Researchers from across the globa have come together to create a developed and efficient radiation-free technique that can be used to detect and eliminate breast cancer tumours.
The team including researchers from California Institute of Technology (Caltech), the Israel Institute of Technology (Technion) and the Cedars-Sinai Medical Centre have shown that combining a compound known as a gallium corrole with a protein carrier can effectively detect and remove tumours with fewer side effects.
The conventional method used to treat breast cancer is known as photodynamic therapy (PDT), in which involves killing tumours with the help of laser light.
The new technique involves corroles that don't require a laser boost for killing tumours.
"The striking thing about gallium corroles is that they apparently kill cancer cells in the dark," said Harry Gray, Caltech's Arnold O. Beckman Professor of Chemistry and founding director of the Beckman Institute.
"We don't yet know exactly how this works, but what we've seen so far tells us that it does work," he added.
During the study, the team paired a gallium corrole with a carrier protein, and then aimed it at cells that carry the human epidermal growth factor receptor 2 (HER2).
The presence of a HER2 receptor is the hallmark of about 25 percent of breast cancers, and marks those tumours as particularly aggressive and difficult to treat.
While experimenting on mice, the researchers observed that the targeted corrole was able to shrink tumours at doses five times lower than that of the standard chemotherapeutic agent for HER2-positive tumours, a drug called doxorubicin.
"We looked at three groups of mice with human tumours," said coauthor Lali Medina-Kauwe, an assistant professor of medicine at the David Geffen School of Medicine at UCLA.
"In one, we introduced just the protein carrier, without the corrole; tumor growth in those mice did not change. In other mice, we gave the corrole without the carrier protein; this led to some tumour suppression.
"But it was the last group, the ones that got the corrole with the carrier protein, that experienced the most therapeutic effect," Medina-Kauwe added.
The study appears in the Proceedings of the National Academy of Sciences.