New hope in the fight against breast cancer. Australian researchers at the Harry Perkins Institute at the University of Perth have discovered a gene implicated in a particularly aggressive and particularly deadly type of breast cancer. They detail their discovery in the review Nature Communications March 26, 2021.

Bigger, more aggressive, more deadly

In this study, the team of researchers looked at a group of so-called hormone-dependent breast cancers, that is, in which hormones play a role in the proliferation of cancer cells.

This group of unidentified cancers were larger, particularly aggressive, spread more frequently to the lymph nodes, generally resisted treatment and had a high mortality rate since half of the patients affected died.

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The role of the AAMDC protein

Surprising characteristics, because hormone-dependent breast cancers generally have a good chance of survival and respond well to hormonal cancer treatments.

To understand this group of cancers, the researchers therefore looked at data from thousands of breast cancers. And they found that these aggressive cancers all had a particular gene, used to make a protein called AAMDC at higher than normal levels.

Multiplication of cancer cells

But what roles does this protein play? First, it triggers the growth of the tumor by promoting the multiplication of cancer cells.

And that’s not all: it would protect cancer cells from the action of anti-cancer hormone treatments, thus preventing cancer from healing.

When cancer cells are subjected to the stress of treatment, the AAMDC protein makes them “more adaptable“, explains Dr. Pilar Blancafort, head of the epigenetics group of cancer at the Harry Perkins Institute and co-author of the study in a university press release.

Tumor “survival kit”

“Usually, depriving hormone-dependent breast cancers of estrogen (by hormonal anticancer treatments, editor’s note) makes them regress“recalls the specialist. But for this type of cancer, it’s the opposite: estrogen deprivation”triggers a signal that causes the tumor to grow“.

In other words, the AAMDC protein acts like a “survival kit“, allowing tumors to adapt to these stressful conditions by promoting the growth and multiplication of cancer cells.

Identify to better treat them

What will this discovery be used for? First, to identify this type of aggressive cancer by looking for high levels of AAMDC protein in cancer cells.

Then, in a second step to adapt the treatment. There is no longer any question of administering a classic hormonal anticancer drug, which risks acting against the grain by making the tumor grow. Treatments that block the action of the AAMDC protein must now be developed, the researchers suggest.

After using this medicine, “we may be able to directly kill cancer cells and restore their sensitivity to usual hormone treatments“, finally hopes Pilar Blancafort.