), but they also display a remarkable immunity to cancer. Until recently, this immunity remained a mystery to scientists, but a group lead by graduate student Xiao Tian from the University of Rochester has uncovered a molecular explanation for this phenomenon.
According to the study, the answer lies in the difference between the composition of the hyaluronan (HA) found in naked mole rats and the HA present in other mammals. HA is a polysaccharide (large, complex sugar) important in the structure of the cell membrane of many animals. What distinguishes the HA found in naked mole rats is that it has a molecular mass more than four times greater than the molecular mass of HA in any of its close relatives. The researchers in the study hypothesize that synthesizing HA at a higher molecular mass is evolutionarily advantageous because it increases the elasticity of the rats’ skin, allowing for easier travelling through the complex tunnel systems in which all naked mole rats live their lives. The fact that producing higher molecular mass HA also promotes longevity and cancer resistance is an additional, beneficial side effect.
In a previous study, researchers named the mechanism by which naked mole rats protect themselves from cancer early contact inhibition (ECI). ECI allows naked mole rat cells to stop the growth of other cells when they come into contact with one another. When a cell become cancerous, it begins to grow at a very fast rate, and the naked mole rat is the only organism that has developed the ECI mechanism which is able to halt a cancerous cell’s growth. Without this mechanism, all animals, including very close relatives to the naked mole rat, are more susceptible to malignant cell transformations.
Tian and his team included preliminary research in this report that suggests that human cells may be able to be modified so that they produce HA at a molecular mass similar to that of naked mole rats. This may one day provide a novel cancer treatment, but there is no suggestion that such a treatment would be available anytime soon. Nonetheless, this research reminds us that when searching for solutions to some of our greatest challenges, we do not need to reinvent the wheel. Billions of years of evolution have provided life with a diverse array of unique mechanisms and solutions to disease and sickness, and studying the animals that live among us is an excellent way to find solutions to some of our greatest challenges.
