New York, Mar 27 (IANS): A new drug that may stop a gene associated with obesity from triggering breast and lung cancer, as well as prevent these cancers from growing, is in testing stages, scientists say.

The drug, I-BET-762, was found showing signs of significantly delaying the development of existing breast and lung cancers by zeroing in on how a cancerous gene, called c-Myc, acts.

"I-BET-762 works by targeting DNA so that this gene can't be expressed," said Karen Liby, Associate Professor at the Michigan State University.

"It does this by inhibiting a number of important proteins -- both in cancer and immune cells -- ultimately reducing the amount of cancer cells in mice by 80 per cent," Liby added.

For example, a particular protein, known as pSTAT3, can become activated in immune cells and stop them from doing their job, such as fighting off an invading cancer.

The offending protein also can become overproduced in cancer cells and act as a shield - ultimately protecting the tumour, the researchers said.

"In our study, the drug decreased pSTAT3 levels by 50 per cent in both types of cells," Liby noted.

Another study led by Jamie Bernard, Assistant Professor at the varsity applied the finding to precancerous cells and found that the drug prevented more than 50 per cent of these cells from becoming cancerous.

The c-Myc gene is induced by visceral fat, which is found around the inner organs of the body as opposed to subcutaneous fat, which is located under the skin. This visceral fat is more dangerous to your health.

"Almost half a million of all new cancers have been linked to obesity," Bernard said.

"There is evidence that visceral fat and high-fat diets can increase cancer risk; and while current cancer treatments have helped to lower cancer mortality, the number of obesity-associated cancers continues to climb."

Both studies are published in the journal Cancer Prevention Research.