New York, Jan 7 (IANS): A team of researchers, including an Indian-origin scientist, has discovered a key cancer-promoting gene that may explain how a protein - TGF-beta - can prevent cancer from forming and encourage its aggressive growth.

With the new insight into the cancer mystery, considered to be a major paradox of cancer biology, the findings could provide a potential target for treatment.

The researchers, including Shyam Nyati from University of Michigan, identified Bub1 as a key gene involved in regulating TGF-beta receptor.

"Bub1 is well-known for its role in cell division. But this is the first study that links it to TGF-beta. We think this may explain the paradox of TGF-beta as a tumour promoter and a tumour suppressor," said study director Alnawaz Rehemtulla from University of Michigan Medical School.

"Our data that Bub1 is involved at the receptor level is completely unexpected," Rehemtulla added.

TGF-beta is known as a tumour suppressor, meaning it is necessary to keep cells in check and growing normally. But at some point, its function flips and it becomes a tumor promoter, fostering aggressive growth and spread of cancer.

The team of researchers developed a way to screen for genes that regulate the TGF-beta receptor.

When 720 genes from the human genome were screened against lung cancer and breast cancer cells, Bub1 emerged as playing a strong role in TGF-beta signaling.

Bub1 was shown to bind to the TGF-beta receptor and allows it to turn on aggressive cell growth. When the researchers blocked Bub1, it shut down the TGF-beta pathway completely.

Because Bub1 is found in many types of cancer, developing a drug to target it could potentially impact multiple cancers.

The study was in Science Signaling, a weekly journal published by the American Association for the Advancement of Science.