Chinese scientists claim to have made a major step towards a breakthrough in cancer treatment by programming stem cells to “seek and destroy” the disease. Professor Wang Jinyong and a team from the Guangzhou Institutes of Biomedicine and Health, under the Chinese Academy of Sciences, say that the technique was successfully used to treat mice with cancer of the thymus, an organ central to the body’s immune system. According to a paper published last week in the peer-reviewed scientific journal Cell Research , the team used stem cells to create infant immune cells that would later develop into T cells, which are produced in the thymus and play a central role in the body’s immune response. After a period of time, the tumours disappeared. And because the new T cells had memory, the mice were immune from this type of cancer for life, the report said. In a statement on the academy’s website, the team said the method could lead to a breakthrough in cancer treatment. Chinese scientists find cancer hope in old pest remedy Immune therapies are becoming increasingly popular in the fight against cancer, and while the use of T cells is not new, they are usually extracted from human blood rather than created from a stem cell. Also, the cost of the extraction process is very high, running into thousands of US dollars in China. Once the cells have been extracted they must be programmed to target cancer cells, which remains a technical challenge. Also, some patients do not generate enough of the cells because of their poor health. Scientists around the world have thus been trying to generate T cells from stem cells – a kind of blank canvas that can be programmed to become any other type of cell in the body. Rather than try to produce mature T cells, the Chinese team programmed the stem cells to be precursor cells that would grow into T cells over time. The technology could “successfully regenerate a complete T cell immune system containing T cell groups that perform various functions”, the report said. It meant that the research team had “an endless source of T cells … to form a large army with regenerative immunity for body protection”, it said. Professor Wang Shengdian, a researcher with the Institute of Biophysics in Beijing who was not involved in the study, said scientists had made some significant breakthroughs in the fight against cancer in recent years. For instance, with the help of immunotherapy, patients with some forms of leukaemia now had a 90 per cent chance of beating the disease, he said. While Wang Jinyong’s team had not succeeded in creating a full T cell it had made an important step towards that goal, Wang Shengdian said, adding that it was now important to work out how to create T cells specific to each form of cancer. “The biggest challenge is to find a precise target for the T cell, otherwise it just flies around like a missile without guidance,” he said.