A team of veterinary and human medical researchers at the University of California, Davis identified a protein that appears to play a key role in the formation of lymphoma and other tumors by inhibiting a tumor-suppressing gene.
In a study funded in part by the National Institutes for Health, researchers found the protein may be a potential target for diagnosing and treating lymphoma in animals and humans.
“Results from this study suggest that a gene known as RNPC1 may play a key role in the development of lymphoma,” said Xinbin Chen, a veterinary oncologist and lead researcher in the study with appointments in the UC Davis School of Veterinary Medicine and the UC Davis School of Medicine.
Lymphoma occurs spontaneously in dogs, representing 6 percent of all canine cancers.
In their study, UC Davis researchers examined several types of human cancer cells as well as cells isolated from a mouse embryo, known as embryonic mouse fibroblasts. The team showed that the RNPC1 gene inhibited the activity of the p53 gene and reduced levels of the p53 protein in these cells. Conversely, p53 protein levels increased when RNPC1 was out of the picture.
The researchers examined the expression of RNPC1 in spontaneously occurring dog lymphomas and in noncancerous canine lymph node tissue. Data from the dog lymphoma tests showed that the RNPC1 gene is frequently overactive in dog lymphomas and may play a role in the formation of lymphomas by inactivating the p53 gene.
“Our findings are consistent with data from other cancer studies, which showed that RNPC1 is highly expressed in human cancers,” Dr. Chen said. “This suggests that further studies are needed to analyze the expression of patterns of both RNPC1 and p53 in human tumor tissues.”
Chen said that because dogs and humans are vulnerable to lymphoma and similar gene processes may be at work in each species, the dog may serve both as a valuable sentinel for environmental causes of the disease and as a model for exploring its causes and treatments.