Carvedilol is a beta-blocker commonly used to lower blood pressure and treat heart failure.
An error in the laboratory, however, has led to the discovery of another possible use for the drug: the prevention of skin cancer.
Researchers from the Western University of Health Sciences in California found that carvedilol can protect skin from the damaging effects ultraviolet B (UVB) radiation.
UVB radiation is the shortwave radiation emitted by the sun. It is the primary cause of sunburn and it plays a significant role in the development of skin cancer.
Skin cancer is the most common form of cancer.
More than 3 million people in the United States are diagnosed with basal or squamous cell skin cancers each year.
In 2017, more than 87,000 people will be diagnosed with melanoma – the deadliest form of skin cancer.
Excessive exposure to UV radiation from the sun or indoor tanning is one of the biggest risk factors for the disease.
UV radiation can damage the DNA of skin cells, which can lead to genetic mutations that give rise to skin cancer.
One of the best ways to protect against the harmful effects of UV radiation is to wear sunscreen.
However, Dr. Ying Huang, a study co-leader and assistant professor in the College of Pharmacy at Western University, and her colleagues say they discovered carvedilol may be more effective than sunscreen when it comes to skin cancer prevention.
Tumor reduction in mice
The researchers came across their findings by accident.
Rather than testing whether carvedilol increases the risk of cancer, as planned, a former graduate student working in Huang’s laboratory mistakenly tested the anti-cancer effects of the drug.
To their surprise, the research team found that carvedilol showed some protection against skin cancer.
"What began as an experimental error led to a very interesting scientific discovery," said Huang.
The researchers decided to further explore the relationship between carvedilol and skin cancer by conducting experiments on mouse-derived skin cells and hairless mice.
The team exposed skin cells to UVB radiation before treating them with carvedilol. The beta-blocker was found to protect the skin cells against DNA damage and death.
Next, hairless mice were given carvedilol topically six hours and 24 hours after exposure to UVB radiation.
The rodents showed a reduction in number of tumors that formed as well as a decrease in tumor severity, compared with mice that did not receive the beta-blocker.
Furthermore, the researchers found that carvedilol was more effective than sunscreen for preventing tumor formation in the rodents.
Possible use in skin creams
The team notes that not all beta-blockers demonstrate anti-cancer properties.
They add that the mechanism by which carvedilol protects against skin cancer is independent of its mechanisms as a beta-blocker.
"We have preliminary data indicating that the cellular targets for carvedilol are not related to the beta-adrenergic receptors that are the commonly accepted targets for all beta-blockers,” said Bradley T. Andresen, PhD, a study co-leader and assistant professor in the College of Pharmacy at Western University. “They likely target unexpected mechanisms involved in cancer development."
The team plans to gain a better understanding of carvedilol’s anti-cancer processes in future research.
The long-term goal is to include carvedilol and similar beta-blockers in skin creams or sprays that can protect against the damaging effects of UV exposure.
"Our research could lead to the development of a class of new cancer-preventive agents,” said Andresen.
The researchers note that topical administration of carvedilol would protect the skin without having any impact on blood pressure and heart rate, as it does with oral administration.