Genetically modified adult stem cells armed with a cancer-killing protein show promise as a new way to destroy several types of tumors while sparing healthy cells, British researchers reported on Tuesday.

In laboratory cultures, the stem cells taken from bone marrow, carrying TNF-related apoptosis-inducing ligand or TRAIL, prove their ability to destroy lung, squamous, breast and cervical cancer cells, the researchers said.

Research tests on mice also found that the cells could reduce the growth of subcutaneous breast tumors by approximately 80 percent. When injected intravenously, they could eliminate 38 percent of metastasized lung tumors.

The research was presented at the American Thoracic Society's 105th International Conference in San Diego.

Michael Loebinger and S. M. Janes of the University College of London said they combined two disparate areas of research. One found that the adult stem cells known as mesenchymal stem cells or MSCs can seek out tumor cells, while another found that TRAIL killed cancer cells, but not normal cells.

"This is the first study to demonstrate a significant reduction in tumor burden with inducible TRAIL-expressing MSCs in a well-controlled and specifically directed therapy," the authors said in a statement.

They hope that human trials could begin in two or three years.

(Xinhua News Agency May 20, 2009)