Newswise — New Brunswick, N.J. – April 2, 2019 - In the search for more effective therapies for breast cancer, Rutgers University researchers are targeting opioid receptors to potentially reduce the development and spread of certain breast cancer subtypes. Dipak K. Sarkar, PhD, a research member in the Clinical Investigations and Precision Therapeutics Program at Rutgers Cancer Institute of New Jersey and director of the Endocrinology Program at the Rutgers School of Environmental and Biological Sciences, is the senior investigator of work being presented today at the American Association for Cancer Research Annual Meeting in Atlanta. Dr. Sarkar, who is also a Board of Governors professor and distinguished professor of animal science in the Rutgers School of Environmental and Biological Sciences, shares more about the findings.

Q: What prompted your team to focus on breast cancer?

A: Breast cancer is the second most prevalent cancer after lung cancer among American women. Better therapy is needed to prevent the growth and progression of this disease.  We have previously found that our body opioid system when activated enhances immune function and prevents cancer growth and progression in various animal models of cancers. Therefore, we tested if targeting the endogenous opioid peptides receptors in the regulation of cancer chemoprevention may offer new promise for the design of therapeutic strategies.

Q:  How was the study conducted and what did you find?

A: Our previous studies have shown differential actions of mu-opioid receptor (MOR) and delta opioid receptor (DOR) on various cell types. In this study we tested the effects of a MOR antagonist naltrexone (NTX) and a DOR agonist (D-Ala2-,N-Me-Phe4,Gly-ol Enkephalin; DPDPE) on proliferation and invasion of human breast cancer cells of different molecular subtype such as T47D (Luminal A), MDA-MB-231 (triple negative, Claudin-Low) and MDA-MB- 468 (triple negative, basal A) in cultures. We found that both NTX and DPDPE inhibit the growth as measured by determining tumor cell proliferation and metastasis as determined by formation of colony, migration and invasion of cancer cells in a concentration-dependent manner.

Q:  What do these results mean for advancing breast cancer treatment?

A: These data suggest that naltrexone and DPDPE have anticancer efficacy in subtypes of human breast cancer cells. The anticancer effects varied depending on the concentration of the drugs and the subtype of breast cancer cells.

Other authors on the work are: Sergottuvelan Murugan and Vanisha Patel, Rutgers School of Arts and Sciences.

This work was funded in part by the National Institutes of Health (R01 CA20863201). The authors report no disclosures. Additional information can be found at:!/6812/presentation/3212.