in benign breast tissue, potentially pointing the way toward the use of the pioneer transcription factor as a helpful biomarker for breast cancer researchers.
The findings were released at the annual meeting of the American Association for Cancer Research.
In the study, researchers who were led by Bruce F. Kimler, PhD, a radiation biologist and breast cancer researcher at the University of Kansas Medical Center, Kansas City, examined benign breast tissue cells aspirated from 12 women (mean age, 53 years; 7 on low-dose hormone replacement) before and after 6 months of high-dose omega-3 fatty acid supplementation. After the supplementation, FOXA1 positive cells fell in 11 of 12 women (P = .019). “There was a robust linear relationship between stain positivity for FOXA1 and AGR2,” the researchers reported (P < .001).
Increased FOXA1 activity along with GRHL2) transcription factor can boost endocrine resistance, while omega-3 fatty acids can reduce it.
In an interview, Robert S. Chapkin, PhD, the Allen Endowed Chair in Nutrition and Chronic Disease Prevention at Texas A&M University, College Station, said it’s important to examine the value of omega-3 fatty acid supplementation, and the understanding of biomarkers is crucial. “Omega 3 fatty acids are pleiotropic, dose dependent, and likely impact multiple signaling mechanisms in select cells types and cancer contexts. The key is to dissect out the highest impact targets and pursue them in the context of preclinical and clinical studies.”
However, he said, “in many cases, the lack of a mechanistic understanding detracts from the merit of the work.”
Studies like this are useful in the development of clinical trials to test the value of high-dose omega-3 fatty acids in breast cancer prevention trials, said Carol Fabian, MD, a breast medical oncologist with the University of Kansas Medical Center, and the study’s first author.
“They help us understand both what dose will be needed and biomarkers that will likely be helpful in predicting response. Early-phase trials with biomarker modulation as a primary endpoint are generally necessary to make sure you have the right dose for the target population prior to committing to a long-term cancer incidence study involving thousands of women and tens of millions of dollars,” she said.
What’s next? “This work was done on reserved specimens from a prior pilot trial,” Dr. Fabian said. “We need a placebo-controlled study to know for sure that omega-3 FA in a dose of about 3.2g daily, or about 2% of calories, modulates FOXA1 and/or AGR2 in postmenopausal women.”
Previously, she said, the researchers “found that high dose omega-3 administered to overweight peri- and postmenopausal high-risk women undergoing a 6-month weight loss intervention increased the number of systemic risk biomarkers which were favorably modulated compared to placebo despite the same median weight loss in each group [–10%],” Dr. Fabian said. “We want to duplicate that finding in a larger study as well as determine if omega-3 fatty acids can block tamoxifen-induced increases in AGR2 associated with endocrine resistance.”
The study was funded by the Breast Cancer Research Foundation, the Morris Family Foundation, and the University of Kansas Cancer Center. The authors and Chapkin report no relevant disclosures.