Researchers at the Winship Cancer Institute of Emory University have found that the hormone adiponectin may reduce the ability of cancer cells to migrate from the breast and invade other tissues. Adiponectin appears to protect against the effects of obesity on metabolism, the heart and blood vessels, the researchers say.
Fat cells make up most of the breast tissue, and some of the hormones produced by fat cells can have tumor-stimulating effects. Previous studies have shown that women with high body mass index (highest fifth) have double the death rate from breast cancer compared to those in the lowest fifth.
The key to translating this research for patient care lies in finding a way to increase a person’s adiponectin, says Dipali Sharma, PhD, assistant professor of hematology and medical oncology at Winship.
Currently, Winship scientists are testing a molecule found in certain foods that appears to mimic the effects of adiponectin. The molecule is found in grapes, cabbage and green tea.
Anti-diabetic drugs known as thiazolidinediones increase adiponectin’s activity, but they have toxic side effects. Also getting adiponectin to where it needs to go is a challenge, Sharma says, along with determining what an injection of a high level of adiponectin might trigger.
What can increase adiponectin is weight loss. Obese people have lower levels of adiponectin than people of normal weight, and as a consequence, those with obesity have an increased risk of breast cancer. Sharma and team also have found low levels of adiponectin in patients with aggressive breast cancer tumors. Read more about Sharmaâ€™s work in Emory Health magazine.
Sharma, who has published previous results of research in Cancer Research and Oncogene, says that researchers have only scratched the surface. The hormone leptin also is under investigation by breast cancer researchers. She notes that although leptin has long been linked to obesity, the hormone itself has only recently been found to play a major role in carcinogenesis, the transformation of normal cells into cancer cells. Obesity itself does not directly cause cancer, she says.
Leptin increases the incidence of cancer, the aggressiveness of the disease and reduces the effectiveness of both chemotherapy and endocrine therapy in cancer patients. The only way to counteract this is to address the problem through different compounds and therapies, perhaps using a combination of approaches that includes standard treatments with new ones,” she says.