Israeli researchers identify a protein that may put the brakes on a particularly aggressive form of cancer.

Pancreatic cancer

Pancreatic cancer is a particularly aggressive, rapidly spreading disease for which there is no effective treatment.

Israeli researchers have discovered that a protein known to retard the aging process also seems to prevent the growth of pancreatic cancer. If it could be produced commercially without significant side effects, this substance could provide a needed weapon against this and other fast-growing cancers.

Researchers from the Cancer Research Center at Sheba Medical Center in Tel Hashomer studied the behavior of the protein klotho, a natural hormone emitted by the brain and kidneys. It is named after one of the Three Fates in Greek mythology, who spun thread to keep people alive.

A laboratory study done at Sheba in 2008 found that klotho prevented breast cancer cells from multiplying. Later, researchers discovered that mutations of this protein, called BRCA1 and BRCA2, greatly increase the risk of women developing breast cancer:

The Israeli study follows recent findings in other countries indicating that klotho may prevent the spread of liver and cervical cancer.

In the current experiments using mice with pancreatic cancer, scientists wanted to determine how klotho could work against this particularly aggressive, rapidly spreading disease for which there is no effective treatment.

About 610 Israelis are diagnosed with pancreatic cancer every year, and it causes eight out of every 100,000 deaths among Israeli men and six out of every 100,000 deaths among Israeli women. In the United States, an estimated 37,660 people will die of pancreatic cancer this year.

Klotho stops the spread

The scientists noticed that healthy pancreatic cells contain klotho, but cancerous cells do not. When they injected the cancerous mice with klotho, they discovered that it not only prevented the cancer from spreading, but actually caused tumors to shrink.

“Within a week or two after the protein was injected, the [cancerous] growths stopped spreading and began to shrink,” said lead researcher Dr. Ido Wolf, who heads Sheba’s oncology department and one of the labs at the Cancer Research Center. Dr. Lilach Abramovitz and Dr. Tami Rubinek were also involved in the study, funded by the Israel Cancer Association.

Results are to be published in the journal Clinical Cancer Research.

Before looking for partners to cooperate in advancing the use of klotho on the commercial level, the scientists’ next step is to figure out how to reduce an unwanted and potentially dangerous side effect of klotho.

“This protein is vital for controlling the level of calcium and phosphorus in the body, and administering the protein is like administering any other hormone: It has the side effect of increasing hormonal activity,” Wolf explained.

“There is a known connection between cancer and diabetes, [a disease] that involves unusual hormonal activity, and the current research provides an additional source for examining the connection between hormones and cancer,” Wolf said.