Now, a new gene therapy technique being developed by researchers at MIT is showing promise as a way to prevent breast cancer tumors from metastasizing.
The treatment, described in a paper published today in the journal Nature Communications, uses microRNAs — small noncoding RNA molecules that regulate gene expression — to control metastasis.
The therapy could be used alongside chemotherapy to treat early-stage breast cancer tumors before they spread, according to Natalie Artzi, a principal research scientist at MIT’s Institute for Medical Engineering and Science (IMES) and an assistant professor of medicine at Brigham and Women’s Hospital, who led the research in collaboration with Noam Shomron, an assistant professor on the faculty of medicine at Tel-Aviv University in Israel.
“The idea is that if the cancer is diagnosed early enough, then in addition to treating the primary tumor [with chemotherapy], one could also treat with specific microRNAs, in order to prevent the spread of cancer cells that cause metastasis,” Artzi says.
The regulation of gene expression by microRNAs is known to be important in preventing the spread of cancer cells. Recent studies by the Shomron team in Tel-Aviv have shown that disruption of this regulation, for example by genetic variants known as single nucleotide polymorphisms (SNPs), can have a significant impact on gene expression levels and lead to an increase in the risk of cancer.
A new gene therapy technique being developed by researchers at MIT uses microRNAs — small noncoding RNA molecules that regulate gene expression — to control breast cancer metastasis. Image: MIT News
Schematic diagram of a stepwise omic-data integration which informs the in vivo therapeutic approach.
They developed a method to deliver engineered microRNAs to breast cancer tumors. They embedded nanoparticles containing the microRNAs into a hydrogel scaffold, which they then implanted into mice.
They found that this allowed efficient and precise delivery of the microRNAs to a target breast cancer tumor site. The treatment resulted in a dramatic reduction in breast cancer metastasis, says Artzi.
“We can locally change the cells in order to prevent metastasis from occurring,” she says.
To increase the effectiveness of the treatment even further, the researchers then added the chemotherapy drug cisplatin to the nanoparticles. This led to a significant reduction in both the growth of the primary tumor, and its metastasis.
Metastasis is the primary cause for mortality in breast cancer. MicroRNAs, gene expression master regulators, constitute an attractive candidate to control metastasis. Here we show that breast cancer metastasis can be prevented by miR-96 or miR-182 treatment, and decipher the mechanism of action. We found that miR-96/miR-182 downregulate Palladin protein levels, thereby reducing breast cancer cell migration and invasion. A common SNP, rs1071738, at the miR-96/miR-182-binding site within the Palladin 3′-UTR abolishes miRNA:mRNA binding, thus diminishing Palladin regulation by these miRNAs. Regulation is successfully restored by applying complimentary miRNAs. A hydrogel-embedded, gold-nanoparticle-based delivery vehicle provides efficient local, selective, and sustained release of miR-96/miR-182, markedly suppressing metastasis in a breast cancer mouse model. Combined delivery of the miRNAs with a chemotherapy drug, cisplatin, enables significant primary tumour shrinkage and metastasis prevention. Our data corroborate the role of miRNAs in metastasis, and suggest miR-96/miR-182 delivery as a potential anti-metastatic drug.
SOURCES- MIT News, Nature Communications