A study in mice has found that scientists can switch off a gene responsible for an aggressive form of breast cancer. Silencing the gene not only shrinks tumors but also prevents their spread around the body.
Around one in eight females in the United States will develop breast cancer, according to the American Cancer Society.
In 2019, doctors diagnosed an estimated 268,600 new cases of invasive breast cancer in females in the U.S., while around 41,760 individuals died from the disease.
Up to a fifth of breast cancers are a more aggressive form known as triple-negative breast cancer that is difficult to treat.
Unlike the majority of breast cancers, estrogen and progesterone do not fuel the growth of triple-negative tumors, so drugs, such as tamoxifen, that block these hormones are ineffective.
A molecule that switches off a particular gene in triple-negative tumors could be a promising alternative treatment, according to research at Tulane University School of Medicine in New Orleans, LA.
The scientists report their discovery in the Nature journal Scientific Reports.
The research combined in vitro studies of cells growing in dishes with in vivo studies involving mice.
The team began by working with cultures of a triple-negative cancer cell line that originally came from a patient treated in 1973 at the M. D. Anderson Cancer Center in Houston, TX.
The researchers compared the effects of switching off two known breast cancer genes, one called Rab27a and the other TRAF3IP2.
To deactivate or “silence” the genes, they targeted them with molecules of short hairpin RNAs called lentiviral-TRAF3IP2-shRNA. These are strands of RNA twisted back on themselves like a hairpin that prevent a specific gene from being read or “transcribed” to make a protein.
The researchers discovered that switching off TRAF3IP2 had a more disruptive effect on cancer-associated metabolic pathways in the cells than switching off Rab27a.
They confirmed this by switching off the genes individually in a mouse model of breast