Protein makes ovarian cancer cells eat themselves

They say that cures sometimes come from the most unexpected places. In this case, the cancer cure actually works in a very unexpected and unusual way. Meet PEA-15, a protein that make ovarian cancer cells eat themselves

Researchers at The University of Texas M. D. Anderson Cancer Center discovered a protein that can inhibit the growth of ovarian cancer. This protein, called phospho-enriched protein in astrocytes or PEA-15 can actually force cancer cells to cannibalize themselves. The study was based on data from 395 women with ovarian cancer. Results showed that those women with high PEA-15 levels in their tumors had a median survival time of 50.2 months. Those women with low levels of the protein in their tumors, however, had a median survival time of 33.5 months. According to senior author Dr. Naoto Ueno, associate professor of breast medical oncology, the presence of PEA-15 can help determine the woman’s prospects for surviving ovarian cancer.

“These findings provide a foundation for developing a PEA-15 targeted approach for ovarian cancer and for clarifying whether this protein is a novel biomarker that can predict patient outcomes,” according to Ueno.

A series of laboratory experiments led by another researcher Dr. Chandra Bartholomeusz also showed that PEA-15 inhibits the growth of ovarian cancer by making them self-cannibalize. It seems that the cell essentially eats itself until it dies. The experiments showed that if PEA-15 is removed, the cancer cells increase by 115% compared to those cells that still had the protein.

Before the discovery of PEA-15’s self-cannibalization mechanism, Ueno’s research team had also reported that the protein can also inhibit cancer in another way. They discovered that PEA-15 can inhibit a protein called extra-cellular signaling related kinase or ERK. This protein ERK is found in the cell nucleus and enhances cancer growth. What the PEA-15 does is to bind to ERK and take it out from the nucleus and moves it into the cytoplasm preventing it from enhancing cancer growth.

“PEA-15 offers us a new dimension for potentially targeting ERK,” according to Ueno. “We’ve shown with high levels of PEA-15, women with ovarian cancer are surviving longer.” Levels of the protein in tumors also might affect how other drugs work against the disease. Similar research is under way in breast cancer with PEA-15, which is short for phospho-enriched protein in astrocytes.

Cancer of the ovary kills approximately 15,000 women in the United States every year. This type of cancer is very hard to diagnose in its early stages. Most ovarian cancers are discovered at later stages when complete treatment is not possible.

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