A new University of Michigan study found the combination of traditional chemotherapy drug, cisplatin, with an experimental drug destroys a rare type of salivary gland tumor and prevents it from reoccurring within 300 days after treatment. The study was conducted on mice as well as primary human adenoid cystic carcinoma cells in the Nör Lab at the School of Dentistry.
The salivary gland tumor is a product of ACC, which is a rare cancer of the salivary glands and of surrounding head and neck areas. The cancer typically arises in adulthood and affects about 3,000 to 4,000 people per year. Treatment of advanced ACC with traditional chemotherapy has only had limited success.
LSA sophomore Leo Thompson, a pre-dental student, found the results to be inspiring for the future of ACC cancer care. As someone looking forward to attending dental school, Thompson was very interested in the study’s results.
“The study gives a promising outlook towards defeating ACC,” Thompson said. “Hopefully the prevention of recurrence can be achieved in the long term, and we see the treatment curing humans in a few years.”
ACC is known to grow slowly; however, it is often discovered in the late, aggressive stages. There is no cure for the cancer, and the tumor cells have a tendency to reappear later at their original site. This is a serious concern for physicians treating ACC patients. The cancer tends to spread to other parts of the body, especially the lungs, leading to additional life-threatening issues.
The study found mice treated with the experimental drug, MI-773, combined with cisplatin had shrunken tumors, ranging from being the size of an acorn to being nonexistent. Next, the acorn-sized tumors were removed from the mice and subjects continued to take MI-773 for another month. This treatment group eradicated tumor recurrences for more than 300 days.
On the other hand, 62.5 percent of control mice that only received surgical removal of the tumor saw recurrences. These results suggest this combination treatment may be more effective in treating human patients with ACC.
LSA senior Samantha Sciancalepore, a pre-dental student, said she was eager to see what the future holds for this kind of research.
“I think it’s really (admirable) that this research is being done on our campus,” she said. “I feel lucky that we have the tools to research solutions to cancer, especially in facial tumors. As a dentist, I think one of your ultimate goals is to provide help and comfort to your patients, and I think this sort of conclusive research is exactly what they need to advance.”
Most cancers attempt to block the cancer-fighting protein p53 so the protein can no longer kill the cancer. However, this is not the case with ACC tumors, which tend to leave p53 untouched. This makes MI-773 suitable for treating ACC, which works by preventing the tumor from attacking p53.
Primary investigator Jacques Nör, professor of dentistry, otolaryngology and biomedical engineering, explained in an interview with Michigan News the importance of MI-773 in staving off the cancer. MI-773 stops the interaction between cancer cells and p53, which might otherwise be fatal for the patient.
“This drug MI-773 prevents that interaction, so p53 can induce cell death,” Nör said. “In this study, when researchers activated p53 in mice with salivary gland cancer, the cancer stem cells died.”
MI-773 was discovered by study co-author Shaomeng Wang, professor of medicine, pharmacology and medical chemistry. The drug is licensed to Sanofi, a French pharmaceutical company known to engage in the research and development aspects of medicine.
A major drawback of the study is that it was conducted over a 300-day period, whereas studies show ACC tumors tend to reappear after 10 years.