AACR, Author Interviews, Breast Cancer, Cancer Research, Pancreatic, Weight Research / 13.02.2016
Breast and Pancreatic Cancer: Pathway Identified That Accelerates Tumors in Obese Patients
MedicalResearch.com Interview with:
Joao Incio, MD
Edwin L. Steele Laboratory for Tumor Biology
Massachusetts General Hospital | Harvard Medical School | Boston, MA, U.S.A
Department of Internal Medicine | Hospital S. Joao | Porto, Portugal
Medical Research: What is the background for this study? What are the main findings?
Dr. Incio: The study focused on the effects of obesity on pancreatic and breast cancer, since more than half of those diagnosed with such tumors are overweight or obese. In addition, a number of large-scale studies have found that obesity leads to an increased risk of death in pancreatic, breast and other types of cancer. But prior to the current study the mechanism of obesity-induced pancreatic and breast cancer progression was unclear. We have uncovered a novel mechanism behind the ability of obesity to promote cancer progression. We found an association between obesity and an overabundance of a factor called PlGF (placental growth factor) and that PlGF’s binding to its receptor VEGFR-1, which is expressed on immune cells within tumors, promotes tumor progression.
We found that obesity increased infiltration of tumor-promoting immune cells and the growth and metastasis of pancreatic cancers. Blocking VEGFR-1 signaling shifted the immune environment towards prevention of tumor progression in obese but not in lean mice in both pancreatic and breast cancer models. We also found that PlGF was present in excess in obesity and that reduction of PlGF produced similar results to VEGFR-1 inhibition in the tumors of obese mice. We also discovered that targeting the PlGF/VEGFR-1 interaction prevents weight gain in a genetically obese mouse model but worsens a diabetes-like condition, a worsening that was alleviated by use of the common diabetes drug metformin, which also had beneficial anti-tumor effects.
Our findings in cellular and animal models, as well as in patient tumor samples, indicate that targeting the PlGF/ VEGFR-1 pathway may be particularly effective in obese patients.
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