A five-member team of India-born medical researchers in the United States has discovered what may become a potent new weapon in the fight against colon cancer.

The scientists from the University of Texas succeeded in stopping colon cancer growth in mice by halting the activity of a single enzyme called aldose reductase.

Blocking this enzyme shuts down the toxic network of biochemical signals that promotes inflammation and colon cancer cell growth, the scientists reported in the latest issue of journal Cancer Research.

They showed that blocking the production of aldose reductase halts the growth of human colon cancer cells implanted in laboratory mice.

"By inhibiting aldose reductase we were able to completely stop the further growth of colorectal cancer tumour cells," they said. Colon cancer is the second leading cancer killer in the US.

The team included senior author Satish Srivastava and his colleagues - Ravinder Tammali, Kota V. Ramana, Sharad S. Singhal and Sanjay Awasthi.

In their experiments on mice, the researchers implanted human colon cancer cells beneath the skin of "nude mice" - a hairless and immune-deficient variety commonly used in medical research.

Tumour progression stopped completely in the mice treated with genetic material known as small interfering RNA (or "siRNA") that was engineered to prevent cells from making the aldose reductase enzyme.

The treated mice seemed unharmed by the procedure. In contrast, the untreated control animals experienced uncontrolled tumour growth, they reported.

The researchers, however, point out that the gap between a brand new procedure that works in nude mice and one that works in humans is considerable.