Inherited breast cancer: a new way to tackle genetic mutations

Researchers have found a new way to tackle BRCA1 gene mutations, which cause many breast cancers around the world.

In 2013, American actress Angelina Jolie made headlines announcing that she had a double preventive mastectomy because of her genetic risks of breast cancer. Today, researchers have discovered a new way to kill cancers of this genus, caused by a mutation in the BRCA1 gene. The results of their study were published Tuesday, August 27 in the journal Proceedings of the National Academy of Sciences.

Normally, a tiny molecule called microRNA (miR) 223-3p prevents normal cells from making mistakes by repairing their DNA. But in the case of cancers with BRCA1 mutations, the gene represses the action of miR223-3p, which allows the cells to divide. Thus, adding miR223-3p would force the BRCA1 mutant cancer cells to die, say researchers at UT Health in San Antonio, Texas, USA, who conducted the study.

"A new treatment for inherited breast and ovarian cancers"

MiR223-3p acts as a switch, turning off the proteins that mutant BRCA1 cancers need to divide properly. Without these key cell division proteins, mutant BRCA1 mutations kill themselves, says Dr. Hromas, who participated in the study.

"It's a pretty cool way of thinking about treatment, we use the very nature of these BRCA1-deficient cancer cells against them, and we are attacking the very mechanism by which they have turned into cancer," he enthuses. he. What's more, restoring miR223-3p before the cells turn into cancer could even prevent BRCA1-related diseases, he says.

"This represents a new treatment for inherited breast and ovarian cancers, which are very common in our region," the researchers conclude.

21 women with the BRCA1 or BRCA2 mutation in France

Indeed, in the United States, mutations in the BRCA gene affect 1 in 400 patients, or about 825,000 people. After Ashkenazi Jews, Hispanics have the second highest prevalence of mutations causing BRCA1 disease. The Hispanic population is very present in South Texas, so this region is strongly impacted by this burden.

In France, breast cancer is the most common cancer among women (nearly 54,000 new diagnoses in 2015). About 5 to 10% of these cases are of genetic origin. Between 2003 and 2004, nearly 21,000 people were identified with the BRCA1 or BRCA2 mutation in the country. These women therefore have a "higher risk of developing a first breast cancer, especially at an early age, but also a second breast cancer (contralateral or second ipsilateral event)," says the Inca.

According to the health authorities, Angelina Jolie's highly publicized intervention in 2013, however, would have greatly sensitized women on the subject. "At the Breast Cancer Prevention Center at the University Hospital in South Manchester, UK, we have seen a marked increase in the number of women using double preventive mastectomy, which began 9 months after the revelation. Angelina Jolie ", had testified Gareth Evans, professor of clinical genetics, in a commentary published in 2015 in the newspaper Breast Cancer Reasearch. In France too, the actress's testimony had an impact, generating a large increase in requests for genetic consultations.

Video: What you Need to Know About BRCA Gene Testing (November 2019).