The same chemistry that led to the successful cloning of a mule at the University of Idaho this spring may shed new light on behaviors of specific cancers in humans.

UI Professor of Animal and Veterinary Science Gordon Woods, leader of the UI-Utah State University team that produced the first mule clone, believes chemical changes necessary for successful cloning provide new insights into cell growth.

For Woods, also director of the UI’s Northwest Equine Reproduction Laboratory, the horse provides a novel and promising model for studying cancer metastasis and other age-onset diseases in humans.

Mortality rate: horses 8, humans 24

“The mortality rate for horses with metastatic cancer is 8 percent for all cancers and 0 percent for prostate cancer,” says Woods. By comparison, the mortality rate in humans is about 24 percent for all cancers, of which 13 to 14 percent is for prostate cancer. Contrasts and similarities between humans and horses at the cellular level provide a number of insights about how certain body chemicals affect both normal and abnormal cell activity.”

A key is the relationship between amounts of calcium within and outside each cell. Equines have a lower amount of intracellular calcium than humans and a correspondingly slower rate of cell activity.

When his team first started cloning work in 1998, only a few implants resulted in pregnancies, and none of those progressed past four-weeks. Based on new information provided by Cancer2, a private corporation founded by Woods, the scientists agreed part of the problem was the relatively slow rate of cell activity in equines. That slow rate may be why in vitro fertilization doesn’t work in horses and why their cancer mortality rate is so low.

In July 2001 the team supplemented calcium amounts in implanted clones and “saw a sevenfold increase in our week-two pregnancy rates,” Woods said. “We produced 19 pregnancies; the first baby has been born, and two more pregnancies are in advanced stages.”

The team concludes this increase in calcium within implanted clone cells directly impacts cell division speed.

Understanding the role of calcium in equine cell activity was a direct result of work conducted by Cancer2. The Idaho-based company has gifted the intellectual property to the University of Idaho.

“Electrifying similarities”

“There are electrifying similarities between cancer metastasis and embryo division,” said Woods. In humans with metastasizing cancer, the amount of intracellular calcium is higher than normal.

“We’ve identified a suppressor of intracellular calcium and believe its deficiency is the root cause of abnormally high intracellular calcium,” adds Woods.

Now his team is working toward critical testing of the effects of suppressor deficiencies in human clinical trials.