Algae Compound May Lead to Effective New Cancer Drugs

Coibamide A, a compound of blue-green algae, was found to have potent anti-cancer activity in mice and cell cultures that model brain tumors and triple negative breast cancer, a new study found.

Blue-green algae, or cyanobacterium, is one of the oldest life forms on Earth and is found off the coast of Coiba.

In findings presented at the annual Experimental Biology meeting, researchers believe that coibamide A could be a potential new therapy for patients with triple negative breast cancer or brain tumors.

“Patients with many other types of cancer already have some really excellent treatment options, so we were interested in focusing on some of the kinds of cancer that haven't had as much success with pharmacological development,” said lead study author Jane Ishmael, PhD. “For many brain tumors, for example, there are very few options and the prognosis has remained grim for many years.”

Coibamide A was discovered 8 years ago by scientist Kerry McPhail, PhD, who scuba dives all over the world in search of interesting species. During her dive in Panama’s Coiba National Park, she found that cyanobacterium ended up being a mashup of 3 algal species that grow together on rocks.

“The chemical diversity found in nature has always been a significant source of inspiration for drug design and development, but although the medicinal properties of plants have been recognized for thousands of years, marine environments remain relatively unexplored,” Ishmael said. “We think that with this compound, nature has already found a way to target some of the specific proteins that are relevant to the growth of tumors.”

When McPhail isolated coibamide A from the original specimen, it was run through a National Cancer Institute screening system. The system looks for potential anti-cancer activity across 60 different types of cancer.

The screening system showed that coibamide A has a unique activity pattern unlike any other compound. These findings suggested that the compound has the potential to fight cancer through a mechanism of action that differs from existing drugs.

During the current study, researchers used cell cultures to test the activity of coibamide A. The study showed that the compound cuts off the ability of cancer cells to communicate with blood vessels and other cells, which eventually leads to the starvation of the cell, triggering its death.

When an animal model for glioblastoma was treated with coibamide A, researchers found that it significantly reduced the tumor’s size.

Next, researchers plan to test the compound in a mouse model for triple negative breast cancer, as well as a mouse model for brain cancer where the glioblastoma cells are grown in the brain instead of the flank.

Glioblastoma tumors are known to be difficult-to-treat since the tumors grow rapidly and don’t respond well to available chemotherapy drugs. The challenge in developing new drugs to fight these tumors is the ability to cross the blood-brain barrier.

At this time, it is not known if coibamide can cross the blood-brain barrier, but researchers plan to investigate this in the future. If the compound is unable to pass the barrier or has adverse effects, knowing the structure and action can still help researchers develop drugs that mimic coibamide A’s effects.

Researchers hope they can move forward in developing the compound into a cancer drug more rapidly since a newly developed method now produces coibamide A synthetically, meaning the algae no longer needs to be harvested from marine environments.

“So far, there isn't a drug in clinical use or in any clinical trials that works in this way,” Ishmael said. “We're using it to try to reveal a new pathway to trigger cell death in these cancer cells that have traditionally been considered very resistant to cell death.”