Breast cancer drug may protect against killer superbugs: Study

Houston: A common breast cancer drug could wipe out an antibiotic-resistant notorious superbug responsible for several difficult-to-treat infections in different parts of the body, according to a new research.

The study found tamoxifen helps white blood cells in the body clear the bacteria methicillin-resistant Staphylococcus aureus (MRSA).

MRSA infections affect different parts of the body, including the skin and lungs.

US researchers found that tamoxifen gives white blood cells a boost, better enabling them to ensnare and kill bacteria in laboratory experiments and those on mice.

And the study showed tamoxifen treatment in mice also enhanced clearance of the MRSA which had become resistant to antibiotics, and reduced death from it.

Tamoxifen is taken daily by hundreds of thousands of patients worldwide for the treatment of breast cancer.

The study's senior author, Professor Victor Nizet, of the University of California San Diego School of Medicine, said: "The threat of multidrug-resistant bacterial pathogens is growing, yet the pipeline of new antibiotics is drying up."

"We need to open the medicine cabinet and take a closer look at the potential infection-fighting properties of other drugs that we already know are safe for patients," Nizet said.

Through this approach, it was discovered that tamoxifen has pharmacological properties that could aid the immune system in cases where a patient is immuno-compromised or where traditional antibiotics have otherwise failed, he said.

To grow and reproduce, breast cancer cells require the female hormone oestrogen.

Tamoxifen binds to oestrogen receptors in breast cancer cells,blocking oestrogen from reaching them.

This means the cancer either grows more slowly or stops growing altogether.

But, independent of the oestrogen receptor, the drug also influences the way cells produce fatty molecules, known as sphingolipids.

One sphingolipid in particular, ceramide, plays a role in regulating the activities of white blood cells known as neutrophils.

The study's author, Dr Ross Corriden, also of the University of California San Diego School of Medicine, said: "Tamoxifen's effect on ceramides led us to wonder if, when it is administered in patients, the drug would also affect neutrophil behaviour."