University researchers discovered that using particular proteins reduces cancer in mice genetically susceptible to the disease.
The four-year, $1.5 million study began last year and already has the University Cancer Center showing dividends.
The protein endostatin profoundly decreases the growth of mammary cancers in female mice and prostate cancer in male mice.
“The ultimate goal is to find a drug that can potentially prohibit the onset of cancer,” said Sundaram Ramakrishnan, associate professor of pharmacology. “And having developed the protein that shows you can inhibit cancer growth leaves the rest up in the air.”
The study used mice genetically predisposed to develop cancer.
Male mice treated with the protein increased life spans by more than 10 weeks.
In a separate trial, treated female mice showed delayed tumor development after four to six weeks, had significantly decreased tumor size and fewer malignant cancer lesions per mouse.
Endostatin works by inhibiting the development of blood vessels in cancer cells to stop them from forming tumors.
“Cancer cells know how to induce blood vessels to themselves,” Ramakrishnan said. “It is a case of supply and demand.”
According to the University Cancer Center Surveillance System, prostate cancer is the most common cancer for men representing more than one-third of new cancers in men. Breast cancer is the most common type of cancer for women, accounting for about one-third of new cancer cases in women. The annual number of prostate and breast cancer cases each exceeded the number of lung, colon and rectum cancer cases combined.
The average lifetime risk has changed most noticeably in prostate cancer, which has been decreasing since 1992 after a four-year dramatic increase.
“From 1980 to 1996 research indicates there has been a tenfold increase in breast cancer detection for women more than 50 years old and a very slight increase in younger women,” Laurel Habel, a research investigator at Kaiser Permanente Medical Group, said on Monday during a cancer seminar.
Part of the reason for the increase is better detection procedures and awareness.
The American Cancer Society’s nationwide projections suggest the number of prostate and breast cancer cases will each reach more than 180,000 this year with less than 18 percent of prostate and 23 percent of breast cancer cases ending in death.
“Mammograms offer early detection of breast cancer,” Habel said. “There has been a decrease in later stage disease and in breast cancer mortality.”
Ramakrishnan said there is a move toward conducting larger scale clinical trials.
“The treatment is still in the experimental stage and needs to be tested in humans,” Ramakrishnan said.
“I am very happy with the research professor Ramakrishnan is doing,” said Horace Loh, head of the pharmacology department. “It is too early to tell what this means and how it will affect the school.”
The study was funded primarily through a grant from the U.S. Medical Research and Materiel Command through a congressional appropriation of more than $100 million.

Mickie Barg covers the Medical School and welcomes comments at (612) 627-4070 x3223. She can also be reached at [email protected]