Canine Chromosomes Hold Clues to Cancer

By Tracey Peake  

Cancer researchers at North Carolina State University and the University of Minnesota have found that humans and dogs share more than friendship and companionship – they also share the same genetic basis for certain types of cancer. The researchers say their work involving purebred dogs, which have fewer genetic variations than humans, may allow them to identify cancer-associated genes more easily.

Dr. Matthew Breen, researcher with NC State's College of Veterinary Medicine and Center for Comparative Medicine and Translational Research, and Dr. Jaime Modiano, veterinarian and researcher with the University of Minnesota's College of Veterinary Medicine and Cancer Center, collaborated on this research. Their findings are published in the current issue of the journal Chromosome Research.

Genomes are divided into chromosomes, which act as nature's biological filing cabinets, with genes located in specific places. In the normal duplication process of cells, chromosomes can sometimes become rearranged or relocated. This rearrangement or relocation is called translocation. It can lead to a cell losing its normal function, becoming abnormal, and possibly developing into cancer.

Dr. Matthew Breen says dogs and humans have similar genomes.

In their research study, Breen and Modiano compared the chromosomes of humans diagnosed with the three blood and bone marrow cancers to the chromosomes of dogs diagnosed with the same cancers.

"Interestingly, we found that the same translocation of chromosomes happens in dogs as in humans for the three blood and bone marrow cancers we studied," Modiano says.

According to Breen and Modiano, dogs are good spontaneous research subjects because many of the modern breeds have developed over the past few hundred years using restricted gene pools. This selected breeding has preserved the genetics of a breed. It has also made some breeds more susceptible to certain cancers. These factors coupled with the high degree of similarity between the genomes of dogs and humans provided the researchers with an opportunity to compare the genomes and study the evolutionary genetic changes associated with cancer.

"Like ourselves, our pet dogs suffer from a wide range of spontaneous cancers," Breen says. "For thousands of years humans and dogs have shared a unique bond. In the 21st century this relationship is now strengthened to one with a solid biomedical basis; the genome of the dog may hold the keys to unlocking some of nature's most intriguing puzzles about cancer."

Links:

• Center for Comparative Medicine and Translational Research

• NC State College of Veterinary Medicine