The researchers believe the newly identified protein may be a potential target for diagnosing and treating lymphoma in humans and animals.
Lymphoma refers to a group of blood cancers that start in the lymphatic system, which play a vital role in the body’s immune system.
Lymphoma occurs spontaneously in dogs, representing 6 percent of all canine cancers, and is similar to lymphoma in humans.
The Cancer-Suppressing Gene
For decades, researchers have known that the p53 gene plays an important role in suppressing cancer. This tumor suppressor gene checks cells’ DNA for mutations that might cause cancer and then stops cell growth until the mutations can be repaired. If the mutations can’t be repaired, p53 triggers cell death to prevent cancer from developing.
However, if something goes awry, p53 can mutate and produce undesirable proteins, and studies have shown that mutated proteins produced by p53 are present in 60 percent of all cancerous human tumors. When the p53 gene and the process it controls are damaged, cancer often occurs.
Because defects in p53 are so common in human and animal cancers, researchers are interested in the activity of the gene. The UC Davis researchers suspected the RNPC1 gene, which regulates how other genes produce proteins, might play a role in causing lymphomas by activating the p53 gene.
In their new study, the researchers examined several types of human cancer cells and found that the RNPC1 gene inhibited the activity of the p53 gene. Conversely, p53 protein levels increased when RNPC1 was not present. Tests showed the RNPC1 gene is frequently overactive in dog lymphomas and may play a role in the formation of lymphomas by inactivating the p53 gene.
This new research may have applications for treating and curing cancer in both humans and dogs, according to Xinbin Chen, a veterinary oncologist, who led the study.
Chen noted that because dogs and humans are both vulnerable to lymphoma, and similar gene processes may be at work in each species, dogs may serve both as a valuable sentinel for environmental causes of the disease and as a model for exploring its causes and treatments.
All of the dogs in the study were patients at UC Davis Veterinary Medical Teaching Hospital, and all of the dog lymph node samples were provided with the permission of the owners.
By Sarah Zumhofe