A common pinworm medication may stop and reverse cancer growth in Merkel cell carcinoma, according to research out of the University of Arizona Cancer Center in Tucson, AZ.

Pyrvinium pamoate, a medication approved by the Food and Drug Administration in 1955 to treat pinworms, has been shown to have antitumor potential in several different cancers, including breast, colorectal, pancreatic, and bladder cancers.

The new research, which appears in the Journal of Clinical Investigation, marks the first time pyrvinium pamoate has been studied in models of Merkel cell carcinoma.

Reduced Cancer Growth

In laboratory models of Merkel cell carcinoma, pyrvinium pamoate inhibited cancer cell growth and reversed the cancer’s neuroendocrine features. In mouse models of Merkel cell carcinoma, pyrvinium pamoate reduced tumor growth, the study showed.

“Merkel cell carcinoma is increasing in incidence,” sats senior author Megha Padi, PhD, a U of A Cancer Center member and an assistant professor in the U of A College of Science, in a news release. “Even though it’s a rare cancer type, it mimics a lot of properties that other cancers have.

“This is a hypothesis, but some people think the reason an antiparasitic agent could be effective against cancers is because tumors are a little bit like parasites in our body,” Padi says. “Parasites and tumors must develop ways to use scarce resources in their host to feed themselves and allow for unlimited multiplication. If the pathways that they have hijacked to feed themselves are the same, then you get lucky, and you have a tumor type that could be amenable to killing by these antiparasitic drugs.”

Wnt Signaling Pathway

Padi and the research team chose to test pyrvinium pamoate after identifying the Wnt signaling pathway as one of the molecular mechanisms that drives the transition of normal cells into Merkel cell carcinoma. Pyrvinium pamoate is a known Wnt pathway inhibitor.

Further research is needed to optimize treatment protocols for the development of pyrvinium pamoate as a clinically useful medication for Merkel cell carcinoma.

PHOTO CREDIT: DermNet