Cancer prevention: stopping cancer before it can start

The mice developed spontaneous pancreatic lesions as early as four weeks, with 100 percent approaching death within six to eight months, the researchers report. The calorie-restricted animals were significantly protected from spontaneous formation of pancreatic lesions: 7.5 percent of them developed lesions in stark contrast to 45 percent of the overweight group and 57.5 percent of the diet-induced obese group, the researchers report. Furthermore, calorie-restricted mice had smaller lesions than those in the overweight and diet-induced obese groups.

Gemini vitamin D analogs inhibit estrogen receptor positive and estrogen receptor negative mammary tumorigenesis without hypercalcemic toxicity: Abstract 2097

Researchers at Rutgers University have found that, in animal studies, a synthetic form of active vitamin D has a substantive preventive effect on the development of both estrogen receptor (ER)-positive and ER-negative breast cancers. Unlike many of the other synthetic vitamin D agents that have been tested in humans, this compound, known as Gemini 0097, shows no toxicity, they report.

The research team found that daily injections of Gemini 0097 cut growth of ER-positive cancer by 60 percent in rat studies, and reduced ER-negative breast cancer by half in mice.

“These are very promising findings, especially because no toxicity is observed,” said researcher Hong Jin Lee, a graduate student at Rutgers. Lee works in the laboratory of lead investigator Nanjoo Suh, Ph.D., an assistant professor at the Susan Lehman Cullman Laboratory for Cancer Research at Rutgers, the State University of New Jersey. Suh said that Gemini 0097 likely did not cause the most common vitamin D toxicity, an overload of calcium in blood known as hypercalcemia, because the compound has an extra side chain of chemicals.

“It is quite different from the natural shape of active vitamin D,” she said. “Because the binding affinity of Gemini 0097 with vitamin D receptor is low that may contribute to the lower toxicity, but the efficacy stays the same or even better.”

Epidemiologic studies have shown that use of vitamin D is beneficial in preventing colon cancer, but studies in prostate and breast cancer have yielded mixed conclusions, Suh says.

Vitamin D is a pro-hormone that is produced in the skin after exposure to sunlight. Vitamin D dietary supplements are converted into an active, useful form by metabolism in the liver and kidneys. Although the active form of vitamin D has been tested as a cancer treatment, the higher doses needed for prevention or treatment have typically produced intolerable side effects in clinical trials, Suh says.