Research could lead to new cancer assay, aid both dogs and humans

Bladder cancer is particularly common in some dog breeds, such as collies, sheepdogs and terriers, but is rarely diagnosed in animals before it has spread significantly. Some assays exist to detect it in humans, but they often have a high-number of false-positive identifications.

An improved assay to detect this serious disease much earlier in both animals and humans should be possible, scientists said, and may even become affordable enough that it could be used as an over-the-counter product to test urine, much like a human pregnancy test. Some of the work may also contribute to new therapies, they said.

"Research of this type should first help us develop a reliable assay for this cancer in dogs, and improve the chance the disease can be caught early enough that treatments are effective," said Shay Bracha, an assistant professor in the OSU College of Veterinary Medicine.

"However, this type of cancer is essentially the same in dogs and humans," Bracha said. "Dogs are an excellent model for human cancer research, and an assay that works with dogs should be directly relevant to creation of a similar assay for humans. We hope to make it inexpensive and convenient, something that people could use routinely to protect either the health of their pets or themselves."

The findings were published recently in Analytical Chemistry, a professional journal.

In this research, scientists used mass spectrometry and the evolving science of proteomics to identify 96 proteins that appear related to transitional cell carcinoma. This is a fairly common cancer in dogs, often as a result of exposure to pesticides, herbicides, and poor quality foods; and in humans is closely related to smoking.

Advanced-stage disease in both dogs and humans has a poor prognosis, as chemotherapy and radiation treatments are often ineffective. Average survival time is less than one year. Some assays exist to help identify the disease in humans but can produce false positive results, often as a result of urinary tract infections. And the biopsies used to make a definitive diagnosis require general anesthesia and also run the risk of actually spreading the disease.

The group of proteins identified in this research already have a 90 percent accuracy, and researchers say they hope to improve upon that with continued research.

However, researchers say that some of these proteins are more than just biomarkers of the disease -- they are part of the disease process. Identifying proteins that are integral to the spread of the cancer may allow new targets for intervention and cancer therapies, they said.