Medical News Observer

A novel targeted therapy using nanoparticles has enabled researchers at the Georgia Institute of Technology to purge ovarian tumors in limited, in vivo tests in mice. “The dramatic effect we see is the massive reduction or complete eradication of the tumor, when the ‘nanohydrogel’ treatment is given in combination with existing chemotherapy,” said chief researcher John McDonald.

That nanohydrogel is a minute gel pellet that honed in on malignant cells with a payload of an RNA strand. The RNA entered the cell, where it knocked down a protein gone awry that is involved in many forms of cancer.

In trials on mice, it put the brakes on ovarian cancer growth and broke down resistance to chemotherapy. That allowed a common chemotherapy drug, cisplatin, to drastically reduce or eliminate large carcinomas with very similar speed and manner. The successful results in treatment of four mice with the combination of siRNA and cisplatin showed little variance.

The therapeutic short interfering RNA (siRNA) developed by McDonald and Georgia Tech researchers Minati Satpathy and Roman Mezencev, thwarted cancer-causing overproduction of cell structures called epidermal growth factor receptors (EGFRs), which extend out of the wall of certain cell types. EGFR overproduction is associated with aggressive cancers. The nanohydrogel that delivers the siRNA to the cancer cells is a colloid ball of a common, compact organic molecule and about 98 percent water. Another molecule is added to the surface of the nanohydrogel as a guide. In the in vivo trials, the siRNA, which contained a fluorescent tag, allowed researchers to observe nanoparticles successfully honing in on the cancer cells.

The researchers from Georgia Tech’s School of Biological Sciences published their results on Monday, November 7, 2016, in the journal Scientific Reports.

The new treatment has not been tested on humans, and research would be required by science and by law to demonstrate consistent results – efficacy – among other things, before preliminary human trials could become possible.

Citation: Minati Satpathy, Roman Mezencev, Lijuan Wang & John F. McDonald. “Targeted in vivo delivery of EGFR siRNA inhibits ovarian cancer growth and enhances drug sensitivity”
Scientific Reports 6, Article number: 36518 (2016)
DOI: http://dx.doi.org/10.1038/srep36518
Research funding: National Institutes of Health’s IMAT Program, Ovarian Cancer Institute, Deborah Nash Endowment Fund, Curci Foundation and Markel Foundation.
Adapted from press release by Georgia Institute of Technology