U. ROCHESTER (US) — In blind mole rats, precancerous cells are quickly killed by a “clean sweep” mechanism that not only kills the abnormal cells but neighboring cells, too.
The finding could eventually lead to new cancer therapies in people, researchers say.
Blind mole rats and naked mole rats—both subterranean rodents with long life spans—are the only mammals known to have never developed cancer. Three years ago, researchers at the University of Rochester determined that a specific gene—p16—makes the cancerous cells in naked mole rats hypersensitive to overcrowding, and stops them from proliferating when too many crowd together.
“We expected blind mole rats to have a similar mechanism for stopping the spread of cancerous cells,” says Andrei Seluanov, assistant professor of biology. “Instead, we discovered they’ve evolved their own mechanism.”
As reported in Proceedings of the National Academy of Sciences, Seluanov and Vera Gorbunova, professor of biology, made their discovery by isolating cells from blind mole rats and forcing them to proliferate in culture beyond what occurs in the animal. After dividing approximately 15-20 times, all of the cells in the culture dish died rapidly.
The researchers determined that the rapid death occurred because the cells recognized their pre-cancerous state and began secreting a suicidal protein, called interferon beta. The precancerous cells died by a mechanism which kills both abnormal cells and their neighbors, resulting in a “clean sweep.”
Not only were the cancerous cells killed off, but so were the adjacent cells, which may also be prone to tumorous behavior,” says Seluanov.
“While people don’t use the same cancer-killing mechanism as blind mole rats, we may be able to combat some cancers and prolong life, if we could stimulate the same clean sweep reaction in cancerous human cells,” Gorbunova says.
The research team also included Christopher Hine, Xiao Tian, and Julia Ablaeva in Rochester, Andrei Gudkov at Roswell Park Cancer Institute in Buffalo, New York, and Eviatar Nevo at the University of Haifa in Israel.
The next step is to find out exactly what triggers the secretion of interferon beta after cancerous cells begin proliferating in blind mole rats. Gorbunova believes the anti-cancer mechanism is an adaptation to subterranean life.
“Blind mole rats spend their lives in underground burrows protected from predators,” she says. “Living in this environment, they could perhaps afford to evolve a long lifespan, which includes developing efficient anticancer defenses.”
Source: University of Rochester