Mouse Studies Break New Ground in Fighting Breast Cancer
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October is Breast Cancer Awareness month, and while breast cancer incidence rates and death rates have both been declining for years, breast cancer is still the second-most commonly diagnosed cancer among American women, and has the second-highest death rates.
Fortunately, scientists all over the world are working to understand how it works and find a cure, many of them using mouse models in their research.
Stopping the Spread of Breast Cancer Tumors
Inflammation is usually a sign that something is amiss, but a new study has found evidence that inflammation can actually be beneficial when it comes to breast cancer.
Researchers using mouse models in the Division of Hematology at Brigham and Women’s Hospital have discovered that inflammation may help prevent the growth of breast cancer tumor cells that have spread to other sites in the body—an important discovery since 30% of breast cancer patients experience metastasis.
Secondary tumors are started when ‘breakaway cells’ leave the primary tumor to establish new tumors elsewhere in the body. In these cases the primary tumor has an inflammatory response that sends immune cells to the sites where breakaway cells have settled and freezes them, which stops them from forming new tumors.
“Our findings flip the current thinking on its head,” said Sandra McAllister, PhD, who is the co-author of the study. “Our work suggests that, while inflammation can help tumor cells escape and land elsewhere in the body, if inflammation is there when they land, it keeps the cells in check. When inflammation is suppressed, the cells grow out.”
“This new research has yielded that rare thing,” said co-author Dr. Christine Chaffer of the Garvan Institute of Medical Research in Australia, “a clue from the cancer itself about new possibilities to fight its spread. Our goal is to work out how we can mimic this ‘freezing’ of secondary cancers, so that one day we might influence all breast cancers to keep their secondary tumors in check.”
Identifying & Removing a Breast-Cancer-Causing Enzyme
Researchers at Virginia Commonwealth University's Massey Cancer Center in Richmond have identified an enzyme that, when removed, can stop the growth of breast cancer cells.
The enzyme, called cyclophilin A (CypA), is involved in the production of breast milk, and has now also been connected to the growth of breast cancer tumors.
When the researchers tried deleting CypA in mouse models, it slowed down or stopped the growth of breast cancer cells in the rodents. Removal of the CypA enzyme did not affect the mice’s ability to express milk.
The authors of the study are hopeful that the discovery may lead to more targeted therapies for breast cancer.
A Dietary Supplement with Hidden Breast-Cancer-Fighting Properties
Some sports drinks may have a surprise benefit beyond helping people recover from their workouts—the ability to reduce the growth of breast cancer tumors.
Studies led by researchers at the Mayo Clinic found that a dietary supplement added to sports drinks—cyclocreatine—can reduce the growth of drug-resistant HER2-positive breast cancer tumors in mice.
HER2-positive breast cancers tend to be more aggressive than other types of breast cancers. While drugs such as trastuzumab have been shown to improve outcomes for some patients with HER2-positive breast cancer, tumors can develop a resistance to the drug.
In the new study, mice with trastuzumab-resistant HER2 positive tumors that were treated with cyclocreatine saw reduced cancer growth with no toxicity.
A New Tool in Fighting Triple-Negative Breast Cancer
In triple-negative breast cancer, breast cancer cells test negative for estrogen receptors, progesterone receptors, and HER2, which means they do not respond to hormone therapy or HER2-targted treatments.
Triple-negative breast cancers, which account for 10%-20% of all breast cancers, have a lower five-year survival rate, are more likely to spread to other sites in the body, and have a higher recurrence rate after treatment, so doctors are eager to find new ways to treat it.
A possible solution has been discovered by chemists at Hong Kong Baptist University, who discovered that the metal compound rhodium can be used to suppress the growth of triple-negative breast cancer tumors in mice. According to the researchers, the new compound was less toxic in vivo compared with two well-known clinical anti-cancer drugs—cisplatin and doxorubicin.