CINCINNATI, Dec. 14 (UPI) -- Researchers the University of Cincinnati College of Medicine have generated multifunctional RNA nanoparticles that could overcome treatment-resistant breast cancer and may make existing treatments more effective in those patients.
The study, published in the American Chemical Society's ACS Nano, shows that using a nanodelivery system to target HER2-positive breast cancer and stop the production of the protein MED1, could slow tumor growth, stop cancer from spreading and sensitize the cancer cells to treatment with tamoxifen, a known treatment for estrogen-driven cancer.
The research was led by Xiaoting Zhang, Ph.D., associate professor in the Department of Cancer Biology at UC.
MED1 is a protein that is produced at abnormally high levels in breast cancer cells that when eliminated, is found to stop cancer cell growth. HER2-positive breast cancer involves amplification of a gene encoding or programming the protein known as human epidermal growth factor receptor 2, which also promotes the growth of cancer cells.
"Most breast cancers express estrogen receptors, and the anti-estrogen drug tamoxifen has been widely used for their treatment," Zhang said in a press release. "Unfortunately, up to half of all estrogen receptor-positive tumors are either unresponsive or later develop resistance to the therapy. In this study, we have developed a highly innovative design that takes advantage of the co-overexpression of HER2 and MED1 in these tumors."
Zhang's team found that RNA nanoparticles are able to selectively bind to HER2-overexpressing breast tumors, eliminating MED1 expression and significantly decreasing estrogen receptor-controlled target gene production.
Not only did the nanoparticles reduce the growth and spread of the HER2-overexpressing breast cancer tumors, but it sensitized them to tamoxifen treatment.
"These findings are highly promising for potential clinical treatment of advanced metastatic and tamoxifen-resistant human breast cancer," Zhang said in a press release. "Further studies are still needed and hopefully soon we'll be able to test our nanoparticles in clinical trials at the UC Cancer Institute's Comprehensive Breast Cancer Center."