A key protein in the lactation, aggravates the metastasis in breast cancer cases

A team of researchers has found that a protein that controls the production of milk during breastfeeding is “uncontrolled” in breast cancer, which promotes the entry of cancer cells into the bloodstream and its spread throughout the body (metastasis).

This “double-sided” of the protein Elf5 is published in the scientific journal Plos Biology, in an article that leads the Spanish David Gallego-Ortega, now at the Institute Garvan Medical Research, Sydney (Australia), with professor Christopher Ormandy.

Elf5, a protein essential for breastfeeding, a function that was already described by Ormandy in 2008: in normal conditions, during the period of pregnancy, Elf5 comes into operation preparing the cells of the breast for milk production during lactation, explains Gallego-Ortega.

however, and this is what is described in this work, in breast cancer cells this protein acquires a role and a pro-tumor producing metastases, according to this researcher.

“We have found high levels of Elf5 in breast cancer patients of type lunimal To (the most common form) who present with an advanced disease, and demonstrate how Elf5 is able to produce the spread of breast cancer to the lung in animal models”, says Gallego-Ortega, in a note by the australian institute.

This researcher explains that the major problem in breast cancer is the appearance of lesions secondary -metastases-that are the ones that end up with the life of the patient.

“The ‘negative face’ Elf5 is that cells that express it are able to deceive the immune system to produce inflammation in the tumor and as a consequence to this inflammation increases the occurrence of metastasis”, points out this scientist via e-mail.

The type luminal A is the most common form of breast cancer and is therefore the one that produces more deaths.

This study has focused on this subtype because researchers have a prior work published in 2012 -also in Plos Biology – in which is linked Elf5 with resistance to therapies in this subtype in particular, so I decided to delve into this particular type and extend of the investigation.

“In a previous study we showed that Elf5 is involved in the development of resistance to therapies, and with the data of this new discovery we see how Elf5 is involved in two of the most aggressive breast cancer: drug resistance and metastasis”.

In this sense, this scientist points out that in the mice used for this study were able to immediately see a strong inflammation and the appearance of a greater number of lung metastasis when the levels of Elf5 were highly elevated.

For this researcher, the finding that a protein has dual function “confrontational” is a process common in biology: it all depends on the context, to “simplifying to me I like to say that the cancer hijacks and maligniza the normal functions of the proteins for its own benefit”.

Gallego-Ortega says that this work opens a new door for the treatment of breast cancer by using drugs targeted against inflammatory cells. A key feature is that these drugs might be used in combination with current therapies.

“Elf5 would play a role of biomarker to identify which patients will benefit from this therapy, in function of the presence or absence of Elf5”.