Purdue research to demystify link between obesity and breast cancer

WEST LAFAYETTE, Ind. – Some of obesity’s well-known risks are high blood pressure, Type 2 diabetes and heart disease. Perhaps lesser known is its elevated risk for breast cancer, especially among post-menopausal women.

Explaining the complex cellular mechanisms that link obesity to a higher risk for breast cancer – and to its spread beyond the breast – is the first necessary step in defining ways to inhibit and prevent the disease. To that end, the National Institutes of Health has granted $3.9 million to Purdue University breast cancer researchers Dorothy Teegarden and Michael Wendt. Teegarden is a professor of nutrition science in the College of Health and Human Sciences and director of the Women’s Global Health Institute. Wendt is an associate professor of medicinal chemistry and molecular pharmacology in the College of Pharmacy.

Recent national statistics quantify the urgent need for this work. The Susan G. Komen Breast Cancer Foundation reports that being overweight or obese after menopause can increase the risk of breast cancer from 30% to 60%, and the Centers for Disease Control and Prevention estimates that 42% of American adults are obese (defined as having a body-mass index of 30 or greater) and 74% are overweight.

“The world is facing a growing obesity epidemic,” Teegarden says. “This is particularly alarming in regard to breast cancer because obesity is associated with increased metastases and decreased patient survival.” Metastasis, when a tumor spreads from the principal cancer site to other parts of the body, is the primary cause of breast cancer deaths.

The five-year NIH grant will support the group’s newest study aimed at understanding exactly how obesity decreases oxygen in breast tumors – a process called hypoxia – and how that process helps malignancies progress beyond the breast.

“We hypothesize that hypoxia sets the stage for breast cancer metastasis,” Teegarden says. “Specifically, we will be investigating how hypoxia increases lipid (fat) production and enhances cancer cells’ ability to survive, with fats being used as an energy source.”

They also will examine a specific inflammatory protein, IL6, which is found in higher-than-normal levels in the blood of people with obesity. The protein helps cancer cells make use of fats.

Preliminary studies to support this application were funded by the Purdue Institute for Cancer Research and the Women’s Global Health Institute.

Grant: NIH  R01CA271597, “Impact of hypoxia on lipid metabolism in obesity-driven breast cancer progression”

Writer/Media contact: Amy Raley, araley@purdue.edu
Source: Dorothy Teegarden, dteegard@purdue.edu