Virility drug may boost skin cancer growth
Tübingen biochemists discover signaling pathway in melanoma cells affected by erectile dysfunction drug Sildenafil
Tübingen researchers have found indications that taking the drug Sildenafil, which is frequently used to treat erectile dysfunction in men, can stimulate the growth of skin tumors. Professor Robert Feil and his working group at the University of Tübingen’s Interfaculty Institute of Biochemistry demonstrated in animal experiments and human cell cultures that Sildenafil appears to have a stimulating effect on the messenger molecule cyclic guanosine monophosphate (cGMP) - which in turn promotes the growth of existing malignant melanomas. Interference with the cGMP pathway in melanoma cells could possibly be used to treat skin cancer. The results of the study are published in the latest edition of Cell Reports.
How Sildenafil affects the growth of melanoma cells: The enzyme phosphodiesterase type 5 (PDE5) breaks down cGMP, functioning as a brake on skin cancer growth. Sildenafil inhibits PDE5, releasing the brake and causing the cGMP level to rise. That means melanomas can grow more vigorously. Graphic source: Robert Feil
“We have discovered that the cells of malignant melanoma use the cGMP signaling pathway for their growth,” says Feil. Normally, cells contain an enzyme - phosphodiesterase type 5 (PDE5) - which ensures that newly-formed cGMP is continuously broken down. Sildenafil, however, inhibits the enzyme. “PDE5 is like a brake on cGMP,” says Feil. “Taking Sildenafil basically disables this brake.” Feil adds that as a result, the melanoma begins to grow more vigorously. This biochemical mechanism may explain why men who take Sildenafil have an increased risk of melanoma.