Sildenafil, the active ingredient in the erectile dysfunction drug Viagra, may play a role in slowing the spread of cancer, according to a recent study. The research, published in Cancer Research, suggests that the medication interferes with metastasis by disrupting cancer cells' ability to utilize cholesterol.
Researchers at the Weizmann Institute of Science investigated the effects of sildenafil, focusing on how it impacts cancer cell growth and spread. Their findings indicate that the drug hinders metastasis by interfering with cancer cells' cholesterol supply, a critical component for their rapid proliferation, especially when they detach from a primary tumor and attempt to invade other organs.
Mechanism of Action
Sildenafil functions by inhibiting an enzyme known as phosphodiesterase type 5, which leads to increased levels of cyclic guanosine monophosphate (cGMP). While cGMP is known for relaxing blood vessels and enhancing blood flow, the study discovered it also binds to a protein responsible for transporting cholesterol within cells. This binding action reduces the availability of cholesterol for cancer cells.
"Beyond their therapeutic promise, our findings highlight that cancer biology is shaped not only by mutations in tumor cells but also by the patient’s metabolic state and by medications they are already taking for other conditions," Professor Ayelet Erez, one of the study's leaders, stated in a press release. The research team, which included Dr. Yarden Ariav, analyzed mouse cancer models, human cancer cells, and extensive medical records from approximately 5 million patients in Israel's Clalit Health Services.
Combined Therapies and Cholesterol
Further analysis of the medical records suggested that the use of sildenafil was associated with improved survival rates among cancer patients, particularly when taken in conjunction with statins. Statins are a class of drugs used to lower cholesterol levels, specifically reducing low-density lipoprotein (LDL), often referred to as "bad" cholesterol.
The combination of sildenafil and statins could potentially restrict cancer cells' access to existing cholesterol while simultaneously impeding the body's production of more cholesterol. This dual action may effectively starve tumors of a vital resource needed for growth and spread.
Erez emphasized the importance of a holistic approach to patient care, noting, "the whole patient – not just the cancer."
While cancer cell growth is largely driven by genetic mutations and internal signaling pathways, external factors such as diet have also been shown to influence tumor development and dissemination. For example, some studies have indicated that high-fat diets can accelerate tumor growth and invasion, while the increasing consumption of ultra-processed foods has been linked to a rise in colorectal cancer diagnoses among younger adults.