US scientists decode 125-year-old element to boost cancer treatments

New Delhi, July 15: US researchers have decoded an element that could destroy cancerous cells, and advance treatment options for the deadly disease that claims millions of lives globally. The element, actinium, was first discovered by French scientist Andre-Louis Debierne in 1899 and is number 89 on the Periodic Table.

Now after 125 years of its existence, there is a bright chance it could improve cancer treatments, as found by the Department of Energy’s Lawrence Berkeley National Laboratory.

Even after 125 years, actinium remains an enigmatic element of science because to date it is found in extremely small quantities, and special facilities are needed to work with it, not just any ordinary radioactive lab.

The team of scientists tried growing it and while elements can behave very similarly to their lightweight counterparts, actinium behaved differently than its counterpart lanthanum.

From nuclear energy to medicine, these elements can serve the purpose admirably, for both are radioactive and earthy minerals, it is not actinium itself that saves the day, it is an isotope -- a distinct nuclear species of any element -- named actinium 225 that has shown promise in a method called targeted alpha therapy (TAT).

The TAT technique transports radioactive elements to the cancer site via biological delivery mechanisms such as peptides or antibodies.

When actinium decays, it emits energetic particles that travel a short distance, killing local cancer cells while sparing healthy tissue further away.

“If we can engineer proteins to bind the actinium with a high affinity, and either be fused with an antibody or serve as the targeting protein that would really enable new ways to develop radiopharmaceuticals.” said Rebecca Abergel, Associate Professor of nuclear engineering at the University of California- Berkeley.

Researchers employed a revolutionary way to create the crystals with only 5 micrograms of pure actinium, which is about one-tenth the weight of a grain of salt and unnoticeable to the naked eye.

They initially refined the actinium using a complicated filtration method that removed other elements and chemical contaminants.

They next attached the actinium to a metal-trapping molecule known as a ligand and encased the bundle inside a protein identified and purified by Roland Strong's team at the Fred Hutchinson Cancer Centre, resulting in a "macromolecular scaffold."

The crystals, which grew for a week inside the Heavy Element Research Laboratory, were then cryocooled in liquid nitrogen and irradiated with X-rays at Berkeley Lab's Advanced Light Source.

X-rays revealed the compound's three-dimensional structure and demonstrated how this elusive element works with other surrounding atoms.

This study used the longest-living isotope of actinium, Actinium 227 although Actinium 225 is the preferred one for the Targeted Alpha method (as it has been used for prostate cancer as well with positive results).

The final word has not yet been said but the initial prose is the melodious beginning of a future scientific opera which would herald a new era of cancer treatment, the researchers said.