Light-activated cancer drugs may minimize chemotherapy side effects

Feb. 13 (UPI) — Chemotherapy drugs activated by light to treat cancer can minimize side effects by targeting strictly non-healthy cells, according to new research in Britain and Australia.

The Monash Warwick Alliance, an intercontinental collaboration between the University of Warwick in Britain and Monash University in Australia, examined how a platinum-based chemotherapy drug candidate kills cancer cells in targeted areas after being activated by light — but can be directed away from healthy tissue.

‘”The current shortcomings of most chemotherapeutic agents are unfortunately undeniable, and therefore there is ongoing effort to develop new therapies and improve our understanding of how these agents work in effort to develop not only more effective, but also more selective, therapies to reduce the burden on patients,” said Robbin Vernooij, a joint doctoral student from the Monash Warwick Alliance who led the study, said in a press release from Warwick.

The treatment was originally developed by Professor Peter Sadler’s research group in the University of Warwick’s Department of Chemistry.

Roughly 650,000 cancer patients receive chemotherapy in an outpatient oncology clinic in the United States each year, according to the Centers for Disease Control and Prevention.

Platinum-based chemotherapy compounds, such as cisplatin, were developed more than half a century ago. Chemotherapy can cause side effects, including feeling ill or very tired, as it attacks healthy and cancerous cells. Healthy cells that get destroyed can include skin, hair, intestines and bone marrow.

“About half of all chemotherapy treatments for cancer current[ly] use a platinum compound, but if we can introduce new platinum compounds that avoid side effects and are active against resistant cancers, that would be a major advance,” Sadler said. “We hope that new approaches involving the combination of light and chemotherapy can play a role in combating the current shortcomings of cancer therapy and help to save lives.”

For the study, published in Chemistry: A European Journal, researchers used infrared spectroscopy to see what happens to the compound’s structure by following the metal as well as molecules released from the compound.

When the treatment is inserted into cancerous areas, and exposed to directed light, the compound degrades into active platinum and releases ligand molecules to attack cancer cells.

In the laboratory, researchers shone infrared light on the inorganic-metal compound and measured the molecules’ vibrations while it was activated.

”This is an exciting step forward, demonstrating the power of vibrational spectroscopic techniques combined with modern computing to provide new insights on how this particular photoactive chemotherapeutic agent works, which brings us one step closer to our goal of making more selective and effective cancer treatments,” Vernooij said.

Researchers hope to develop photoactive chemotherapy drugs for clinical trial.

“Photoactivated platinum compounds offer such possibilities,” Sadler said. “They do not kill cells until irradiated with light, and the light can be directed to the tumor so avoiding unwanted damage to normal tissue.”