Tel Aviv University researchers say genetic therapy with chemo in mice ‘extremely effective’ in preventing breast cancer metastasis
September 20, 2016, 1:44 pm
A new Tel Aviv University study on mice has found that combining genetic therapy with chemotherapy and delivering the treatment to a primary tumor site is “extremely effective” in preventing breast cancer metastasis — its ability to spread to other organs.
The results might be applicable to humans, the researchers said in a statement.
“The situation is bleak. Death rates from breast cancer remain high and relatively unchanged despite advances in medicine and technology,” said Dr. Noam Shomron of Tel Aviv University’s Sackler School of Medicine, who led the study. “We wanted to find a way to stop metastasis from happening altogether. It’s the turning point, where survival rates drop exponentially.”
“Our mission was to block a cancer cell’s ability to change shape and move,” he said.
According to research, one in eight women worldwide are diagnosed with breast cancer in their lifetime and the disease is the second leading cause of cancer death in women. The chance that a woman will die from breast cancer is about 1 in 36.
Early detection, while increasingly common, is not sufficient to preventing metastasis, the lethal movement of cancerous cells from a primary tumor site to colonies in vital organs. About 80 percent of women with metastatic cancer die from the disease within just five years of being diagnosed.
The research — led by Tel Aviv’s Shomron in collaboration with Dr. Natalie Artzi of the Massachusetts Institute of Technology — was published in the September 19, 2016, online issue of Nature Communications.
Researchers began their work by investigating the range of cell mutations in a tumor and looked at sites within the genes that play regulatory roles. Cancer cells change their structure to squeeze past other cells, enter blood vessels and ride along to their next stop: the lungs, the brain, or other vital organs. While studying the cells the researchers noticed that mutations were involved in metastasis.
They also developed a naturally occurring RNA-based drug (RNAs are regulators of genes) to control cell movement and created a safe nanovehicle with which to deliver the microRNA to the tumor site.
Two weeks after initiating cancer in the breasts of their lab mice, the researchers injected into primary tumor sites a hydrogel that contained naturally occurring RNAs to target the movement of cancer cells from primary to secondary sites. Two days after this treatment, the primary breast tumors were removed.
The mice were evaluated three weeks later using CT imaging, flourescent labeling, biopsies and pathology. The researchers discovered that the mice that had been treated with two different microRNAs had very few or no metastatic sites, whereas the control group — injected with random scrambled RNAs — exhibited a fatal proliferation of metastatic sites.